stent system results: Topics by WorldWideScience.org

Sample records for stent system results

Long-term results after carotid artery stenting. Restenosis after carotid artery stenting using self-expandable stent

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Matsumoto, Yasushi; Furui, Eisuke; Tsuboi, Ken; Takahashi, Akira; Ezura, Masayuki

2008-01-01

Carotid artery stenting has emerged as an acceptable treatment alternative in patients with carotid artery stenosis. Although early clinical results of carotid artery stenting have shown promise, long, term clinical results remain less certain. We report the frequency, management, and clinical results of in-stent restenosis after carotid artery stenting using a self-expandable stent. Between August 1998 and September 2004, 80 carotid artery stenting procedures in 78 patients were performed. We evaluated 76 of the 80 procedures in 75 of the 78 patients treated during this period who had a minimum 6-month clinical and imaging (ultrasound and/or magnetic resonance angiography) follow-up. Recurrent stenosis (≥50%) after carotid artery stenting occurred in 3 (3.9%) patients. The recurrent stenosis occurred within one year after the procedure in all cases. The low rate of in-stent restenosis using self-expandable stent suggested that carotid artery stenting may be an effective alternative treatment for carotid artery stenosis, but more data of long-term follow-up are required. (author)
Delayed thrombosis or stenosis following enterprise-assisted stent-coiling: is it safe? Midterm results of the interstate collaboration of enterprise stent coiling.

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Mocco, J; Fargen, Kyle M; Albuquerque, Felipe C; Bendok, Bernard R; Boulos, Alan S; Carpenter, Jeffrey S; Fiorella, David J; Hoh, Brian L; Howington, Jay U; Liebman, Kenneth M; Natarajan, Sabareesh K; Rai, Ansaar T; Rodriguez-Mercado, Rafael; Siddiqui, Adnan H; Snyder, Kenneth V; Veznedaroglu, Erol; Hopkins, L Nelson; Levy, Elad I

2011-10-01

Stent-assisted coiling of intracranial aneurysms with self-expanding stents has widened the applicability of neuroendovascular therapies to those aneurysms previously considered "uncoilable" because of poor morphology. The Enterprise Vascular Reconstruction Device and Delivery System (Cordis) has demonstrated promising initial short-term results. However, the rates of delayed in-stent stenosis or thrombosis are not known. To report midterm results of the Enterprise stent system. A 10-center registry was created to provide a large volume of data on the safety and efficacy of the Enterprise stent system. Pooled data were compiled for consecutive patients undergoing Enterprise stent-assisted coiling at each institution. Available follow-up data were evaluated for the incidence of in-stent stenosis, thrombosis, and aneurysm occlusion. In total, 213 patients (176 females) with 219 aneurysms were treated with the Enterprise stent. One hundred ten patients had undergone delayed angiography (≥ 30 days from stent placement, mean follow-up 174.6 days). Forty percent of patients demonstrated total occlusion with 88% having ≥ 90% aneurysm occlusion. Six percent of patients had delayed (>30 days) angiographic findings, of which 3% demonstrated significant (≥ 50%) in-stent stenosis or occlusion. Seven delayed thrombotic events occurred (3%), along with 2 additional immediate periprocedural events. All 7 delayed events were concomitant to cessation of double-antiplatelet therapy. Midterm occlusion rates are excellent, and stenosis and thrombosis rates are comparable to other available neurovascular stents. Interruption of antiplatelet therapy appears to be a factor in those developing delayed stenosis or thrombosis.
Configuration affects parallel stent grafting results.

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Tanious, Adam; Wooster, Mathew; Armstrong, Paul A; Zwiebel, Bruce; Grundy, Shane; Back, Martin R; Shames, Murray L

2018-05-01

A number of adjunctive "off-the-shelf" procedures have been described to treat complex aortic diseases. Our goal was to evaluate parallel stent graft configurations and to determine an optimal formula for these procedures. This is a retrospective review of all patients at a single medical center treated with parallel stent grafts from January 2010 to September 2015. Outcomes were evaluated on the basis of parallel graft orientation, type, and main body device. Primary end points included parallel stent graft compromise and overall endovascular aneurysm repair (EVAR) compromise. There were 78 patients treated with a total of 144 parallel stents for a variety of pathologic processes. There was a significant correlation between main body oversizing and snorkel compromise (P = .0195) and overall procedural complication (P = .0019) but not with endoleak rates. Patients were organized into the following oversizing groups for further analysis: 0% to 10%, 10% to 20%, and >20%. Those oversized into the 0% to 10% group had the highest rate of overall EVAR complication (73%; P = .0003). There were no significant correlations between any one particular configuration and overall procedural complication. There was also no significant correlation between total number of parallel stents employed and overall complication. Composite EVAR configuration had no significant correlation with individual snorkel compromise, endoleak, or overall EVAR or procedural complication. The configuration most prone to individual snorkel compromise and overall EVAR complication was a four-stent configuration with two stents in an antegrade position and two stents in a retrograde position (60% complication rate). The configuration most prone to endoleak was one or two stents in retrograde position (33% endoleak rate), followed by three stents in an all-antegrade position (25%). There was a significant correlation between individual stent configuration and stent compromise (P = .0385), with 31
Flexibility and trackability of laser cut coronary stent systems.

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Szabadíts, Péter; Puskás, Zsolt; Dobránszky, János

2009-01-01

Coronary stents are the most important supports in present day cardiology. Flexibility and trackability are two basic features of stents. In this paper, four different balloon-expandable coronary stent systems were investigated mechanically in order to compare their suitability. The coronary stent systems were assessed by measurements of stent flexibility as well as by comparison of forces during simulated stenting in a self-investigated coronary vessel model. The stents were cut by laser from a single tube of 316L stainless steel or L-605 (CoCr) cobalt chromium alloy. The one-and four-point bending tests were carried out to evaluate the stent flexibility E x I (Nmm(2)), under displacement control in crimped and expanded configurations. The flexibility of stents would be rather dependent on the design than on raw material. In general a more flexible stent needs lower tracking force during the implantation. The L-605 raw material stents need lower track force to pass through in the vessel model than the 316L raw material stents. The sort and long stents passed through the curved vessel model in different ways. The long stents nestled to the vessel wall at the outer arc and bent, while the short stents did not bend in the curve, only the delivery systems bent.
[Tracheobronchial stents: a retrospective analysis of indications, results and in particular complications].

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Tonn, H; Mall, W; Schneider, K-D; Schönhofer, B

2008-10-01

Tracheobronchial stents are inserted mainly in cases of malignant and benign airway stenosis. Further indications are esophago-tracheal fistulas, mediastinal fistulas and tracheomalacia. A retrospective analysis was conducted on patients' records, information provided by the general practitioners and relatives of the patients from July 1993 to December 2006 in the Department of Pneumology of the Heidehaus Hospital Hannover (since 6/05 Department of Pneumology and Internal Intensive Care Medicine, Oststadt-Heidehaus Hospital). During the observation period of 13 years a total of 269 stents (177 permanent, 92 temporary) were implanted in 207 patients (1.3 stents per patient). The vast majority of patients (173/207) suffered from an underlying malignancy. About half of the stents were deployed in the trachea. The median length of placement was 116 days in patients with malignancies and 313 days in patients with benign diseases. In about 40 % of the patients notable complications were observed which were directly or indirectly associated with the stents. These findings show the importance of a critical indication for stent implantation. In benign diseases a stent can remain for years inside the tracheobronchial system, if it is well tolerated in the beginning. In malignant diseases the result depends decisively on the stage of the tumour: has the stent been implanted before any other tumour therapy is started or is it an end-stage tumor with no other therapeutic option? In general, complications of stents occur quite frequently. The analysis of stent data leads to some aspects for the prevention of stent-related complications. There should be a strict indication and appropriate choice of stent material. Nevertheless, there remains an ethical dilemma in patients with end-stage disease as to whether to implant a stent or to do nothing against the tumor, because the benefit immediately after stent insertion vanishes with progression of the tumour, so causing extra
A method to determine the kink resistance of stents and stent delivery systems according to international standards

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Brandt-Wunderlich Christoph

2016-09-01

Full Text Available The kink behavior of vascular stents is of particular interest for clinicians, stent manufacturers and regulatory as a kinked stent generates a lumen loss in the stented vessel and can lead to in-stent restenosis. In this study methods to determine the kink resistance of stents and stent delivery systems according to the ISO 25539-2 and FDA guidance no. 1545 were presented. The methods are applicable for balloon expandable stents as well as for self-expanding stents and determine the lumen loss and residual diameter change dependent on the specific bending radius.
Clinical Results and Mechanical Properties of the Carotid CGUARD Double-Layered Embolic Prevention Stent.

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Wissgott, Christian; Schmidt, Wolfram; Brandt-Wunderlich, Christoph; Behrens, Peter; Andresen, Reimer

2017-02-01

To report early clinical outcomes with a novel double-layer stent for the internal carotid artery (ICA) and the in vitro investigation of the stent's mechanical properties. A prospective single-center study enrolled 30 consecutive patients (mean age 73.1±6.3 years; 21 men) with symptomatic (n=25) or high-grade (n=5) ICA stenosis treated with the new double-layer carotid CGUARD Embolic Prevention System (EPS) stent, which has an inner open-cell nitinol design with an outer closed-cell polyethylene terephthalate layer. The average stenosis of the treated arteries was 84.1%±7.9% with a mean lesion length of 16.6±2.1 mm. In the laboratory, 8×40-mm stents where tested in vitro with respect to their radial force during expansion, the bending stiffness of the stent system and the expanded stent, as well as the collapse pressure in a thin and flexible sheath. The wall adaptation was assessed using fluoroscopy after stent release in step and curved vessel models. The stent was successfully implanted in all patients. No peri- or postprocedural complications occurred; no minor or major stroke was observed in the 6-month follow-up. The bending stiffness of the expanded stent was 63.1 N·mm 2 and (not unexpectedly) was clearly lower than that of the stent system (601.5 N·mm 2 ). The normalized radial force during expansion of the stent to 7.0 mm, consistent with in vivo sizing, was relatively high (0.056 N/mm), which correlates well with the collapse pressure of 0.17 bars. Vessel wall adaptation was harmonic and caused no straightening of the vessel after clinical application. Because of its structure, the novel CGUARD EPS stent is characterized by a high flexibility combined with a high radial force and very good plaque coverage. These first clinical results demonstrate a very safe implantation behavior without any stroke up to 6 months after the procedure.
Stent implantation into the tracheo-bronchial system in rabbits: histopathologic sequelae in bare metal vs. drug-eluting stents.

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Sigler, Matthias; Klötzer, Julia; Quentin, Thomas; Paul, Thomas; Möller, Oliver

2015-12-01

Stent implantation into the tracheo-bronchial system may be life-saving in selected pediatric patients with otherwise intractable stenosis of the upper airways. Following implantation, significant tissue proliferation may occur, requiring re-interventions. We sought to evaluate the effect of immunosuppressive coating of the stents on the extent of tissue proliferation in an animal model. Bare metal and sirolimus-coated stents (Bx Sonic and Cypher Select, Johnson & Johnson, Cordis) were implanted into non-stenotic lower airways of New Zealand white rabbits (weight 3.1 to 4.8 kg). Three stents with sirolimus coating and six bare metal stents could be analyzed by means of histology and immunohistochemistry 12 months after implantation. On a macroscopic evaluation, all stents were partially covered with a considerable amount of whitish tissue. Histologically, these proliferations contained fiber-rich connective tissue and some fibromuscular cells without significant differences between both stent types. The superficial tissue layer was formed by typical respiratory epithelium and polygonal cells. Abundant lymphocyte infiltrations and moderate granulocyte infiltrations were found in both groups correspondingly, whereas foreign-body reaction was more pronounced around sirolimus-eluting stents. After stent implantation in the tracheo-bronchial system of rabbits, we found tissue reactions comparable to those seen after stent implantation into the vascular system. There was no difference between coated and uncoated stents with regard to quality and quantity of tissue proliferation. We found, however, a significantly different inflammatory reaction with a more pronounced foreign-body reaction in sirolimus-coated stents. In our small series, drug-eluting stents did not exhibit any benefit over bare metal stents in an experimental setting.
The EPIC nitinol stent system in the treatment of iliac artery lesions: one-year results from the ORION clinical trial.

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Clair, Daniel G; Adams, Julie; Reen, Bernard; Feldman, Robert; Starr, Jean; Diaz-Cartelle, Juan; Dawkins, Keith D

2014-04-01

To report the 1-year results of a pivotal study for a new-generation nitinol stent for the treatment of iliac atherosclerotic lesions. The ORION trial (ClinicalTrials.gov identifier NCT00896337) was a single-arm, non-randomized, prospective, multicenter clinical trial that enrolled 125 patients (81 men; mean age 61.1±9.3 years) implanted with the EPIC self-expanding nitinol stent system in 166 de novo or restenotic iliac artery lesions ≤13 cm long. The primary endpoint was the 9-month major adverse event rate [i.e., device- or procedure-related death within 30 days, myocardial infarction during the index hospitalization, target vessel revascularization (TVR), or index limb amputation]. Follow-up occurred at hospital discharge and at 1, 9, and 12 months. An independent core laboratory evaluated ultrasound results at 1, 9, and 12 months. The primary endpoint met the prespecified performance goal, with only 3.4% (4/117) of patients experiencing a major adverse event by 9 months (p<0.0001). By 12 months, 6 (5.4%) of 111 patients had TVR; none had an index limb amputation. The ankle-brachial index, Walking Impairment Questionnaire, and Rutherford classifications all showed sustained improvements through 12 months. Primary patency was 94.4% with comparable results for lesions classified as complex (TASC II C/D 95.5%) or non-complex (TASC II A/B 95.0%). The EPIC stent system demonstrated safety and effectiveness through 12 months, including improvements for complex lesions. The EPIC stent is a viable alternative to surgery for patients with either complex or non-complex lesions.
Six-Month Clinical and Angiographic Results of Paclitaxel Eluting Simpax Stent

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Mehmet Muhsin Türkmen

2012-08-01

Full Text Available Introduction: We aimed to evaluate the safety and efficacy of the simpax stent in the treatmentof different patient groups.Patients and Methods: Forty-five patients were treated with the simpax stent. Of these patients,23 patients gave consent for six months of follow-up by quantitative coronary angiography (QSAand six patients were evaluated by exercise electrocardiographic test. Only the patients havinglesions with stenosis > 50% of diameter and lengths > 16 mm with reference diameters < 2.75mm were included.Results: The device success rate was 100% and procedure success rate was 97.7%. The meanstent length was 24.6 ± 7.3 mm and stent size was 2.54 ± 0.24 mm. The overall six months incidenceof major adverse cardiac events (MACE was 8.8%. MACE was consisted of two casesof non-Q wave myocardial infarction and two cases of repeated revascularization of the targetlesion. MACE rate was higher in chronic total occlusion (CTO group than non-CTO group (respectively33.3% and 5.1. Also when compared to stent size, MACE rate was 25% in < 2.5 mm,0% ≥ 2.5 mm. The QSA results at six months showed in-stent late lumen loss witha diameter of0.25 ± 0.15 mm in 17 patients.Conclusion: The six month results in this study demonsrated excellent procedural and devicesuccess. Simpax stent was associated with a low in-stent late lumen loss. Also this study showedsimpax stent was a safe and effective device in non-CTO group with stent size ≥ 2.5 mm.
Novel silicone stent to treat tracheobronchial lesions: results of 35 patients.

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Saueressig, Maurício G; Sanches, Paulo R S; Macedo Neto, Amarilio V; Moreschi, Alexandre H; Oliveira, Hugo G; Xavier, Rogerio G

2010-12-01

We describe a case series of 35 patients with either benign (14) or malignant (21) tracheal stenosis who were treated using a novel silicone stent, the HCPA-1, designed to prevent migration. Between March 2001 and September 2008, 13 women and 22 men received 41 HCPA-1 stents. The median duration of stenting in benign cases was 457 days (range, 4-2,961 days). Successful stent removal with curative results was accomplished in 2 patients with tracheomalacia and 1 with post-intubation stenosis. In malignant cases, the median duration of stenting was 162 days (range, 1-1,279 days). Five patients had tumor progression with obstruction requiring repeated laser resection, dilatation, or additional stents. Two patients died due to airway obstruction despite bronchoscopic intervention. Twelve patients with malignant lesions died with the stent in place. At the end of the study, 3 patients with malignant disease remained alive; 2 were lost to follow-up. The HCPA-1 stent proved to be safe, with no severe complications during the study period, and effective in improving quality of life with relief of dyspnea.
Metallic ureteral stents in malignant ureteral obstruction: short-term results and radiological features predicting stent failure in patients with non-urological malignancies.

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Chow, Po-Ming; Hsu, Jui-Shan; Wang, Shuo-Meng; Yu, Hong-Jheng; Pu, Yeong-Shiau; Liu, Kao-Lang

2014-06-01

To provide short-term result of the metallic ureteral stent in patients with malignant ureteral obstruction and identify radiological findings predicting stent failure. The records of all patients with non-urological malignant diseases who have received metallic ureteral stents from July 2009 to March 2012 for ureteral obstruction were reviewed. Stent failure was detected by clinical symptoms and imaging studies. Survival analysis was used to estimate patency rates and factors predicting stent failure. A total of 74 patients with 130 attempts of stent insertion were included. A total of 113 (86.9 %) stents were inserted successfully and 103 (91.2 %) achieved primary patency. After excluding cases without sufficient imaging data, 94 stents were included in the survival analysis. The median functional duration of the 94 stents was 6.2 months (range 3-476 days). Obstruction in abdominal ureter (p = 0.0279) and lymphatic metastasis around ureter (p = 0.0398) were risk factors for stent failure. The median functional durations of the stents for abdominal and pelvic obstructions were 4.5 months (range 3-263 days) and 6.5 months (range 4-476 days), respectively. The median durations of the stents with and without lymphatic metastasis were 5.3 months (range 4-398 days) and 7.8 months (range 31-476 days), respectively. Metallic ureteral stents are effective and safe in relieving ureteral obstructions resulting from non-urological malignancies, and abdominal ureteral obstruction and lymphatic metastasis around ureter were associated with shorter functional duration.
Risk of stent thrombosis among bare-metal stents, first-generation drug-eluting stents, and second-generation drug-eluting stents: results from a registry of 18,334 patients.

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Tada, Tomohisa; Byrne, Robert A; Simunovic, Iva; King, Lamin A; Cassese, Salvatore; Joner, Michael; Fusaro, Massimiliano; Schneider, Simon; Schulz, Stefanie; Ibrahim, Tareq; Ott, Ilka; Massberg, Steffen; Laugwitz, Karl-Ludwig; Kastrati, Adnan

2013-12-01

This study sought to compare the risk of stent thrombosis among patients treated with bare-metal stents (BMS), first-generation drug-eluting stents (G1-DES), and second-generation drug-eluting stents (G2-DES) for a period of 3 years. In patients undergoing coronary stenting, there is a scarcity of long-term follow-up data on cohorts large enough to compare rates of stent thrombosis across the stent generations. A total of 18,334 patients undergoing successful coronary stent implantation from 1998 to 2011 at 2 centers in Munich, Germany, were included in this study. Patients were stratified into 3 groups according to treatment with BMS, G1-DES, and G2-DES. The cumulative incidence of definite stent thrombosis at 3 years was 1.5% with BMS, 2.2% with G1-DES, and 1.0% with G2-DES. On multivariate analysis, G1-DES compared with BMS showed a significantly higher risk of stent thrombosis (odds ratio [OR]: 2.05; 95% confidence interval [CI]: 1.47 to 2.86; p stent thrombosis compared with BMS (OR: 0.82; 95% CI: 0.56 to 1.19; p = 0.30). Beyond 1 year, the risk of stent thrombosis was significantly increased with G1-DES compared with BMS (OR: 4.72; 95% CI: 2.01 to 11.1; p stenting, compared with BMS, there was a significant excess risk of stent thrombosis at 3 years with G1-DES, driven by an increased risk of stent thrombosis events beyond 1 year. G2-DES were associated with a similar risk of stent thrombosis compared with BMS. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
Differentiated analysis of an everolimus-eluting stent and a paclitaxel-eluting stent among higher risk subgroups for restenosis: results from the SPIRIT II trial.

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Khattab, Ahmed A; Richardt, Gert; Verin, Vitali; Kelbaek, Henning; Macaya, Carlos; Berland, Jacques; Miquel-Hebert, Karine; Dorange, Cécile; Serruys, Patrick W

2008-03-01

Restenosis is higher among certain subpopulations when subjected to percutaneous coronary interventions even when using drug-eluting stents. The randomised SPIRIT II trial demonstrated the superiority of the XIENCE V Everolimus Eluting Coronary Stent System over the TAXUS Paclitaxel-Eluting Stent System in terms of in-stent late loss at six months among 300 patients treated for de novo native coronary artery lesions. In this post-hoc analysis of SPIRIT II we focused on six-month angiographic outcomes of diabetic patients (n=69), left anterior descending arteries (n=149), long lesions >20 mm (n=43), small vessels B2 and C lesions (n=233). In-stent late loss was consistently less among all subgroups when treated by everolimus-eluting stents compared to paclitaxel-eluting stents: diabetics 0.15+/-0.26 mm versus 0.39+/-0.34 mm, p=0.006; LAD 0.12+/-0.23 mm versus 0.44+/-0.37 mm, pB2/C lesions 0.12+/-0.31 mm versus 0.36+/-0.36 mm, pSPIRIT II trial population.
Implante de stent dentro de stent recém-implantado em ponte de veia safena para otimização do resultado angiográfico Stenting a stent in saphenous vein graft to optimize the angiographic result

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Antonio Esteves Fº

1998-03-01

Full Text Available Mulher de 60 anos, com angina progressiva e revascularização do miocárdio, há oito anos, com ponte de veia safena para coronária direita e anastomose de artéria mamaria esquerda para artéria descendente anterior. Submetida a implante de stent Gianturco-Roubin II em terço proximal da ponte de veia safena para artéria coronária direita, com resultado insatisfatório pela persistência de lesão residual, provavelmente, decorrente de prolapso para dentro da luz de material aterosclerótico através dos coils. Foi implantado outro stent (Palmaz-Schatz biliar dentro do stent GRII com sucesso e ótimo resultado angiográfico. Um 2º stent Palmaz-Schatz biliar foi implantado em lesão distal no corpo da ponte, ultrapassando os dois stents, anteriormente implantados, com sucesso. Em algumas situações, implante de stent dentro de outro stent é recurso útil para otimização de resultado angiográfico do implante de um stent.A 60 year-old woman with progressive angina who had been submitted to saphenous bypass-graft to right coronary artery and a left mammary artery graft to anterior descending artery eight years previously, underwent implantation of a Gianturco Roubin II stent in the proximal third of the saphenous vein graft. The result was suboptimal by persistence of a residual stenosis probably due to prolapse of atherosclerotic material through the coil spaces. Another stent (Palmaz-Schatz biliar stent was implanted at the previously stented site with no residual stenosis. Another Palmaz-Schatz biliar stent was successfully implanted in the distal body of the graft to treat another lesion (passing through the previously stents without difficulty. Stenting a stent, in selected situations, is a useful tool to optimize the angiographic result of stent implantation.
Long-Term Results after Placement of Aortic Bifurcation Self-Expanding Stents: 10 Year Mortality, Stent Restenosis, and Distal Disease Progression

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Houston, J. Graeme; Bhat, Raj; Ross, Rose; Stonebridge, Peter A.

2007-01-01

Purpose. To retrospectively evaluate the 10 year follow-up results in patients who had 'kissing' self-expanding stent aortic bifurcation reconstruction. Methods. Forty-three patients were treated with 'kissing' self-expanding stents for aortoiliac occlusive disease. Early follow-up with clinical and ankle brachial pressure indices (ABPI) was performed at 3, 6, 12, and 24 months and with intra-arterial digital subtraction angiography at 12-24 months; clinical and angiographic follow-up was performed for symptom recurrence up to 10 years after treatment. Retrospective record review was performed to assess mortality, clinical patency, angiographic patency, and secondary assisted patency of both stents and downstream peripheral vessels at 5 and 10 years follow-up. Results. The 2 year primary angiographic and secondary assisted stent patencies were 89% and 93%, respectively. At 10 years follow-up in 40 patients the mortality was 38% (due to myocardial infarction, stroke, chronic renal failure, malignancy, and liver failure). At 5 and 10 years follow-up the primary clinical stent patency was 82% and 68%, and the secondary assisted stent patency 93% and 86%, respectively. At 5 and 10 years, the distal vessel patency was 86% and 72%, and the secondary assisted distal vessel patency treated by surgical or endovascular techniques was 94% and 88%, respectively. At 10 years there was no limb loss. Conclusion. The long-term (10 year) results of aortic bifurcation arterial self-expanding stent placement in patients with arterial occlusive disease show a 10 year primary stent patency rate of 68% but a secondary assisted patency rate of 86%. In addition there is a high overall mortality due to other cardiovascular causes and the rate of distal disease progression and loss of patency is similar to the loss of stent patency rate
Mechanical behavior of peripheral stents and stent-vessel interaction: A computational study

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Dottori, Serena; Flamini, Vittoria; Vairo, Giuseppe

2016-05-01

In this paper stents employed to treat peripheral artery disease are analyzed through a three-dimensional finite-element approach, based on a large-strain and large-displacement formulation. Aiming to evaluate the influence of some stent design parameters on stent mechanics and on the biomechanical interaction between stent and arterial wall, quasi-static and dynamic numerical analyses are carried out by referring to computational models of commercially and noncommercially available versions of both braided self-expandable stents and balloon-expandable stents. Addressing isolated device models, opening mechanisms and flexibility of both opened and closed stent configurations are numerically experienced. Moreover, stent deployment into a stenotic peripheral artery and possible postdilatation angioplasty (the latter for the self-expandable device only) are simulated by considering different idealized vessel geometries and accounting for the presence of a stenotic plaque. Proposed results highlight important differences in the mechanical response of the two types of stents, as well as a significant influence of the vessel shape on the stress distributions arising upon the artery-plaque system. Finally, computational results are used to assess both the stent mechanical performance and the effectiveness of the stenting treatment, allowing also to identify possible critical conditions affecting the risk of stent fracture, tissue damage, and/or pathological tissue response.
Polyurethane-Covered Self-expandable Nitinol Stent for Malignant Biliary Obstruction: Preliminary Results

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Han, Young-Min; Hwang, Seung-Bae; Lee, Soo-Teik; Lee, Jeong-Min; Chung, Gyung-Ho

2002-01-01

Purpose: To evaluate the immediate and long-term results in ten patients with malignant biliary obstruction using a polyurethane-covered, self-expandable nitinol stent.Methods: A nitinol stent, fully covered with high-elasticity polyurethane, with an unconstrained diameter of 10 mm and a total length of 60-80 mm, was placed transhepatically under fluoroscopic guidance in ten patients. The length of the biliary obstruction varied between 30-50 mm. The follow-up examination included a clinical assessment, serum bilirubin measurement, and ultrasound examinations at one-month intervals in all patients. Results: Initial stent deployment was successful in eight patients. Two patients experienced proximal migration,which was solved by insertion of two, uncovered Wallstents. One patient had the stent removed after two weeks because of severe nausea and vomiting. One patient had delayed migration of the covered stent after 40 weeks. The follow-up duration was 3-40 weeks (Mean: 16.9 weeks). Seven patients died(3-26 weeks) and three patients survived (24-40 weeks). The bilirubin measurements in all patients had significantly decreased one week after stent insertion. The levels of amylase and lipase had did not increase after stent insertion. Conclusions: Apolyurethane-covered, self-expandable nitinol stent can be used effectively and safely in the treatment of malignant biliary obstruction. The preliminary results are favorable, but there is a need for further large studies to determine both long-term survival and patency
Renal artery stenting in solitary functioning kidneys: Technical and clinical results

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Sahin, Sinan; Cimsit, Cagatay; Andac, Nurten; Baltacioglu, Feyyaz; Tuglular, Serhan; Akoglu, Emel

2006-01-01

Objective: To evaluate the clinical and technical results of renal artery stenting for the treatment of renovascular hypertension and renal failure in patients with solitary functioning kidney. Materials and methods: Fifteen patients with solitary functioning kidney underwent renal artery stenting and were followed up for 12-60 months. Before the procedures, systolic and diastolic blood pressures and serum creatinine levels were measured and the number of antihypertensive drugs was recorded and followed up after stenting. In case of restenosis, either in-stent percutaneous transluminal renal angioplasty or stent-in-stent placement was performed. Results: Primary technical success rate was 100%. One lesion was nonostial while 14 were ostial. Primary patency rates were 100% for 6 months, 92.3% for 12 months, and 69.2% for 24 months. The secondary patency rate at 24 months was 100%. The differences between the baseline and postprocedural values of systolic blood pressures, diastolic blood pressures and the number of antihypertensive drug were statistically significant (P < 0.05), except the values of serum creatinine. Hypertension was cured in 1 (6.7%) patient, improved in 4 (26.6%) and stabilized in 10 (66.7%) patients. Renal function improved in 9 (60%), stabilized in 4 (26.6%), and deteriorated in 2 (13.4%) patients. Minor complication rate was 13.4% and major complication rate was 13.4%. Conclusion: Revascularization of renal artery stenosis using stent in solitary functioning kidneys is a safe and efficient procedure with high primary technical results, low restenosis rates and acceptable complication rates. It has an improving and controlling effect on blood pressure and renal functions
Renal artery stenting in solitary functioning kidneys: Technical and clinical results

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Sahin, Sinan [Dr. Siyami Ersek Thoracic and Cardiovascular Surgery Hospital, Department of Radiology, Istanbul (Turkey)]. E-mail: sinan.sahin@e-kolay.net; Cimsit, Cagatay [Marmara University, School of Medicine, Department of Radiology, Istanbul (Turkey); Andac, Nurten [Marmara University, School of Medicine, Department of Radiology, Istanbul (Turkey); Baltacioglu, Feyyaz [Marmara University, School of Medicine, Department of Radiology, Istanbul (Turkey); Tuglular, Serhan [Marmara University, School of Medicine, Department of Nephrology, Istanbul (Turkey); Akoglu, Emel [Marmara University, School of Medicine, Department of Nephrology, Istanbul (Turkey)

2006-01-15

Objective: To evaluate the clinical and technical results of renal artery stenting for the treatment of renovascular hypertension and renal failure in patients with solitary functioning kidney. Materials and methods: Fifteen patients with solitary functioning kidney underwent renal artery stenting and were followed up for 12-60 months. Before the procedures, systolic and diastolic blood pressures and serum creatinine levels were measured and the number of antihypertensive drugs was recorded and followed up after stenting. In case of restenosis, either in-stent percutaneous transluminal renal angioplasty or stent-in-stent placement was performed. Results: Primary technical success rate was 100%. One lesion was nonostial while 14 were ostial. Primary patency rates were 100% for 6 months, 92.3% for 12 months, and 69.2% for 24 months. The secondary patency rate at 24 months was 100%. The differences between the baseline and postprocedural values of systolic blood pressures, diastolic blood pressures and the number of antihypertensive drug were statistically significant (P < 0.05), except the values of serum creatinine. Hypertension was cured in 1 (6.7%) patient, improved in 4 (26.6%) and stabilized in 10 (66.7%) patients. Renal function improved in 9 (60%), stabilized in 4 (26.6%), and deteriorated in 2 (13.4%) patients. Minor complication rate was 13.4% and major complication rate was 13.4%. Conclusion: Revascularization of renal artery stenosis using stent in solitary functioning kidneys is a safe and efficient procedure with high primary technical results, low restenosis rates and acceptable complication rates. It has an improving and controlling effect on blood pressure and renal functions.

Expandable metallic stents: An experimental study in the nasolacrimal systems of dogs

Energy Technology Data Exchange (ETDEWEB)

Song, Ho Young [Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Lee, Jeong Min; Han, Young Min; Hwang, Eui Il; Chung, Gyung Ho; Shon, Myung Hee; Kim, Chong Soo; Choi, Ki Chul [Chonbuk National University Medical School, Chonju(Korea, Republic of)

1993-11-15

Balloon dacryocystoplasty has been reported to be a safe, easy and effective nonoperative treatment for nasolacrimal stenosis. The results were not encouraging, however, because of its high failure and recurrence rates. To evaluate the feasibility of using modified Gianturco expandable metallic stents for maintenance of the dilated nasolacrimal system(NLS), 20 stents of 3 mm in diameter and 10 mm long were placed in 20 nasolacrimal ducts of 10 dogs for 1 month to 10 months. It was more difficult to introduce the stents into the proximal portion(A) of the NLS than into the distal portion(B) due to the narrow and bony canal of the A portion. Twenty stents showed no migration in follow-up studies of up to 10 months. One complete occlusion occurred in a stent placed in A portion. Autopsy studies showed stents were covered with epithelium within 2 months after placement. Our experience suggest that the placement of Gianturco self-expandable stents may be a useful method of dilating and maintaining the luminal diameter of the NLS, although care must be taken to select the proper stent size.
Expandable metallic stents: An experimental study in the nasolacrimal systems of dogs

International Nuclear Information System (INIS)

Song, Ho Young; Lee, Jeong Min; Han, Young Min; Hwang, Eui Il; Chung, Gyung Ho; Shon, Myung Hee; Kim, Chong Soo; Choi, Ki Chul

1993-01-01

Balloon dacryocystoplasty has been reported to be a safe, easy and effective nonoperative treatment for nasolacrimal stenosis. The results were not encouraging, however, because of its high failure and recurrence rates. To evaluate the feasibility of using modified Gianturco expandable metallic stents for maintenance of the dilated nasolacrimal system(NLS), 20 stents of 3 mm in diameter and 10 mm long were placed in 20 nasolacrimal ducts of 10 dogs for 1 month to 10 months. It was more difficult to introduce the stents into the proximal portion(A) of the NLS than into the distal portion(B) due to the narrow and bony canal of the A portion. Twenty stents showed no migration in follow-up studies of up to 10 months. One complete occlusion occurred in a stent placed in A portion. Autopsy studies showed stents were covered with epithelium within 2 months after placement. Our experience suggest that the placement of Gianturco self-expandable stents may be a useful method of dilating and maintaining the luminal diameter of the NLS, although care must be taken to select the proper stent size
Genous endothelial progenitor cell-capturing stent system: a novel stent technology

NARCIS (Netherlands)

Klomp, Margo; Beijk, Marcel A. M.; de Winter, Robbert J.

2009-01-01

Drug-eluting stents have been demonstrated to significantly reduce clinical and angiographic restenosis in patients with coronary artery disease compared with bare-metal stents. Intuitively, however, a prohealing approach for the prevention of in-stent restenosis by promoting accelerated
Serial Versus Direct Dilation of Small Diameter Stents Results in a More Predictable and Complete Intentional Transcatheter Stent Fracture: A PICES Bench Testing Study.

Science.gov (United States)

Crystal, Matthew A; Morgan, Gareth J; Danon, Saar; Gray, Robert G; Gruenstein, Daniel H; Gordon, Brent M; Goldstein, Bryan H

2018-01-01

Balloon-expandable stents, implanted in infants and children with congenital heart disease (CHD), often require redilation to match somatic growth. Small diameter stents may eventually require longitudinal surgical transection to prevent iatrogenic vascular stenosis. Intentional transcatheter stent fracture (TSF) is an emerging alternative approach to stent transection, but little is known about the optimal stent substrate and best protocol to improve the likelihood of successful TSF. Bench testing was performed with a stent dilation protocol. After recording baseline characteristics, stents were serially or directly dilated using ultra-high-pressure balloons (UHPB) until fracture occurred or further stent dilation was not possible. Stent characteristics recorded were as follows: cell design, metallurgy, mechanism, and uniformity of fracture. Stents tested included bare-metal coronary stents, premounted small diameter stents, and ePTFE-covered small diameter premounted stents. Ninety-four stents representing 9 distinct models were maximally dilated, with 80 (85%) demonstrating evidence of fracture. Comprehensive fracture details were recorded in 64 stents: linear and complete in 34/64 stents (53.1%), linear and incomplete in 9/64 stents (14.1%), transverse/complex and complete in 6/64 stents (9.4%), and transverse/complex and incomplete in 15/64 stents (23.4%). Stent fracture was not accomplished in some stent models secondary to significant shortening, i.e., "napkin-ring" formation. Serial dilation resulted in evidence of fracture in 62/67 (92.5%) stents compared with 18/27 (66.7%) stents in the direct dilation group (p = 0.003). Intentional TSF is feasible in an ex vivo model. Serial dilation more reliably expanded the stent and allowed for ultimate stent fracture, whereas direct large diameter dilation of stents was more likely to generate a "napkin-ring" configuration, which may be more resistant to fracture. In vivo animal and human testing is necessary to
Comparison of everolimus- and paclitaxel-eluting stents in patients with acute and stable coronary syndromes: pooled results from the SPIRIT (A Clinical Evaluation of the XIENCE V Everolimus Eluting Coronary Stent System) and COMPARE (A Trial of Everolimus-Eluting Stents and Paclitaxel-Eluting Stents for Coronary Revascularization in Daily Practice) Trials.

Science.gov (United States)

Planer, David; Smits, Pieter C; Kereiakes, Dean J; Kedhi, Elvin; Fahy, Martin; Xu, Ke; Serruys, Patrick W; Stone, Gregg W

2011-10-01

This study sought to compare the clinical outcomes of everolimus-eluting stents (EES) versus paclitaxel-eluting stents (PES) in patients with acute coronary syndromes (ACS) and stable coronary artery disease (CAD). Although randomized trials have shown superiority of EES to PES, the safety and efficacy of EES in ACS is unknown. We performed a patient-level pooled analysis from the prospective, randomized SPIRIT (Clinical Evaluation of the XIENCE V Everolimus Eluting Coronary Stent System) II, III, IV, and COMPARE (A Trial of Everolimus-Eluting Stents and Paclitaxel-Eluting Stents for Coronary Revascularization in Daily Practice) trials in which 2,381 patients with ACS and 4,404 patients with stable CAD were randomized to EES or to PES. Kaplan-Meier estimates of death, myocardial infarction (MI), ischemia-driven target lesion revascularization, and stent thrombosis were assessed at 2 years and stratified by clinical presentation (ACS vs. stable CAD). At 2 years, patients with ACS compared with stable CAD had higher rates of death (3.2% vs. 2.4%, hazard ratio [HR]: 1.37 [95% confidence interval (CI): 1.02 to 1.85], p = 0.04) and MI (4.9% vs. 3.4%, HR: 1.45 [95% CI: 1.14 to 1.85], p = 0.02). In patients with ACS, EES versus PES reduced the rate of death or MI (6.6% vs. 9.3%, HR: 0.70 [95% CI: 0.52 to 0.94], p = 0.02), stent thrombosis (0.7% vs. 2.9%, HR: 0.25 [95% CI: 0.12 to 0.52], p = 0.0002), and ischemia-driven target lesion revascularization (4.7% vs. 6.2%, HR: 0.69 [95% CI: 0.48 to 0.99], p = 0.04). In patients with stable CAD, EES reduced the rate of death or MI (4.5% vs. 7.1%, HR: 0.62 [95% CI: 0.48 to 0.80], p = 0.0002), stent thrombosis (0.7% vs. 1.8%, HR: 0.34 [95% CI: 0.19 to 0.62], p = 0.0002), and ischemia-driven target lesion revascularization (3.9% vs. 6.9%, HR: 0.55 [95% CI: 0.42 to 0.73], p SPIRIT II]; NCT00180310; SPIRIT III: A Clinical Evaluation of the Investigational Device XIENCE V Everolimus Eluting Coronary Stent System [EECSS] in the
The forgotten ureteric JJ stent and its prevention: a prospective audit of the value of a ureteric stent logbook.

Science.gov (United States)

Thomas, A Z; Casey, R G; Grainger, R; McDermott, T; Flynn, R; Thornhill, J A

2007-01-01

Temporary ureteric stent insertion is an integral part of modern endo-urological practice. Delayed stent removal or forgotten stents are associated with increased patient morbidity and complications which are often difficult to manage. We prospectively audited our ureteric stent insertion and removal logbook system to determine the value and effectiveness of our stent follow-up. Over a 1-year period, 210 ureteric stents were inserted in our urological unit. Of these, 47 (22.4%) patients were unaccounted as having their stents removed within the stent logbooks. One patient was lost to follow-up and re-presented with stent encrustation 10 months later. Our results in this audit suggest that our system of ureteric stent follow-up is not effective. We have now introduced a new system that we feel is a safer and a satisfactory alternative to the stent logbooks. This includes a patient education leaflet and removal date scheduling prior to discharge from hospital.
Long-term Results of Endovascular Stent Graft Placement of Ureteroarterial Fistula

Energy Technology Data Exchange (ETDEWEB)

Okada, Takuya, E-mail: okabone@gmail.com; Yamaguchi, Masato, E-mail: masato03310402@yahoo.co.jp [Kobe University Hospital, Department of Radiology (Japan); Muradi, Akhmadu, E-mail: muradiakhmadu@gmail.com; Nomura, Yoshikatsu, E-mail: y_katsu1027@yahoo.co.jp [Kobe University Hospital, Center for Endovascular Therapy (Japan); Uotani, Kensuke, E-mail: uotani@tenriyorozu.jp [Tenri Hospital, Department of Radiology (Japan); Idoguchi, Koji, E-mail: idoguchi@ares.eonet.ne.jp [Kobe University Hospital, Center for Endovascular Therapy (Japan); Miyamoto, Naokazu, E-mail: naoka_zu@yahoo.co.jp; Kawasaki, Ryota, E-mail: kawaryo1999@yahoo.co.jp [Hyogo Brain and Heart Center at Himeji, Department of Radiology (Japan); Taniguchi, Takanori, E-mail: tan9523929@yahoo.co.jp [Tenri Hospital, Department of Radiology (Japan); Okita, Yutaka, E-mail: yokita@med.kobe-u.ac.jp [Kobe University Hospital, Department of Cardiovascular Surgery (Japan); Sugimoto, Koji, E-mail: kojirad@med.kobe-u.ac.jp [Kobe University Hospital, Department of Radiology (Japan)

2013-08-01

PurposeTo evaluate the safety, efficacy, and long-term results of endovascular stent graft placement for ureteroarterial fistula (UAF).MethodsWe retrospectively analyzed stent graft placement for UAF performed at our institution from 2004 to 2012. Fistula location was assessed by contrast-enhanced computed tomography (CT) and angiography, and freedom from hematuria recurrence and mortality rates were estimated.ResultsStent graft placement for 11 UAFs was performed (4 men, mean age 72.8 {+-} 11.6 years). Some risk factors were present, including long-term ureteral stenting in 10 (91 %), pelvic surgery in 8 (73 %), and pelvic radiation in 5 (45 %). Contrast-enhanced CT and/or angiography revealed fistula or encasement of the artery in 6 cases (55 %). In the remaining 5 (45 %), angiography revealed no abnormality, and the suspected fistula site was at the crossing area between urinary tract and artery. All procedures were successful. However, one patient died of urosepsis 37 days after the procedure. At a mean follow-up of 548 (range 35-1,386) days, 4 patients (36 %) had recurrent hematuria, and two of them underwent additional treatment with secondary stent graft placement and surgical reconstruction. The hematuria recurrence-free rates at 1 and 2 years were 76.2 and 40.6 %, respectively. The freedom from UAF-related and overall mortality rates at 2 years were 85.7 and 54.9 %, respectively.ConclusionEndovascular stent graft placement for UAF is a safe and effective method to manage acute events. However, the hematuria recurrence rate remains high. A further study of long-term results in larger number of patients is necessary.
Treatment of intracranial stenoses using the Neuroform stent system: initial experience in five cases

International Nuclear Information System (INIS)

Haehnel, Stefan; Hartmann, Marius; Ringleb, Peter

2006-01-01

We assessed the technical feasibility of balloon-assisted angioplasty with consecutive stenting using a flexible, self-expanding neurovascular stent for the treatment of intracranial arteriosclerotic vascular stenoses. Five consecutive patients with symptomatic drug-resistant stenoses of the intracranial internal carotid artery (ICA) or the main stem of the middle cerebral artery (MCA) were treated by balloon-assisted angioplasty with consecutive stenting using the Neuroform stent system. Balloon dilatation of the stenoses and consecutive stent placement with complete coverage of the stenoses was feasible in all patients. One patient suffered acute thrombosis distally to the stented vessel segment which was successfully treated by fibrinolysis, and one patient suffered acute subarachnoid and parenchymal hemorrhage probably due to vessel perforation. In the other three patients, no complications occurred during or immediately after angioplasty. All patients were free of further ischemic events up to the 6-month follow-up. Our findings demonstrate that the Neuroform stent system can used successfully for the treatment of intracranial stenoses of the ICA and the main stem of the MCA. Although immediate angiographic results are promising, long-term angiographic and clinical follow-up is essential to demonstrate long-term outcome. (orig.)
Angiographic CT: in vitro comparison of different carotid artery stents-does stent orientation matter?

Science.gov (United States)

Lettau, Michael; Bendszus, Martin; Hähnel, Stefan

2013-06-01

Our aim was to evaluate the in vitro visualization of different carotid artery stents on angiographic CT (ACT). Of particular interest was the influence of stent orientation to the angiography system by measurement of artificial lumen narrowing (ALN) caused by the stent material within the stented vessel segment to determine whether ACT can be used to detect restenosis within the stent. ACT appearances of 17 carotid artery stents of different designs and sizes (4.0 to 11.0 mm) were investigated in vitro. Stents were placed in different orientations to the angiography system. Standard algorithm image reconstruction and stent-optimized algorithm image reconstruction was performed. For each stent, ALN was calculated. With standard algorithm image reconstruction, ALN ranged from 19.0 to 43.6 %. With stent-optimized algorithm image reconstruction, ALN was significantly lower and ranged from 8.2 to 18.7 %. Stent struts could be visualized in all stents. Differences in ALN between the different stent orientations to the angiography system were not significant. ACT evaluation of vessel patency after stent placement is possible but is impaired by ALN. Stent orientation of the stents to the angiography system did not significantly influence ALN. Stent-optimized algorithm image reconstruction decreases ALN but further research is required to define the visibility of in-stent stenosis depending on image reconstruction.
A rapid-exchange monorail stent system for salvage of failing femoropopliteal bypass grafts.

Science.gov (United States)

Jahnke, Thomas; Brossmann, Joachim; Walluscheck, Knut; Heller, Martin; Müller-Hülsbeck, Stefan

2003-08-01

To analyze the safety and effectiveness of a new monorail stent system for the treatment of failing femoropopliteal bypass grafts. Acute distal occlusions or stenoses of femoropopliteal bypass grafts were treated with balloon-expandable stents (13 or 18-mm diameter) pre-mounted on a monorail balloon catheter system. The delivery system was assessed subjectively for (1). compatibility with the sheath, (2). lesion crossing potential, (3). radiopacity, (4). flexibility of the catheter, (5). adequacy of stent expansion, and (5). balloon refolding. In 8 failing bypass grafts with distal lesions, the delivery system successfully deployed the stent at the desired location. Sheath compatibility, catheter flexibility, lesion crossing, and stent expansion were rated "excellent" by all examiners for the 18-mm device. Radiopacity of the mounted stent was graded "good" before and during positioning, but only "sufficient" following expansion. For this type of lesion, the investigators rated the overall performance of the device superior to conventional "over-the-wire" systems. The monorail balloon-expandable stent delivery system provides rapid introduction of the device over the guidewire, and its low profile facilitates the use of small sheaths to minimize access-site complications.
A novel self-expanding fully retrievable intracranial stent (SOLO): experience in nine procedures of stent-assisted aneurysm coil occlusion

International Nuclear Information System (INIS)

Liebig, Thomas; Henkes, Hans; Reinartz, Joerg; Miloslavski, Elina; Kuehne, Dietmar

2006-01-01

The endovascular treatment of large and broad-necked aneurysms may require the use of a remodelling balloon or a stent system to achieve proper occlusion while maintaining the patency of the parent vessel. With the advent of self-expanding stents that can be delivered through a microcatheter, this kind of treatment has improved and problems with the previously used balloon expandable stents have largely been overcome. However, rigidity, insufficient trackability, and limited or non-existent retrievability may still restrict the application of self-expanding stents in some situations. Recently, a stent system with a new and different design has been introduced. This stent is highly flexible, fully retrievable, and can be delivered through a standard 0.021-inch microcatheter without a wire. We describe the first nine cases of stent-assisted coil occlusion of intracranial aneurysms with the use of this stent system. Between May and June of 2004, nine patients with large or broad-necked aneurysms were treated in two endovascular centres. The anatomy of the aneurysms and parent vessels, technical details of the procedure, performance of the stent system, and follow-up results were evaluated. In all procedures, the SOLO stent could be introduced without difficulty, in one procedure after positioning of a different self-expanding stent system had failed due to vessel tortuosity. Overlapping stents were placed in one patient and stent retrieval or repositioning was successfully performed in two procedures. There was no interference or limitation of subsequent coil occlusion after stenting. With regard to the stent, immediate postprocedure and follow-up angiograms were unremarkable in terms of thromboembolic events and signs of intimal hyperplasia. From our experience, we conclude that the SOLO stent shows satisfactory performance overall. Its unique design gives the stent properties that may help overcome some of the difficulties experienced with other self
Self-Expandable Metallic Stent for the Palliative Treatment of Obstructing Left-Sided Colorectal Cancer under Fluoroscopic Guidance: A Comparison of the Clinical Results according to Stent Diameter

Energy Technology Data Exchange (ETDEWEB)

Kang, Pyeong Guk; Hong, Hyun Pyo; Choi, Yoon Jung; Lee, Min Hee; Park, Hae Won; Chung, Eun Chul [Kangbuk Samsung Hospital, Seoul (Korea, Republic of); Kim, Sam Soo [Kangwon National University College of Medicine, Chuncheon (Korea, Republic of)

2010-03-15

To evaluate the feasibility, effectiveness, and safety of self-expandable metallic stent for the palliative treatment of obstructing left-sided colorectal cancer under fluoroscopic guidance, and to compare results according to the stent diameter. Under fluoroscopic guidance, 31 self-expandable metallic stents were placed into 25 patients for palliative purposes. The rates of technical success, clinical success, complications associated with stent insertion, patient survival, and primary stent patency were evaluated. The results were also compared between two groups: 13 patients using stents with a diameter of 22 mm and 12 patients using stents with a diameter of 26 mm. The technical and clinical success rates were 93.5 and 90.3%, respectively. The complications included severe abdominal pain (6.5%), minor rectal bleeding (9.7%), stent migration (9.7%), and tumor ingrowth or overgrowth (9.7%). No statistical differences in technical were detected between the two groups for the clinical success rate and complication rates. The mean survival time was 5.5 +- 1.4 months. The primary stent patency rates were 91.3% at 5 months, 85.2% at 10 months, and 77.4% at 15 months. The mean period of stent patency was 12.4 +- 2.6 months. The mean period of primary stent patency was 16.4 +- 2.6 months in the 26 mm stent group, and significantly higher than 5.4 +- 1.4 months in the 22 mm stent group (p=0.031). A self-expandable metallic stent under fluoroscopic guidance, for the palliative treatment of obstructing left-sided colorectal cancer, was feasible and effective, and yielded good clinical results. The period of primary stent patency of the 26 mm stent group was longer than the 22 mm stent group, and the complication rate was not significantly different between the two stent groups
Self-Expandable Metallic Stent for the Palliative Treatment of Obstructing Left-Sided Colorectal Cancer under Fluoroscopic Guidance: A Comparison of the Clinical Results according to Stent Diameter

International Nuclear Information System (INIS)

Kang, Pyeong Guk; Hong, Hyun Pyo; Choi, Yoon Jung; Lee, Min Hee; Park, Hae Won; Chung, Eun Chul; Kim, Sam Soo

2010-01-01

To evaluate the feasibility, effectiveness, and safety of self-expandable metallic stent for the palliative treatment of obstructing left-sided colorectal cancer under fluoroscopic guidance, and to compare results according to the stent diameter. Under fluoroscopic guidance, 31 self-expandable metallic stents were placed into 25 patients for palliative purposes. The rates of technical success, clinical success, complications associated with stent insertion, patient survival, and primary stent patency were evaluated. The results were also compared between two groups: 13 patients using stents with a diameter of 22 mm and 12 patients using stents with a diameter of 26 mm. The technical and clinical success rates were 93.5 and 90.3%, respectively. The complications included severe abdominal pain (6.5%), minor rectal bleeding (9.7%), stent migration (9.7%), and tumor ingrowth or overgrowth (9.7%). No statistical differences in technical were detected between the two groups for the clinical success rate and complication rates. The mean survival time was 5.5 ± 1.4 months. The primary stent patency rates were 91.3% at 5 months, 85.2% at 10 months, and 77.4% at 15 months. The mean period of stent patency was 12.4 ± 2.6 months. The mean period of primary stent patency was 16.4 ± 2.6 months in the 26 mm stent group, and significantly higher than 5.4 ± 1.4 months in the 22 mm stent group (p=0.031). A self-expandable metallic stent under fluoroscopic guidance, for the palliative treatment of obstructing left-sided colorectal cancer, was feasible and effective, and yielded good clinical results. The period of primary stent patency of the 26 mm stent group was longer than the 22 mm stent group, and the complication rate was not significantly different between the two stent groups
Creation of individual ideally shaped stents using multi-slice CT: in vitro results from the semi-automatic virtual stent (SAVS) designer

International Nuclear Information System (INIS)

Hyodoh, Hideki; Katagiri, Yoshimi; Hyodoh, Kazusa; Akiba, Hidenari; Hareyama, Masato; Sakai, Toyohiko

2005-01-01

To plan stent-grafting for thoracic aortic aneurysm with complicated morphology, we created a virtual stent-grafting program [Semi Automatic Virtual Stent (SAVS) designer] using three-dimensional CT data. The usefulness of the SAVS designer was evaluated by measurement of transformed anatomical and straight stents. Curved model images (source, multi-planer reconstruction and volume rendering) were created, and a hollow virtual stent was produced by the SAVS designer. A straight Nitinol stent was transformed to match the curved configuration of the virtual stent. The accuracy of the anatomical stent was evaluated by experimental strain phantom studies in comparison with the straight stent. Mean separation length was 0 mm in the anatomical stent [22 mm outer diameter (OD)] and 5 mm in the straight stent (22 mm OD). The straight stent strain voltage was four times that of the anatomical stent at the stent end. The anatomical stent is useful because it fits the curved structure of the aorta and reduces the strain force compared to the straight stent. The SAVS designer can help to design and produce the anatomical stent. (orig.)
Intracranial Stent Implantation for Drug Resistant Atherosclerotic Stenosis: Results of 52 Cases

International Nuclear Information System (INIS)

Kim, Kuk Seon; Hwang, Dae Hyun; Ko, Young Hwan; Kang, Ik Won; Lee, Eil Seong; Han, You Mie; Kim, In Soo; Hur, Choon Woong

2011-01-01

We evaluated the usefulness of intracranial stent implantation for treatment of drug resistant atherosclerotic stenoses. Between March 2004 and July 2007, we tried intracranial stent implantation in 49 patients with 52 lesions (anterior circulation 48 cases, posterior circulation 4 cases) who had an ischemic stroke with more than 50% of major cerebral artery stenosis. We classified the lesions by their location and morphology, analyzed the results in terms of the success rate, complication rate, and restenosis rate during the follow-up period. Intracranial stent implantation was performed successfully in 43 cases (82.7%). In eight of the nine cases, the stent implantation failure was due to the tortuosity of the target vessel. There was no major periprocedural complication. One patient showed cerebellar infarction after the procedure. Mean residual stenoses decreased from 70.2% to 13.0%. Four cases (9.3%) demonstrated in-stent restenoses and more than 50% during the mean and 25.3/month after the follow-up period. Success rate of intracranial stent implantation may improve on developing technique and more experience. Low rate of complication and restenosis suggest that we can consider intracranial stent implantation for treatment of drug resistant atherosclerotic stenoses.
Coronary artery aneurysm after stent implantation: acute and long-term results after percutaneous treatment with a stent graft.

Science.gov (United States)

Rubartelli, Paolo; Terzi, Giacomo; Borgo, Lorenzo; Giachero, Corinna

2002-03-01

A patient with unstable angina was treated with elective Palmaz-Schatz stent implantation on a focal stenosis of the left circumflex artery. One year later, a large (13 mm in diameter) coronary artery aneurysm was diagnosed at angiography in the stented site. Intravascular ultrasound examination confirmed the presence of a true aneurysm located at the proximal end of the stent. The aneurysm was successfully treated with a Jostent Graft (Jomed Implantate) consisting of two slotted tube stainless steel stents supporting a polytetrafluoroethylene tube. The stent graft was implanted under intravascular ultrasound guidance. The 18-month angiographic follow-up showed good patency of the stent graft and complete exclusion of the aneurysm.
Impact on outcome of different types of carotid stent: results from the European Registry of Carotid Artery Stenting.

Science.gov (United States)

Stabile, Eugenio; Giugliano, Giuseppe; Cremonesi, Alberto; Bosiers, Marc; Reimers, Bernhard; Setacci, Carlo; Cao, Piergiorgio; Schmidt, Andrej; Sievert, Horst; Peeters, Patrick; Nikas, Dimitrios; Sannino, Anna; de Donato, Gianmarco; Parlani, Giambattista; Castriota, Fausto; Hornung, Marius; Rubino, Paolo; Esposito, Giovanni; Tesorio, Tullio

2016-06-12

Conflicting data exist on the impact on outcome of the use of different stent types during carotid artery stenting (CAS). The aim of this study was to evaluate clinical outcomes according to different carotid stent design among the population of the European Registry of Carotid Artery Stenting (ERCAS). The present study was conducted in 1,604 patients who underwent neuroprotected CAS in ERCAS. All types of commercially available carotid stent were used. Open-cell design stents were classified according to free cell area into 7.5 mm2. A total of 713 closed-cell, 456 hybrid-cell, 238 7.5 mm2 open-cell stents were implanted. Overall, the 30-day stroke and death rate was 1.37%. At 30 days, 19 strokes occurred (1.18%): eight in the group of patients treated with a closed-cell (1.12%), two in those with a hybrid-cell (0.44%), three in those with a 7.5 mm2 open-cell stent (3.05%) (p=0.045). Data of the present study suggest that, in the setting of neuroprotected CAS performed in high-volume centres by properly trained operators, the use of an open-cell design stent with a free cell area >7.5 mm2 may be associated with an increased 30-day stroke risk.
Auxetic coronary stent endoprosthesis

DEFF Research Database (Denmark)

Amin, Faisal; Ali, Murtaza Najabat; Ansari, Umar

2014-01-01

BACKGROUND: Cardiovascular heart disease is one of the leading health issues in the present era and requires considerable health care resources to prevent it. The present study was focused on the development of a new coronary stent based on novel auxetic geometry which enables the stent to exhibit...... a negative Poisson's ratio. Commercially available coronary stents have isotropic properties, whereas the vascular system of the body shows anisotropic characteristics. This results in a mismatch between anisotropic-isotropic properties of the stent and arterial wall, and this in turn is not favorable...... for mechanical adhesion of the commercially available coronary stents with the arterial wall. It is believed that an auxetic coronary stent with inherent anisotropic mechanical properties and negative Poisson's ratio will have good mechanical adhesion with the arterial wall. METHODS: The auxetic design...
Combined-stent covered technique and single covered stent technique for transjugular intrahepatic porto-systemic shunt: a prospective randomized controlled study

International Nuclear Information System (INIS)

Wang Changming; Li Xuan; Fu Jun; Lu Xianjun; Luan Jingyuan; Li Tianrun; Zhao Jun; Dong Guoxiang

2014-01-01

Objective: To compare the technique of combined stents with that of single stent-graft for the construction of transjugular intrahepatic porto-systemic shunt (TIPS) and to discuss their clinical outcomes. Methods: During the period from April 2011 to Dec. 2012, a total of 30 patients with upper gastrointestinal bleeding due to portal hypertension were admitted to the hospital. TIPS procedure was carried out in all the 30 patients. The patients were randomly allocated into either combined-stent group (n=17) or stent-graft group (control group, n=13) on the basis of a computer-generated randomization sequence. The PSC quality control, the patency rate of portal vein branches and the shunts, the incidence of encephalopathy and the survival rate of the two groups were documented and analyzed. Results: Technical success rate was 100%. After the treatment, in both groups the PSG became significantly lower than the PSG determined before the treatment (P<0.000). According to quality control chart, the of combined stents was superior to stent-graft technique in effectively controlling PSG. Five days after TIPS, the ammonia level in the combined- stent group was significantly decreased (P=0.029), while in the control group the ammonia level showed no significant changes (P=0.065). One patient died shortly after TIPS. The median follow- up time was 181 days. During the follow-up period death occurred in 3 cases in each group. The difference in the survival rate between the two groups was no significant (P=0.906). Of the three patients who developed encephalopathy, two were in the combined-stent group and one was in the control group. After medication the symptoms of encephalopathy were relieved. The patency rate of the shunts was 100% and the re-bleeding rate was 0% for both groups. The patency rate of portal vein branches was significantly higher in the combined-stent group than that in the control group (P=0.039). Conclusion: For the construction of TIPS, the technique of
Mechanical thrombectomy using Rotarex system and stent-in-stent placement for treatment of distal femoral artery occlusion secondary to stent fracture – a case report and literature review

International Nuclear Information System (INIS)

Dys, Krzysztof; Drelichowska-Durawa, Justyna; Dołega-Kozierowski, Bartosz; Lis, Michał; Sokratous, Kyriakos; Iwanowski, Wojciech; Drelichowski, Stanisław; Witkiewicz, Wojciech

2013-01-01

Treatment of peripheral arterial diseases may be distinguished into conservative and interventional management; the latter is divided into surgical and endovascular procedures. Management of peripheral artery stenosis and occlusion with vascular stents is associated with the risk of late complications such as restenosis, stent fracture or dislocation. A 62-year-old woman with generalized atherosclerosis, particularly extensive in lower limb arteries, was admitted to the Department of Angiology 11 months after having an endovascular procedure performed due to critical ischemia of left lower limb. Because of stent occlusion, a decision to perform angiographic examination of lower limb arteries was made. Examination revealed occlusion of the superficial femoral artery along its entire length, including previously implanted stents. Distal stent was fractured with slight dislocation of the proximal segment. A decision was made to perform mechanical thrombectomy using a Rotarex system followed by a stent-in-stent placement procedure. Follow-up angiography and ultrasound scan performed 24 hours after the procedure revealed a patent vessel with satisfactory blood flow. Nowadays, imaging diagnostics of peripheral artery stenosis involves non-invasive examinations such as ultrasound, minimally invasive examinations such as angio-MRI and MDCT, or invasive examinations such as DSA and IVUS. DSA examinations are used to confirm significant stenosis or occlusion of a vessel, particularly when qualifying a patient for endovascular treatment. Due to their anatomic location, the superficial femoral artery and the popliteal artery are subject to various forces e.g. those exerted by the working muscles. Mechanical thrombectomy and atherectomy are efficient methods of arterial recanalization used in the treatment of acute, subacute or even chronic occlusions or stenosis of peripheral vessels. Frequency of angioplasty and vascular stent implantation procedures is increased in patients

Predictors of early stent occlusion among plastic biliary stents.

Science.gov (United States)

Khashab, Mouen A; Kim, Katherine; Hutfless, Susan; Lennon, Anne Marie; Kalloo, Anthony N; Singh, Vikesh K

2012-09-01

A major disadvantage of plastic biliary stents is their short patency rates. The aim of this study was to identify predictors of early stent occlusion among patients receiving conventional plastic biliary stents. Early stent occlusion was defined as worsening cholestatic liver test results of a severity sufficiently significant to warrant ERCP with stent exchange prior to the planned stent exchange, or as symptoms of cholangitis. The association of cumulative stent diameter, demographics, stricture location, procedure indication, Charlson comorbidity index, history of prior early stent occlusion, presence of gallbladder, and performance of sphincteromy with the occurrence of early stent occlusion was studied using logistic regression and multivariate analysis. Our patient cohort comprised 343 patients (mean age 59.3 years) who underwent 561 ERCP procedures with the placement of one or more plastic biliary stents (mean number of stents per procedure 1.2, mean total diameter of stents per procedure 12 Fr). Early stent occlusion occurred in 73 (13 %) procedures. Female gender was protective against early stent occlusion (adjusted OR 0.54, 95 % CI 0.32-0.90, p = 0.02), while hilar stricture location was independently associated with a significantly increased risk of early stent occlusion (adjusted OR 3.41, 95 % CI 1.68-6.90, p = 0.0007). Early occlusion of conventional biliary stents occurred in 13 % of cases. While female gender decreased the risk of early stent occlusion, hilar stricture location was a significant predictor of early stent occlusion. Our results suggest that physicians should consider early elective stent exchange in patients with hilar strictures.
The risk and prognostic impact of definite stent thrombosis or in-stent restenosis after coronary stent implantation

DEFF Research Database (Denmark)

Thayssen, Per; Jensen, Lisette Okkels; Lassen, Jens Flensted

2012-01-01

Aims: Data are limited on the prognostic impact of stent thrombosis and in-stent restenosis in patients treated with coronary stents. We examined the prognostic impact of stent thrombosis and in-stent restenosis in patients treated with percutaneous coronary intervention (PCI). Methods and results......: All patients who underwent stent implantation from 2002 to 2005 were identified in the Western Denmark Heart Registry. The hazard ratio (HR) for death associated with stent thrombosis or in-stent restenosis was estimated with a Cox regression analysis with stent thrombosis or in-stent restenosis...... as time-dependent variables. A total of 12,277 patients were treated with stent implantation. Stent thrombosis was observed in 111 (0.9%) patients and in-stent restenosis in 503 (4.1%) patients within 12 months after the index PCI. Occurrence of stent thrombosis was associated with an increased risk...
Results of the new nitinol self-expandable stents for distal biliary structures

NARCIS (Netherlands)

Smits, M.; Huibregtse, K.; Tytgat, G.

1995-01-01

The nitinol stent is a self-expandable spiral stent made of nickel-titanium alloy. We performed a pilot study to evaluate the method of stent insertion and stent efficacy. Twenty-eight patients with irresectable malignancy had nitinol stents inserted for obstructive jaundice due to distal biliary
The impact of precise robotic lesion length measurement on stent length selection: ramifications for stent savings.

Science.gov (United States)

Campbell, Paul T; Kruse, Kevin R; Kroll, Christopher R; Patterson, Janet Y; Esposito, Michele J

2015-09-01

Coronary stent deployment outcomes can be negatively impacted by inaccurate lesion measurement and inappropriate stent length selection (SLS). We compared visual estimate of these parameters to those provided by the CorPath 200® Robotic PCI System. Sixty consecutive patients who underwent coronary stent placement utilizing the CorPath System were evaluated. The treating physician assessed orthogonal images and provided visual estimates of lesion length and SLS. The robotic system was then used for the same measures. SLS was considered to be accurate when visual estimate and robotic measures were in agreement. Visual estimate SLSs were considered to be "short" or "long" if they were below or above the robotic-selected stents, respectively. Only 35% (21/60) of visually estimated lesions resulted in accurate SLS, whereas 33% (20/60) and 32% (19/60) of the visually estimated SLSs were long and short, respectively. In 5 cases (8.3%), 1 less stent was placed based on the robotic lesion measurement being shorter than the visual estimate. Visual estimate assessment of lesion length and SLS is highly variable with 65% of the cases being inaccurately measured when compared to objective measures obtained from the robotic system. The 32% of the cases where lesions were visually estimated to be short represents cases that often require the use of extra stents after the full lesion is not covered by 1 stent [longitudinal geographic miss (LGM)]. Further, these data showed that the use of the robotic system prevented the use of extra stents in 8.3% of the cases. Measurement of lesions with robotic PCI may reduce measurement errors, need for extra stents, and LGM. Copyright © 2015 Elsevier Inc. All rights reserved.
Drug-eluting stents to prevent stent thrombosis and restenosis.

Science.gov (United States)

Im, Eui; Hong, Myeong-Ki

2016-01-01

Although first-generation drug-eluting stents (DES) have significantly reduced the risk of in-stent restenosis, they have also increased the long-term risk of stent thrombosis. This safety concern directly triggered the development of new generation DES, with innovations in stent platforms, polymers, and anti-proliferative drugs. Stent platform materials have evolved from stainless steel to cobalt or platinum-chromium alloys with an improved strut design. Drug-carrying polymers have become biocompatible or biodegradable and even polymer-free DES were introduced. New limus-family drugs (such as everolimus, zotarolimus or biolimus) were adopted to enhance stent performances. As a result, these new DES demonstrated superior vascular healing responses on intracoronary imaging studies and lower stent thrombotic events in actual patients. Recently, fully-bioresorbable stents (scaffolds) have been introduced, and expanding their applications. In this article, the important concepts and clinical results of new generation DES and bioresorbable scaffolds are described.
Spectral Imaging for Intracranial Stents and Stent Lumen.

Science.gov (United States)

Weng, Chi-Lun; Tseng, Ying-Chi; Chen, David Yen-Ting; Chen, Chi-Jen; Hsu, Hui-Ling

2016-01-01

Application of computed tomography for monitoring intracranial stents is limited because of stent-related artifacts. Our purpose was to evaluate the effect of gemstone spectral imaging on the intracranial stent and stent lumen. In vitro, we scanned Enterprise stent phantom and a stent-cheese complex using the gemstone spectral imaging protocol. Follow-up gemstone spectral images of 15 consecutive patients with placement of Enterprise from January 2013 to September 2014 were also retrospectively reviewed. We used 70-keV, 140-keV, iodine (water), iodine (calcium), and iodine (hydroxyapatite) images to evaluate their effect on the intracranial stent and stent lumen. Two regions of interest were individually placed in stent lumen and adjacent brain tissue. Contrast-to-noise ratio was measured to determine image quality. The maximal diameter of stent markers was also measured to evaluate stent-related artifact. Two radiologists independently graded the visibility of the lumen at the maker location by using a 4-point scale. The mean of grading score, contrast/noise ratio and maximal diameter of stent markers were compared among all modes. All results were analyzed by SPSS version 20. In vitro, iodine (water) images decreased metallic artifact of stent makers to the greatest degree. The most areas of cheese were observed on iodine (water) images. In vivo, iodine (water) images had the smallest average diameter of stent markers (0.33 ± 0.17mm; P stent lumen (160.03 ±37.79; P stent-related artifacts of Enterprise and enhance contrast of in-stent lumen. Spectral imaging may be considered a noninvasive modality for following-up patients with in-stent stenosis.
Clinical results from first use of prostate stent as fiducial for radiotherapy of prostate cancer

Energy Technology Data Exchange (ETDEWEB)

Carl, Jesper; Nielsen, Jane (Dept. of Medical Physics, Dept. of Oncology, Aalborg Hospital, Aarhus Univ. Hospital, Aalborg (Denmark)), e-mail: jhc@rn.dk; Holmberg, Mats (Dept. of Oncology, Aalborg Hospital, Aarhus Univ. Hospital, Aalborg (Denmark)); Larsen, Erik Hoejkjaer; Fabrin, Knud (Dept. of Urology, Aalborg Hospital, Aarhus Univ. Hospital, Aalborg (Denmark)); Fisker, Rune V. (Dept. of Radiology, Aalborg Hospital, Aarhus Univ. Hospital, Aalborg (Denmark))

2011-05-15

Purpose. A clinical feasibility study using a removable prostate stent as fiducial for image-guided radiotherapy (IGRT) of localized prostate cancer (PC). Material and methods. The study included patients with local or locally advanced PC. The clinical target volume (CTV) was outlined on magnetic resonance (MR) images co-registered to planning computer tomography (CT) images. Daily online IGRT was delivered using the stent as fiducial. Risk of migration was estimated using multiple MR. Acute urinary toxicity was scored using the international prostate symptom score (IPSS). Late gastro-intestinal (GI) and genito-urinary (GU) toxicity was scored using the Radio Therapy Oncology Group (RTOG) score, biochemical failure (BF) was defined as an elevation of prostate specific antigen (PSA) above nadir plus 2 ng/ml after radiotherapy. Results. One hundred men were enrolled in the study. Ninety completed radiotherapy with the stent as fiducial. No migration of the stent was seen, but three cases of dislocation of the stent to the bladder were observed. Acute urinary toxicity based on IPSS was comparable to toxicity in patients who had gold markers (GM) as fiducials. Removal of the stent was associated with a high frequency of urinary retention. Late GI and GU toxicity and BF were comparable to those of other studies, but longer observation time is needed. Conclusions. This study reports the first clinical results of using a prostate stent as fiducial. No migration of the stent observed. Dislocation of the stent to the urinary bladder was observed in three cases, requiring removal of the stent and insertion of a new fiducial. Acute toxicity during radiotherapy evaluated from IPSS was comparable to toxicity in patients with GM. Removal of the stent was associated with a high frequency of post procedural urinary retention. Late toxicity and BF were comparable to those of other studies, though longer observation time is needed
Clinical results from first use of prostate stent as fiducial for radiotherapy of prostate cancer

International Nuclear Information System (INIS)

Carl, Jesper; Nielsen, Jane; Holmberg, Mats; Larsen, Erik Hoejkjaer; Fabrin, Knud; Fisker, Rune V.

2011-01-01

Purpose. A clinical feasibility study using a removable prostate stent as fiducial for image-guided radiotherapy (IGRT) of localized prostate cancer (PC). Material and methods. The study included patients with local or locally advanced PC. The clinical target volume (CTV) was outlined on magnetic resonance (MR) images co-registered to planning computer tomography (CT) images. Daily online IGRT was delivered using the stent as fiducial. Risk of migration was estimated using multiple MR. Acute urinary toxicity was scored using the international prostate symptom score (IPSS). Late gastro-intestinal (GI) and genito-urinary (GU) toxicity was scored using the Radio Therapy Oncology Group (RTOG) score, biochemical failure (BF) was defined as an elevation of prostate specific antigen (PSA) above nadir plus 2 ng/ml after radiotherapy. Results. One hundred men were enrolled in the study. Ninety completed radiotherapy with the stent as fiducial. No migration of the stent was seen, but three cases of dislocation of the stent to the bladder were observed. Acute urinary toxicity based on IPSS was comparable to toxicity in patients who had gold markers (GM) as fiducials. Removal of the stent was associated with a high frequency of urinary retention. Late GI and GU toxicity and BF were comparable to those of other studies, but longer observation time is needed. Conclusions. This study reports the first clinical results of using a prostate stent as fiducial. No migration of the stent observed. Dislocation of the stent to the urinary bladder was observed in three cases, requiring removal of the stent and insertion of a new fiducial. Acute toxicity during radiotherapy evaluated from IPSS was comparable to toxicity in patients with GM. Removal of the stent was associated with a high frequency of post procedural urinary retention. Late toxicity and BF were comparable to those of other studies, though longer observation time is needed
Comparison of midterm results for the Talent and Endurant stent graft.

Science.gov (United States)

't Mannetje, Yannick W; Cuypers, Philippe W M; Saleem, Ben R; Bode, Aron S; Teijink, Joep A W; van Sambeek, Marc R H M

2017-09-01

Stent graft evolution is often addressed as a cause for improved outcomes of endovascular aneurysm repair for patients with an abdominal aortic aneurysm. In this study, we directly compared the midterm result of Endurant stent graft with its predecessor, the Talent stent graft (both Medtronic, Santa Rosa, Calif). Patient treated from January 2005 to December 2010 in a single tertiary center in The Netherlands with a Talent or Endurant stent graft were eligible for inclusion. Ruptured abdominal aortic aneurysms or patients with previous aortic surgery were excluded. The primary end point was the Kaplan-Meier estimated freedom from secondary interventions. Secondary end points were perioperative outcomes and indications for secondary interventions. In total, 221 patients were included (131 Endurant and 90 Talent). At baseline, the median aortic bifurcation was narrower for the Endurant (30 mm vs 39 mm; P Talent and Endurant, respectively. The estimated freedom from secondary interventions at 30 days, 1 year, 5 years, and 7 years was 94.3%, 89.4%, 72.2%, and 64.1% for Talent and 96.8%, 89.3%, 75.2%, and 69.2% for Endurant (P = .528). The indication for secondary interventions does differ; more patients required an intervention for a proximal neck-related complication (type Ia endoleak or migration) in the Talent group (18.2% vs 4.8%; P = .001), whereas more interventions for iliac limb stenosis were seen in the Endurant group (0.0% vs 4.8%; P = .044). In a binomial regression analysis, suprarenal angulation, infrarenal neck length, and type of stent graft were independent predictors of neck-related complications. Evolution from the Talent stent graft into the Endurant has resulted in significant reduction of infrarenal neck-related complications; on the other hand, iliac interventions increased. The overall midterm secondary intervention rate was comparable. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.
Stent fabric fatigue of grafts supported by Z-stents versus ringed stents: an in vitro buckling test.

Science.gov (United States)

Lin, Jing; Wang, Lu; Guidoin, Robert; Nutley, Mark; Song, Ge; Zhang, Ze; Du, Jia; Douville, Yvan

2014-03-01

Stent-grafts externally fitted with a Z-shaped stents were compared to devices fitted with ringed stents in an in vitro oscillating fatigue machine at 200 cycles per minute and a pressure of 360 mmHg for scheduled durations of up to 1 week. The devices fitted with Z-stents showed a considerably lower endurance limit to buckling compared to the controls. The contact between the apexes of adjacent Z-stents resulted in significant damage to the textile scaffolds and polyester fibers due to the sharp angle of the Z-stents. The ringed stents did not cause any fraying in the textile scaffolds.
Stent insertion in patients with malignant biliary obstruction: problems of the Hanaro stent

Energy Technology Data Exchange (ETDEWEB)

Kwon, Jae Hyun; Seong, Chang Kyu; Shin, Tae Beom; Kim, Yong Joo [School of Medicine, Kyungpook National Univ., Daegu (Korea, Republic of); Jung, Gyoo Sik [School of Medicine, Kosin National Univ., Pusan (Korea, Republic of); Park, Byeung Ho [School of Medicine, Donga National Univ., Pusan (Korea, Republic of)

2002-07-01

To investigate the problems of the Hanaro stent (Solco Intermed, Seoul, Korea) when used in the palliative treatment of patients with inoperable malignant biliary obstruction. Between January 2000 and May 2001, the treatment of 46 patients with malignant biliary obstruction involved percutaneous placement of the Hanaro stent. Five patients encountered problems during removal of the stent's introduction system. The causes of obstruction were pancreatic carcinoma (n=2), cholangiocarcinoma (n=2), and gastric carcinoma with biliary invasion (n=1). In one patient, percutaneous transhepatic cholangiography and stent insertion were performed as a one-step procedure, while the others underwent conventional percutaneous transhepatic biliary drainage for at least two days prior to stent insertion. A self-expandable Hanaro stent, 8-10 mm in deameter and 50-100 mm in lengh, and made from a strand of nitinol wire, was used in all cases. Among the five patients who encountered problems, breakage of the olive tip occourred in three, upward displacement of the stent in two, and improper expansion of the distal portion of the stent, unrelated with the obstruction site, in one. The broken olive tip was pushed to the duodenum in two cases and to the peripheral intrahepatic duct in one. Where the stent migrated during withdrawal of its introduction system, an additional stent was inserted. In one case, the migrated stent was positioned near the liver capsule and the drainage catheter could not be removed. Although the number of patients in this study was limited, some difficulties were encountered in withdrawing the stent's introduction system. To prevent the occurrence of this unusual complication, the stent should be appropriately expansile, and shape in the olive tip should be considered.
Gianturco metallic biliary stent in malignant biliary obstruction: results of follow-up in dead patients

Energy Technology Data Exchange (ETDEWEB)

Roh, Byung Suk; Kim, Chan Soo; Lee, Kyung Soo; Choi, See Sung; Won, Jong Jin; Kim, Haak Cheul; Chae, Kwon Mook [Wonkwang University School of Medicine, Iri (Korea, Republic of)

1994-04-15

In order to study the patency, restenosis, efficacy, and complication of the metallic stent in the course of treatment of malignant biliary obstruction, the results of follow up of the dead patients after stent insertion were reviewed. Self-expandable Gianturco metallic stent with 10-mm diameter was successfully inserted in 33 patients: 10 with Klatskin tumor, 7 with common bile duct cancer, 7 with gallbladder cancer, 5 with pancreatic cancer, 2 with recurred stomach cancer, one with periampullary cancer, one with hepatocellular carcinoma. The overall duration of survival and patency of the stents in 33 patients were 5.2 months(1-12 months) and 4.9 months(1-14 months), respectively. Restenosis of metallic stents was found in 9 cases(27%), after 6.1 months in average. Causes of stent occlusion were overgrowing of tumor in 5, overgrowing and ingrowing of tumor in 3, extraductal dislodgement in one case. Two cases of symptomatic cholangitis after stent placement were successfully treated with percutaneous cholecystostomy. Three cases of destruction and migration of metallic stents were found after 6 months. On the basis of our experience, insertion of Gianturco metallic biliary stent is an acceptable treatment method in the malignant biliary obstruction, especially for whom short term survival is expected.
Symptomatic stent cast.

LENUS (Irish Health Repository)

Keohane, John

2012-02-03

Biliary stent occlusion is a major complication of endoscopic stent insertion and results in repeat procedures. Various theories as to the etiology have been proposed, the most frequently studied is the attachment of gram negative bacteria within the stent. Several studies have shown prolongation of stent patency with antibiotic prophylaxis. We report the case of stent occlusion from a cast of a previously inserted straight biliary stent; a "stent cast" in an 86-year-old woman with obstructive jaundice. This was retrieved with the lithotrypter and she made an uneventful recovery. This is the first reported case of a biliary stent cast.
Intravascular ultrasound-guided optimized stent deployment. Immediate and 6 months clinical and angiographic results from the Multicenter Ultrasound Stenting in Coronaries Study (MUSIC Study)

Science.gov (United States)

de Jaegere, P; Mudra, H; Figulla, H; Almagor, Y; Doucet, S; Penn, I; Colombo, A; Hamm, C; Bartorelli, A; Rothman, M; Nobuyoshi, M; Yamaguchi, T; Voudris, V; DiMario, C; Makovski, S; Hausmann, D; Rowe, S; Rabinovich, S; Sunamura, M; van Es, G A

1998-08-01

.3%. When the two patients with documented stent thrombosis are included, the restenosis rate amounts to 97%. These data confirm that, in selected patients, stents can safely be implanted without the use of systemic anticoagulation, provided optimal stent expansion is achieved. The exact role of intravascular ultrasound in the achievement of these results needs to be established by appropriately designed studies. In the meantime, intravascular ultrasound coupled with the Palmaz-Schatz stent incorporating a spiral bridge, may have contributed considerably to the immediate angiographic outcome, which in turn may explain the favourable clinical and angiographic outcome at 6 months.
Therapies targeting inflammation after stent implantation.

Science.gov (United States)

Okura, Hiroyuki; Takagi, Tsutomu; Yoshida, Kiyoshi

2013-07-01

Since the introduction of coronary vessel scaffold by metallic stent, percutaneous coronary intervention has become widely performed all over the world. Although drug-eluting stent technology has further decrease the incidence of in-stent restenosis, there still remaining issues related to stent implantation. Vessel inflammation is one of the causes that may be related to stent restenosis as well as stent thrombosis. Therefore, systemic therapies targeting inflammation emerged as adjunctive pharmacological intervention to improve outcome. Statins, corticosteroids, antiplatelets, and immunosuppresive or anti-cancer drugs are reported to favorably impact outcome after bare-metal stent implantation. In type 2 diabetic patients, pioglitazone may be the most promising drug that can lower neointimal proliferation and, as a result, lower incidence of restenosis and target lesion revascularization. On the other hand, several new stent platforms that might decrease inflammatory response after drug-eluting stent implantation have been introduced. Because durable polymer used in the first generation drug-eluting stents are recognized to be responsible for unfavorable vessel response, biocompatible or bioabsorbable polymer has been introduce and already used clinically. Furthermore, polymer-free drug-eluting stent and bioresorbable scaffold are under investigation. Although vessel inflammation may be reduced by using these new drug-eluting stents or scaffold, long-term impact needs to be investigated further.
The Effect of Stent Cell Geometry on Carotid Stenting Outcomes

Energy Technology Data Exchange (ETDEWEB)

Alparslan, Burcu, E-mail: burcu.alparslan@gmail.com [Yozgat State Hospital, Radiology Clinic (Turkey); Nas, Omer Fatih, E-mail: omerfatihnas@gmail.com [Uludag University Faculty of Medicine, Department of Radiology (Turkey); Eritmen, Ulku Turpcu, E-mail: drulkutur@hotmail.com.tr [Special Eregli Anatolia Hospital, Radiology Clinic (Turkey); Duran, Selcen, E-mail: selcenduran16@hotmail.com [Yerkoy State Hospital, Neurology Clinic (Turkey); Ozkaya, Guven, E-mail: ozkaya@uludag.edu.tr [Uludag University Faculty of Medicine, Department of Biostatistics (Turkey); Hakyemez, Bahattin, E-mail: bhakyemez@uludag.edu.tr [Uludag University Faculty of Medicine, Department of Radiology (Turkey)

2016-04-15

PurposeThe aim of this study was to investigate the effect of stent cell geometry on midterm results of carotid artery stenting (CAS).Materials and MethodOne hundred fifty-five patients underwent CAS between February 2010 and December 2012. Ninety-one open- and 84 closed-cell stents were used in this non-randomized, retrospective study. Periprocedural complications were defined as the ones happened during the procedure or within 30 days afterwards. Starting from the 6th month after the procedure, in-stent restenosis was detected with multidetector computed tomography angiography and classified into four groups from focal restenosis to occlusion.ResultsEleven complications were encountered in the periprocedural period (four on the open- and seven on the closed-cell group). Total complication rate was 6.3 % (11/175). No significant difference was detected in terms of periprocedural complications between two groups (p = 0.643). There was statistically significant difference between stent design groups in regard to radiological findings (p = 0.002). Sixteen of open-cell stents and three of closed-cell stents had focal restenosis. One closed-cell stent had diffuse proliferative restenosis and one open-cell stent had total occlusion.ConclusionIn-stent restenosis was more common in open-cell stent group, which have larger free cell area than closed-cell stents. Although our radiologic findings promote us to use closed-cell design if ‘possible’, no difference was detected in terms of clinical outcomes.
Dutch iliac stent trial : Long-term results in patients randomized for primary or selective stent placement

NARCIS (Netherlands)

Klein, W.M.; van der Graaf, Y.; Seegers, J.; Spithoven, J.H.; Buskens, E.; van Baal, J.G.; Buth, J.; Moll, F.L.; Overtoom, T.T.C.; van Sambeek, M.R.H.M.; Mali, W.P.T.M.

Purpose: To determine long-term results of the prospective Dutch Iliac Stent Trial. Materials and Methods: The study protocol was approved by local institutional review boards. All patients gave written informed consent. Two hundred seventy-nine patients (201 men, 78 women; mean age, 58 years) with
The stenting strategy of drug-eluting stents for coronary artery disease in patients on dialysis

Directory of Open Access Journals (Sweden)

Hiroshi Fujita

2014-12-01

Full Text Available Background: Reports regarding the relationship between the length and diameter of implanted drug-eluting stents and clinical and angiographic outcomes in dialysis patients are limited. Aim: We investigated the efficiency of drug-eluting stents for coronary artery disease in patients on dialysis from the viewpoint of stent sizing. Methods: Sirolimus-eluting stents were implanted in 88 lesions and bare metal stents were implanted in 43 lesions. We compared stenting strategy, major adverse cardiac events, and angiographic results between sirolimus-eluting stent and bare metal stent groups. Results: Stent diameter was smaller and stent length was longer in the sirolimus-eluting stent group than in the bare metal stent group in our routine practices. There was no significant between-group difference in late diameter loss. Rates of angiographic restenosis and target lesion revascularization were significantly higher in the sirolimus-eluting stent group than in the bare metal stent group. Although stent length was significantly longer and stent diameter was smaller in the sirolimus-eluting stent group, sirolimus-eluting stents did not improve the subsequent clinical and angiographic results compared with bare metal stents in dialysis patients. Conclusion: In dialysis patients, a longer length and/or smaller diameter sirolimus-eluting stent implantation was associated with high rates of restenosis and target lesion revascularization compared with bare metal stents.
Mechanical Properties of Metallic Stents: How Do These Properties Influence the Choice of Stent for Specific Lesions?

International Nuclear Information System (INIS)

Dyet, John F.; Watts, William G.; Ettles, Duncan F.; Nicholson, Anthony A.

2000-01-01

Purpose: To assess selected balloon-expandable and self-expanding stents for radial force, flexibility, radio-opacity, and trackability, and to relate these physical characteristics to potential indications for placement.Methods: Force-strain curves were plotted for each stent and the force required to produce 50% luminal narrowing was recorded. The ability of the stent to show elastic recoil following deformation was also noted. Flexibility was measured by bending the stents against a force transducer and recording the force required per degree of flexion. Radio-opacity was measured by comparing each stent against a standard aluminum step wedge. Trackability was measured by testing the ability of the stent on its delivery system to track over angles of 90 deg. and 60 deg. Results: The balloon-expandable stents showed greater radial strength and radio-opacity but, apart from the AVE Iliac Bridge stent, showed poorer flexibility and trackability. The self-expanding stents showed less radial force but were able to re-expand following deformity. They were generally more flexible and had better trackability but lower radio-opacity.Conclusion: There is no stent which exhibits all the ideal properties required and therefore the interventionist will need to keep a range of stents available if all lesions are to be addressed
A clinical study on perforator stroke resulting from Wingspan stent angioplasty for symptomatic intracranial artery stenosis

International Nuclear Information System (INIS)

Wang Ziliang; Xu Haowen; Li Tianxiao; Zhu Liangfu; Li Zhaoshuo; Xue Jiangyu; Bai Weixing; Li Li; Guan Sheng

2011-01-01

Objective: To evaluate the incidence, potential hazards and effective countermeasure for perforator stroke (PS) resulting from stent angioplasty of symptomatic intracranial artery stenosis. Methods: Peri-operation PS complications of 258 patients receiving Gateway balloon-Wingspan stenting for severe symptomatic intracranial stenosis were analyzed. The incidence, clinical course, and prognosis of PS resulting from stenting were recorded. Special attention was given to the anatomical features, clinical manifestation and video materials of patients with PS. χ 2 test was used for statistics. Results: Two hundred and fifty-five patients received stent angioplasty successfully and 7 patients had PS (incidence rate 2.7%). The patients with basilar artery stenosis had a higher incidence of PS resulting from intracranial stenting (6.1%, 4/66) than patients with middle cerebral artery stenosis (2.5%, 3/118) (χ 2 =2.320, P= 0.025). The potential hazards for PS included preoperative perforator stroke adjacent to the stenotic segment and prominent dissection during operation. Six patients presented symptoms after awake from general anaesthesia and one had symptoms 3 hours after stenting. One deteriorated gradually and the others reached the maximum deficit almost at once. At the follow-up of 3 months, 3 patients were disabled and scored one, two, two by mRS respectively. Conclusion: The incidence of PS resulting from intracranial stenting was low and the prognosis was not disastrous. Stenosis at basilar artery and preoperative perforator stroke adjacent to the stenotic segment were potential risk factors for PS complication. Proper maneuver of angioplasty may decrease the incidence of PS and improve the prognosis. (authors)

Drug-eluting stent thrombosis: results from the multicenter Spanish registry ESTROFA (Estudio ESpañol sobre TROmbosis de stents FArmacoactivos).

Science.gov (United States)

de la Torre-Hernández, José M; Alfonso, Fernando; Hernández, Felipe; Elizaga, Jaime; Sanmartin, Marcelo; Pinar, Eduardo; Lozano, Iñigo; Vazquez, Jose M; Botas, Javier; Perez de Prado, Armando; Hernández, Jose M; Sanchis, Juan; Nodar, Juan M Ruiz; Gomez-Jaume, Alfredo; Larman, Mariano; Diarte, Jose A; Rodríguez-Collado, Javier; Rumoroso, Jose R; Lopez-Minguez, Jose R; Mauri, Josepa

2008-03-11

This study sought to assess the incidence, predictors, and outcome of drug-eluting stent(DES) thrombosis in real-world clinical practice. The DES thromboses in randomized trials could not be comparable to those observed in clinical practice, frequently including off-label indications. We designed a large-scale, nonindustry-linked multicentered registry, with 20 centers in Spain. The participant centers provided follow-up data for their patients treated with DES, reporting a detailed standardized form in the event of any angiography-documented DES-associated thrombosis occurring. Of 23,500 patients treated with DES, definite stent thrombosis(ST) developed in 301: 24 acute, 125 subacute, and 152 late. Of the late, 62 occurred >1 year(very late ST). The cumulative incidence was 2% at 3 years. Antiplatelet treatment had been discontinued in 95 cases(31.6%). No differences in incidences were found among stent types. Independent predictors for subacute ST analyzed in a subgroup of 14,120 cases were diabetes, renal failure, acute coronary syndrome, ST-segment elevation myocardial infarction, stent length, and left anterior descending artery stenting, and for late ST were ST-segment elevation myocardial infarction, stenting in left anterior descending artery, and stent length. Mortality at 1-year follow-up was 16% and ST recurrence 4.6%. Older age, left ventricular ejection fraction <45%, nonrestoration of Thrombolysis In Myocardial Infarction flow grade 3, and additional stenting were independent predictors for mortality. The cumulative incidence of ST after DES implantation was 2% at 3 years. No differences were found among stent types. Patient profiles differed between early and late ST. Short-term prognosis is poor, especially when restoration of normal flow fails.
Angulated Stents-A Novel Stent Improvisation to Manage Difficult Post-tuberculosis Bronchial Stenosis.

Science.gov (United States)

Tay, Chee Kiang; Jeong, Byeong-Ho; Kim, Hojoong

2017-10-18

Post-tuberculosis bronchostenosis (PTBS), a complication of endobronchial tuberculosis is currently treated by bronchial stenting. However, in cases of angulated bronchial stenoses, difficulty is often encountered in stent insertion and maintenance, resulting in stent migration, granulation tissue overgrowth, and restenosis. To accommodate the angulated alignment of the stenosis, we devised an "angulated stent"-a novel improvisation of the conventional stent via splicing and suturing to achieve a resultant angulated shape. A retrospective review was undertaken to evaluate the performance of this stent. Among 283 PTBS patients who underwent interventional bronchoscopy at our center from 2004 to 2014, 21 were treated with at least one angulated stent. Clinical outcomes, including the stenting duration were investigated. After a median follow-up of 26 months, stent removal was successful in 7 (33.3%) out of 21 patients. In patients managed with angulated stents, the median duration to stent change or eventual removal was longer than those treated with straight tube stents (392 days vs. 86 days; p < 0.05). Angulated stents are a feasible treatment option in patients with angulated PTBS by reducing complications and prolonging the stent-changing interval.
Technical feasibility of the implantation of a monorail stent system into the renal arteries without pre-dilatation

International Nuclear Information System (INIS)

Neumann, C.; Dorffner, R.; Gschwendtner, M.; Karnel, F.; Mair, J.; Dorffner, G.

2005-01-01

Purpose: to evaluate the technical feasibility of the implantation of the monorail RX Herculink trademark system into the renal arteries without pre-dilatation. Materials and methods: forty-two patients (mean age 71 years) from four centers with a total of 44 renal artery stenoses underwent implantation of the RX Herculink trademark stent. The mean grade of the stenosis was 83.8%, the mean length 7.5 mm. The stenoses were ostial in 38 cases and in immediate proximity to the ostium in 6 cases. The mean follow-up-period was 57 weeks (24 - 176 weeks). Results: in 42 cases, the implantation was successful without pre-dilatation. In 2 cases, pre-dilatation was carried out. In none of the cases, detachment of the stent from the balloon was observed. In one stenosis with a length of 17 mm, implantation of two stents was performed. In 9 cases, post-dilatation with a larger balloon or higher balloon pressure was necessary. Residual stenoses exceeding 30% were not observed. Two patients developed local bleeding at the puncture site. During the follow-up, restenoses were observed in 5 stents after 26 to 126 weeks, which necessitated a second intervention in 3 cases (PTA in 2 cases, re-stenting in 1 case). The primary patency rate after 6 and 12 months was 0.92 ± 0.056 according to Kaplan-Meier, the secondary patency rate after 6 and 12 months was 1.0 ± 0.0. Conclusion: implantation of the RX Herculink trademark stent system into the renal arteries without pre-dilatation is technically feasible and safe. Even without pre-dilatation, the stent-system can be advanced through the stenosis without detachment. The complication rate is low. Our clinical results are comparable to previous studies. (orig.)
Clinical results from first use of prostate stent as fiducial for radiotherapy of prostate cancer.

Science.gov (United States)

Carl, Jesper; Nielsen, Jane; Holmberg, Mats; Larsen, Erik Hoejkjaer; Fabrin, Knud; Fisker, Rune V

2011-05-01

A clinical feasibility study using a removable prostate stent as fiducial for image-guided radiotherapy (IGRT) of localized prostate cancer (PC). The study included patients with local or locally advanced PC. The clinical target volume (CTV) was outlined on magnetic resonance (MR) images co-registered to planning computer tomography (CT) images. Daily online IGRT was delivered using the stent as fiducial. Risk of migration was estimated using multiple MR. Acute urinary toxicity was scored using the international prostate symptom score (IPSS). Late gastro-intestinal (GI) and genito-urinary (GU) toxicity was scored using the Radio Therapy Oncology Group (RTOG) score, biochemical failure (BF) was defined as an elevation of prostate specific antigen (PSA) above nadir plus 2 ng/ml after radiotherapy. One hundred men were enrolled in the study. Ninety completed radiotherapy with the stent as fiducial. No migration of the stent was seen, but three cases of dislocation of the stent to the bladder were observed. Acute urinary toxicity based on IPSS was comparable to toxicity in patients who had gold markers (GM) as fiducials. Removal of the stent was associated with a high frequency of urinary retention. Late GI and GU toxicity and BF were comparable to those of other studies, but longer observation time is needed. This study reports the first clinical results of using a prostate stent as fiducial. No migration of the stent observed. Dislocation of the stent to the urinary bladder was observed in three cases, requiring removal of the stent and insertion of a new fiducial. Acute toxicity during radiotherapy evaluated from IPSS was comparable to toxicity in patients with GM. Removal of the stent was associated with a high frequency of post procedural urinary retention. Late toxicity and BF were comparable to those of other studies, though longer observation time is needed.
Percutaneous Intraductal Radiofrequency Ablation for Clearance of Occluded Metal Stent in Malignant Biliary Obstruction: Feasibility and Early Results

Energy Technology Data Exchange (ETDEWEB)

Pai, Madhava, E-mail: madhava.pai@imperial.ac.uk [Hammersmith Hospital, Imperial College, HPB Unit, Department of Surgery (United Kingdom); Valek, Vlastimil; Tomas, Andrasina [University Hospital Brno Bohunice, Department of Radiology (Czech Republic); Doros, Attila [Semmelweis University, Radiology Unit, Department of Transplantation and Surgery (Hungary); Quaretti, Pietro [IRCCS Policlinico San Matteo, Department of Radiology (Italy); Golfieri, Rita; Mosconi, Cristina [University of Bologna, Department of Radiology, Policlinico S. Orsola-Malpighi (Italy); Habib, Nagy, E-mail: nagy.habib@imperial.ac.uk [Hammersmith Hospital, Imperial College, HPB Unit, Department of Surgery (United Kingdom)

2013-07-11

PurposeThe major complication occurring with biliary stents is stent occlusion, frequently seen because of tumour in-growth, epithelial hyperplasia, and sludge deposits, resulting in recurrent jaundice and cholangitis. We report a prospective study with the results of first in man percutaneous intraductal radiofrequency (RF) ablation to clear the blocked metal stents in patients with malignant biliary obstruction using a novel bipolar RF catheter.MethodsNine patients with malignant biliary obstruction and blocked metal stents were included. These patients underwent intraductal biliary RF ablation through the blocked metal stent following external biliary decompression with an internal–external biliary drainage.ResultsAll nine patients had their stent patency restored successfully without the use of secondary stents. Following this intervention, there was no 30-day mortality, haemorrhage, bile duct perforation, bile leak, or pancreatitis. Of the nine patients, six are alive and three patients are dead with a median follow-up of 122 (range 50–488) days and a median stent patency of 102.5 (range 50–321) days. Six patients had their stent patent at the time of last follow-up or death. Three patients with stent blockage at 321, 290, and 65 days postprocedure underwent percutaneous transhepatic drain insertion and repeat ablation.ConclusionsIn this selective group of patients, it appears that this new approach is safe and feasible. Efficacy remains to be proven in future, randomized, prospective studies.
Percutaneous Intraductal Radiofrequency Ablation for Clearance of Occluded Metal Stent in Malignant Biliary Obstruction: Feasibility and Early Results

International Nuclear Information System (INIS)

Pai, Madhava; Valek, Vlastimil; Tomas, Andrasina; Doros, Attila; Quaretti, Pietro; Golfieri, Rita; Mosconi, Cristina; Habib, Nagy

2014-01-01

PurposeThe major complication occurring with biliary stents is stent occlusion, frequently seen because of tumour in-growth, epithelial hyperplasia, and sludge deposits, resulting in recurrent jaundice and cholangitis. We report a prospective study with the results of first in man percutaneous intraductal radiofrequency (RF) ablation to clear the blocked metal stents in patients with malignant biliary obstruction using a novel bipolar RF catheter.MethodsNine patients with malignant biliary obstruction and blocked metal stents were included. These patients underwent intraductal biliary RF ablation through the blocked metal stent following external biliary decompression with an internal–external biliary drainage.ResultsAll nine patients had their stent patency restored successfully without the use of secondary stents. Following this intervention, there was no 30-day mortality, haemorrhage, bile duct perforation, bile leak, or pancreatitis. Of the nine patients, six are alive and three patients are dead with a median follow-up of 122 (range 50–488) days and a median stent patency of 102.5 (range 50–321) days. Six patients had their stent patent at the time of last follow-up or death. Three patients with stent blockage at 321, 290, and 65 days postprocedure underwent percutaneous transhepatic drain insertion and repeat ablation.ConclusionsIn this selective group of patients, it appears that this new approach is safe and feasible. Efficacy remains to be proven in future, randomized, prospective studies
Expandable stents.

Science.gov (United States)

Nesbitt, J C; Carrasco, H

1996-05-01

tissue is less likely to occur in areas of established scar than in areas of acute inflammation. In circumstances in which it is essential that a stent remain only temporarily, an expandable stent should not be inserted in favor of a silicone stent, which can be removed. In the future, expandable stents may have silicone coverings or may be constructed of materials that facilitate removal. Until that time, expandable stents should be considered permanent and nonremovable. Subtle differences exist among the available stents. Standard is low-profile expandable construction from wire mesh. A relatively minor difference is the slightly wider expansibility of the Gianturco stent, a quality that makes it the best suited of the three stents for lesions that involve tracheomalacia. Perhaps the only major difference between the Wallstent and the Gianturco and Palmaz stents is its better ability to conform to tortuous lesions. In an acutely angled stricture, a Wallstent offers a better opportunity for successful placement than other stents. The filamentous meshwork of the Wallstent allows it to bend and conform better to distorted airways. The Gianturco and Palmaz stents have little longitudinal elasticity, which makes them less effective in a tortuous or highly angulated airway stenosis. Expandable stents have demonstrated their efficacy and exposed their limitations in the treatment of airway stenoses. Refinements in design should help to lessen specific disadvantages and problems. Covered expandable stents, a realistic prospect, have specific advantages over standard expandable stents; they will be removable and prevent tumor ingrowth. Current investigative work with such prostheses for the vascular system may provide the foundation for their investigative use in the airway. In essence, two categories of expandable stents are evolving, covered and uncovered, each having unique features adaptable to the specific clinical needs.
Emergency and elective implantation of covered stent systems in iatrogenic arterial injuries

International Nuclear Information System (INIS)

Goltz, J.P.; Kickuth, R.; Bastuerk, P.; Hoppe, H.; Triller, J.

2011-01-01

Purpose: To evaluate the effectiveness and safety of covered stents for the management of iatrogenic arterial injury. Materials and Methods: Between 03/1998 and 12/2009, 31 patients underwent selective covered stent implantation after iatrogenic arterial injury. 12/31 of these patients (38.7 %) were hemodynamically unstable. Six different endovascular covered stent types were utilized. The primary endpoints of this study were technical and clinical success and rates of minor and major complications. Results: Initial angiograms demonstrated active extravasation in 19 (61.3 %) patients and pseudoaneurysms in 12 (38.7 %) patients. The following sites of bleeding origin were detected: axillary artery, subclavian artery, common iliac artery, external iliac artery, internal iliac artery, common femoral artery, superficial femoral artery, popliteal and fibular artery, femoro-popliteal and popliteo-crural bypasses, common hepatic artery, aberrant hepatic artery, cystic and gastroduodenal artery. In all patients bleeding was effectively controlled by covered stent implantation resulting in an immediate technical success of 100 %. Clinical success attributed to covered stent implantation was documented in 30 of the 31 patients (96.8 %). Major complications included death in four patients (11.1 %), acute thrombosis with arm ischemia in one patient (2.8 %) and stent fracture with associated pseudoaneurysm in another patient (2.8 %). In 2/31 patients (6.5 %) covered stent failure was detected and successfully treated by implantation of a second covered stent. Conclusion: Emergency and elective implantation of covered stents may be used for minimally invasive and effective management of iatrogenic arterial injury. (orig.)
Long term results of kissing stents in the aortic bifurcation

NARCIS (Netherlands)

Hinnen, J.W.; Konickx, M.A.; Meerwaldt, Robbert; Kolkert, J.L.P.; van der Palen, Jacobus Adrianus Maria; Huisman, A.B.

2015-01-01

BACKGROUND: To evaluate the long-term outcome after aortoiliac kissing stent placement and to analyze variables, which potentially influence the outcome of endovascular reconstruction of the aortic bifurcation. METHODS: All patients treated with aortoiliac kissing stents at our institution between
Carotid artery stenting in high surgical risk patients using the FiberNet embolic protection system: the EPIC trial results.

Science.gov (United States)

Myla, Subbarao; Bacharach, J Michael; Ansel, Gary M; Dippel, Eric J; McCormick, Daniel J; Popma, Jeffrey J

2010-05-01

The multicenter EPIC (FiberNet Embolic Protection System in Carotid Artery Stenting Trial) single-arm trial evaluated the 30-day outcomes of a new design concept for embolic protection during carotid artery stenting (CAS). Embolic protection filters available for use during CAS include fixed and over-the-wire systems that rely on embolic material capture within a "basket" structure. The FiberNet Embolic Protection System (EPS), which features a very low crossing profile, consists of a three-dimensional fiber-based filter distally mounted on a 0.014 inch guidewire with integrated aspiration during filter retrieval. The trial enrolled 237 patients from 26 centers. Demographics, clinical and lesion characteristics, as well as adverse events through a 30-day follow-up were recorded. The mean age of the patients was 74 years, 64% were male and 20% had symptomatic carotid artery disease. The combined major adverse event (MAE) rate at 30 days for all death, stroke, and myocardial infarction was 3.0%. There were three major strokes (two ischemic and one hemorrhagic) and two minor strokes (both ischemic) for a 2.1% 30-day stroke rate. The procedural technical success rate was 97.5% and macroscopic evidence of debris was reported in 90.9% of the procedures. The FiberNet EPS, used with commercially available stents, produced low stroke rates following CAS in high surgical risk patients presenting with carotid artery disease. The unique filter design including aspiration during retrieval may have contributed to the low 30-day stroke rate reported during CAS in patients considered at high risk for complications following carotid endarterectomy (CEA). Copyright 2010 Wiley-Liss, Inc.
MR Angiography of Peripheral Arterial Stents: In Vitro Evaluation of 22 Different Stent Types

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Matthias C. Burg

2011-01-01

Full Text Available Purpose. To evaluate stent lumen visibility of a large sample of different peripheral arterial (iliac, renal, carotid stents using magnetic resonance angiography in vitro. Materials and Methods. 21 different stents and one stentgraft (10 nitinol, 7 316L, 2 tantalum, 1 cobalt superalloy, 1 PET + cobalt superalloy, and 1 platinum alloy were examined in a vessel phantom (vessel diameters ranging from 5 to 13 mm filled with a solution of Gd-DTPA. Stents were imaged at 1.5 Tesla using a T1-weighted 3D spoiled gradient-echo sequence. Image analysis was performed measuring three categories: Signal intensity in the stent lumen, lumen visibility of the stented lumen, and homogeneity of the stented lumen. The results were classified using a 3-point scale (good, intermediate, and poor results. Results. 7 stents showed good MR lumen visibility (4x nitinol, 2x tantalum, and 1x cobalt superalloy. 9 stents showed intermediate results (5x nitinol, 2x 316L, 1x PET + cobalt superalloy, and 1x platinum alloy and 6 stents showed poor results (1x nitinol, and 5x 316L. Conclusion. Stent lumen visibility varies depending on the stent material and type. Some products show good lumen visibility which may allow the detection of stenoses inside the lumen, while other products cause artifacts which prevent reliable evaluation of the stent lumen with this technique.
Concepts to optimize stent-grafting of abdominal aortic aneurysms based on results of experimental studies

International Nuclear Information System (INIS)

Chavan, A.; Kirchhoff, T.; Baus, S.; Galanski, M.; Pichlmaier, M.

2001-01-01

Purpose. In the endoluminal therapy of abdominal aortic aneurysms, a short proximal aneurysm neck, endoleaks and the large size and stiffness of the introducer systems are responsible for many of the complications and sub-optimal outcomes. The purpose of the present review article is to to suggest strategies to minimize these complications based on the results of experimental studies in animals. Material and methods. After implanting various types of stents across the renal artery origins, the functional and morphological changes in the kidneys and renal vessels were studied by various authors. In order to prevent progressive widening of the proximal aneurysmal neck and graft dislocation, Sonesson et al. performed a laparoscopic banding around the proximal neck in pigs. To study the effects of endoleaks, Marty, Schurink and Pitton carried out pressure measurements in experimental aneurysms with and without endoleaks. Sakaguchi and Pavcnik developed the 'Twin-tube endografts' (TTEG) and the 'Bifurcated drum occluder endografts' (BDOEG) and tested them in dogs. Results. Up to 3 months after suprarenal stent placement, Chavan et al. detected no significant fall in the mean inulin clearance in sheep (140±46 ml/min before, 137±58 ml/min after). Nasim et al. and Malina et al. reported similar observations with respect to renal function. Suprarenal fixation may result in isolated thrombotic occlusions of the renal arteries and microinfarcts in the kidneys. Mean aortic diameters at the level of banding were significantly smaller in the animals with aortic banding as opposed to those in the control group without banding (8 mm vs 11 mm, p=0.004). The banding caused a secure proximal fixation of the stent-graft. Persistent endoleaks resulted in significantly higher intraaneurysmal pressures. Although the TTEG and the BDOEG stent-grafts required smaller sheaths, occlusions were observed in 8% (TTEG) and 60% (BDOEG) of the graft limbs. (orig.) [de
TOKYO criteria 2014 for transpapillary biliary stenting.

Science.gov (United States)

Isayama, Hiroyuki; Hamada, Tsuyoshi; Yasuda, Ichiro; Itoi, Takao; Ryozawa, Shomei; Nakai, Yousuke; Kogure, Hirofumi; Koike, Kazuhiko

2015-01-01

It is difficult to carry out meta-analyses or to compare the results of different studies of biliary stents because there is no uniform evaluation method. Therefore, a standardized reporting system is required. We propose a new standardized system for reporting on biliary stents, the 'TOKYO criteria 2014', based on a consensus among Japanese pancreatobiliary endoscopists. Instead of stent occlusion, we use recurrent biliary obstruction, which includes occlusion and migration. The time to recurrent biliary obstruction was estimated using Kaplan-Meier analysis with the log-rank test. We can evaluate both plastic and self-expandable metallic stents (uncovered and covered). We also propose specification of the cause of recurrent biliary obstruction, identification of complications other than recurrent biliary obstruction, indication of severity, measures of technical and clinical success, and a standard for clinical care. Most importantly, the TOKYO criteria 2014 allow comparison of biliary stent quality across studies. Because blocked stents can be drained not only using transpapillary techniques but also by an endoscopic ultrasonography-guided transmural procedure, we should devise an evaluation method that includes transmural stenting in the near future. © 2014 The Authors. Digestive Endoscopy © 2014 Japan Gastroenterological Endoscopy Society.
First Approval of Improved Medical Device Conditional on Use-Result Survey in Japan　- Regulatory Review of Polymer-Free Drug-Coated BioFreedom Coronary Stent.

Science.gov (United States)

Konishi, Akihide; Ho, Mami; Shirai, Yuko; Shirato, Haruki

2018-05-25

A prospective randomized clinical trial showed that the BioFreedom stent (Biosensors International), which is a polymer-free and carrier-free drug-coated stent, was significantly superior to a bare-metal stent (BMS) in patients at high bleeding risk who were receiving a 1-month course of dual antiplatelet therapy (DAPT). However, the stent thrombosis rate (2.01% for BioFreedom vs. 2.20% for BMS) was 4-6-fold higher than that of approved drug-eluting stents based on real-world data in Japan. Furthermore, the frequency of stent thrombosis at more than 1 month with the BioFreedom stent was slightly higher than that at less than 1 month. This result suggested that it would not be acceptable to stop DAPT universally at 1 month. Thus, the target patients for the BioFreedom stent are unspecified patients at high bleeding risk needing to continue DAPT for as long as necessary in Japan. Therefore, based on the pre- and post-marketing balance of medical devices regulations, regulatory approval was given for unspecified patients conditionally upon real-world data collection of 2,000 patients with a Use-Results Survey, instead of conducting additional pre-marketing clinical trial(s). The Use-Results Survey System is part of a strategy to expedite patients' access to innovative medical devices and to accelerate the development of medical devices.
Bilateral metal stents for hilar biliary obstruction using a 6Fr delivery system: outcomes following bilateral and side-by-side stent deployment.

Science.gov (United States)

Law, Ryan; Baron, Todd H

2013-09-01

Controversy exists on optimal endoscopic management for palliation of malignant hilar obstruction, with advocates for metal "side-by-side" (SBS) and "stent-in-stent" (SIS) techniques. We sought to evaluate the technical feasibility, efficacy, and outcomes of bilateral biliary self-expanding metal stents (SEMS) for treatment of malignant hilar obstruction using a stent with a 6Fr delivery system. This was a single-center, retrospective review of all patients who underwent bilateral placement of Zilver® biliary SEMS for malignant hilar obstruction from January 2010 to August 2012. Patients underwent endoscopic retrograde cholangiopancreatography with placement of stents using either the SIS or SBS stent techniques. Twenty-four patients (19 men, mean age 63 years) underwent bilateral stenting for malignant hilar obstruction during the study period. Seventeen and seven patients underwent the SBS and SIS technique, respectively. Cholangiocarcinoma (n=14) was the most common cause of hilar obstruction. Initial technical success was achieved in 24/24 (100%) of patients; however, 12 (50%) patients required re-intervention during the study period (median 98 days). Comparison of the SBS and SIS groups revealed no statistical difference with respect to need for re-intervention (P=0.31), successful re-intervention (P=0.60), or procedural length (P=0.89). Use of bilateral Zilver® SEMS in either the SBS or SIS configuration is safe, technically feasible, and effective for drainage of malignant hilar obstruction; however, duration of stent patency and procedure-free survival remain variable.
Percutaneous intraductal radiofrequency ablation for clearance of occluded metal stent in malignant biliary obstruction: feasibility and early results.

Science.gov (United States)

Pai, Madhava; Valek, Vlastimil; Tomas, Andrasina; Doros, Attila; Quaretti, Pietro; Golfieri, Rita; Mosconi, Cristina; Habib, Nagy

2014-02-01

The major complication occurring with biliary stents is stent occlusion, frequently seen because of tumour in-growth, epithelial hyperplasia, and sludge deposits, resulting in recurrent jaundice and cholangitis. We report a prospective study with the results of first in man percutaneous intraductal radiofrequency (RF) ablation to clear the blocked metal stents in patients with malignant biliary obstruction using a novel bipolar RF catheter. Nine patients with malignant biliary obstruction and blocked metal stents were included. These patients underwent intraductal biliary RF ablation through the blocked metal stent following external biliary decompression with an internal-external biliary drainage. All nine patients had their stent patency restored successfully without the use of secondary stents. Following this intervention, there was no 30-day mortality, haemorrhage, bile duct perforation, bile leak, or pancreatitis. Of the nine patients, six are alive and three patients are dead with a median follow-up of 122 (range 50-488) days and a median stent patency of 102.5 (range 50-321) days. Six patients had their stent patent at the time of last follow-up or death. Three patients with stent blockage at 321, 290, and 65 days postprocedure underwent percutaneous transhepatic drain insertion and repeat ablation. In this selective group of patients, it appears that this new approach is safe and feasible. Efficacy remains to be proven in future, randomized, prospective studies.
Drug eluting stents and modern stent technologies for in-stent restenosis.

Science.gov (United States)

Werner, Martin

2017-08-01

The implantation of metallic stents has become a standard procedure to improve the outcome after angioplasty of peripheral vessels. However, the occurrence of in-stent restenosis is hampering the long-term efficacy of these procedures and is associated with re-occurrence of symptoms. The optimal treatment modality for in-stent-restenosis in the peripheral vasculature is not well examined. This review discusses the existing evidence for the treatment of in-stent restenosis with drug eluting stents and modern stent technologies.
Airway stents

Science.gov (United States)

Keyes, Colleen

2018-01-01

Stents and tubes to maintain the patency of the airways are commonly used for malignant obstruction and are occasionally employed in benign disease. Malignant airway obstruction usually results from direct involvement of bronchogenic carcinoma, or by extension of carcinomas occurring in the esophagus or the thyroid. External compression from lymph nodes or metastatic disease from other organs can also cause central airway obstruction. Most malignant airway lesions are surgically inoperable due to advanced disease stage and require multimodality palliation, including stent placement. As with any other medical device, stents have significantly evolved over the last 50 years and deserve an in-depth understanding of their true capabilities and complications. Not every silicone stent is created equal and the same holds for metallic stents. Herein, we present an overview of the topic as well as some of the more practical and controversial issues surrounding airway stents. We also try to dispel the myths surrounding stent removal and their supposed use only in central airways. At the end, we come to the long-held conclusion that stents should not be used as first line treatment of choice, but after ruling out the possibility of curative surgical resection or repair. PMID:29707506
Palliation of Postoperative Gastrointestinal Anastomotic Malignant Strictures with Flexible Covered Metallic Stents: Preliminary Results

International Nuclear Information System (INIS)

Lee, Jeong-Min; Han, Young Min; Lee, Sang Yong; Kim, Chong Soo; Yang, Doo Hyun; Lee, Seung Ok

2001-01-01

Purpose: To evaluate the efficacy of the placement of covered metallic stents for palliation of gastrointestinal anastomotic strictures secondary to recurrent gastric cancer.Methods: Under fluoroscopic guidance, placement of one or two self-expandable covered metallic stents was attempted perorally in 11 patents (aged 48-76 years) with anastomotic stenoses due to recurrent gastric malignancies. The strictures involved both the afferent and efferent loops in three patients. All patients had poor peroral food intake with severe nausea and vomiting after ingestion. The technical and clinical success was evaluated.Results: Placement of the covered stent was technically successful in 13 of 15 (87%) attempts in ten patients. After the procedure, 9 of 11 (82%) patients overall were able to ingest at least a liquid diet and had markedly decreased incidence of vomiting. During the follow-up of 2-31 weeks (mean 8.5 weeks) there were no major complications.Conclusion: These preliminary results suggest that flexible, covered stents may provide effective palliation of malignant anastomotic stricture secondary to recurrent gastric cancer
The effect of stent coating on stent deliverability: direct randomised comparison of drug eluting and bare metal stents using the same stent platform.

Science.gov (United States)

Siminiak, Tomasz; Link, Rafał; Wołoszyn, Maciej; Kałmucki, Piotr; Baszko, Artur

2012-01-01

There is certain experimental and clinical evidence indicating that the covering of bare metal stents (BMS) with drug eluting polymers to produce drug eluting stents (DES) results in increased stent stiffness and modifies the mechanical properties of the stent platform. In addition, it has been speculated that the mechanical performance of DES, compared to BMS, may be related to the type of polymer used to cover stents. We aimed at evaluating the deliverability of DES with a lactate based biodegradable polymer and BMS in patients with stable coronary artery disease in a prospective randomised study. One hundred eleven consecutive patients (age: 36-77, mean 58.8 years) scheduled for routine angioplasty due to stable coronary disease were randomised to receive BMS (Chopin II(TM), Balton, Poland) or paclitaxel eluting stent (Chopin Luc(TM), Balton, Poland) using the same metal platform. Only patients scheduled for angioplasty using the direct implantation technique of a single stent were randomised. The exclusion criteria included patients 〉 80 years, multivessel disease and reference diameter of the target vessel 〉 3.5 mm. In the BMS group (n = 55; 35 males and 20 females), the mean diameter of implanted stents was 3.09 ± 0.40 and the mean length was 11.37 ± 2.80, whereas in the DES group (n = 56; 34 males and 22 females) the mean stent sizes were 3.02 ± 0.34 and 17.90 ± 7.38 mm, respectively (p 〉 0.05 for length). The groups did not significantly differ regarding the frequency of stent implantation to particular coronary vessels. The direct stenting technique was attempted and failed, leading to the stents' implantation after predilatation in five patients in the BMS group and six patients in the DES group. Failure of stent implantation and subsequent implantation of another stent type was observed in no BMS patients and in one DES patient (NS). Although stent covering with lactate based drug eluting polymer may increase its stiffness, it does not affect

Stenting is improving and stabilizing anatomical results of coiled intracranial aneurysms

International Nuclear Information System (INIS)

Lubicz, Boris; Bandeira, Alexandra; Baleriaux, Danielle; Bruneau, Michael; Witte, Olivier de; Dewindt, Aloys

2009-01-01

Stent-assisted coiling (SAC) is an alternative to surgical clipping for the treatment of wide-necked intracranial aneurysms (IA). However, little information is available concerning the long-term results of this treatment. The aim of this study was to report the long-term clinical and anatomical findings in 32 patients with 34 wide-necked IA treated by SAC. A retrospective review of our prospectively maintained database identified all patients followed up for wide-necked IA treated by SAC. The clinical charts, procedural data, and angiographic results were reviewed. Thirty-two patients with 34 IA were identified including 25 asymptomatic patients, four with cranial nerve palsies, two with a subarachnoid hemorrhage, and one with transient ischemic attacks. Mean aneurysm size was 10.2 mm (range 3.5 to 26 mm). Embolization was successful in all patients and no procedure-related neurological morbidity or mortality was observed. Immediate anatomical results included nine complete occlusions (26.5%), two neck remnants (6%), and 23 incomplete occlusions (67.5%). Mean imaging follow-up of 20 months showed 18 further thrombosis (53%) and 16 stable results (47%). Finally, 27 aneurysms were completely occluded (79%), three had a neck remnant (9%), and four were incompletely occluded (12%). Asymptomatic and nonsignificant in-stent stenosis occurred in seven patients (22%). SAC is safe and effective for the treatment of wide-necked IA. Despite unsatisfying immediate aneurysm occlusion, the adjunctive effect of the stent is stabilizing or significantly improving long-term anatomical results. (orig.)
[Technical feasibility of the implantation of a monorail stent system into the renal arteries without pre-dilatation].

Science.gov (United States)

Neumann, C; Gschwendtner, M; Karnel, F; Mair, J; Dorffner, G; Dorffner, R

2005-01-01

To evaluate the technical feasibility of the implantation of the monorail RX Herculink system into the renal arteries without pre-dilatation. Forty-two patients (mean age 71 years) from four centers with a total of 44 renal artery stenoses underwent implantation of the RX Herculink stent. The mean grade of the stenosis was 83.8 %, the mean length 7.5 mm. The stenoses were ostial in 38 cases and in immediate proximity to the ostium in 6 cases. The mean follow-up-period was 57 weeks (24 - 176 weeks). In 42 cases, the implantation was successful without pre-dilatation. In 2 cases, pre-dilatation was carried out. In none of the cases, detachment of the stent from the balloon was observed. In one stenosis with a length of 17 mm, implantation of two stents was performed. In 9 cases, post-dilatation with a larger balloon or higher balloon pressure was necessary. Residual stenoses exceeding 30 % were not observed. Two patients developed local bleeding at the puncture site. During the follow-up, restenoses were observed in 5 stents after 26 to 126 weeks, which necessitated a second intervention in 3 cases (PTA in 2 cases, re-stenting in 1 case). The primary patency rate after 6 and 12 months was 0.92 +/- 0.056 according to Kaplan-Meier, the secondary patency rate after 6 and 12 months was 1.0 +/- 0.0. Implantation of the RX Herculink stent system into the renal arteries without pre-dilatation is technically feasible and safe. Even without pre-dilatation, the stent-system can be advanced through the stenosis without detachment. The complication rate is low. Our clinical results are comparable to previous studies.
The management of unimplantable stent during endovascular procedure:report of three cases

International Nuclear Information System (INIS)

Xiong Jiang; Wang Lijun; Guo Wei; Liu Xiaoping; Yin Tai; Jia Xin; Ma Xiaohui; Liu Meng; Zhang Hongpeng; Zhang Minhong

2010-01-01

Objective: To summarize the experience of dealing with the difficulty of the stent implantation encountered in the endovascular procedure. Methods: The causes of unimplantable stent encountered in the endovascular procedure included the delivery system entraping due to the stenosis and shrinking of peripheral self-expandable stent, the balloon expandable stent implantation and retrievement failure due to the rupture-balloon or stent edge opening, and the delivery system entraping due to aortic stent graft for aorta kinking. The balloon dilation for the stenosis and shrinking stent, the large caliber introducer sheath for removal of the rupture-balloon and edge opening, the expandable stent and balloon-assisted delivery system retrieve were used to solve the above three dilemma of unimplantable stent occurred in the endovascular procedure. Results: These three dilemma of stent unimplantable problem in the endovascular therapy were solved by endovascular method while little additional incision injury was added to the patients. Conclusion: For solving stent unimplantable problem the endovascular technique is the method of first choice, nevertherless, it is very important for the operator to be highly skilled in manipulating endovascular procedure. (authors)
Lean manufacturing and Toyota Production System terminology applied to the procurement of vascular stents in interventional radiology.

Science.gov (United States)

de Bucourt, Maximilian; Busse, Reinhard; Güttler, Felix; Wintzer, Christian; Collettini, Federico; Kloeters, Christian; Hamm, Bernd; Teichgräber, Ulf K

2011-08-01

OBJECTIVES: To apply the economic terminology of lean manufacturing and the Toyota Production System to the procurement of vascular stents in interventional radiology. METHODS: The economic- and process-driven terminology of lean manufacturing and the Toyota Production System is first presented, including information and product flow as well as value stream mapping (VSM), and then applied to an interdisciplinary setting of physicians, nurses and technicians from different medical departments to identify wastes in the process of endovascular stent procurement in interventional radiology. RESULTS: Using the so-called seven wastes approach of the Toyota Production System (waste of overproducing, waiting, transport, processing, inventory, motion and waste of defects and spoilage) as well as further waste characteristics (gross waste, process and method waste, and micro waste), wastes in the process of endovascular stent procurement in interventional radiology were identified and eliminated to create an overall smoother process from the procurement as well as from the medical perspective. CONCLUSION: Economic terminology of lean manufacturing and the Toyota Production System, especially VSM, can be used to visualise and better understand processes in the procurement of vascular stents in interventional radiology from an economic point of view.
Long-term results of percutaneous self-expandable metallic stents in malignant biliary obstruction

International Nuclear Information System (INIS)

Kobashi, Yuko; Hoshikawa, Yoshikazu

2004-01-01

Evaluation of the long-term follow-up data of 155 patients with inoperable malignant biliary obstruction who received percutaneous placement of self expandable metallic stent (EMS) and external beam radiotherapy (EBR) combined with self-expandable metallic stent. One-hundred sixty EMS were inserted in 155 patients with inoperable malignant biliary obstruction. One-hundred forty-three patients (Group A) were inserted EMS alone. Twelve patients (Group B) underwent external radiotherapy (40∼45 Gy) after stent insertion. We compared to the Group A and Group B about survival, stent patency and administration. The mean length of survival for the entire group was 111±87 days, while the mean period of patency for all stents was 103±74. We found no statistically significant difference in patient survival or stent patency periods in regard to the level and cause of obstruction. Prolongation of actuarial survival was observed in Group B (316±231 days) as compared to Group A (126±85 days,). Mean length of survival rate and mean period of stent patency rate were not significantly different in regard to the level, cause of obstruction and each stent. External radiotherapy combined EMS could achieve effective palliation and improve the quality of life in selected patients with malignant biliary obstruction. (author)
XIENCE V everolimus-eluting coronary stent system: a novel second generation drug-eluting stent

NARCIS (Netherlands)

Beijk, Marcel A. M.; Piek, Jon J.

2007-01-01

Drug-eluting stents (DES) have been shown to be safe and significantly reduce clinical events and angiographic restenosis in the percutaneous treatment of coronary artery disease. Currently, three DES have been approved in Europe and Northern America: the sirolimus-eluting stent (SES), the
Endeavour zotarolimus-eluting stent reduces stent thrombosis and improves clinical outcomes compared with cypher sirolimus-eluting stent : 4-year results of the PROTECT randomized trial

NARCIS (Netherlands)

Wijns, William; Steg, Ph. Gabriel; Mauri, Laura; Kurowski, Volkhard; Parikh, Keyur; Gao, Runlin; Bode, Christoph; Greenwood, John P.; Lipsic, Erik; Alamgir, Farqad; Rademaker-Havinga, Tessa; Boersma, Eric; Radke, Peter; van Leeuwen, Frank; Camenzind, Edoardo

2014-01-01

Aims To compare the long-term clinical safety between two drug-eluting stents with different healing characteristics in the Patient Related Outcomes with Endeavour (E-ZES) vs. Cypher (C-SES) Stenting Trial (PROTECT). At 3 years, there was no difference in the primary outcome of definite or probable
Wingspan stent system in the treatment of symptomatic intracranial atherosclerotic stenosis

International Nuclear Information System (INIS)

Li Tianxiao; Li Zhaoshuo; Wang Ziliang; Xue Jiangyu; Bai Weixing; Li Li; Zhai Shuiting; Feng Yingpu

2010-01-01

Objective: To assess the safety, feasibility, short- and mid-term efficacy of wingspan stent for treating patients with symptomatic intracranial artery stenosis. Methods: A total of 113 patients with severe symptomatic intracranial stenosis were enrolled and Gateway-wingspan stenting were performed on all patients. The technical success, the pre- and post-stenting stenosis, perioperative complications, clinical outcome and restenosis rates were recorded, and chi-square test was used for analysis of complication rate by comparing our results with the results of Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) study and NIH multi-center Wingspan stenting trial. Results: The technical success rate was 99.1% (112/ 113). The mean pre and post-stent stenoses were (80.7±9.3)% and (27.7±9.7)% (χ 2 =9.397, P<0.05). The total complication rate was 4.4% (5/113) during the follow-up (mean 14.5 months, range 1-28 months), and the frequency of' restenosis was 12.5% (5/40) at 6 months. The primary endpoint events, ischemic stroke, and lesion-related ischemic stroke were lower in our study (4.5%, 3.5%, 3.5%) compared with the results of WASID trial (21.1%, 20.4%, 15.0%, P<0.05). For those with poor outcome in the three high-risk sub-groups which were with more than 70% stenosis, or last event from the treatment was less than 17 days, or NIHSS was above 1, a better outcome was observed in our group (4.5%, 4.7% and 2.0% in our study, 19.0%, 17.0% and 19.6% in previous study, P<0.05). The medium-term efficacy in this group (4.5%) significantly improved compared with NIH study (14.0%, P< 0.05). Conclusions: Wingspan stenting for symptomatic intracranial arterial stenosis is with good safety, feasibility and low perioperative stroke rate and mortality. The incidence of primary endpoint events and the ischemic events are lower than those of medication group, and the efficacy of stenting is significantly better than medication even in high-risk population. (authors)
Clinical results with the Resolute zotarolimus-eluting stent in total coronary occlusions

DEFF Research Database (Denmark)

Kelbæk, Henning; Holmvang, Lene; Richardt, Gert

2015-01-01

Aims: We conducted a pooled post hoc analysis (RESOLUTE All Comers and RESOLUTE International) of patients who had the Resolute® zotarolimus-eluting stent (R-ZES) implanted in revascularised total occlusions (TO) compared with patients treated with R-ZES for non-occluded lesions. Methods and resu......Aims: We conducted a pooled post hoc analysis (RESOLUTE All Comers and RESOLUTE International) of patients who had the Resolute® zotarolimus-eluting stent (R-ZES) implanted in revascularised total occlusions (TO) compared with patients treated with R-ZES for non-occluded lesions. Methods...... lesion revascularisation) and Academic Research Consortium definite or probable stent thrombosis. The rate of TLF at two years was not significantly different among patients in the CTO (9.1%), TO (9.8%), and no occlusion (10.4%) groups (log-rank p=0.800); neither were the components of TLF. Definite...... or probable stent thrombosis occurred more frequently in the TO group (2.8% vs. 1.2% in the CTO and 1.1% in the group with no occlusion, p=0.027). There were 10 late and six very late stent thrombosis events. Conclusions: Apart from a higher rate of stent thrombosis in patients with TO, patients with totally...
Primary Self-Expandable Nitinol Stent Placement in Focal Lesions of Infrarenal Abdominal Aorta: Long Term Results

International Nuclear Information System (INIS)

Lastovickova, Jarmila; Peregrin, Jan H.

2008-01-01

Purpose. To evaluate the technical and clinical success, safety and long term results of percutaneous transluminal angioplasty/self-expandable nitinol stent placement of infrarenal abdominal aorta focal lesions. Materials and Methods. Eighteen patients underwent PTA of focal atherosclerotic occlusive disease of distal abdominal aorta. Two symptomatic occlusions and 16 stenoses in 10 male and 8 female patients (mean age 68.2 years) were treated with primary self-expandable nitinol stent placement. Results. Primary self-expandable nitinol stent placement was technically successful in all 18 procedures; clinical success was achieved in 100% of patients. No complications associated with the procedure occurred. During the 49.4 months of mean follow up (range 3-96, 4 months) all treated aortic segments remained patent. Conclusions. Endovascular treatment (primary self-expandable nitinol stent placement) of focal atherosclerotic lesions of distal abdominal aorta is a safe method with excellent primary technical and clinical success rates and favourable Long term results
Stent Coating Integrity of Durable and Biodegradable Coated Drug Eluting Stents.

Science.gov (United States)

Yazdani, Saami K; Sheehy, Alexander; Pacetti, Stephen; Rittlemeyer, Brandon; Kolodgie, Frank D; Virmani, Renu

2016-10-01

Coatings consisting of a polymer and drug are widely used in drug-eluting stents (DES) and are essential in providing programmable drug release kinetics. Among other factors, stent coating technologies can influence blood compatibility, affect acute and sub-acute healing, and potentially trigger a chronic inflammatory response. The aim of this study was to investigate the short-term (7 and 28 days) and long-term (90 and 180 days) coating integrity of the Xience Prime Everolimus-Eluting Stent (EES), Resolute Zotarolimus-Eluting Stent (ZES), Taxus Paclitaxel-Eluting Stent (PES), and Nobori Biolimus A9-Eluting Stent (BES) in a rabbit ilio-femoral stent model. Stented arteries (n = 48) were harvested and the tissue surrounding the implanted stents digested away with an enzymatic solution. Results demonstrated that the majority of struts of EES were without any coating defects with a few struts showing minor defects. Similarly, for the ZES, most of the struts were without coating defects at all time points except at 180 days. The majority of PES demonstrated mostly webbing and uneven coating. In the BES group, the majority of strut coating showed polymer cracking. Overall, the EES and ZES had fewer coating defects than the PES and BES. Coating defects, however increase over time for the ZES, whereas the percent of coating irregularities remained constant for the EES. These results provide, for the first time, a comparison of the long-term durability of these drug-eluting stent coatings in vivo. © 2016, Wiley Periodicals, Inc.
Temporary urethral covered stent - third year of experience

International Nuclear Information System (INIS)

Stojanovis, V.; Maksimovis, H.; Markovis, B.; Markovis, Z.

2006-01-01

Full text: In October 2003, a new generation of urethral stents ALLIUM, produced in Israel, were used at the Department of Interventional Radiology, CCS, in 18 patients with chronic stricture of bulbar urethra. The indications for insertion were determined according to well-known and recognized therapeutical protocols. The stent is made of nitinol wire with polyurethane cover. It is inserted under local anesthesia by a special self-expandable system that may be fixed or flexible. The stents we used were 3-6 cm long and 28 Fr wide. Radioscopic-assisted insertion was performed over formerly placed metal guide. Prior to insertion, balloon-catheter dilatation of stricture matching the stent width was carried out. Pre-insertion urethrotomy was performed in one case. The insertion technique is simple, presupposing the knowledge of older generations of techniques of urethral dilatation and insertion of self-expandable stents. The follow-up of results was done according to a priori established protocol including the following: UCG, uroflowmetry and interview with patients. Due to stent migration, the 'stent over stent' technique was applied in one case, while reposition by balloon-catheter outward traction was performed in two cases of caudal migration. No irritative discomforts were reported in the first 4 months after stent dwelling. Uroflowmetric controls verified at least four times better results than before the insertion. Given it is the question of covered stent, there is no possibility of proliferative secondary lumen obstruction. On account of soft structure and conic shape of posterior part of stent, no lesions of the external urethral sphincter were manifested. The stent is simply withdrawn after 6 months by outward traction using the forceps at the time when the stent construction turns into soft and straight wire. The first clinical experiences are very favorable and ALLIUM stent may be expected to be the stent of choice for chronic bulbar strictures
Self-Expandable Metal Stents and Trans-stent Light Delivery: Are Metal Stents and Photodynamic Therapy Compatible?

Science.gov (United States)

Wang, Luo-Wei; Li, Li-Bo; Li, Zhao-Shen; Chen, Yang K; Hetzel, Fred W.; Huang, Zheng

2008-01-01

Background and Objectives: Obstructive non-small cell lung cancer and obstructive esophageal cancer are US FDA approved indications of photodynamic therapy (PDT). The usefulness of PDT for the treatment of cholangiocarcinoma is currently under clinical investigation. Endoscopic stenting for lumen restoration is a common palliative intervention for those indications. It is important to assess whether self-expandable metal stents are compatible with trans-stent PDT light delivery. Study Design/Materials and Methods: Direct effects of various components of metal biliary (n = 2), esophageal (n = 2), and bronchial (n = 1) stents on PDT light transmittance and distribution were examined using a point or linear light source (630 or 652 nm diode laser). Resected pig biliary duct and esophageal wall tissues were used to examine the feasibility of PDT light delivery through the fully expanded metal stents. Results: While using a point light source, the metal components (thread and joint) of the stent could cause a significant shadow effect. The liner material (polytetrafluoroethylene or polyurethane) could cause various degrees of light absorption. When the stent was covered with a thin layer of biliary duct and esophageal tissues containing all wall layers, the shadow effect could be mitigated due to tissue scattering. Conclusions: This study clearly demonstrates that it is feasible to combine stenting and PDT for the treatment of luminal lesions. PDT light dose should be adjusted to counteract the reduction of light transmittance caused by the metal and liner materials of stent. PMID:18951422
Long-Term Results of Everolimus-Eluting Stents Versus Drug-Eluting Balloons in Patients With Bare-Metal In-Stent Restenosis: 3-Year Follow-Up of the RIBS V Clinical Trial.

Science.gov (United States)

Alfonso, Fernando; Pérez-Vizcayno, María José; García Del Blanco, Bruno; Otaegui, Imanol; Masotti, Mónica; Zueco, Javier; Veláquez, Maite; Sanchís, Juan; García-Touchard, Arturo; Lázaro-García, Rosa; Moreu, José; Bethencourt, Armando; Cuesta, Javier; Rivero, Fernando; Cárdenas, Alberto; Gonzalo, Nieves; Jiménez-Quevedo, Pilar; Fernández, Cristina

2016-06-27

The aim of this study was to compare the long-term efficacy of everolimus-eluting stents (EES) and drug-eluting balloons (DEB) in patients with bare-metal stent in-stent restenosis (ISR). The relative long-term clinical efficacy of current therapeutic modalities in patients with ISR remains unknown. The 3-year clinical follow-up (pre-specified endpoint) of patients included in the RIBS V (Restenosis Intra-Stent of Bare-Metal Stents: Drug-Eluting Balloon vs Everolimus-Eluting Stent Implantation) randomized clinical trial was analyzed. All patients were followed yearly using a pre-defined structured questionnaire. A total of 189 patients with bare-metal stent ISR were allocated to either EES (n = 94) or DEB (n = 95). Clinical follow-up at 1, 2, and 3 years was obtained in all patients (100%). Compared with patients treated with DEB, those treated with EES obtained better angiographic results, including larger minimal luminal diameter at follow-up (primary study endpoint; 2.36 ± 0.6 mm vs. 2.01 ± 0.6 mm; p 1 year) target vessel (3 [3.2%] vs. 3 [3.2%]; p = 0.95) and target lesion (1 [1%] vs. 2 [2.1%]; p = 0.54) revascularization was low and similar in the 2 arms. Rates of definite or probable stent thrombosis (1% vs. 0%) were also similar in the 2 arms. The 3-year clinical follow-up of the RIBS V clinical trial confirms the sustained safety and efficacy of EES and DEB in patients treated for bare-metal stent ISR. In this setting, EES reduce the need for target lesion revascularization at very long-term follow-up. (RIBS V [Restenosis Intra-Stent of Bare Metal Stents: Paclitaxel-Eluting Balloon vs Everolimus-Eluting Stent] [RIBS V]; NCT01239953). Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
Application of a novel retrievable self-expanding stent in intracranial aneurysm treatment

International Nuclear Information System (INIS)

Yang Zhigang; Liu Jianmin; Xu Yi; Huang Qinghai; Hong Bo; Zhao Wenyuan; Zhao Rui

2008-01-01

Objective: To assess the value of a novel retrievable self-expanding stent system (LEO) in intracranial aneurysm treatment. Methods: 43 patients with 44 intracranial aneurysms treated with LEO stent were retrospectively analized, including 16 aneurysms with single-stent deployment, 25 with stent-assisted technique, 2 with double-stent deployment and one with double-stent assisted coils. Follow up was carried out through imaging and clinical course. Results: The stent was easy for repositioning and all the stents were delivered successfully, except 1 stent with unsatisfactory position, 1 with acute in-stent thrombosis. During follow up, 1 case showed chronic in-stent thrombus and one with intimal hyperplasia. 22 aneurysms got compact coiled during procedure. Among 29 follow up cases, 72.4% aneurysms were cured or improved, 13.8% were stable and three dissection aneurysms enlarged within short period and two patients died. Conclusion: The new retrievable self-expanding stent (LEO), with the advantages of controlled delivery, easy deployment and choice for various types is a valuable system for vascular reconstruction of intracranial aneurysm with thrombosis. (authors)
In-hospital management and outcome of patients on warfarin undergoing coronary stent implantation: results of the multicenter, prospective WARfarin and coronary STENTing (WAR-STENT) registry.

Science.gov (United States)

Rubboli, Andrea; Sciahbasi, Alessandro; Briguori, Carlo; Saia, Francesco; Palmieri, Cataldo; Moroni, Luigi Andrea; Calabrò, Paolo; Leone, Antonio Maria; Franco, Nicoletta; Valgimigli, Marco; Varani, Elisabetta; Santi, Michela; Pasqualini, Paola; Capecchi, Alessandro; Piccalò, Giacomo; Margheri, Massimo; di Pasquale, Giuseppe; Galvani, Marcello; Bolognese, Leonardo; Gonzini, Lucio; Maggioni, Aldo Pietro

2013-04-01

The in-hospital management of patients on warfarin undergoing coronary stent implantation (PCI-S) is variable, and the in-hospital outcome incompletely defined. To determine the adherence to the current recommendations, and the incidence of adverse events, we carried out the prospective, multicenter, observational WARfarin and coronary STENTing (WAR-STENT) registry (ClinicalTrials.gov identifier NCT00722319). All consecutive patients on warfarin undergoing PCI-S at 37 Italian centers were enrolled and followed for 12 months. Outcome measures were: major adverse cardiovascular events (MACE), including cardiovascular death, non-fatal myocardial infarction, need for urgent revascularization, stroke, and venous thromboembolism, and major and minor bleeding. In this paper, we report the in-hospital findings. Out of the 411 patients enrolled, 92% were at non-low (ie, moderate or high) thromboembolic risk. The radial approach and bare-metal stents were used in 61% and 60% of cases, respectively. Drug-eluting stents were essentially reserved to patients with diabetes, which in turn, significantly predicted the implantation of drug-eluting stents (odds ratio [OR], 2.02; 95% confidence interval [CI], 1.29-3.17; P=.002). The in-hospital MACE and major bleeding rates were 2.7% and 2.1%, respectively. At discharge, triple therapy (TT) of warfarin, aspirin, and clopidogrel was prescribed to 76% of patients. Prescription of TT was significantly more frequent in the non-low thromboembolic risk group. Non-low thromboembolic risk, in turn, was a significant predictor of TT prescription (OR, 11.2; 95% CI, 4.83-26.3; P<.0001). In conclusion, real-world warfarin patients undergoing PCI-S are largely managed according to the current recommendations. As a consequence, the risk of in-hospital MACE and major bleedings appears limited and acceptable.
Interdisciplinary interventional therapy for tracheobronchial stenosis with modern metal net stents

International Nuclear Information System (INIS)

Rieger, J.; Linsenmaier, U.; Fedorowski, A.; Pfeifer, K.J.; Hautmann, H.; Huber, R.M.

2002-01-01

Study objectives: Assessment of the therapeutic potential of tracheobronchial stenting for obstructive tracheobronchial disease, in-vivo comparison of different stent types and development of helpful criteria for choosing the suitable stent type. Material and Methods: Prospective case analysis. Between 1993 and 1999 53 stents were implanted into the tracheobronchial system of 39 consecutive patients with benign or malignant airway obstruction. Every single stent (26 Strecker Stents, 18 Wallstents, 6 Accuflex Nitinolstents, 1 Dumon-, 1 Ruesch- and 1 Palmazstent) was recorded in an unified database. Analysis comprised clinical effectiveness, lung function if possible, relevant complications and radiologic follow-up parameters. The probability of their remaining within the tracheobronchial system, of their remaining undislocated and uncompressed was calculated using Kaplan-Meier analysis for three stent types. Results: Stent placement proved itself to be an effective treatment in 86% of the patients. Resistance could be normalized in 9/9 patients. Kaplan-Meier analysis clearly revealed a higher probability for the Wall- and Nitinolstent to remain within the tracheobronchial system and to remain uncompressed. Dislocation also occurred more rarely. Explanation of the Wallstent, however, if desired, was much more difficult compared to the Strecker stent. The Wallstent also occasionally led to the formation of granulation tissue especially at the proximal stent end and, as such, required reintervention. (orig.) [de
Effects of 32P radioactive stents on in-stent restenosis in a double stent injury model of the porcine coronary arteries

International Nuclear Information System (INIS)

Kim, Han-Soo; Chan, Rosanna C.; Kollum, Marc; Au, Arthur; Tio, Fermin O.; Yazdi, Hamid A.; Ajani, Andrew E.; Waksman, Ron

2001-01-01

Background: The major limitation of coronary stenting remains in-stent restenosis, due to the development of neointimal proliferation. Radioactive stents have demonstrated the ability to reduce this proliferation in the healthy nonatherosclerotic porcine animal model. However, inhibition of tissue proliferation in the in-stent restenotic lesion in a porcine model is not well characterized. The objective of this study was to examine the efficacy and safety of the 32 P radioactive stent for the treatment of in-stent restenosis in a double stent injury model of the porcine coronaries. Methods and Materials: Eighteen coronary arteries in 9 pigs underwent nonradioactive stent (8 mm in length) implantation. Thirty days after the initial stent implantation, a 32 P radioactive stent (18 mm in length) with an activity of 0 and 18 μCi was implanted to cover the initial stent. The swine were killed 30 days after the second stent implantation. Histomorphometric analysis was performed for vessel area (VA), stent strut area (SSA), intimal area (IA), and lumen area (LA). Results: Injury scores, VA, SSA, and LA were similar among the control and radiated groups. Neointimal formation was significantly reduced after placement of radioactive stents as compared to control in both the overlapped (0.93±0.12 vs. 1.31±0.51 mm 2 , p 2 , p 32 P radioactive stents may be safe and effective in reducing neointimal formation leading to in-stent restenosis. Longer follow-up will be required to examine whether these positive findings can be maintained
'Stent in a stent'--an alternative technique for removing partially covered stents following sleeve gastrectomy complications.

Science.gov (United States)

Vasilikostas, Georgios; Sanmugalingam, Nimalan; Khan, Omar; Reddy, Marcus; Groves, Chris; Wan, Andrew

2014-03-01

Endoscopic stenting is a relatively new technique for the treatment of post sleeve gastrectomy complications. Partially covered stents are used in this method to minimise the risk of migration but they are associated with difficulties with removal. Patients requiring emergency stenting following sleeve gastrectomy underwent insertion of a partially covered metallic stent. One month later, if the stent was not easily removable, a fully covered overlapping stent was inserted and the patient was readmitted 2 weeks later for removal of both stents. Four patients required stenting following sleeve gastrectomy leaks, and one patient required stenting for a stricture. In these cases, a 'stent in a stent' technique was used for removal. This technique allows the safe removal of partially covered stents inserted following sleeve gastrectomy complications.
Preliminary Report of Carotid Artery Stenting Using a Tapered Stent

Energy Technology Data Exchange (ETDEWEB)

Jeong, Chang Woo; Kim, Dong Hyun; Hong, Seung; Jeong; Kim, Young Suk; Byun, Joo Nam; Oh, Jae Hee [Dept. of Radiology, Chosun University College of Medicine, Gwangju (Korea, Republic of); Ahn, Seong Hwan [Dept. of Neurology, Chosun University College of Medicine, Gwangju (Korea, Republic of)

2011-10-15

To analyze the results of carotid artery stenting using a tapered stent and to evaluate the effectiveness of the tapered stent compared to previously reported studies using non-tapered stents. From October 2008 to August 2010, elective carotid artery stenting using a tapered stent was attempted in 39 lesions from 36 consecutive patients. Post-procedural complications were evaluated by neurologic symptoms and magnetic resonance imaging. Restenosis or occlusion was evaluated by carotid Doppler ultrasound and computerized tomography with angiography. Newly developed neurologic symptoms were evaluated clinically. The self-expandable tapered stent was placed across the carotid artery stenosis. A total stroke was noted in 3 patients, while a major stroke was noted in 1 patient. On diffusion weighted imaging, new lesions were observed in 15 patients, but 13 patients were clinically silent. Follow-up imaging studies were performed in the 13 clinically silent lesions, and no evidence of restenosis or occlusion was found any of the 13 lesions. During clinical follow-up in 34 lesions from 31 patients, there were newly developed neurological symptoms in only 1 patient.

Introduction of a high-throughput double-stent animal model for the evaluation of biodegradable vascular stents.

Science.gov (United States)

Borinski, Mauricio; Flege, Christian; Schreiber, Fabian; Krott, Nicole; Gries, Thomas; Liehn, Elisa; Blindt, Rüdiger; Marx, Nikolaus; Vogt, Felix

2012-11-01

Current stent system efficacy for the treatment of coronary artery disease is hampered by in-stent restenosis (ISR) rates of up to 20% in certain high-risk settings and by the risk of stent thrombosis, which is characterized by a high mortality rate. In theory, biodegradable vascular devices exhibit crucial advantages. Most absorbable implant materials are based on poly-L-lactic acid (PLLA) owing to its mechanical properties; however, PLLA might induce an inflammatory reaction in the vessel wall. Evaluation of biodegradable implant efficacy includes a long-term examination of tissue response; therefore, a simple in vivo tool for thorough biocompatibility and biodegradation evaluation would facilitate future stent system development. Rats have been used for the study of in vivo degradation processes, and stent implantation into the abdominal aorta of rats is a proven model for stent evaluation. Here, we report the transformation of the porcine double-stent animal model into the high-throughput rat abdominal aorta model. As genetic manipulation of rats was introduced recently, this novel method presents a powerful tool for future in vivo biodegradable candidate stent biocompatibility and biodegradation characterization in a reliable simple model of coronary ISR. Copyright © 2012 Wiley Periodicals, Inc.
Long-term results of endoscopic stenting and surgical drainage for biliary stricture due to chronic pancreatitis

NARCIS (Netherlands)

Smits, M. E.; Rauws, E. A.; van Gulik, T. M.; Gouma, D. J.; Tytgat, G. N.; Huibregtse, K.

1996-01-01

A retrospective evaluation was made of the long-term results of endoscopic stenting in 58 patients with benign biliary stricture due to chronic pancreatitis. Immediate relief of jaundice and cholestasis was achieved in all patients after endoscopic stent insertion. Median follow-up was 49 months.
A Novel Attempt to Standardize Results of CFD Simulations Basing on Spatial Configuration of Aortic Stent-Grafts.

Directory of Open Access Journals (Sweden)

Andrzej Polanczyk

Full Text Available Currently, studies connected with Computational Fluid Dynamic (CFD techniques focus on assessing hemodynamic of blood flow in vessels in different conditions e.g. after stent-graft's placement. The paper propose a novel method of standardization of results obtained from calculations of stent-grafts' "pushing forces" (cumulative WSS--Wall Shear Stress, and describes its usefulness in diagnostic process. AngioCT data from 27 patients were used to reconstruct 3D geometries of stent-grafts which next were used to create respective reference cylinders. We made an assumption that both the side surface and the height of a stent-graft and a reference cylinder were equal. The proposed algorithm in conjunction with a stent-graft "pushing forces" on an implant wall, allowed us to determine which spatial configuration of a stent-graft predispose to the higher risk of its migration. For stent-grafts close to cylindrical shape (shape factor φ close to 1 WSS value was about 267 Pa, while for stent-grafts different from cylindrical shape (φ close to 2 WSS value was about 635 Pa. It was also noticed that deformation in the stent-graft's bifurcation part impaired blood flow hemodynamic. Concluding the proposed algorithm of standardization proved its usefulness in estimating the WSS values that may be useful in diagnostic process. Angular bends or tortuosity in bifurcations of an aortic implant should be considered in further studies of estimation of the risk of implantation failure.
Comparison of self-expandable and balloon-expanding stents for hybrid ductal stenting in hypoplastic left heart complex.

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Goreczny, Sebastian; Qureshi, Shakeel A; Rosenthal, Eric; Krasemann, Thomas; Nassar, Mohamed S; Anderson, David R; Morgan, Gareth J

2017-07-01

We aimed to compare the procedural and mid-term performance of a specifically designed self-expanding stent with balloon-expandable stents in patients undergoing hybrid palliation for hypoplastic left heart syndrome and its variants. The lack of specifically designed stents has led to off-label use of coronary, biliary, or peripheral stents in the neonatal ductus arteriosus. Recently, a self-expanding stent, specifically designed for use in hypoplastic left heart syndrome, has become available. We carried out a retrospective cohort comparison of 69 neonates who underwent hybrid ductal stenting with balloon-expandable and self-expanding stents from December, 2005 to July, 2014. In total, 43 balloon-expandable stents were implanted in 41 neonates and more recently 47 self-expanding stents in 28 neonates. In the balloon-expandable stents group, stent-related complications occurred in nine patients (22%), compared with one patient in the self-expanding stent group (4%). During follow-up, percutaneous re-intervention related to the ductal stent was performed in five patients (17%) in the balloon-expandable stent group and seven patients (28%) in self-expanding stents group. Hybrid ductal stenting with self-expanding stents produced favourable results when compared with the results obtained with balloon-expandable stents. Immediate additional interventions and follow-up re-interventions were similar in both groups with complications more common in those with balloon-expandable stents.
Treating Epiphora in Adults With the Wilhelm Plastic Nasolacrimal Stent: Mid-Term Results of a Prospective Study

International Nuclear Information System (INIS)

Ciampi, Juan J.; Lanciego, Carlos; Navarro, Sofia; Cuena, Rafael; Velasco, Javier; Perea, Miguel; García-García, Lorenzo

2011-01-01

The objective of the present study was to evaluate, in a prospective, single-center study, the effectiveness of the Wilhelm-type stent used in interventional radiology for the management of epiphora. Patients (n = 104; mean age 64 [range 25–88]; 33 male and 71 female) with severe epiphora had the stents inserted (135 stents in 115 eyes) to treat obstruction of the nasolacrimal system. The etiology of the obstruction was idiopathic in 83 cases, chronic dacryocystitis in 31, cases and postsurgical status in 1 case. The overall technical success rate of stent placement was near 94%. Resolution of epiphora was complete in 105 cases and partial in 3 cases. During a mean 13-month follow-up (range 1 week to 28 months), the median duration of primary patency was 11 months, and the percentage of patency at 6 months was 60.8%, at 1 year was 39.6%, and at 2 years was 25%. Stents malfunctioned in 54 cases, and all were easily withdrawn except in 1 case. Of these 27 cases, patency recovered spontaneously in 9 and by way of a second stent in 18. Secondary patency was 50%. Factors presdisposing to lower primary patency are inflammatory etiology and location of the obstruction. The benefit of stent deployment is clear with respect to the resolution of epiphora in candidate patients for percutaneous treatment. Technical and/or design improvements would be welcomed.
Randomized Comparison of Ridaforolimus- and Zotarolimus-Eluting Coronary Stents in Patients With Coronary Artery Disease: Primary Results From the BIONICS Trial (BioNIR Ridaforolimus-Eluting Coronary Stent System in Coronary Stenosis).

Science.gov (United States)

Kandzari, David E; Smits, Pieter C; Love, Michael P; Ben-Yehuda, Ori; Banai, Shmuel; Robinson, Simon D; Jonas, Michael; Kornowski, Ran; Bagur, Rodrigo; Iniguez, Andres; Danenberg, Haim; Feldman, Robert; Jauhar, Rajiv; Chandna, Harish; Parikh, Manish; Perlman, Gidon Y; Balcells, Mercedes; Markham, Peter; Ozan, Melek Ozgu; Genereux, Philippe; Edelman, Elazer R; Leon, Martin B; Stone, Gregg W

2017-10-03

The safety and efficacy of a novel cobalt alloy-based coronary stent with a durable elastomeric polymer eluting the antiproliferative agent ridaforolimus for treatment of patients with coronary artery disease is undetermined. A prospective, international 1:1 randomized trial was conducted to evaluate in a noninferiority design the relative safety and efficacy of ridaforolimus-eluting stents (RESs) and slow-release zotarolimus-eluting stents among 1919 patients undergoing percutaneous coronary intervention at 76 centers. Inclusion criteria allowed enrollment of patients with recent myocardial infarction, total occlusions, bifurcations lesions, and other complex conditions. Baseline clinical and angiographic characteristics were similar between the groups. Overall, mean age was 63.4 years, 32.5% had diabetes mellitus, and 39.7% presented with acute coronary syndromes. At 12 months, the primary end point of target lesion failure (composite of cardiac death, target vessel-related myocardial infarction, and target lesion revascularization) was 5.4% for both devices (upper bound of 1-sided 95% confidence interval 1.8%, P noninferiority =0.001). Definite/probable stent thrombosis rates were low in both groups (0.4% RES versus 0.6% zotarolimus-eluting stent, P =0.75); 13-month angiographic in-stent late lumen loss was 0.22±0.41 mm and 0.23±0.39 mm ( P noninferiority =0.004) for the RES and zotarolimus-eluting stent groups, respectively, and intravascular ultrasound percent neointimal hyperplasia was 8.10±5.81 and 8.85±7.77, respectively ( P noninferiority =0.01). In the present trial, which allowed broad inclusion criteria, the novel RESs met the prespecified criteria for noninferiority compared with zotarolimus-eluting stents for the primary end point of target lesion failure at 12 months and had similar measures of late lumen loss. These findings support the safety and efficacy of RESs in patients who are representative of clinical practice. URL: http
Delayed complications after flow-diverter stenting: reactive in-stent stenosis and creeping stents.

Science.gov (United States)

Cohen, José E; Gomori, John Moshe; Moscovici, Samuel; Leker, Ronen R; Itshayek, Eyal

2014-07-01

We assessed the frequency and severity of changes in stent configuration and location after the treatment of intracranial aneurysms, and patterns of in-stent stenosis. We retrospectively reviewed data for consecutive aneurysm patients managed with endovascular implantation of flow-diverter stents (Silk Flow Diverter [Balt Extrusion, Montmorency, France] and Pipeline Embolization Device [ev3/Coviden, Minneapolis, MN, USA]) from October 2011 to July 2012. Routine 2, 6, 9-12, and 16-20 month follow-up angiograms were compared, with a focus on changes in stent configuration and location from immediately after deployment to angiographic follow-up, and the incidence and development of in-stent stenosis. Thirty-four patients with 42 aneurysms met inclusion criteria. The Silk device was implanted in 16 patients (47%, single device in 15), the Pipeline device in 18 (53%, single device in 16). On first follow-up angiography, in-stent stenosis was observed in 38% of Silk devices and 39% of Pipeline devices. In-stent stenosis was asymptomatic in 12 of 13 patients. One woman presented with transient ischemic attacks and required stent angioplasty due to end tapering and mild, diffuse in-stent stenosis. Configuration and location changes, including stent creeping and end tapering were seen in 2/16 patients (13%) with Silk devices, and 0/18 patients with Pipeline devices. We describe stent creeping and end tapering as unusual findings with the potential for delayed clinical complications. In-stent stenosis, with a unique behavior, is a frequent angiographic finding observed after flow-diverter stent implant. The stenosis is usually asymptomatic; however, close clinical and angiographic monitoring is mandatory for individualized management. Copyright © 2013 Elsevier Ltd. All rights reserved.
One Year Outcomes of 101 BeGraft Stent Grafts used as Bridging Stents in Fenestrated Endovascular Repairs.

Science.gov (United States)

Spear, Rafaelle; Sobocinski, Jonathan; Hertault, Adrien; Delloye, Matthieu; Azzauiu, Richard; Fabre, Dominique; Haulon, Stéphan

2018-04-01

To evaluate the outcomes of the second generation BeGraft balloon expandable covered stent Graft System (Bentley InnoMed, Hechingen, Germany) implanted as bridging stent grafts during fenestrated endovascular aortic repair (FEVAR) of complex aneurysms. This was a single centre prospective study including all consecutive patients treated by FEVAR performed with second generation BeGraft stent grafts as bridging stents. Demographics of patients, diameter and length of the bridging stent grafts, technical success, re-interventions, occlusions, post-operative events, and imaging (Cone Beam CT and/or CT scan, and contrast enhanced ultrasound) were prospectively collected in an electronic database. Duplex ultrasound was performed before discharge and at 6 month follow-up. At 1 year, patients were evaluated clinically and by imaging (CT and ultrasound). Between November 2015 and September 2016, 39 consecutive patients (one woman) were treated with custom made fenestrated endografts (2-5 fenestrations) for complex aneurysms or type 1 endoleak after EVAR, using a variety of bridging stents including the BeGraft. All 101 BeGraft stent grafts were successfully delivered and deployed. There was no in hospital mortality. Early fenestration patency rate was 99% (96/97); the sole target vessel post-operative occlusion was secondary to a dissection of the renal artery distal to the stent. Complementary stenting was unsuccessful in recovering renal artery patency; bilateral renal stent occlusion was observed in the same patient on a CT scan performed 2 months after the procedure. He required post-operative dialysis. No additional renal impairment was observed. During follow-up (median 13 months [11-15]), all fenestrations stented with BeGraft stent grafts remained patent (95/97, 98%). One type 1b endoleak was detected and treated (2.6%). BeGraft stent grafts used as bridging stents during FEVAR are associated with favourable outcomes at 1 year follow-up. Long-term follow-up is
[Absorbable coronary stents. New promising technology].

Science.gov (United States)

Erbel, Raimund; Böse, Dirk; Haude, Michael; Kordish, Igor; Churzidze, Sofia; Malyar, Nasser; Konorza, Thomas; Sack, Stefan

2007-06-01

Coronary stent implantation started in Germany 20 years ago. In the beginning, the progress was very slow and accelerated 10 years later. Meanwhile, coronary stent implantation is a standard procedure in interventional cardiology. From the beginning of permanent stent implantation, research started to provide temporary stenting of coronary arteries, first with catheter-based systems, later with stent-alone technology. Stents were produced from polymers or metal. The first polymer stent implantation failed except the Igaki-Tamai stent in Japan. Newly developed absorbable polymer stents seem to be very promising, as intravascular ultrasound (IVUS) and optical coherence tomography have demonstrated. Temporary metal stents were developed based on iron and magnesium. Currently, the iron stent is tested in peripheral arteries. The absorbable magnesium stent (Biotronik, Berlin, Germany) was tested in peripheral arteries below the knee and meanwhile in the multicenter international PROGRESS-AMS (Clinical Performance and Angiographic Results of Coronary Stenting with Absorbable Metal Stents) study. The first magnesium stent implantation was performed on July 30, 2004 after extended experimental testing in Essen. The magnesium stent behaved like a bare-metal stent with low recoil of 5-7%. The stent struts were absorbed when tested with IVUS. Stent struts were not visible by fluoroscopy or computed tomography (CT) as well as magnetic resonance imaging (MRI). That means, that the magnesium stent is invisible and therefore CT and MRI can be used for imaging of interventions. Only using micro-CT the stent struts were visible. The absorption process could be demonstrated in a patient 18 days after implantation due to suspected acute coronary syndrome, which was excluded. IVUS showed a nice open lumen. Stent struts were no longer visible, but replaced by tissue indicating the previous stent location. Coronary angiography after 4 months showed an ischemia-driven target lesion
Stenting or not prior to extracorporeal shockwave lithotripsy for ureteral stones? Results of a prospective randomized study.

Science.gov (United States)

Sfoungaristos, Stavros; Polimeros, Nikolaos; Kavouras, Adamantios; Perimenis, Petros

2012-06-01

To determine the need for pre-treatment stenting in patients undergoing extracorporeal shockwave lithotripsy (ESWL) for ureteral stones sized 4-10 mm. A prospective randomized study was conducted between September 2009 and March 2011. Included 156 patients randomized in stented and non-stented groups and underwent a maximum of 3 ESWL sessions. Radiographic follow-up was used to assess the stone fragmentation and clearance. Results were compared in terms of stone-free rates, post-treatment morbidity and complications. Overall efficacy was 76.9%. Stone-free rates were statistically significantly lower (P = 0.026) in the stented group (68.6%) compared to the non-stented ones (83.7%). Furthermore, stenting was significantly correlated with post-treatment lower urinary tract symptoms (P ≤ 0.001), need for more ESWL sessions (P = 0.019) and possibility for operation due to ESWL failure (P = 0.026). A multivariate analysis was conducted to identify the parameters which may predict complete stone removal after ESWL. Stone size (P = 0.026), stone location (P = 0.011) and stenting (P = 0.007) were the most significant factors. ESWL is an efficient and safe treatment for 4- to 10-mm ureteral stones. Pre-treatment stenting is limiting stone-free rates and is significantly influencing post-ESWL morbidity and quality of life in a negative manner, while it contributes minimally to the prophylaxis of complications.
Early results with a monorail-stent-balloon device for endovascular treatment of renal artery stenosis

International Nuclear Information System (INIS)

Mueller-Huelsbeck, S.; Jahnke, T.; Grimm, J.; Behm, C.; Hilbert, C.; Frahm, C.; Biederer, J.; Brossmann, J.; Heller, M.

2002-01-01

Objective: To evaluate the technical feasibility of a new monorail-stent-balloon device for treatment of renal artery stenosis (RAS). Patients and Methods: During a study period of 18 months, 38 patients with proven RAS in 41 cases (hypertension n = 36, renal insufficiency n = 13) and indication for stenting (calicified ostial lesions n = 35, insufficient PTA n = 4, dissection n = 2) were enrolled into this prospective evaluation. Pre-mounted stents (Rx-Herculink TM 5 mm = 13, 6 mm = 34, 7 mm = 1) were implanted a transfermoral (n = 35) or transbrachial approach (n = 6). Mean grade and lengths of stenosis measured were 88% ±10 and 9 mm ±5. Results: Renal stent implantation was technically successful in all cases (100%). In 7 cases a second stent had to be implanted to cover the entire lesion. The transstenotic pressure drop decreased from 88 mmHg ± 10 before to 1 mmHg ± 1.8 after the procedure. Remaining stenosis measured 0.7% ±4.2. Serum creatine levels decreased from 1.9 mm/dl to 1.5 mg/dl (n.s.), blood pressure decreased from 178/94 mmHg to 148/79 mmHg (p [de
Percutaneous biliary drainage and stenting

International Nuclear Information System (INIS)

Totev, M.

2012-01-01

stents for benign strictures. In cases of malignant obstruction, stents are placed as a palliative measure only if the tumor is unresectable. Various stents are approved for use in the biliary system, including self-expanding and balloon-mounted stents. Tumor ingrowth through the stent, proximal or distal tumor overgrowth, and biliary sludge can cause stent obstruction. Covered stents are now being investigated to overcome the problem of tumor ingrowth. The stent is usually placed at an interval of a few days after percutaneous biliary drainage (PBD), though in cases of uncomplicated percutaneous transhepatic cholangiography (PTC), the stent procedure can be accomplished at the same time. Through our institutional experience and literature overview, we will provide a review outlining the vast array of biliary stenting for both benign and malignant disease. We provided a thorough, concise, and informative review and show that the decompression of the biliary system by drainage or biliary stents is well tolerated by the patients procedure that provide an excellent and minimally invasive palliation, mainly in malignant obstructive jaundice.
Early and mid-term results with the Growth Stent--a possible concept for transcatheter treatment of aortic coarctation from infancy to adulthood by stent implantation?

Science.gov (United States)

Ewert, Peter; Peters, Bjoern; Nagdyman, Nicole; Miera, Oliver; Kühne, Titus; Berger, Felix

2008-01-01

Evaluation of the Growth Stent-a stent consisting of two stent halves connected by reabsorbable sutures-for the treatment of aortic coarctation in infants. Surveillance study of 13 Growth Stents implanted in 12 patients aged 1-15 months (median 5 months). Body weight ranged from 3.4-12.8 kg (median 5.4 kg). Eight patients suffered from aortic (re-)coarctation, four of them from stenosis of the aortic anastomosis after a Norwood I procedure. The follow-up period was 24 months (11-51 months). Pressure gradients immediately after stent implantation decreased from 30 mm Hg (range 20-50 mm Hg) to 8 mm Hg (range 0-15 mm Hg). Five patients had one (3 pts) or two (2 pts) balloon dilations 3-28 months (median 12 months) after Growth Stent implantation. The median pressure gradient decreased from 25 mm Hg (range 15-30 mm Hg) to 15 mm Hg (range 5-25 mm Hg). Six patients received a large stent after 19-34 months. Median body weight was 11.8 kg (9.4-15 kg). The Growth Stent is suitable for the acute treatment of aortic coarctation in infants and can be overstented later on--if necessary--with a larger stent without causing restriction. Copyright 2008 Wiley-Liss, Inc.
[Numerical simulation of the effect of virtual stent release pose on the expansion results].

Science.gov (United States)

Li, Jing; Peng, Kun; Cui, Xinyang; Fu, Wenyu; Qiao, Aike

2018-04-01

The current finite element analysis of vascular stent expansion does not take into account the effect of the stent release pose on the expansion results. In this study, stent and vessel model were established by Pro/E. Five kinds of finite element assembly models were constructed by ABAQUS, including 0 degree without eccentricity model, 3 degree without eccentricity model, 5 degree without eccentricity model, 0 degree axial eccentricity model and 0 degree radial eccentricity model. These models were divided into two groups of experiments for numerical simulation with respect to angle and eccentricity. The mechanical parameters such as foreshortening rate, radial recoil rate and dog boning rate were calculated. The influence of angle and eccentricity on the numerical simulation was obtained by comparative analysis. Calculation results showed that the residual stenosis rates were 38.3%, 38.4%, 38.4%, 35.7% and 38.2% respectively for the 5 models. The results indicate that the pose has less effect on the numerical simulation results so that it can be neglected when the accuracy of the result is not highly required, and the basic model as 0 degree without eccentricity model is feasible for numerical simulation.
Long-Term Results After Simple Versus Complex Stenting of Coronary Artery Bifurcation Lesions Nordic Bifurcation Study 5-Year Follow-Up Results

DEFF Research Database (Denmark)

Maeng, M.; Holm, N. R.; Erglis, A.

2013-01-01

Objectives This study sought to report the 5-year follow-up results of the Nordic Bifurcation Study. Background Randomized clinical trials with short-term follow-up have indicated that coronary bifurcation lesions may be optimally treated using the optional side branch stenting strategy. Methods...... complex strategy of planned stenting of both the main vessel and the side branch. (C) 2013 by the American College of Cardiology Foundation...
Endovascular occlusion of intracranial wide-necked aneurysms with stenting (Neuroform) and coiling: mid-term and long-term results

Energy Technology Data Exchange (ETDEWEB)

Sedat, Jacques; Chau, Yves; Mondot, Lydiane [CHU Nice, Unite de Neurointerventionnelle, Hopital St. Roch, Nice (France); Vargas, Julian; Szapiro, Jacek; Lonjon, Michel [CH Bastia, Service de Neurochirurgie, Bastia (France)

2009-06-15

Coiling associated with placement of self-expandable intracranial stents has amplified the treatment of intracranial wide-necked aneurysms, but the durability of this treatment and the existence of delayed recurrence are not yet well known. The purpose of this report is to present our experience with the Neuroform Stent associated with coiling and to evaluate complications, effectiveness, and long-term results of this technique. A retrospective study of 42 patients with wide-necked cerebral aneurysms treated with the Neuroform Stent was performed. Mean aneurysm size was 11.3 mm. Mean neck size was 5.33 mm. All patients were treated with coiling and stenting. Clinical and angiographic follow-up was available in 38 patients (90.5%). The overall follow-up time ranged from 6 months to 5 years (mean, 42 months), but most of the patients (92%) had a follow-up period superior to 1 year. Successful deployment of 41 stents (97%) was obtained. Permanent procedural morbidity was observed in only one patient (2.4%). Long-term complete aneurysmal occlusion was obtained in 27 patients (71%). Aneurysmal regrowth was observed in four patients (9.5%) on the first control angiogram. After the first control angiogram, no delayed recanalization or regrowth was observed. During the follow-up period, there were no hemorrhagic events, no delayed thrombosis, and no stent displacement. Our results demonstrate the effectiveness of the technique, a small rate of procedural complications, and long-term tolerance of the Neuroform Stent. Despite some evidence of early aneurysmal recurrence, long-term durability of stent-assisted aneurysm occlusion is stable after the first year. (orig.)
Treatment of traumatic internal carotid artery pseudoaneurysms with willis covered stents: a midterm follow-up result

International Nuclear Information System (INIS)

Wang Wu; Li Minghua; Li Yongdong; Gu Binxian; Fang Chun; Tan Huaqiao; Wang Ju; Zhang Peilei

2010-01-01

Objective: To evaluate the efficacy and mid-term follow-up results of endovascular treatment with Willis covered stent for traumatic pseudoaneurysms located in the internal carotid artery (ICA). Methods: ICA angiography was performed in 38 patients with traumatic brain and neck injury. Of the 38 patients, 13 delayed traumatic pseudoaneurysms were found. All the pseudoaneurysms were treated with Willis covered stents. Follow-up angiography was performed at 1, 3, 6 and 12 months after the procedure, and the results were categorized as complete or incomplete occlusion. Clinical manifestations were graded as full recovery, improvement, unchanged and aggravation. Results: Willis covered stent placement was technically successful in all traumatic pseudoaneurysms. No procedure-related complications occurred. The initial angiographic results showed a complete occlusion in 9 patients, and an incomplete occlusion in 4. The angiographic follow-up within 3-12 months exhibited a complete occlusion in 12 patients and the parent arteries remained patency in all patients. The clinical follow-up observation demonstrated that full recovery was obtained in 11 patients, clinical improvement in one, and unchanged condition in one. No morbidity or mortality occurred. Conclusion: Willis covered stent implantation is a feasible and practical treatment for traumatic pseudoaneurysms located in the ICA. This technique can well preserve the parent artery with excellent therapeutic results. (authors)
Semi-Automatic Electronic Stent Register: a novel approach to preventing ureteric stents lost to follow up.

Science.gov (United States)

Macneil, James W H; Michail, Peter; Patel, Manish I; Ashbourne, Julie; Bariol, Simon V; Ende, David A; Hossack, Tania A; Lau, Howard; Wang, Audrey C; Brooks, Andrew J

2017-10-01

Ureteric stents are indispensable tools in modern urology; however, the risk of them not being followed-up once inserted poses medical and medico-legal risks. Stent registers are a common solution to mitigate this risk; however, manual registers are logistically challenging, especially for busy units. Western Sydney Local Health District developed a novel Semi-Automatic Electronic Stent Register (SAESR) utilizing billing information to track stent insertions. To determine the utility of this system, an audit was conducted comparing the 6 months before the introduction of the register to the first 6 months of the register. In the first 6 months of the register, 457 stents were inserted. At the time of writing, two of these are severely delayed for removal, representing a rate of 0.4%. In the 6 months immediately preceding the introduction of the register, 497 stents were inserted, and six were either missed completely or severely delayed in their removal, representing a rate of 1.2%. A non-inferiority analysis found this to be no worse than the results achieved before the introduction of the register. The SAESR allowed us to improve upon our better than expected rate of stents lost to follow up or severely delayed. We demonstrated non-inferiority in the rate of lost or severely delayed stents, and a number of other advantages including savings in personnel costs. The semi-automatic register represents an effective way of reducing the risk associated with a common urological procedure. We believe that this methodology could be implemented elsewhere. © 2017 Royal Australasian College of Surgeons.
Predictive Factors of In-Stent Restenosis in Renal Artery Stenting: A Retrospective Analysis

International Nuclear Information System (INIS)

Vignali, Claudio; Bargellini, Irene; Lazzereschi, Michele; Cioni, Roberto; Petruzzi, Pasquale; Caramella, Davide; Pinto, Stefania; Napoli, Vinicio; Zampa, Virna; Bartolozzi, Carlo

2005-01-01

Purpose. To retrospectively evaluate the role of clinical and procedural factors in predicting in-stent restenosis in patients with renovascular disease treated by renal artery stenting. Methods. From 1995 to 2002, 147 patients underwent renal artery stenting for the treatment of significant ostial atherosclerotic stenosis. Patients underwent strict clinical and color-coded duplex ultrasound follow-up. Ninety-nine patients (111 stents), with over 6 months of continuous follow-up (mean 22±12 months, range 6-60 months), were selected and classified according to the presence (group A, 30 patients, 32 lesions) or absence (group B, 69 patients, 79 lesions) of significant in-stent restenosis. A statistical analysis was performed to identify possible preprocedural and procedural predictors of restenosis considering the following data: sex, age, smoking habit, diabetes mellitus, hypertension, serum creatinine, cholesterol and triglyceride levels, renal artery stenosis grade, and stent type, length and diameter. Results. Comparing group A and B patients (χ 2 test), a statistically significant relation was demonstrated between stent diameter and length and restenosis: the risk of in-stent restenosis decreased when the stent was ≥6 mm in diameter and between 15 and 20 mm in length. This finding was confirmed by multiple logistic regression analysis. Stent diameter and length were proved to be significantly related to in-stent restenosis also when evaluating only patients treated by Palmaz stent (71 stents). Conclusion. Although it is based on a retrospective analysis, the present study confirms the importance of correct stent selection in increasing long-term patency, using stents of at least 6 mm in diameter and with a length of approximately 15-20 mm
Stented Vessels: A Challenge for Histological Preparation and Microscopy

Directory of Open Access Journals (Sweden)

Andrea Nolte

2013-06-01

Full Text Available Objective: The first procedure to treat blocked coronary arteries was coronary artery bypass graft surgery. In 1977, Andreas Gruntzig introduced percutaneous transluminal coronary angioplasty (PTCA. Today, several stent systems exist ranging from bare metal stents to various drug-eluting stents. Unfortunately, our understanding of the arterial reaction to stent implantation is incomplete primarily due to technical limitations in the histological study of stented vascular tissue. Methods: In our study, we examined different histological preparation methods based on the embedding material methacrylate. The procedure of embedding and sectioning stented porcine arteries was optimized for the specific requirements, like histochemistry, immunohistochemistry or pre-stained fluorescence. Furthermore, we used a microscopical technique described as fluorescence intensity decay shape analysis microscopy (FIDSAM to eliminate auto-fluorescence from fluorescently labeled tissue. Results: The sections were suitable for histochemical and immunohistochemical staining. Additionally, pre-labeled fluorescence in the porcine tissue was not lost by the embedding process. The evaluation of arterial cross sections with FIDSAM technology gave new, very important insights into the examination possibilities of fluorescently labeled tissue. Conclusions: Future studies of the vascular response to a variety of new stent materials will provide important clues to the pathogenesis resulting in restenosis and occlusion of stents. [J Interdiscipl Histopathol 2013; 1(3.000: 104-112

Nasolacrimal Stenting: Toward Improving Outcomes with a Simple Modification of the Song Stent

International Nuclear Information System (INIS)

Lanciego, Carlos; Miguel, Silvia De; Padilla, Manuel; Perea, Miguel; Rodriguez-Merlo, Rufo; Garcia-Garcia, Lorenzo

2006-01-01

The purpose of this study was to evaluate, in a prospective, single-center study, the effectiveness of Song's polyurethane stents, modified 'in-house,' in the percutaneous management of epiphora. Patients (n = 170; age range 18-83, mean = 64; 50 male, 120 female) with severe epiphora had the modified stents inserted (183 eyes/195 stents) to treat unilateral/bilateral and complete/partial obstruction of the nasolacrimal system. The etiology of the obstruction was idiopathic in 119 cases (61%) and chronic dacryocystitis in 76 (39%). The set designed by Song was used in all patients but modified by us such that the extreme end is cone-shaped. The original technique was slightly modified by us and the procedure was conducted on an outpatient basis. The initial technical success rate of stent placement was 97%. Resolution of epiphora was complete in 180 eyes and partial in 3. On follow-up (mean = 18 months; range: 2 days to 24 months), 165 of 195 stents (85%) remained patent. Primary patency rates at follow-up were 86%, 84%, 84%, and 79% in the first 6 months, second and third 6 months, and the present (24 months), respectively. Stents became obstructed in 30 patients, but all but 2 were easily withdrawn and 20 of these patients remained asymptomatic for a mean of 14 months (secondary patency of 67%). Following stent removal, the withdrawn stent was replaced with a new stent in the same intervention on 14 occasions. In another six cases, patency was re-established without the need of a second stent. The procedure is simple and safe, both in stent insertion as well as in mechanical de-blocking and withdrawal when occluded. Success was >80 % in the short term (1-year follow-up). Stenting failure does not preclude other treatment because with the modification that we had introduced, the extreme end of the stent becomes more accessible to mechanical de-blocking, withdrawal, and relocation. The levels of primary and secondary patencies are promising and warrant more
A randomized study to compare bioactive titanium stents and everolimus-eluting stents in diabetic patients (TITANIC XV): 1-year results.

Science.gov (United States)

López-Mínguez, José R; Nogales-Asensio, Juan M; Doncel-Vecino, Luis J; Merchán-Herrera, Antonio; Pomar-Domingo, Francisco; Martínez-Romero, Pedro; Fernández-Díaz, José A; Valdesuso-Aguilar, Raúl; Moreu-Burgos, José; Díaz-Fernández, José

2014-07-01

Up to 25% of patients who undergo a percutaneous coronary intervention show some limitation in the use of drug-eluting stents. The aim of this study was to evaluate if titanium-nitride-oxide-coated stents could be a good alternative to everolimus-eluting stents in diabetic patients. A total of 173 diabetic patients with lesions at moderate risk of restenosis (exclusion criteria: diameter 28 mm in vessels < 3mm, chronic occlusion) were randomized to a titanium group (83 patients) or an everolimus group (90 patients). Baseline characteristics were well balanced; 28.3% of patients were insulin dependent. At 1 year, the incidence of major adverse cardiac events (death, nonfatal myocardial infarction, stroke, or repeat target vessel revascularization) was significantly higher in the titanium group than in the everolimus group (total, 14.5% vs 4.4%; P = .02; noninsulin-dependent subgroup, 9.7% vs 3.2%; P = .14; insulin-dependent subgroup, 28.6% vs 7.1%; P = .04). The incidence of death, nonfatal myocardial infarction, stroke, or any revascularization was 16.9% in the titanium group and 7.8% in the everolimus group (P = .06). Target lesion and vessel revascularizations occurred in 8.4% compared with 3.3% (P = .15) and in 13.3% compared with 3.3% (P = .01) in the titanium and everolimus groups, respectively. Angiographic follow-up at 9 months showed significantly less late lumen loss in the everolimus group (in-segment, 0.52 [standard deviation, 0.58) mm vs -0.05 [0.32] mm; in-stent, 0.76 [0.54] mm vs 0.13 [0.31] mm; P < .0001). The everolimus-eluting stent is superior to the titanium stent for clinical and angiographic end points in diabetic patients with lesions at moderate risk of restenosis. Copyright © 2013 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.
The implantation of esophageal stent with radioactive 125I particles for advanced esophageal carcinomas: observation of therapeutic results

International Nuclear Information System (INIS)

Zhao Peng; Cui Hongkai; Yang Ruimin; Zhang Xizhong

2011-01-01

Objective: To investigate the therapeutic effect of the implantation of esophageal stent with radioactive 125 I particles in treating advanced esophageal carcinomas in aged patients. Methods: During the period from Sep. 2009 to Dec. 2010, implantation of esophageal stent was used to treat 43 aged patients with advanced esophageal cancer. Based on the patient's free will, the patients were divided into study group (n=18) receiving stent with 125 I particles and control group (n=25) receiving ordinary stent without 125 I particles. No significant difference in the age, the lesion length, the degree of stenosis and the disease stage existed between the study group and the control group. The technical success rate, the remission rate of dysphagia, the occurrence of complications and the mean survival time were calculated and analyzed. The results were compared between the two groups. Results: The technical success rate was 100% in both groups. The short-term remission rate of dysphagia was also 100% in both groups. The mean survival time in the study group and in the control group was 9.8 months and 4.8 months respectively, the difference between the two groups was statistically significant (P 0.05). Conclusion: This results of study indicate that for the treatment of advanced esophageal carcinomas the implantation of esophageal stent with radioactive 125 I particles can surely and markedly prolong the patient's survival time and relive the symptom of dysphagia. This technique is safe, feasible and effective in clinical practice. The use of the stent with radioactive 125 I particles is superior to the use of the traditional stent in treating patients with advanced esophageal cancer. (authors)
Esophageal Stent for Refractory Variceal Bleeding: A Systemic Review and Meta-Analysis

Directory of Open Access Journals (Sweden)

Xiao-Dong Shao

2016-01-01

Full Text Available Background. Preliminary studies suggest that covered self-expandable metal stents may be helpful in controlling esophageal variceal bleeding. Aims. To evaluate the effectiveness and safety of esophageal stent in refractory variceal bleeding in a systematic review and meta-analysis. Methods. A comprehensive literature search was conducted on PubMed, EMBASE, and Cochrane Library covering the period from January 1970 to December 2015. Data were selected and abstracted from eligible studies and were pooled using a random-effects model. Heterogeneity was assessed using I2 test. Results. Five studies involving 80 patients were included in the analysis. The age of patients ranged from 18 to 91 years. The mean duration of follow-up was 46.8 d (range, 30–60 d. The success rate of stent deployment was 96.7% (95% CI: 91.6%–99.5% and complete response to esophageal stenting was in 93.9% (95% CI: 82.2%–99.6%. The incidence of rebleeding was 13.2% (95% CI: 1.8%–32.8% and the overall mortality was 34.5% (95% CI: 24.8%–44.8%. Most of patients (87.4% died from hepatic or multiple organ failure, and only 12.6% of patients died from uncontrolled bleeding. There was no stent-related complication reported and the incidence of stent migration was 21.6% (95% CI: 4.7%–46.1%. Conclusion. Esophageal stent may be considered in patients with variceal bleeding refractory to conventional therapy.
Modified gianturco biliary stent in benign and malignant obstruction: Results of long-term follow up

International Nuclear Information System (INIS)

Chung, Jin Young; Song, Ho Young; Han, Hyun Young; Han, Young Min; Chung, Gyung Ho; Kim, Chong Soo; Choi, Ki Chul; Roh, Byung Suk; Kim, Jae Kyu

1993-01-01

Modified biliary gianturco stents were placed in 27 patients with obstructive jaundice. From July 1990 to October 1992, 46 two-seven connected stents of 8-12 mm in diameter (Myungsung Meditech, Seoul, Korea) were placed in 5 patients with benign biliary stricture and 22 patients with malignant biliary stricture in three university hospitals; 12 in Chonbuk National University Hospital, 12 in Wonkwang University Hospital, and 3 in Chonnam National University Hospital. Nineteen were men and eight were women, ranged in age from 34 to 76 years (average, 55 years). The stents were placed percutaneously through a transhepatic approach using a 8.5 Fr. introducing sheath. All stents were placed successfully without any technical failures or procedural morbidity or mortality. All patients complained dull abdominal pain for 1 to 3 days after the stent placement. In a follow-up period of 7-46 weeks, reocclusions were observed in one of the patients with benign stricture (20%) and three of the patients with malignant stricture (16%). Two patients with recurrent jaundice due to the obstruction of the stent were treated with placement of additional stent, one patient was treated with external catheter drainage. Migration of stent occurred in one patient. The application of the expandable biliary metallic stent is suggested as an effective treatment for benign and malignant biliary obstructive jaundice
Modified gianturco biliary stent in benign and malignant obstruction: Results of long-term follow up

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Chung, Jin Young; Song, Ho Young; Han, Hyun Young; Han, Young Min; Chung, Gyung Ho; Kim, Chong Soo; Choi, Ki Chul; Roh, Byung Suk; Kim, Jae Kyu [College of Medicine, Chonbuk National University, Chonju (Korea, Republic of)

1993-05-15

Modified biliary gianturco stents were placed in 27 patients with obstructive jaundice. From July 1990 to October 1992, 46 two-seven connected stents of 8-12 mm in diameter (Myungsung Meditech, Seoul, Korea) were placed in 5 patients with benign biliary stricture and 22 patients with malignant biliary stricture in three university hospitals; 12 in Chonbuk National University Hospital, 12 in Wonkwang University Hospital, and 3 in Chonnam National University Hospital. Nineteen were men and eight were women, ranged in age from 34 to 76 years (average, 55 years). The stents were placed percutaneously through a transhepatic approach using a 8.5 Fr. introducing sheath. All stents were placed successfully without any technical failures or procedural morbidity or mortality. All patients complained dull abdominal pain for 1 to 3 days after the stent placement. In a follow-up period of 7-46 weeks, reocclusions were observed in one of the patients with benign stricture (20%) and three of the patients with malignant stricture (16%). Two patients with recurrent jaundice due to the obstruction of the stent were treated with placement of additional stent, one patient was treated with external catheter drainage. Migration of stent occurred in one patient. The application of the expandable biliary metallic stent is suggested as an effective treatment for benign and malignant biliary obstructive jaundice.
Indications for stenting during thrombolysis

DEFF Research Database (Denmark)

Bækgaard, N; Broholm, R; Just, Sven Richardt Lundgren

2013-01-01

of a stent in this position is the treatment of choice facilitating the venous flow into an unobstructed outflow tract either from the femoral vein or the deep femoral vein or both. The stent, made of stainless steel or nitinol, has to be self-expandable and flexible with radial force to overcome...... the challenges in this low-pressure system. The characteristics of the anatomy with external compression and often a curved vein segment with diameter difference make stent placement necessary. Ballooning alone has no place in this area. The proportion of inserted stents varies in the published materials...
Stent underexpansion in angiographic guided percutaneous coronary intervention, despite adjunctive balloon post-dilatation, in drug eluting stent era

Directory of Open Access Journals (Sweden)

Mehrdad Taherioun

2014-01-01

Full Text Available BACKGROUND: Stent underexpansion is the most powerful predictor of long-term stent patency and clinical outcome. The purpose of this study was to evaluate the incidence and predictors of stent underexpansion despite adjunctive post-dilatation with non-compliant balloon. METHODS: After elective coronary stent implantation and adjunctive post-dilatation with non-compliant balloon and optimal angiographic result confirmed by the operator, intravascular ultrasound (IVUS was performed for all the treated lesions. If the treated lesions fulfilled the IVUS criteria, they are considered as the optimal stent group; if not, they are considered as the suboptimal group. RESULTS: From 50 patients enrolled in this study 39 (78% had optimal stent deployment and 11 (22% had suboptimal stent deployment. In the suboptimal group 7 (14% had underexpansion, 2 (4% malposition, and 2 (4% had asymmetry. There were no stent edge dissections detected by IVUS. We did not find any correlation between lesion calcification, ostial lesions, stent length, and stent underexpansion. Stent diameter ≤ 2.75 mm had a strong correlation with stent underexpansion. CONCLUSION: Despite adjunctive post-dilatation with noncompliant balloon, using a relatively small stent diameter was a strong predictor for underexpansion. IVUS guided percutaneous coronary intervention (PCI may be considered for drug eluting stent (DES implantation in relatively small vessels. Keywords: Stent, Percutaneous Coronary Intervention, Ultrasound, Post-dilatation
Evaluation of Polyurethane Nasolacrimal Duct Stents: In Vivo Studies in New Zealand Rabbits

International Nuclear Information System (INIS)

Wilhelm, K.E.; Grabolle, B.; Urbach, H.; Tolba, R.; Schild, H.; Paulsen, F.

2006-01-01

The purpose of this study was to evaluate the radiographic and biological effects of different polyurethane nasolacrimal duct stents in an animal model. Fifteen polyurethane nasolacrimal duct stents (n = 5 mushroom-type stents, n = 5 newly designed S-shaped TearLeader stents without hydrophilic coating, and n = 5 S-shaped TearLeader stents with hydrophilic coating) were implanted in the nasolacrimal ducts of eight unaffected New Zealand rabbits. One nasolacrimal system served as control. Clinical and radiographic follow-up was performed at 1-, 2-, and 4-week intervals, then after a 3-month interval, after which the animals were euthanized. All stents were implanted without major periprocedural complications. The stents proved to be patent by the end of the procedure. During follow-up, all mushroom-type stents were occluded at 4 weeks. None of these stents opened to forced irrigation. Clinically, all rabbits demonstrated severe dacryocystitis. Three out of five TearLeader stents without hydrophilic coating were blocked at 4 weeks; one out of five was open to irrigation. Best results were observed in the stent group with hydrophilic coating. Follow-up dacryocystography demonstrated patent stents in nasolacrimal ducts of all animals after 4 weeks. In only one of five cases, the coated stent became partially occluded after 2 months. These animals were free of clinical symptoms. After 3 months, at least three out of five stents still opened to forced irrigation and only one stent was completely blocked. Dislocation of the stents was not observed. Refinement of the stent surface and stent design improves the results of nasolacrimal duct stenting in this animal model. Implantation of hydrophilic-coated S-shaped stents is highly superior to conventional mushroom-type stents and noncoated stent types. Hydrophilic coating seems to prevent foreign-body reactions, resulting in maximized stent patency
Implantation of modified Y-shaped self-expandable stent for the treatment of stenosis of gastroenteric stoma: preliminary results in five cases

International Nuclear Information System (INIS)

Wu Gang; Si Jiangtao; Han Xinwei; Jiao Dechao; Ding Pengxu; Fu Mingti; Li Zhen; Ma Ji

2010-01-01

Objective To investigate the feasibility and therapeutic effect of stenting therapy by using modified Y-shaped self-expandable metal stent for the stenosis of gastroenteric stoma. Methods: According to the particular anatomic structures and the pathological features of the narrowed gastroenteric stoma,the authors designed a modified Y-shaped self-expandable metal stent. Under the fluoroscopic guidance, implantation of modified Y-shaped self-expandable metal stent was performed in 5 patients with narrowed gastroenteric stoma. The technical safety and the clinical results were evaluated. Results: The modified Y-shaped self-expandable metal stent was successfully implanted with one procedure in all five patients. After the implantation the symptoms such as nausea, vomiting, abdominal distension were promptly relieved, and the patients' living quality was markedly improved. Conclusion: The stenting therapy with modified Y-shaped self-expandable metal stent can rapidly relieve the stenosis of gastroenteric stoma once for all. The technique is feasible and the short-term effect is reliable, therefore, it is worth popularizing this therapy in clinical practice. (authors)
Study on the application of big cup membranate stent on restenosis after stenting for carcinoma of esophago cardia

International Nuclear Information System (INIS)

Wang Xiuping; Yao Zhongqiang; Liu Jian; Zhang Yan

2007-01-01

Objective: To evaluate the clinical value of self-designed big cup membranate stent on restenosis after stenting for carcinoma of esophago-cardia. Methods: 12 cases of restenosis after stenting for carcinoma of esophago-cardia were involved in the study. Self-designed big cup membranate stent made by Nanjing Weichuang Company (the length of the cup was 3.5 cm)was placed into the constricted stent under guidance of fluoroscopy. Clinical effect, restenosis, and complications were observed during followed up. Results: All the 12 cases of big cup membranat stent placement went along smoothly without indigitation of the cup of the stent. Follow-up of 1.5-8 months showed that 2 cases developed severe restenosis on the big cup of the stem, resulting in third grade difficult deglutition. Among them, one occurred 1 month after stenting, caused by hyperplasia of large amount of granulation tissue; another occurred 6 months after stenting, caused by growth of tumor tissue. 3 cases developed mild to moderate restenosis, 2.3-7 months (mean: 4.6 months) after stenting, with result of first grade difficult deglutition. The remaining 7 cases (mean 5.6 months follow-up) did not have difficulty during deglutition. Conclusions: Application of big cup membranate stent on restenosis after stenting for carcinoma of esophago-cardia can effectively prevent the stent from moving downwards and thus lower down the rate of restenosis, and postpone the occurrence of restenosis. (authors)
Surgical stent for dental implant using cone beam CT images

International Nuclear Information System (INIS)

Choi, Hyung Soo; Kim, Gyu Tae; Choi, Yong Suk; Hwang, Eui Hwan

2010-01-01

The purpose of this study is to develop a surgical stent for dental implant procedure that can be easily applied and affordable by using cone beam computerized tomography (CBCT). Aluminum, Teflon-PFA (perfluoroalkoxy), and acetal (polyoxymethylene plastic) were selected as materials for the surgical stent. Among these three materials, the appropriate material was chosen using the CBCT images. The surgical stent, which could be easily placed into an oral cavity, was designed with chosen material. CBCT images of the new surgical stent on mandible were obtained using Alphard-3030 dental CT system (Asahi Roentgen Co., Ltd., Kyoto, Japan). The point of insertion was prescribed on the surgical stent with the multiplanar reconstruction software of OnDemand3D (CyberMed Inc., Seoul, Korea). Guide holes were made at the point of insertion on the surgical stent using newly designed guide jig. CBCT scans was taken for the second time to verify the accuracy of the newly designed surgical stent. Teflon-PFA showed radiologically excellent image characteristics for the surgical stent. High accuracy and reproducibility of implantation were confirmed with the surgical stent. The newly designed surgical stent can lead to the accurate implantation and achieve the clinically predictable result.
Heterogeneous Intravascular Ultrasound Findings of Stent Thrombosis

OpenAIRE

Morofuji, Toru; Inaba, Shinji; Aisu, Hiroe; Takahashi, Kayo; Saito, Makoto; Higashi, Haruhiko; Yoshii, Toyofumi; Sumimoto, Takumi

2017-01-01

Objective The underlying mechanisms of stent thrombosis are not completely understood. Methods We experienced 12 definite stent thrombosis cases (1 early, 1 late, and 10 very late) at our hospital from July 2011 to April 2016 and evaluated the possible causes of stent thrombosis by intravascular ultrasound (IVUS). Results Five different potential morphological causes of stent thrombosis (neoatherosclerosis, stent malapposition, stent fracture, edge dissection, and stent underexpansion) were d...
Partially Covered Metal Stents May Not Prolong Stent Patency Compared to Uncovered Stents in Unresectable Malignant Distal Biliary Obstruction

Science.gov (United States)

Kim, Jae Yun; Ko, Gyu Bong; Lee, Tae Hoon; Park, Sang-Heum; Lee, Yun Nah; Cho, Young Sin; Jung, Yunho; Chung, Il-Kwun; Choi, Hyun Jong; Cha, Sang-Woo; Moon, Jong Ho; Cho, Young Deok; Kim, Sun-Joo

2017-01-01

Background/Aims Controversy still exists regarding the benefits of covered self-expandable metal stents (SEMSs) compared to uncovered SEMSs. We aimed to compare the patency and stent-related adverse events of partially covered SEMSs (PC-SEMSs) and uncovered SEMSs in unresectable malignant distal biliary obstruction. Methods A total of 134 patients who received a PC-SEMS or uncovered SEMS for palliation of unresectable malignant distal biliary obstruction were reviewed retrospectively. The main outcome measures were stent patency, stent-related adverse events, and overall survival. Results The median stent patency was 118 days (range, 3 to 802 days) with PC-SEMSs and 105 days (range, 2 to 485 days) with uncovered SEMSs (p=0.718). The overall endoscopic revision rate due to stent dysfunction was 36.6% (26/71) with PC-SEMSs and 36.5% (23/63) with uncovered SEMSs (p=0.589). Tumor ingrowth was more frequent with uncovered SEMSs (4.2% vs 19.1%, p=0.013), but migration was more frequent with PC-SEMSs (11.2% vs 1.5%, p=0.04). The incidence of stent-related adverse events was 2.8% (2/71) with PC-SEMSs and 9.5% (6/63) with uncovered SEMSs (p=0.224). The median overall survival was 166 days with PC-SEMSs and 168 days with uncovered SEMSs (p=0.189). Conclusions Compared to uncovered SEMSs, PC-SEMSs did not prolong stent patency in unresectable malignant distal biliary obstruction. Stent migration was more frequent with PC-SEMSs. However, tumor ingrowth was less frequent with PC-SEMSs compared to uncovered SEMSs. PMID:28208003
Treatment of Complete and Partial Obstruction of the Nasolacrimal System with Polyurethane Stents: Initial Experience

International Nuclear Information System (INIS)

Pulido-Duque, Juan M.; Reyes, Ricardo; Carreira, Jose M.; Vega, Francisco; Gorriz, Elias; Pardo, M. Dolores; Perez, Francisco; Maynar, Manuel

1998-01-01

Purpose: To present our experience in the treatment of nasolacrimal occlusion by means of polyurethane stents. Methods: Forty polyurethane stents were placed under fluoroscopic guidance in 35 consecutive patients with epiphora due to total or partial obstruction of the nasolacrimal system. The set designed by Song was used in all patients. The procedure was performed by introducing a guidewire through the superior punctum into the canaliculus and advancing it across the obstruction into the inferior meatus of the nasal cavity. After pulling out the guidewire, the stent was advanced in retrograde fashion and released into the sac and the nasolacrimal duct.Results: The technical success rate was 100%. The average time for the procedure was 25 min (range 10-60 min). Immediate complications were: mild pain (n= 5), severe pain (n= 1), minimal epistaxis (n= 7), and moderate epistaxis (n= 1). No major complications occurred. The last clinical control revealed complete resolution of epiphora in 35 eyes and partial resolution in four; one patient did not improve. Conclusion: This technique for treatment of obstruction of the nasolacrimal system is simple and safe, and may obviate the use of more invasive procedures
4D phase contrast flow imaging for in-stent flow visualization and assessment of stent patency in peripheral vascular stents – A phantom study

International Nuclear Information System (INIS)

Bunck, Alexander C.; Jüttner, Alena; Kröger, Jan Robert; Burg, Matthias C.; Kugel, Harald; Niederstadt, Thomas; Tiemann, Klaus; Schnackenburg, Bernhard; Crelier, Gerard R.

2012-01-01

Purpose: 4D phase contrast flow imaging is increasingly used to study the hemodynamics in various vascular territories and pathologies. The aim of this study was to assess the feasibility and validity of MRI based 4D phase contrast flow imaging for the evaluation of in-stent blood flow in 17 commonly used peripheral stents. Materials and methods: 17 different peripheral stents were implanted into a MR compatible flow phantom. In-stent visibility, maximal velocity and flow visualization were assessed and estimates of in-stent patency obtained from 4D phase contrast flow data sets were compared to a conventional 3D contrast-enhanced magnetic resonance angiography (CE-MRA) as well as 2D PC flow measurements. Results: In all but 3 of the tested stents time-resolved 3D particle traces could be visualized inside the stent lumen. Quality of 4D flow visualization and CE-MRA images depended on stent type and stent orientation relative to the magnetic field. Compared to the visible lumen area determined by 3D CE-MRA, estimates of lumen patency derived from 4D flow measurements were significantly higher and less dependent on stent type. A higher number of stents could be assessed for in-stent patency by 4D phase contrast flow imaging (n = 14) than by 2D phase contrast flow imaging (n = 10). Conclusions: 4D phase contrast flow imaging in peripheral vascular stents is feasible and appears advantageous over conventional 3D contrast-enhanced MR angiography and 2D phase contrast flow imaging. It allows for in-stent flow visualization and flow quantification with varying quality depending on stent type
Long-Term Results of Stent Placement in Patients with Outflow Block After Living-Donor-Liver Transplantation

Energy Technology Data Exchange (ETDEWEB)

Fujimori, Masashi, E-mail: fujimorim@clin.medic.mie-u.ac.jp [Mie University School of Medicine, Department of Radiology (Japan); Yamakado, Koichiro, E-mail: yamakado47@gmail.com; Takaki, Haruyuki, E-mail: takaki-h@clin.medic.mie-u.ac.jp [Hyogo College of Medicine, Department of Radiology (Japan); Nakatsuka, Atsuhiro, E-mail: nakatuka@clin.medic.mie-u.ac.jp; Uraki, Junji, E-mail: junji@clin.medic.mie-u.ac.jp; Yamanaka, Takashi, E-mail: t-yama@clin.medic.mie-u.ac.jp; Hasegawa, Takaaki, E-mail: hasegawat@clin.medic.mie-u.ac.jp; Sugino, Yuichi, E-mail: ysugino23@clin.medic.mie-u.ac.jp; Nakajima, Ken, E-mail: k-nakajima@clin.medic.mie-u.ac.jp; Matsushita, Naritaka, E-mail: n-matsushita@clin.medic.mie-u.ac.jp [Mie University School of Medicine, Department of Radiology (Japan); Mizuno, Shugo, E-mail: mizunos@clin.medic.mie-u.ac.jp [Mie University School of Medicine, Hepatobiliary Pancreatic and Transplant Surgery (Japan); Sakuma, Hajime, E-mail: sakuma.mie@gmail.com [Mie University School of Medicine, Department of Radiology (Japan); Isaji, Shuji, E-mail: isaji-s@clin.medic.mie-u.ac.jp [Mie University School of Medicine, Hepatobiliary Pancreatic and Transplant Surgery (Japan)

2016-04-15

PurposeTo evaluate long-term results of stent placement retrospectively in patients with outflow block after living-donor-liver transplantation (LDLT).Materials and MethodsFor this institutional review board approved retrospective study conducted during 2002–2012, stents were placed in outflow veins in 15 patients (11.3 %, 15/133) (12 men; 3 female) in whom outflow block developed after LDLT. Their mean age was 52.3 years ± 15.3 (SD) (range, 4–69 years). Venous stenosis with a pressure gradient ≥5 mmHg (outflow block) was observed in the inferior vena cava in seven patients, hepatic vein in seven patients, and both in one patient. Technical success, change in a pressure gradient and clinical manifestations, and complications were evaluated. Overall survival of 15 patients undergoing outflow block stenting was compared with that of 116 patients without outflow block after LDLT.ResultsStents were placed across the outflow block veins without complications, lowering the pressure gradient ≤ 3 mmHg in all patients (100 %, 15/15). Clinical manifestations improved in 11 patients (73.3 %, 11/15), and all were discharged from the hospital. However, they did not improve in the other 4 patients (26.7 %, 4/15) who died in the hospital 1.0–3.7 months after stenting (mean, 2.0 ± 1.2 months). No significant difference in 5-year survival rates was found between patients with and without outflow block after LDLT (61.1 vs. 72.2 %, p = .405).ConclusionStenting is a feasible, safe, and useful therapeutic option to resolve outflow block following LDLT, providing equal survival to that of patients without outflow block.
The INNOVATION Trial: four-year safety and effectiveness of the INCRAFT® AAA Stent-Graft System for endovascular repair.

Science.gov (United States)

Pratesi, Giovanni; Pratesi, Carlo; Chiesa, Roberto; Coppi, Gioacchino; Scheinert, Dierk; Brunkwall, Jan S; van der Meulen, Stefaan; Torsello, Giovanni

2017-10-01

This paper reports the 4-year safety and effectiveness of the INCRAFT® AAA Stent-Graft System (Cordis Corp., Milpitas, CA, USA), an ultra-low-proﬁle device for the treatment of abdominal aortic aneurysms. The INNOVATION Trial is the prospective, first-in-human, multicenter trial to evaluate the safety and effectiveness of the INCRAFT® System. Patients underwent annual clinical and computed tomography angiography examination as part of the study protocol. The INCRAFT® AAA Stent-Graft System is a customizable tri-modular design, with an ultra-low profile (14-Fr) delivery system. Patient were treated under approved protocol, the prescribed clinical and imaging follow-up at annually through 5 years. Results analyzed and adjudicated by a clinical events committee, independent core laboratory, and a data safety and monitoring board. This manuscript reports results through 4 years of follow-up. A total of 60 patients were enrolled in the trial, all of whom were successfully treated. Follow-up rates at 1 and 4 years were 93% (56/60) and 85% (51/60), respectively. All-cause mortality at 4 years was 17.6% and no death was AAA-, device-, or procedure-related. The secondary reintervention rate at 1 year was 4.6%, primarily the result of stent thrombosis. In total, 10 patients required 13 post-procedure interventions within 4-years of follow-up (2 to repair a type I endoleak, 4 to repair a type II endoleak, 1 for stent thrombosis, 1 for renal stenosis, 1 for aneurysm enlargement, 2 for limb migration and 2 for prosthesis stenosis or occlusion). There were 4 cases (10%) of aneurysm enlargement reported at the 4 year follow-up. At 4 years, 38 out of 39 patients were free from type I and III endoleaks. There were no proximal type I or type III endoleaks at 4-year follow-up. Core laboratory evaluation of the postoperative imaging studies indicated absence of endograft migration while a single fracture was demonstrated without any clinical sequelae. The INCRAFT® AAA Stent
Treatment of Benign and Malignant Tracheobronchial Obstruction with Metal Wire Stents: Experience with a Balloon-Expandable and a Self-Expandable Stent Type

International Nuclear Information System (INIS)

Rieger, Johannes; Hautmann, Hubert; Linsenmaier, Ulrich; Weber, Cristoph; Treitl, Markus; Huber, R.M.; Pfeifer, Klaus-Juergen

2004-01-01

Over the last few years various types of metal wire stents have been increasingly employed in the treatment of both malignant and benign tracheobronchial obstruction. To date, however, few studies have investigated the in vivo properties of different stent types. We implanted 26 balloon-expandable tantalum Strecker stents (18 patients) and 18 self-expandable Wallstents (16 patients) into the tracheobronchial system of 30 patients with combined stenting in 4 patients. Mean age was 51 years (range: 0.5-79 years). Malignant disease was present in 23 patients, benign disease in seven patients. Both patients and individual stents were monitored clinically and radiographically. The probability of stents remaining within the tracheobronchial system, and of their remaining undislocated and uncompressed was calculated using Kaplan-Meier analysis for both stent types. Average stent follow-up time was 112 days until explantation and 115 days until patients' death or discharge. Kaplan-Meier analysis revealed a higher probability for the Wallstent to remain within the tracheobronchial system. Dislocation and compression occurred more rarely. Explantation, however, if desired, was more difficult compared to the Strecker stent. The Wallstent also led to the formation of granulation tissue, especially at the proximal stent end, frequently requiring reintervention. Both stent types proved to be effective therapeutic options in the management of obstructive tracheobronchial disease. The mechanical properties of the Strecker stent seem to be less favorable compared to the Wallstent but removal is easy. For benign disease, however, the Wallstent reveals limitations due to significant side effects
Intravascular ultrasound assessed incomplete stent apposition and stent fracture in stent thrombosis after bare metal versus drug-eluting stent treatment the Nordic Intravascular Ultrasound Study (NIVUS)

DEFF Research Database (Denmark)

Kosonen, Petteri; Vikman, Saila; Jensen, Lisette Okkels

2012-01-01

This prospective multicenter registry used intravascular ultrasound (IVUS) in patients with definite stent thrombosis (ST) to compare rates of incomplete stent apposition (ISA), stent fracture and stent expansion in patients treated with drug-eluting (DES) versus bare metal (BMS) stents. ST...... is a rare, but potential life threatening event after coronary stent implantation. The etiology seems to be multifactorial....

An in Vitro Twist Fatigue Test of Fabric Stent-Grafts Supported by Z-Stents vs. Ringed Stents

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Jing Lin

2016-02-01

Full Text Available Whereas buckling can cause type III endoleaks, long-term twisting of a stent-graft was investigated here as a mechanism leading to type V endoleak or endotension. Two experimental device designs supported with Z-stents having strut angles of 35° or 45° were compared to a ringed control under accelerated twisting. Damage to each device was assessed and compared after different durations of twisting, with focus on damage that may allow leakage. Stent-grafts with 35° Z-stents had the most severe distortion and damage to the graft fabric. The 45° Z-stents caused less fabric damage. However, consistent stretching was still seen around the holes for sutures, which attach the stents to the graft fabric. Larger holes may become channels for fluid percolation through the wall. The ringed stent-graft had the least damage observed. Stent apexes with sharp angles appear to be responsible for major damage to the fabrics. Device manufacturers should consider stent apex angle when designing stent-grafts, and ensure their devices are resistant to twisting.
An in Vitro Twist Fatigue Test of Fabric Stent-Grafts Supported by Z-Stents vs. Ringed Stents.

Science.gov (United States)

Lin, Jing; Guidoin, Robert; Du, Jia; Wang, Lu; Douglas, Graeham; Zhu, Danjie; Nutley, Mark; Perron, Lygia; Zhang, Ze; Douville, Yvan

2016-02-16

Whereas buckling can cause type III endoleaks, long-term twisting of a stent-graft was investigated here as a mechanism leading to type V endoleak or endotension. Two experimental device designs supported with Z-stents having strut angles of 35° or 45° were compared to a ringed control under accelerated twisting. Damage to each device was assessed and compared after different durations of twisting, with focus on damage that may allow leakage. Stent-grafts with 35° Z-stents had the most severe distortion and damage to the graft fabric. The 45° Z-stents caused less fabric damage. However, consistent stretching was still seen around the holes for sutures, which attach the stents to the graft fabric. Larger holes may become channels for fluid percolation through the wall. The ringed stent-graft had the least damage observed. Stent apexes with sharp angles appear to be responsible for major damage to the fabrics. Device manufacturers should consider stent apex angle when designing stent-grafts, and ensure their devices are resistant to twisting.
Forgotten Ureteral Stents: An Avoidable Morbidity

International Nuclear Information System (INIS)

Murtaza, B.; Alvi, S.

2016-01-01

Objective: To assess the clinical presentation of forgotten ureteral stents and highlight the etiological factors resulting in the retention of these stents. Study Design: Observational study. Place and Duration of Study: Department of Urology, Armed Forces Institute of Urology, Rawalpindi, from January 2010 to Jun 2011. Methodology: Thirty-eight patients, with forgotten ureteral stents, retained for more than 6 months duration, were enrolled. A detailed evaluation was performed, along with the questions regarding the patients' opinion about the ureteral stents. They were specially asked whether they knew about the stents or were they formally informed regarding the stents. Subsequently, the patients were managed according to their clinical condition. Results: The male to female ratio was 2.1:1 aged 23 - 69 years, mean being 40.24 ± 12.59 years. The time of presentation after the ureteral stenting was 7 - 180 months (mean = 28.89 ± 33.435 years). Seven patients (18.4 percentage) reported with chronic kidney disease, including ESRD in two cases. Recurrent UTI was seen in 28 cases (73.6 percentage), calculus formed over the stents in 20 cases (52.6 percentage), and stent fragmented in 5 patients (13.1 percentage). Majority of patients, (n = 23, 60.5 percentage), were not even aware of the placement of these stents while 8 (21.0 percentage) knew but were reluctant about its removal. In 3 cases (7.8 percentage), the relatives knew about the stent but never informed the patients. The stent had been removed in 2 cases (5.2 percentage), but the other broken fragment was missed. One case (2.6 percentage) each had a misconception about the permanent placement of the stents like cardiac stents and regarding degradation of the stents in situ. Conclusion: Forgotten ureteral stents produce clinical features ranging from recurrent UTI to ESRD. This preventable urological complication is primarily due to the unawareness or ignorance of the patients and their relatives
Nasolacrimal Polyurethane Stent: Complications with CT Correlation

International Nuclear Information System (INIS)

Pinto, Isabel T.; Paul, Laura; Grande, Carlos

1998-01-01

Purpose: To evaluate initial results in patients with epiphora secondary to obstruction of the nasolacrimal duct treated by placement of a polyurethane stent, and to discuss the technical problems and complications arising during the procedure, with visualization of the anatomy of the drainage apparatus using computed tomography (CT). Methods: We inserted 20 polyurethane Song stents under fluoroscopic guidance after dacryocystography in 19 patients with grade 3-4 epiphora caused by idiopathic obstruction of the nasolacrimal duct. CT scans were obtained following stent placement in all patients. Results: We focus on the technical problems and complications that arose during these procedures. During negotiation of the guidewire past the obstruction at the level of the junction of the duct with the lacrimal sac, the guidewire created a false passage in a posterior suborbital direction in two cases and towards the posterior midline in another. In all cases the guidewire was withdrawn and reinserted through the proper anatomic route without further difficulty or complications. In two cases the stent was improperly positioned wholly or partially outside the nasolacrimal system (one medially, one posteriorly). In one case the stent was removed and reinserted; in the other it remains in place and functional. CT was performed in all these cases to ensure proper anatomic alignment and determine what had gone wrong. The epiphora was completely resolved in 13 cases and partially relieved in four; there were three cases of stent obstruction. Epistaxis of short duration (1 hr) occurred in seven patients and headache in one. Conclusions: Treatment of epiphora with polyurethane stents is a technique that is well tolerated by patients and achieves a high success rate, yet problems in placement may be encountered. Though no major consequences for patients are involved, cognizance of such difficulties is important to avoid incorrect positioning of stents
Stent

Science.gov (United States)

... Drugs & Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Stent URL of this page: //medlineplus.gov/ency/article/002303.htm Stent To use the sharing features on this page, please enable JavaScript. A stent is a tiny tube placed into a hollow structure in your ...
Primary and revision efficacy of cross-wired metallic stents for endoscopic bilateral stent-in-stent placement in malignant hilar biliary strictures.

Science.gov (United States)

Lee, T H; Moon, J H; Kim, J H; Park, D H; Lee, S S; Choi, H J; Cho, Y D; Park, S H; Kim, S J

2013-01-01

Endoscopic bilateral drainage for inoperable malignant hilar biliary strictures (HBS) using metal stents is considered to be technically difficult. Furthermore, endoscopic revision of bilateral stenting after occlusion can be challenging. This study was performed to evaluate the long-term efficacy of endoscopic bilateral stent-in-stent placement of cross-wired metallic stents in high-grade malignant HBS and planned endoscopic bilateral revision. A total of 84 patients with inoperable high-grade malignant HBS were enrolled from three academic tertiary referral centers. Two cross-wired metal stents were inserted using a bilateral stent-in-stent placement method. Bilateral endoscopic revision was also performed during follow-up using either identical metal stents or plastic stents. The main outcome measurements were technical and functional success, complications, stent patency, and endoscopic revision efficacy. The technical and clinical success rates of endoscopic bilateral stent-in-stent placement of cross-wired metallic stents were 95.2% (80/84) and 92.9% (78/84), respectively. Median patency (range) and survival were 238 days (10-429) and 256 days (10-1130), respectively. Obstruction of primary bilateral stents occurred in 30.8% (24/78) of patients with functionally successful stent placement. The technical and clinical success rates of planned bilateral endoscopic revision for occluded stents were 83.3% (20/24) and 79.2% (19/24), respectively. For revision, bilateral metallic stents were placed in 11 patients (55.0%); the remaining patients received plastic stents. Palliative endoscopic bilateral stent-in-stent placement of cross-wired metallic stents was effective in patients with inoperable HBS. Revision endoscopic bilateral stenting may be feasible and successful in cases where the primary deployed metal stents are occluded. © Georg Thieme Verlag KG Stuttgart · New York.
Modified nasolacrimal duct stenting

International Nuclear Information System (INIS)

Tian Min; Jin Mei; Chen Huanjun; Li Yi

2008-01-01

Objective: Traditional nasolacrimal duct stenting possesses some shortcoming including difficulty of pulling ball head guide wire from the nasal cavity with turbinate hypertrophy and nasal septal deviation. The new method of nose-oral tube track establishment can overcome the forementioned and increase the successful rate. Methods: 5 F catheter and arterial sheath were modified to be nasolacrimal duct stent delivery device respectively. Antegrade dacryocystography was taken firstly to display the obstructed site and followed by the modified protocol of inserting the guide wire through nasolacrimal duct and nasal cavity, and establishing the stent delivery track for retrograde stent placement. Results: 5 epiphora patients with failure implantation by traditional method were all succeeded through the modified stenting (100%). During 6-mouth follow-up, no serious complications and reocclusion occurred. Conclusion: The establishment of eye-nose-mouth-nose of external nasal guide wire track can improve the successful rate of nasolacrimal duct stenting. (authors)
Circumferential Stent Fracture: Novel Detection and Treatment with the Use of StentBoost

OpenAIRE

Ramegowda, Raghu T.; Chikkaswamy, Srinivas B.; Bharatha, Ashalatha; Radhakrishna, Jayashree; Krishnanaik, Geetha B.; Nanjappa, Manjunath C.; Panneerselvam, Arunkumar

2012-01-01

Circumferential stent fracture is extremely uncommon, and in rare cases, it can cause stent thrombosis. Recognizing stent fracture can be difficult on conventional fluoroscopy because of poor stent radiopacity. We found that StentBoost image acquisition yields improved visibility of stent struts, enabling the identification of stent fracture and the precise positioning of new stents over previously stented segments.
Metallic ureteral stents in malignant ureteral obstruction: clinical factors predicting stent failure.

Science.gov (United States)

Chow, Po-Ming; Hsu, Jui-Shan; Huang, Chao-Yuan; Wang, Shuo-Meng; Lee, Yuan-Ju; Huang, Kuo-How; Yu, Hong-Jheng; Pu, Yeong-Shiau; Liang, Po-Chin

2014-06-01

To provide clinical outcomes of the Resonance metallic ureteral stent in patients with malignant ureteral obstruction, as well as clinical factors predicting stent failure. Cancer patients who have received Resonance stents from July 2009 to March 2012 for ureteral obstruction were included for chart review. Stent failure was detected by clinical symptoms, image studies, and renal function tests. Survival analysis for stent duration was used to estimate patency rate and factors predicting stent failure. A total of 117 stents were inserted successfully into 94 ureteral units in 79 patients. There were no major complications. These stents underwent survival analysis and proportional hazard regression. The median duration for the stents was 5.77 months. In multivariate analysis, age (P=0.043), preoperative serum creatinine level (P=0.0174), and cancer type (P=0.0494) were significant factors associated with stent failure. Cancer treatment before and after stent insertion had no effect on stent duration. Resonance stents are effective and safe in relieving malignant ureteral obstructions. Old age and high serum creatinine level are predictors for stent failure. Stents in patients with lower gastrointestinal cancers have longer functional duration.
Vertebral artery origin stent placement with distal protection: technical and clinical results.

Science.gov (United States)

Qureshi, A I; Kirmani, J F; Harris-Lane, P; Divani, A A; Ahmed, S; Ebrihimi, A; Al Kawi, A; Janjua, N

2006-05-01

To report the feasibility, safety, and 1-month results of performing stent placement for vertebral origin stenosis with the use of a distal protection device. Distal protection devices have been shown to reduce the number of cerebral emboli and subsequent ischemic events when used as adjuncts to percutaneous carotid intervention; however, one case of the use of a distal protection device for vertebral artery has been reported in the literature. We retrospectively determined rates of technical success and 1-month stroke or death associated with stent placement by using distal protection (Filter EX; Boston Scientific, Natick, Mass) in patients with symptomatic vertebral artery origin stenosis. Technical success was defined as successful deployment of distal protection device and stent at target lesion followed by successful retrieval of the device and a final residual stenosis of less than 30%. Other outcomes ascertained included any stroke, death, and semiquantitative assessment of particulate material retained by the filter device. The mean age of the 12 treated patients was 68 years (range, 52-88 years) and the group included 9 men and 3 women. The mean percentage of vertebral artery origin stenosis was 71 +/- 6%. Femoral and radial approaches were used in 9 and 3 cases, respectively. Technical success was achieved in 11 of the 12 patients in whom distal protection device placement was attempted. Postprocedure residual stenosis was 5 +/- 4%. Eight devices held macroscopically visible embolic debris (large and small amounts in 3 and 5 devices, respectively). No stroke or death was observed in the 1-month follow-up. The present study demonstrates the feasibility of performing stent placement for vertebral artery origin stenosis by using a distal protection device. Further studies are required to determine the effectiveness of this approach for vertebral artery origin atherosclerosis.
Comparison of closed-cell and hybrid-cell stent designs in carotid artery stenting: clinical and procedural outcomes

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Ersan TatlI

2017-05-01

Full Text Available Introduction: Carotid artery stenting (CAS is a promising alternative to surgery in high-risk patients. However, the impact of stent cell design on outcomes in CAS is a matter of continued debate. Aim : To compare the periprocedural and clinical outcomes of different stent designs for CAS with distal protection devices. Material and methods : All CAS procedures with both closed- and hybrid-cell stents performed at our institution between February 2010 and December 2015 were analyzed retrospectively. Adverse events were defined as death, major stroke, minor stroke, transient ischemic attack and myocardial infarction. Periprocedural and 30-day adverse events and internal carotid artery (ICA vasospasm rates were compared between the closed-cell and hybrid-cell stent groups. Results : The study included 234 patients comprising 146 patients with a closed-cell stent (Xact stent, Abbott Vascular (mean age: 68.5 ±8.6; 67.1% male and 88 patients with a hybrid-cell stent (Cristallo Ideale, Medtronic (mean age: 67.2 ±12.8; 68.2% male. There was no significant difference between the groups with respect to periprocedural or 30-day adverse event rates. While there was no difference in terms of tortuosity index between the groups, there was a higher procedural ICA vasospasm rate in the closed-cell stent group (35 patients, 23% compared with the hybrid-cell stent group (10 patients, 11% (p = 0.017. Conclusions : The results of this study showed no significant difference in the clinical adverse event rates after CAS between the closed-cell stent group and the hybrid-cell stent group. However, procedural ICA vasospasm was more common in the closed-cell stent group.
Radial force measurement of endovascular stents: Influence of stent design and diameter.

Science.gov (United States)

Matsumoto, Takuya; Matsubara, Yutaka; Aoyagi, Yukihiko; Matsuda, Daisuke; Okadome, Jun; Morisaki, Koichi; Inoue, Kentarou; Tanaka, Shinichi; Ohkusa, Tomoko; Maehara, Yoshihiko

2016-04-01

Angioplasty and endovascular stent placement is used in case to rescue the coverage of main branches to supply blood to brain from aortic arch in thoracic endovascular aortic repair. This study assessed mechanical properties, especially differences in radial force, of different endovascular and thoracic stents. We analyzed the radial force of three stent models (Epic, E-Luminexx and SMART) stents using radial force-tester method in single or overlapping conditions. We also analyzed radial force in three thoracic stents using Mylar film testing method: conformable Gore-TAG, Relay, and Valiant Thoracic Stent Graft. Overlapping SMART stents had greater radial force than overlapping Epic or Luminexx stents (P stents was greater than that of all three endovascular stents (P stents, site of deployment, and layer characteristics. In clinical settings, an understanding of the mechanical characteristics, including radial force, is important in choosing a stent for each patient. © The Author(s) 2015.
Initial and mid-term results of a 4F compatible self-expanding low strut profile nitinol stent in the superficial femoral artery

International Nuclear Information System (INIS)

Muehlenbruch, G.; Brock, H.; Das, M.; Hohl, C.; Mahnken, A.H.; Wildberger, J.; Guenther, R.W.; Haage, P.

2007-01-01

Purpose: To evaluate the initial and mid-term results of a new self-expanding low strut profile nitinol stent for treatment of atherosclerotic lesions stenoses and occlusions in the superficial femoral artery (SFA). Materials and Methods: In 8 patients (4 male, 4 female, mean age 74.8 ± 8.8 years) with SFA lesions and non-satisfying results after PTA treatment alone, 10 self-expanding nitinol Xpert stents were deployed via a 4 F sheath. Stent characteristics and handling were graded by the interventionalist. Fontaine classification, duplex flow measurements and ankle brachial index (ABI) at rest and stress were taken prior and one day after stent placement. Patients were followed 3, 6 and 12 months after the procedure obtaining the same parameters at each appointment. Results: Initial stent treatment was successful in all patients. Stent handling and positioning were rated very good and safe. All patients improved clinically by at least one Fontaine stage (range before treatment: stage IIb to IV). The mean ABI at rest (stress) improved initially from 0.68 (0.70) to 1.07 (0.99). During a mean follow-up period of 8.3 months no case of clinically relevant in-stent stenosis was observed with stable values of ABI at rest and stress. (orig.)
In vitro stent lumen visualisation of various common and newly developed femoral artery stents using MR angiography at 1.5 and 3 tesla.

Science.gov (United States)

Syha, R; Ketelsen, D; Kaempf, M; Mangold, S; Sixt, S; Zeller, T; Springer, F; Schick, F; Claussen, C D; Brechtel, K

2013-02-01

To evaluate stent lumen assessment of various commonly used and newly developed stents for the superficial femoral artery (SFA) using MR angiography (MRA) at 1.5 and 3 T. Eleven nitinol stents and one cobalt-chromium stent were compared regarding stent lumen visualisation using a common three-dimensional MRA sequence. Maximum visible stent lumen width and contrast ratio were analysed in three representative slices for each stent type. A scoring system for lumen visualisation was applied. Nitinol stents showed significantly better performance than the cobalt chromium stent (P stent lumen ranged between 43.4 and 95.5 %, contrast ratio between 7.2 and 110.6 %. Regarding both field strengths, seven of the nitinol stents were classified as "suitable". Three nitinol stents were "limited", and one nitinol stent and the cobalt chromium stent were "not suitable". Intraluminal loss of signal and artefacts of most of the SFA stents do not markedly limit assessment of stent lumen by MRA at 1.5 and 3 T. MRA can thus be considered a valid technique for detection of relevant in-stent restenosis. Applied field strength does not strongly influence stent lumen assessment in general, but proper choice of field strength might be helpful.
Predictors of stent dysfunction after self-expandable metal stent placement for malignant gastric outlet obstruction: tumor ingrowth in uncovered stents and migration of covered stents.

Science.gov (United States)

Hori, Yasuki; Naitoh, Itaru; Hayashi, Kazuki; Ban, Tesshin; Natsume, Makoto; Okumura, Fumihiro; Nakazawa, Takahiro; Takada, Hiroki; Hirano, Atsuyuki; Jinno, Naruomi; Togawa, Shozo; Ando, Tomoaki; Kataoka, Hiromi; Joh, Takashi

2017-10-01

Endoscopic metallic stenting is widely accepted as a palliation therapy for malignant gastric outlet obstruction (GOO). However, the predictors of stent dysfunction have not been clarified. We aimed to evaluate the predictors, especially tumor ingrowth in uncovered self-expandable metallic stents (U-SEMS) and migration of covered self-expandable metallic stents (C-SEMS), which are the main causes related to the stent characteristics. In this multicenter retrospective study, we compared patients with U-SEMS and C-SEMS in terms of clinical outcomes, and predictors of stent dysfunction. In total, 252 patients (126 with U-SEMS and 126 with C-SEMS) were enrolled. There were no significant differences in technical success, clinical success, GOO score, or time to stent dysfunction. Tumor ingrowth was significantly more frequent in U-SEMS (U-SEMS, 11.90% vs. C-SEMS, 0.79%; p = 0.002), and stent migration was significantly more frequent for C-SEMS (C-SEMS, 8.73% vs. U-SEMS, 0.79%; p = 0.005). Karnofsky performance status (p = 0.04), no presence of ascites (p = 0.02), and insufficient (stent expansion (p = 0.003) were significantly associated with tumor ingrowth in U-SEMS. Meanwhile, a shorter stent length (p = 0.05) and chemotherapy (p = 0.03) were predictors of C-SEMS migration. Both U-SEMS and C-SEMS are effective with comparable patencies. Tumor ingrowth and stent migration are the main causes of stent dysfunction for U-SEMS and C-SEMS, respectively. With regard to stent dysfunction, U-SEMS might be a good option for patients receiving chemotherapy, while C-SEMS with longer stents for patients in good condition. (Clinical trial registration number: UMIN000024059).
Long term results of endovascular treatment in renal arterial stenosis from Takayasu arteritis: Angioplasty versus stent placement

Energy Technology Data Exchange (ETDEWEB)

Park, Hong Suk, E-mail: hongsukpark@gmail.com [Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, 135-710 Seoul (Korea, Republic of); Do, Young Soo, E-mail: ysdo@skku.edu [Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, 135-710 Seoul (Korea, Republic of); Park, Kwang Bo, E-mail: kbjh.park@samsung.com [Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, 135-710 Seoul (Korea, Republic of); Kim, Duk-Kyung, E-mail: dukkyung.kim@samsung.com [Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, 135-710 Seoul (Korea, Republic of); Choo, Sung Wook, E-mail: sw.choo@samsung.com [Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, 135-710 Seoul (Korea, Republic of); Shin, Sung Wook, E-mail: sw88.shin@samsung.com [Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, 135-710 Seoul (Korea, Republic of); Cho, Sung Ki, E-mail: sungkismc@samsung.com [Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, 135-710 Seoul (Korea, Republic of); Hyun, Dongho, E-mail: mesentery.hyun@samsung.com [Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, 135-710 Seoul (Korea, Republic of); Choo, In Wook, E-mail: inwook.choo@samsung.com [Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, 135-710 Seoul (Korea, Republic of)

2013-11-01

Purpose: To retrospectively evaluate and compare the long term patency and antihypertensive effect of angioplasty and stent insertion in renal artery stenosis caused by Takayasu arteritis, with CT angiography and clinical follow-up. Materials and methods: We retrospectively analyzed and compared effects on hypertension and patency of renal artery in 16 patients (age ranging from 16 to 58 years, mean: 32.1 years) with renovascular hypertension caused by Takayasu arteritis who underwent endovascular treatment including angioplasty (n = 13) and stent placement (n = 9) for 22 stenotic renal arteries. Results: Technical success was 95% (21/22) without major complications. In the last follow-up CT angiogram (mean 85 ± 41 months), restenosis was 8% (1/12) in angioplasty and 66% (6/9) in stent. Patency rates of angioplasty were 100%, 91.7%, 91.7% and primary unassisted and primary assisted patency rates of stent placement were 55.6%, 33.3%, 33.3% and 88.9%, 66.7%, 55.6% at 1-, 3- and 5-years, respectively. In clinical follow-up (mean 120 ± 37.8 months, range 48–183 months), beneficial effects on hypertension were obtained in 87% of patients (13/15) and there was no significant difference between the patients who were treated by only angioplasty and the patients who received stent placement in at least one renal artery, regardless of whether or not angioplasty had been performed in the other renal artery. Conclusion: Compared with stent placement, angioplasty demonstrated better long term patency and similar clinical benefit on renovascular hypertension in renal artery stenosis of Takayasu arteritis. We suggest that stent placement should be reserved for obvious angioplasty failure.
Stenting in the treatment of acute ischemic stroke: literature review.

Directory of Open Access Journals (Sweden)

Edgar A Samaniego

2011-12-01

Full Text Available Recanalization of acute large artery occlusions is a strong predictor of good outcome. The development of thrombectomy devices resulted in a significant improvement in recanalization rates compared to thrombolytics alone. However, clinical trials and registries with these thrombectomy devices in acute ischemic stroke (AIS have shown recanalization rates in the range of 40-81%. The last decade has seen the development of nickel titanium self-expandable stents (SES. These stents, in contrast to balloon-mounted stents, allow better navigability and deployment in tortuous vessels and therefore are optimal for the cerebral circulation. SES were initially used for stent-assisted coil embolization of intracranial aneurysms and for treatment of intracranial stenosis. However, a few authors have recently reported feasibility of deployment of SES in AIS. The use of these devices yielded higher recanalization rates compared to traditional thrombectomy devices. Encouraged by these results, retrievable SES systems have been recently used in AIS. These devices offer the advantage of resheathing and retrieving of the stent even after full deployment. Some of these stents can also be detached in case permanent stent placement is needed. Retrievable SES are being used in Europe and currently tested in clinical trials in the United States. We review the recent literature in the use of stents for the treatment of AIS secondary to large vessel occlusion.
One Year Clinical Outcomes of Renal Artery Stenting: The Results of ODORI Registry

International Nuclear Information System (INIS)

Sapoval, M.; Tamari, I.; Goffette, P.; Downes, M.; Senechal, Q.; Fanelli, F.; Reimer, P.; Negaiwi, Z.; Cassin, P. De; Heye, S.; Korobov, V.; Tsetis, D.; Abada, H.

2010-01-01

The safety, efficacy and long term clinical benefits of renal artery revascularization by stenting are still a matter of debate. The aim of our study was to define the safety and efficacy of renal artery stenting with the Tsunami peripheral stent (Terumo Corporation, Tokyo, Japan). The ODORI was a prospective, multicentre registry which enrolled 251 consecutive patients, (276 renal arteries) in 36 centres across Europe. The primary endpoint was acute procedural success defined as <30% residual stenosis after stent placement. Secondary endpoints included major adverse events, blood pressure control, serum creatinine level, and target lesion revascularization (TLR) at 6 and 12 months. Patients were 70 ± 10 years old, 59% were male, 33% had diabetes, and 96% hypertension. The main indications for renal stent implantation were hypertension in 83% and renal salvage in 39%. Direct stent implantation was performed in 76% of the cases. Acute success rate was 100% with residual stenosis of 2.5 ± 5.4%. Systolic/diastolic blood pressure decreased from a mean of 171/89 at baseline to 142/78 mmHg at 6 months (p < 0.0001 vs. baseline), and 141/80 mmHg at 12 months (p < 0.0001 vs. baseline). Mean serum creatinine concentration did not change significantly in the total population. However, there was significant improvement in the highest tercile (from 283 μmol/l at baseline to 205 and 209 μmol/l at 6 and 12 months respectively). At 12-months, rates of restenosis and TLR were 6.6 and 0.8% respectively. The 12 month cumulative rate of all major clinical adverse events was 6.4% while the rate of device or procedure related events was 2.4%. In hypertensive patients with atherosclerotic renal artery stenosis Tsunami peripheral balloon-expandable stent provides a safe revascularization strategy, with a potential beneficial impact on hypertension control and renal function in the highest risk patients.
Insertion of Self-Expandable Nitinol Stents Without Previous Balloon Angioplasty Reduces Restenosis Compared with PTA Prior to Stenting

International Nuclear Information System (INIS)

Harnek, Jan; Zoucas, Evita; Stenram, Unne; Cwikiel, Wojciech

2002-01-01

Purpose: To compare the development of intimal hyperplasia after deployment of a self-expanding nitinol stent with and without previous percutaneous transluminal balloon angioplasty (PTA), with the results after PTA alone. Methods: In nine healthy pigs, the iliac arteries were divided into three groups: group 1 (n = 6 arteries) was treated with PTA; group 2 n 6)with insertion of self-expanding stents after PTA; and group 3 (n = 6) with stent insertion without previous PTA. After 8 weeks the vessels were examined with intravascular ultrasonography,histologic examination and morphometric analysis. Results: Although the injury index in group 1 (0.17± 0.57) was lower (p <0.05) than in group 2 (0.26 ± 0.06) and group 3 (0.26 ± 0.08), PTA-treated arteries showed significantly (p <0.05) reduced mean luminal gain (0.53 ± 2.84) compared with arteries treated with PTA prior to stenting (2.58 ± 1.38) and compared with stenting alone (4.65 ±5.34). Stenting after PTA resulted in a higher (p<0.05) restenosis index (2.63 ± 1.06) compared with stenting without PTA (1.35 ± 0.59). Group 2 also had a significantly thicker intimap <0.05) and 83% and 74% higher intima/mediaratio (p <0.05) compared with groups 1 and 3, respectively. Conclusion: Insertion of a self-expandable nitinol stent without previous PTA results in less intimalhyperplasia than if PTA is performed prior to stenting, suggesting that direct stenting can be used in angioplasty sessions with a favorable outcome
Endothelial cell repopulation after stenting determines in-stent neointima formation: effects of bare-metal vs. drug-eluting stents and genetic endothelial cell modification.

Science.gov (United States)

Douglas, Gillian; Van Kampen, Erik; Hale, Ashley B; McNeill, Eileen; Patel, Jyoti; Crabtree, Mark J; Ali, Ziad; Hoerr, Robert A; Alp, Nicholas J; Channon, Keith M

2013-11-01

Understanding endothelial cell repopulation post-stenting and how this modulates in-stent restenosis is critical to improving arterial healing post-stenting. We used a novel murine stent model to investigate endothelial cell repopulation post-stenting, comparing the response of drug-eluting stents with a primary genetic modification to improve endothelial cell function. Endothelial cell repopulation was assessed en face in stented arteries in ApoE(-/-) mice with endothelial-specific LacZ expression. Stent deployment resulted in near-complete denudation of endothelium, but was followed by endothelial cell repopulation, by cells originating from both bone marrow-derived endothelial progenitor cells and from the adjacent vasculature. Paclitaxel-eluting stents reduced neointima formation (0.423 ± 0.065 vs. 0.240 ± 0.040 mm(2), P = 0.038), but decreased endothelial cell repopulation (238 ± 17 vs. 154 ± 22 nuclei/mm(2), P = 0.018), despite complete strut coverage. To test the effects of selectively improving endothelial cell function, we used transgenic mice with endothelial-specific overexpression of GTP-cyclohydrolase 1 (GCH-Tg) as a model of enhanced endothelial cell function and increased NO production. GCH-Tg ApoE(-/-) mice had less neointima formation compared with ApoE(-/-) littermates (0.52 ± 0.08 vs. 0.26 ± 0.09 mm(2), P = 0.039). In contrast to paclitaxel-eluting stents, reduced neointima formation in GCH-Tg mice was accompanied by increased endothelial cell coverage (156 ± 17 vs. 209 ± 23 nuclei/mm(2), P = 0.043). Drug-eluting stents reduce not only neointima formation but also endothelial cell repopulation, independent of strut coverage. In contrast, selective targeting of endothelial cell function is sufficient to improve endothelial cell repopulation and reduce neointima formation. Targeting endothelial cell function is a rational therapeutic strategy to improve vascular healing and decrease neointima formation after stenting.

Advantages of novel BioMimeTM Sirolimus Eluting Coronary Stent system. Moving towards biomimicry.

Science.gov (United States)

Upendra, K; Sanjeev, B

2012-02-01

Since the first reported use of percutaneous transluminal coronary angioplasty (PTCA), advancements in interventional cardiology arena have been fast paced. Within the last ten years, these developments have been exponential. Developers & clinicians are fast adapting from the learning curve awarded by the time course of DES evolution. In that light BioMimeTM Sirolimus Eluting Coronary Stent comes as a fresh thought in taking stents towards a biomimicry concept. The stent is built on an ultra-low strut thickness (65 µm) cobalt chromium stent platform, using an intelligent hybrid of close and open cells allowing for morphology mediated expansion, employs a well known anti-proliferative - Sirolimus that elutes from a biodegradable co-polymer formulation in 30 days and ensures high coating integrity and low coating thickness of 2 µm. The resultant stent demonstrates almost 100% endothelialization at 30 days in preclinical model and zero percent MACE >18 months in the primary efficacy and safety clinical study.
Recurrence of Subacute Stent Thrombosis and In-Stent Restenosis during Five Months after Stent Implantation in the LAD. A Case Report.

OpenAIRE

島田, 弘英; 大和, 眞史; 櫻井, 俊平; 疋田, 博之; 池田, 修一

2001-01-01

A coronary stent was deployed in the left anterior descending artery of an 82-year-old woman with unstable angina.Recurrence of subacute stent thrombosis and in-stent restenosis occurred frequently during the five months after initial stent implantation.Balloon angioplasty and cutting balloon angioplasty failed to prevent these complications,but they ceased after re-stenting in the initial stent.In this case,tissue protrusion through the stent strut, deformation of the coil stent and inadequa...
MRT of carotid stents: influence of stent properties and sequence parameters on visualization of the carotid artery lumen

International Nuclear Information System (INIS)

Straube, T.; Wolf, S.; Alfke, K.; Jansen, O.; Flesser, A.; Deli, M.; Nabavi, A.

2005-01-01

Purpose: To evaluate MR artifacts of carotid artery stents and to optimize stent properties and sequence parameters. Material and Methods: Four carotid artery stents - Wallstent (mediloy), Precise (nitinol), ACCULINK (nitinol) and a stent prototype (nitinol) - were investigated in a flow model of the cervical vessels. The model was made of silicon tubing and a flow pump that produces realistic flow curves of the carotid artery. To investigate the effects of magnetic susceptibility and radiofrequency induced shielding artifacts, turbo spin echo and gradient echo sequences as well as CE-MRAs were measured. To improve the visualization of the stent lumen in a CE-MRA, flip angle as well as geometry and covering of the stent prototype were altered. Results: Susceptibility artifacts in stents of the carotid artery only influence the lumen visualization at the proximal and distal end of the braided mediloy stent. A change of stent coverings has no significant influence on radiofrequency artifacts, whereas a reduction in linking elements between stent segments and a change in diameter of stent struts improves visualization of the stent lumen. By increasing the flip angle in a CE-MRA, visualization of the stent lumen is possible in both mediloy and nitinol stents. Conclusion: The choice of stent material and changes in stent geometry as well as the optimization of the flip angle of the CE-MRA may reduce susceptibility and radiofrequency artifacts, rendering feasible the CE-MRA of a stented carotid artery. (orig.)
Short-term results of self-expanding metal stents for acute malignant large bowel obstruction

DEFF Research Database (Denmark)

Kobborg, M; Broholm, M; Frostberg, E

2017-01-01

AIM: Self-expanding metal stents (SEMSs) can be used as a palliative treatment or to initially decompress colon prior to definitive surgery (as a so-called 'bridge to surgery'). The purpose of this study was to investigate the efficacy and safety of SEMS used as palliation and bridge to surgery...... for malignant large bowel obstruction. METHOD: A multicentre retrospective study was conducted from January 2010 to December 2013 to identify patients undergoing stent placement for acute large bowel obstruction. Patients were included from four Danish colorectal centres. Outcomes identified included clinical...... success, 30-day mortality, stent related complications and surgery related complications. Furthermore, we analysed for predictive factors for successful stenting. Clinical success was defined as relief of obstructive symptoms, without the need of other additional surgical interventions during the hospital...
Endovascular implantation of stent-grafts in the thoracic aorta - mid-term results of a prospective controlled study

International Nuclear Information System (INIS)

Duda, S.H.; Pusich, B.; Tepe, G.; Pereira, P.; Feuls, R.; Claussen, C.D.; Raygrotzki, S.; Aebert, H.; Ziemer, G.; Uckmann, F.P.

2002-01-01

Purpose: To evaluate the effectiveness and safety of endovascular treatment of various descending thoracic aortic pathologies with covered stent-grafts as an alternative to open surgery. Methods: Among 16 patients (5 type B dissections, 5 contained ruptures, 3 aneurysms of the descending aorta, 1 thoraco-abdominal aneurysm, 1 mural thrombosis, 1 patch aneurysm) treated between November 1997 and November 2000, eight patients received Talent TM stent-grafts and another 8 patients underwent a Gore-TAG TM stent-graft implantation. A clinical follow-up and control CT scans were obtained after the procedure and then at six-month intervals. Results: Deployment of the stent-grafts was technically successful in all cases. Sufficient aortic reconstruction was achieved in all but one patient who needed surgical treatment. One patient died two days after the procedure from aortic rupture due to retrograde type A dissection. Another patient died 19 months after the procedure from an unknown cause. There was no occurrence of distal embolization, paralysis or infection. During follow-up, all patients remained free from recurrence or late complications of their disease. Conclusion: Endoluminal treatment of thoracic aortic pathologies with covered stent-grafts appears to be a safe and feasible method with at least mid-term efficacy. (orig.) [de
Influence of a pressure gradient distal to implanted bare-metal stent on in-stent restenosis after percutaneous coronary intervention

DEFF Research Database (Denmark)

Jensen, Lisette Okkels; Thayssen, Per; Thuesen, Leif

2007-01-01

pullback recording in the entire length of the artery. METHODS AND RESULTS: In 98 patients with angina pectoris, 1 de novo coronary lesion was treated with a bare-metal stent. After stent implantation, pressure wire measurements (P(d)=mean hyperemic coronary pressure and P(a)=mean aortic pressure) were......-stent restenosis after 9 months. CONCLUSIONS: A residual abnormal P(d)/P(a) distal to a bare-metal stent was an independent predictor of in-stent restenosis after implantation of a coronary bare-metal stent. Udgivelsesdato: 2007-Dec-11......BACKGROUND: Fractional flow reserve predicts cardiac events after coronary stent implantation. The aim of the present study was to assess the 9-month angiographic in-stent restenosis rate in the setting of optimal stenting and a persisting gradient distal to the stent as assessed by a pressure wire...
StentBoost Visualization for the Evaluation of Coronary Stent Expansion During Percutaneous Coronary Interventions

OpenAIRE

Cura, Fernando; Albertal, Mariano; Candiello, Alfonsina; Nau, Gerardo; Bonvini, Victor; Tricherri, Hernan; Padilla, Lucio T.; Belardi, Jorge A.

2013-01-01

Introduction Inadequate stent implantation is associated with stent thrombosis and restenosis. StentBoost can enhance stent visualization and evaluate stent expansion. Currently, there are limited comparison studies between StentBoost and intravascular ultrasound (IVUS). We aimed to test the correlation and agreement between IVUS and StentBoost measurements. Methods From December 2010 to December 2011, 38 patients (54 stents) were analyzed using IVUS and StentBoost. Minimal stent diameter and...
Stent malapposition, as a potential mechanism of very late stent thrombosis after bare-metal stent implantation: A case report

Energy Technology Data Exchange (ETDEWEB)

Higuma, Takumi, E-mail: higuma@cc.hirosaki-u.ac.jp; Abe, Naoki; Hanada, Kenji; Yokoyama, Hiroaki; Tomita, Hirofumi; Okumura, Ken

2014-04-15

A 90-year-old man was admitted to our hospital with acute ST-segment elevation myocardial infarction. He had a history of post-infarction angina pectoris 79 months ago and had a bare-metal stent (BMS) implanted in the proximal left anterior descending artery at our hospital. Emergent coronary angiography demonstrated thrombotic occlusion in the previously stented segment. After catheter thrombectomy, antegrade flow was restored, but 90% stenosis with haziness persisted in the proximal and distal portions of the previously stented segment. Intravascular ultrasound imaging showed interstrut cavities or stent malapposition at the proximal and distal sites of stented segment. In close proximity to the sites, residual thrombi were also observed. Optical coherence tomography (OCT) demonstrated neither lipid-laden neointimal tissue nor rupture but clearly demonstrated residual thrombus adjacent to the malapposed region in addition to the stent malapposition. PCI with balloon was successfully performed and stent apposition was confirmed by OCT. Stent malapposition is an unusual mechanism of very late stent thrombosis after BMS implantation. OCT can clearly reveal the etiology of stent thrombosis.
Incidence of definite stent thrombosis or in-stent restenosis after drug-eluting stent implantation for treatment of coronary in-stent restenosis. From western denmark heart registry

DEFF Research Database (Denmark)

Jensen, Jesper; Jensen, Lisette Okkels; Terkelsen, Christian Juhl

2012-01-01

There are limited data on the optimal management of in-stent restenosis after percutaneous coronary intervention (PCI) with bare metal stent (BMS) or drug-eluting stent (DES) implantations. We assessed the clinical presentation, the incidence, and prognosis of definite stent thrombosis...
Magnetizable stent-grafts enable endothelial cell capture

Energy Technology Data Exchange (ETDEWEB)

Tefft, Brandon J. [Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN (United States); Uthamaraj, Susheil [Division of Engineering, Mayo Clinic, Rochester, MN (United States); Harburn, J. Jonathan [School of Medicine, Pharmacy and Health, Durham University, Stockton-on-Tees (United Kingdom); Hlinomaz, Ota [Department of Cardioangiology, St. Anne' s University Hospital, Brno (Czech Republic); Lerman, Amir [Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN (United States); Dragomir-Daescu, Dan [Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN (United States); Sandhu, Gurpreet S., E-mail: sandhu.gurpreet@mayo.edu [Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN (United States)

2017-04-01

Emerging nanotechnologies have enabled the use of magnetic forces to guide the movement of magnetically-labeled cells, drugs, and other therapeutic agents. Endothelial cells labeled with superparamagnetic iron oxide nanoparticles (SPION) have previously been captured on the surface of magnetizable 2205 duplex stainless steel stents in a porcine coronary implantation model. Recently, we have coated these stents with electrospun polyurethane nanofibers to fabricate prototype stent-grafts. Facilitated endothelialization may help improve the healing of arteries treated with stent-grafts, reduce the risk of thrombosis and restenosis, and enable small-caliber applications. When placed in a SPION-labeled endothelial cell suspension in the presence of an external magnetic field, magnetized stent-grafts successfully captured cells to the surface regions adjacent to the stent struts. Implantation within the coronary circulation of pigs (n=13) followed immediately by SPION-labeled autologous endothelial cell delivery resulted in widely patent devices with a thin, uniform neointima and no signs of thrombosis or inflammation at 7 days. Furthermore, the magnetized stent-grafts successfully captured and retained SPION-labeled endothelial cells to select regions adjacent to stent struts and between stent struts, whereas the non-magnetized control stent-grafts did not. Early results with these prototype devices are encouraging and further refinements will be necessary in order to achieve more uniform cell capture and complete endothelialization. Once optimized, this approach may lead to more rapid and complete healing of vascular stent-grafts with a concomitant improvement in long-term device performance. - Highlights: • Magnetic stent-grafts were made from 2205 steel stents and polyurethane nanofibers. • Stent-grafts remained patent and formed a thin and uniform neointima when implanted. • Stent-grafts captured endothelial cells labeled with magnetic nanoparticles. �
Safety and efficacy of everolimus-eluting stents for bare-metal in-stent restenosis

Energy Technology Data Exchange (ETDEWEB)

Ota, Hideaki [Division of Interventional Cardiology, MedStar Washington Hospital Center, Washington, DC 20010 (United States); Mahmoudi, Michael [University of Surrey, Guildford Road, Surrey, GU2-7XH (United Kingdom); Torguson, Rebecca; Satler, Lowell F.; Suddath, William O.; Pichard, Augusto D. [Division of Interventional Cardiology, MedStar Washington Hospital Center, Washington, DC 20010 (United States); Waksman, Ron, E-mail: ron.waksman@medstar.net [Division of Interventional Cardiology, MedStar Washington Hospital Center, Washington, DC 20010 (United States)

2015-04-15

Objective: The aim of this study was to compare the safety and efficacy of the everolimus-eluting stents (EES) with the paclitaxel-eluting stent (PES) and sirolimus-eluting stent (SES) for the treatment of bare-metal in-stent restenosis. Background: The optimal treatment for bare-metal in-stent restenosis remains controversial. Methods: The study cohort comprised 322 consecutive patients (543 lesions) who presented with bare-metal in-stent restenosis to our institution and underwent coronary artery stent implantation with EES (114 patients; 181 lesions), PES (65 patients; 116 lesions) and SES (143 patients; 246 lesions). The analyzed clinical parameters were the 1-year rates of death, Q-wave myocardial infarction (MI), target lesion revascularization (TLR), target vessel revascularization (TVR), definite stent thrombosis (ST) and major adverse cardiac events (MACE) defined as the composite of death, MI, or TLR at 1-year. Results: The three groups were well matched for the conventional risk factors except for age and chronic kidney disease. The 1-year analyzed clinical parameters were similar in the three groups: death (EES = 3.5%, PES = 4.6%, SES = 4.2%; p = 0.94), MI (EES = 3.5%, PES = 6.3%, SES = 2.1%; p = 0.31), TLR (EES = 9.8%, PES = 9.5%, SES = 5.7%; p = 0.42), TVR (EES = 14.3%, PES = 11.1%, SES = 11.3%; p = 0.74), definite ST (EES = 0.9%, PES = 3.1%, SES = 3.5%; p = 0.38) and MACE (EES = 14.0%, PES = 15.4%, SES = 10.5%; p = 0.54). Male gender (hazard ratio = 0.47; 95% confidence interval = 0.25–0.88) and number of treated lesions (hazard ratio = 1.47; 95% confidence interval = 1.06–2.05) were found to be independent predictors of MACE. Conclusion: The results of the present study indicate that EES may provide similar safety and efficacy as first generation DES for the treatment of patients presenting with bare-metal in-stent restenosis.
Stent Thrombosis is the Primary Cause of ST-Segment Elevation Myocardial Infarction following Coronary Stent Implantation

DEFF Research Database (Denmark)

Kristensen, Søren Lund; Galløe, Anders M; Thuesen, Leif

2014-01-01

Background: The widespread use of coronary stents has exposed a growing population to the risk of stent thrombosis, but the importance in terms of risk of ST-segment elevation myocardial infarctions (STEMIs) remains unclear. Methods: We studied five years follow-up data for 2,098 all-comer patients...... treated with coronary stents in the randomized SORT OUT II trial (mean age 63.6 yrs. 74.8% men). Patients who following stent implantation were readmitted with STEMI were included and each patient was categorized ranging from definite-to ruled-out stent thrombosis according to the Academic Research...... Consortium definitions. Multivariate logistic regression was performed on selected covariates to assess odds ratios (ORs) for definite stent thrombosis. Results: 85 patients (4.1%), mean age 62.7 years, 77.1% men, were admitted with a total of 96 STEMIs, of whom 60 (62.5%) had definite stent thrombosis...
Removal of retrievable self-expandable urethral stents: experience in 58 stents

International Nuclear Information System (INIS)

Shin, Ji Hoon; Song, Ho-Young; Kim, Jin Hyoung; Ko, Heung-Kyu; Kim, Yong Jae; Woo, Chul-Woong; Kim, Tae-Hyung; Ko, Gi-Young; Yoon, Hyun-Ki; Sung, Kyu-Bo; Park, Hyungkeun

2006-01-01

The purpose of this study was to retrospectively evaluate the safety and efficacy of removing retrievable self-expandable urethral stents using a retrieval hook wire. Under fluoroscopic guidance, the removal of 58 polyurethane or PTFE (polytetrafluoroethylene)-covered stents was attempted in 33 patients using a retrieval hook wire. Indications for removal were elective removal (n=21), stent migration (n=19), formation of tissue hyperplasia around or inside of the stent (n=14), stent deformity (n=3), and severe pain (n=1). The mean time the stents remained in place was 64.8±42.9 days (range, 1-177 days). Fifty-six (97%) of the 58 stents were successfully removed using the retrieval hook wire despite the following difficulties; hook wire disconnection (n=2), untied drawstrings (n=3), and polyurethane membrane disruption/separation (n=4). The removal procedure using a retrieval hook wire failed in two stents (3%) which had migrated into the urinary bladder. One of the two stents with migration into the urinary bladder was removed using a snare through the cystostomy route. The overall complication rate was 14% (seven hematuria cases and one urethral tear case), and all were minor and spontaneously resolved without further treatment. In conclusion, removal of retrievable urethral stents using a retrieval hook wire was safe and effective despite some technical difficulties. It is a useful method for allowing temporary stent placement and solving various complications of stent use. (orig.)
Removal of retrievable self-expandable urethral stents: experience in 58 stents

Energy Technology Data Exchange (ETDEWEB)

Shin, Ji Hoon; Song, Ho-Young; Kim, Jin Hyoung; Ko, Heung-Kyu; Kim, Yong Jae; Woo, Chul-Woong; Kim, Tae-Hyung; Ko, Gi-Young; Yoon, Hyun-Ki; Sung, Kyu-Bo [Asan Medical Center, Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Seoul (Korea); Park, Hyungkeun [Asan Medical Center, Department of Urology, University of Ulsan College of Medicine, Seoul (Korea)

2006-09-15

The purpose of this study was to retrospectively evaluate the safety and efficacy of removing retrievable self-expandable urethral stents using a retrieval hook wire. Under fluoroscopic guidance, the removal of 58 polyurethane or PTFE (polytetrafluoroethylene)-covered stents was attempted in 33 patients using a retrieval hook wire. Indications for removal were elective removal (n=21), stent migration (n=19), formation of tissue hyperplasia around or inside of the stent (n=14), stent deformity (n=3), and severe pain (n=1). The mean time the stents remained in place was 64.8{+-}42.9 days (range, 1-177 days). Fifty-six (97%) of the 58 stents were successfully removed using the retrieval hook wire despite the following difficulties; hook wire disconnection (n=2), untied drawstrings (n=3), and polyurethane membrane disruption/separation (n=4). The removal procedure using a retrieval hook wire failed in two stents (3%) which had migrated into the urinary bladder. One of the two stents with migration into the urinary bladder was removed using a snare through the cystostomy route. The overall complication rate was 14% (seven hematuria cases and one urethral tear case), and all were minor and spontaneously resolved without further treatment. In conclusion, removal of retrievable urethral stents using a retrieval hook wire was safe and effective despite some technical difficulties. It is a useful method for allowing temporary stent placement and solving various complications of stent use. (orig.)
Endoscopic bilateral stent-in-stent placement for malignant hilar obstruction using a large cell type stent.

Science.gov (United States)

Park, Jin Myung; Lee, Sang Hyub; Chung, Kwang Hyun; Jang, Dong Kee; Ryu, Ji Kon; Kim, Yong-Tae; Lee, Jae Min; Paik, Woo Hyun

2016-12-01

Bilateral stent-in-stent (SIS) self-expandable metal stent placement is technically challenging for palliation of unresectable malignant hilar obstruction. In the SIS technique, the uniform large cell type biliary stent facilitates contralateral stent deployment through the mesh of the first metallic stent. This study aimed to assess the technical success and clinical effectiveness of this technique with a uniform large cell type biliary stent. Thirty-one patients who underwent bilateral SIS placement using a large cell type stent were reviewed retrospectively. All patients showed malignant hilar obstruction (Bismuth types II, III, IV) with different etiologies. Sixteen (51.6%) patients were male. The mean age of the patients was 67.0+/-14.0 years. Most patients were diagnosed as having hilar cholangiocarcinoma (58.1%) and gallbladder cancer (29.0%). Technical success rate was 83.9%. Success was achieved more frequently in patients without masses obstructing the biliary confluence (MOC) than those with MOC (95.2% vs 60.0%, P=0.03). Functional success rate was 77.4%. Complications occurred in 29.0% of the patients. These tended to occur more frequently in patients with MOC (50.0% vs 19.0%, P=0.11). Median time to recurrent biliary obstruction was 188 days and median survival was 175 days. The large cell type stent can be used efficiently for bilateral SIS placement in malignant hilar obstruction. However, the risk of technical failure increases in patients with MOC, and caution is needed to prevent complications for these patients.
Stent-assisted coiling of intracranial aneurysms using LEO stents: long-term follow-up in 153 patients.

Science.gov (United States)

Sedat, Jacques; Chau, Yves; Gaudart, Jean; Sachet, Marina; Beuil, Stephanie; Lonjon, Michel

2018-02-01

Coiling associated with placement of a self-expandable intracranial stent has improved the treatment of intracranial wide-necked aneurysms. Little is known, however, about the durability of this treatment. The purpose of this report is to present our experience with the LEO stent and to evaluate the complications, effectiveness, and long-term results of this technique. We analyzed the records of 155 intracranial unruptured aneurysms that were treated by stent-assisted coiling with a LEO stent between 2008 and 2012. Procedural, early post-procedural, and delayed complications were recorded. Clinical and angiographic follow-up of patients was conducted over a period of at least 36 months. No procedural mortality was observed. One-month morbidity was observed in 14 out of 153 patients (9,15%). One hundred thirty-eight patients (with 140 aneurysms) had clinical and angiographic follow-up for more than 36 months. No aneurysm rupture was observed during follow-up. Four patients presented an intra-stent stenosis at 8 months, and 6 patients who had an early recurrence were retreated. Final results showed 85% complete occlusion, 13% neck remnants, and 2% stable incomplete occlusion. Stent-assisted coiling with the LEO stent is a safe and effective treatment for unruptured intracranial aneurysms. The long-term clinical outcomes with the LEO stent are excellent with a high rate of complete occlusion that is stable over time.
A comparative evaluation of early stent occlusion among biliary conventional versus wing stents.

Science.gov (United States)

Khashab, Mouen A; Hutfless, Susan; Kim, Katherine; Lennon, Anne Marie; Canto, Marcia I; Jagannath, Sanjay B; Okolo, Patrick I; Shin, Eun Ji; Singh, Vikesh K

2012-06-01

Conventional plastic stents with a lumen typically have limited patency. The lumenless wing stent was engineered to overcome this problem. The objective of this study was to compare the incidence of early stent occlusion (symptomatic occlusion/cholangitis necessitating re-insertion within 90 days) for wing stents and conventional plastic stents. Patients with biliary pathology treated with plastic biliary stenting during the period 2003-2009 comprised the study cohort. Patients who had at least one biliary wing stent placed comprised the wing stent group, whereas patients who underwent only conventional stent plastic placement comprised the conventional stent group. Patients were stratified by indication: benign biliary strictures (group 1), malignant biliary strictures (group 2), or benign biliary non-stricture pathology (group 3). The association of stent type with the occurrence of primary outcome by indication was analyzed by use of multivariable logistic regression. Three-hundred and forty-six patients underwent 612 ERCP procedures with placement of plastic biliary stent(s). On multivariate analysis, early stent occlusion did not differ between the wing and conventional groups in groups 1, 2, and 3. Among patients who achieved primary outcome in group 2, significantly fewer patients in the wing group had cholangitis (6.7% vs. 39.1%, P = 0.03). Among patients who achieved primary outcome in group 3, significantly fewer patients in the wing group had cholangitis (10% vs. 50%, P = 0.03). Early stent occlusion was similar for wing stents and conventional plastic stents. Wing stents, however, were associated with a lower incidence of cholangitis in patients with malignant biliary obstruction and benign non-stricturing biliary pathology.
Stent Design Affects Femoropopliteal Artery Deformation.

Science.gov (United States)

MacTaggart, Jason; Poulson, William; Seas, Andreas; Deegan, Paul; Lomneth, Carol; Desyatova, Anastasia; Maleckis, Kaspars; Kamenskiy, Alexey

2018-03-23

Poor durability of femoropopliteal artery (FPA) stenting is multifactorial, and severe FPA deformations occurring with limb flexion are likely involved. Different stent designs result in dissimilar stent-artery interactions, but the degree of these effects in the FPA is insufficiently understood. To determine how different stent designs affect limb flexion-induced FPA deformations. Retrievable markers were deployed into n = 28 FPAs of lightly embalmed human cadavers. Bodies were perfused and CT images were acquired with limbs in the standing, walking, sitting, and gardening postures. Image analysis allowed measurement of baseline FPA foreshortening, bending, and twisting associated with each posture. Markers were retrieved and 7 different stents were deployed across the adductor hiatus in the same limbs. Markers were then redeployed in the stented FPAs, and limbs were reimaged. Baseline and stented FPA deformations were compared to determine the influence of each stent design. Proximal to the stent, Innova, Supera, and SmartFlex exacerbated foreshortening, SmartFlex exacerbated twisting, and SmartControl restricted bending of the FPA. Within the stent, all devices except Viabahn restricted foreshortening; Supera, SmartControl, and AbsolutePro restricted twisting; SmartFlex and Innova exacerbated twisting; and Supera and Viabahn restricted bending. Distal to the stents, all devices except AbsolutePro and Innova exacerbated foreshortening, and Viabahn, Supera, Zilver, and SmartControl exacerbated twisting. All stents except Supera were pinched in flexed limb postures. Peripheral self-expanding stents significantly affect limb flexion-induced FPA deformations, but in different ways. Although certain designs seem to accommodate some deformation modes, no device was able to match all FPA deformations.
Robot-assisted laparoscopic pyeloureterostomy in infants with duplex systems and upper pole hydronephrosis: Variations in double-J ureteral stenting techniques.

Science.gov (United States)

Baek, Minki; Au, Jason; Huang, Gene O; Koh, Chester J

2017-04-01

We describe our experience with robot-assisted laparoscopic (RAL) pyeloureterostomy in infants with duplex systems and upper pole hydronephrosis with an emphasis on the various double J (DJ) ureteral stent placement techniques. We used our RAL pyeloureterostomy technique in two female infants with duplex systems and upper pole hydronephrosis. For case 1, we introduced the DJ stent and placed it in the recipient lower pole ureter during the robotic operation in an antegrade fashion. For case 2, we inserted the DJ stent during retrograde pyelography prior to the robotic procedure in a retrograde fashion, and the proximal portion of the stent was placed across the anastomosis into the upper pole renal pelvis. Postoperatively, each of the patients were discharged on postoperative day 1 without complications. The postoperative renal ultrasound at 3 months demonstrated marked improvement of the right upper pole hydronephrosis in both patients. RAL pyeloureterostomy represents a minimally invasive option for upper tract reconstruction of duplex systems with upper pole hydronephrosis in infants. The DJ stent can be placed at the beginning or during the procedure. The stent can be placed in the lower pole ureter or across the anastomosis into the upper pole renal pelvis. Copyright © 2017 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.
Coronary and peripheral stenting in aorto-ostial protruding stents: The balloon assisted access to protruding stent technique.

Science.gov (United States)

Helmy, Tarek A; Sanchez, Carlos E; Bailey, Steven R

2016-03-01

Treatment of aorto-ostial in-stent restenosis lesions represents a challenge for interventional cardiologists. Excessive protrusion of the stent into the aorta may lead to multiple technical problems, such as difficult catheter reengagement of the vessel ostium or inability to re-wire through the stent lumen in repeat interventions. We describe a balloon assisted access to protruding stent technique in cases where conventional coaxial engagement of an aorto-ostial protruding stent with the guide catheter or passage of the guide wire through the true lumen is not feasible. This technique is applicable both in coronary and peripheral arteries. © 2015 Wiley Periodicals, Inc.

2-year clinical outcomes after implantation of sirolimus-eluting, paclitaxel-eluting, and bare-metal coronary stents: results from the WDHR (Western Denmark Heart Registry)

DEFF Research Database (Denmark)

Kaltoft, Anne; Jensen, Lisette Okkels; Maeng, Michael

2009-01-01

OBJECTIVES: This registry study assessed the safety and efficacy of the 2 types of drug-eluting stents (DES), sirolimus-eluting stents (SES) and paclitaxel-eluting stents (PES), compared with bare-metal stents (BMS). BACKGROUND: Drug-eluting stents may increase the risk of stent thrombosis (ST...... databases. We used Cox regression analysis to control for confounding. RESULTS: The 2-year incidence of definite ST was 0.64% in BMS patients, 0.79% in DES patients (adjusted relative risk [RR]: 1.09; 95% confidence interval [CI]: 0.72 to 1.65), 0.50% in SES patients (adjusted RR: 0.63, 95% CI: 0.35 to 1...
Magnetizable stent-grafts enable endothelial cell capture

Science.gov (United States)

Tefft, Brandon J.; Uthamaraj, Susheil; Harburn, J. Jonathan; Hlinomaz, Ota; Lerman, Amir; Dragomir-Daescu, Dan; Sandhu, Gurpreet S.

2017-04-01

Emerging nanotechnologies have enabled the use of magnetic forces to guide the movement of magnetically-labeled cells, drugs, and other therapeutic agents. Endothelial cells labeled with superparamagnetic iron oxide nanoparticles (SPION) have previously been captured on the surface of magnetizable 2205 duplex stainless steel stents in a porcine coronary implantation model. Recently, we have coated these stents with electrospun polyurethane nanofibers to fabricate prototype stent-grafts. Facilitated endothelialization may help improve the healing of arteries treated with stent-grafts, reduce the risk of thrombosis and restenosis, and enable small-caliber applications. When placed in a SPION-labeled endothelial cell suspension in the presence of an external magnetic field, magnetized stent-grafts successfully captured cells to the surface regions adjacent to the stent struts. Implantation within the coronary circulation of pigs (n=13) followed immediately by SPION-labeled autologous endothelial cell delivery resulted in widely patent devices with a thin, uniform neointima and no signs of thrombosis or inflammation at 7 days. Furthermore, the magnetized stent-grafts successfully captured and retained SPION-labeled endothelial cells to select regions adjacent to stent struts and between stent struts, whereas the non-magnetized control stent-grafts did not. Early results with these prototype devices are encouraging and further refinements will be necessary in order to achieve more uniform cell capture and complete endothelialization. Once optimized, this approach may lead to more rapid and complete healing of vascular stent-grafts with a concomitant improvement in long-term device performance.
Directional atherectomy for treatment of restenosis within coronary stents: clinical, angiographic and histologic results

NARCIS (Netherlands)

B.H. Strauss (Bradley); V.A.W.M. Umans (Victor); R-J. van Suylen (Robert-Jan); P.J. de Feyter (Pim); J. Marco (Jean); G. Robertson; J. Renkin; G.R. Heyndrickx (Guy); V.D. Vuzevski (Vojislav); F.T.B. Bosman (Fré); P.W.J.C. Serruys (Patrick)

1992-01-01

textabstractAbstract OBJECTIVES: The safety and long-term results of directional coronary atherectomy in stented coronary arteries were determined. In addition, tissue studies were performed to characterize the development of restenosis. METHODS: Directional coronary atherectomy was performed in
Endoscopic stenting for common bile duct stenoses in chronic pancreatitis: results and impact on long-term outcome.

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Eickhoff, A; Jakobs, R; Leonhardt, A; Eickhoff, J C; Riemann, J F

2001-10-01

The overall incidence of common bile duct strictures due to chronic pancreatitis is reported to be approximately 10-30%. It remains a challenging problem for gastroenterologists and surgeons. The exact role of endoscopic stenting has not yet been clearly defined. Thirty-nine patients with chronic pancreatitis and symptomatic common bile duct stenoses underwent endoscopic stenting and were studied retrospectively. We were particularly interested in how many patients would achieve resolution of the stricture and tolerate removal of the stents in the long term. Indications for endoscopic stenting were symptomatic cholestasis, jaundice or cholangitis. The initial serum bilirubin was 8.3 mg/dl and the diameter of the common bile duct was 14.2 mm before stenting. Within 3-7 days of stenting, all patients presented improvement of jaundice and cholestasis. After a median stenting time of 9 months (range 1-144 months), 46% of the patients demonstrated regression of the stricture and clinical improvement, 26% required further stenting, and 28% were referred to surgery. Five patients received a self-expandable metal Wallstent. Thirty-one per cent demonstrated complete clinical recovery of the stricture as well as 10.2% a complete, radiologically verified stricture regression in a median follow-up of 58 months. There seems to be a therapeutic benefit for short-term endoscopic treatment but medium-term and long-term outcome remains questionable. Endoscopic stenting should be applied as an initial therapy before surgery, but it can be the definitive approach for older and morbid patients or cases with complete stricture regression after stent removal. Overall, it should not be considered as a routine procedure for symptomatic cases.
Biomechanical analysis on stent materials used as cardiovascular implants

Science.gov (United States)

Kumar, Vasantha; Ramesha, C. M.; Sajjan, Sudheer S.

2018-04-01

Atherosclerosis is the most common cause of death in the world, accounting for 48% of all deaths in the world. Atherosclerosis, also known as coronary artery disease occurs when excess cholesterol attaches itself to the walls of blood vessels. Coronary stent implantation is one of the most important procedures to treating coronary artery disease such atherosclerosis. Due to its efficiency, flexibility and simplicity, the use of coronary stents procedures has increased rapidly. In order to have better output of stent implantation, it is needed to study and analyze the biomechanical behavior of this device before manufacturing and put into use. Biomaterials are commonly used for medical application in cardiovascular stent implantation. A biomaterial is a non-viable material used as medical implant, so it is intended to interact with biological system. In this paper, an explicit dynamic analysis is used for analyzing the biomechanical behavior of cardiovascular stent by using finite element analysis tool, ABAQUS 6.10. Results showed that a best suitable biomaterial for cardiovascular stent implants, which exhibits an outstanding biocompatibility and biomechanical characteristics will be aimed at which will be quite useful to the human beings worldwide.
Influence of covered stent versus bare stent on long-term efficacy of transjugular intrahepatic portosystemic shunt: a meta-analysis

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XU Lu

2016-10-01

Full Text Available Objective To investigate the long-term postoperative efficacy of transjugular intrahepatic portosystemic shunt (TIPS using polytetrafluoroethylene (PTFE-covered stent or bare stent, and to provide a basis of evidence-based medicine for the selection of stent in TIPS. Methods CBM, Wanfang Data, CNKI, VIP, MEDLINE, and PubMed were searched for controlled trials on TIPS in the treatment of cirrhotic portal hypertension published form 1989 to 2015; the studies which met the inclusion criteria were selected, and quality assessment was performed for these articles. RevMan 5.3 software was used to analyze the incidence rates of stent dysfunction and hepatic encephalopathy and 1-year survival rate after TIPS, and funnel plots were used to analyze publication bias. Results A total of 11 studies were included, consisting of 698 patients in PTFE-covered stent group and 1283 patients in bare stent group. The results of the meta-analysis showed that the PTFE-covered stent group showed a significantly lower incidence rate of stent dysfunction than the bare stent group (14.8% vs 47.0%, OR=0.18, 95% CI: 0.13-0.24, P＜0.001. There was no significant difference in the incidence rate of hepatic encephalopathy between the two groups (23.5% vs 25.7%, OR=0.88, 95% CI: 0.66-1.17, P=0.37. The PTFE-covered stent group had a significantly higher 1-year survival rate than the bare stent group (76.9% vs 62.7%, OR=2.10, 95% CI: 1.54-2.85, P＜0.001. The funnel plots which were plotted based on the incidence rates of stent dysfunction and hepatic encephalopathy and 1-year survival rate lacked symmetry, which suggested that a certain degree of publication bias might exist. Conclusion Compared with the bare stent, the PTFE-covered stent can improve stent dysfunction and 1-year survival rate after TIPS, while there is no significant change in the incidence rate of hepatic encephalopathy. Therefore, the PTFE-covered stent has certain advantages over the bare stent in TIPS. In
Microvascular stent anastomosis using N-fibroin stents: feasibility, ischemia time, and complications.

Science.gov (United States)

Smeets, Ralf; Vorwig, Oliver; Wöltje, Michael; Gaudin, Robert; Luebke, Andreas M; Beck-Broichsitter, Benedicta; Rheinnecker, Michael; Heiland, Max; Grupp, Katharina; Gröbe, Alexander; Hanken, Henning

2016-05-01

To evaluate a novel microvascular anastomosis technique using N-fibroin stents. Cylinder stents of 1 mm diameter and 5 mm length were fabricated using N-fibroin from silkworms. In 22 rats, aortas were dissected, and the stent was inserted into the two ends of the aorta and fixed using methylmethacrylate. Stent anastomosis was successful in 21 (96%) rats. The mean ischemia time was 7.4 minutes, significantly shorter than the 15.9 minutes in the control group with conventional sutures (P stent anastomosis cases, and marked host rejection was evident at the stent anastomosis sites. Around the stents, thrombi were frequent (52%). Our study demonstrated the basic feasibility of stent anastomosis using N-fibroin stents and reduced ischemia time. However, thrombus formation, frequent and severe abdominal infections, and heavy host rejection remain critical issues. Copyright © 2016 Elsevier Inc. All rights reserved.
Carotid angioplasty and stenting under protection. Techniques, results and limitations.

Science.gov (United States)

Henry, M; Polydorou, A; Henry, I; Anagnostopoulou, I S; Polydorou, I A; Hugel, M

2006-10-01

A carotid stenosis is responsible for about 30% of strokes occurring. Carotid endarterectomy (CEA) is considered to be the gold standard treatment of a carotid stenosis. Carotid angioplasty and stenting (CAS) is emerging as a new alternative treatment for a carotid artery stenosis, but the risk of neurological complications and brain embolism remains the major drawback to this procedure. Therefore, in order to reduce the risks, we need: 1) good indications, good patient and lesion selection; 2) correct techniques; 3) brain protection devices (cerebral protection devices should be routinely used and are mandatory for any procedure); 4) 3 types of protection devices are available, but filters are the most commonly used (all protection devices have limitations and cannot prevent from all embolic events; however, neurological complications can be reduced by 60%); 5) a good choice of the stent and correct implantation (all stents are not equivalent and have different geometrical effects); 6) pharmacological adjuncts; 7) a good team. Recent studies have shown that CAS has superior short-term outcomes than CEA in high surgical risk patients, but there are enough reported data to conclude that CAS is also not inferior to CEA in low-risk patients. CAS under protection is the standard of care and is maybe becoming the gold standard treatment of a carotid stenosis at least in some subgroups of patients.
New treatment of iliac artery disease: focus on the Absolute Pro® Vascular Self-Expanding Stent System

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Gates L

2013-09-01

Full Text Available Lindsay Gates, Jeffrey Indes Vascular and Endovascular Surgery, Yale University School of Medicine, New Haven, CT, USA Abstract: Management of iliac artery disease has evolved over the years, from a surgical-only approach to a primarily endovascular-only approach as the first line treatment option. This has been continuously improved upon with the advent of new devices and applied technologies. Most recently in particular, the literature has shown good, reliable outcomes with the use of self-expandable stents in iliac artery atherosclerotic lesions. Nevertheless, no device is without its limitations, and the Absolute Pro® Vascular Self-Expanding Stent System was designed with the intent of overcoming some of the shortcomings of other available stents while maintaining acceptable postprocedural outcomes. Based on preliminary industry-acquired data, it has achieved these goals and appears to be an emergent competitor for the treatment of both focal and complex iliac artery lesions. Keywords: Absolute-Pro®, iliac stent, self-expanding stents, atherosclerotic disease
Metallic stents provide better QOL than plastic stents in patients with stricture of unresectable advanced esophageal cancer

International Nuclear Information System (INIS)

Ohta, Kazuki; Nagahara, Akihito; Iijima, Katsuyori

2006-01-01

The aim of this study was to elucidate the utility and safety of treatment with esophageal stents (plastic and metallic stents) for unresectable advanced esophageal cancer. Between 1992 and 2002, 14 cases of unresectable advanced esophageal cancer were treated with esophageal stents (the plastic stent group, 7 cases; and the metallic stent group, 7 cases). Of these, 10 cases had a history of chemotherapy and or radiotherapy. An improvement in oral intake and performance status (PS), survival time, periods at home, and adverse events were compared between the two groups. After stenting, oral intake and PS were significantly improved in the metallic stent group. Follow-up at home was possible in 71.4%. There was no significant difference in survival or duration of time at home between the two groups. All adverse events were controllable and there was no difference between the two groups. Stenting not only improved oral intake and PS but also allowed a stay at home, resulting in a marked improvement in patients' quality of life (QOL). Stenting was performed safely even in cases with a history of radiotherapy. There was no difference in survival, ratios of staying at home, and safety between the two groups, but QOL was significantly improved in the metallic stent group. These outcomes indicate that placement of metallic stents should be actively considered to treat stricture due to advanced esophageal cancer. (author)
Experimental study of the preventive effect of 1'03Pd stent on in-stent restenosis in rabbit iliac artery

International Nuclear Information System (INIS)

Luo Quanyong; Chen Libo; Yuan Zhibin; Lu Hankui; Zhu Ruisen

2003-01-01

Objective: To investigate the ability of γ-emitting 103 Pd radioactive stent implantation for preventing in-stent restenosis in iliac artery of rabbits. Methods: Twenty New Zealand white rabbits were divided into six groups on the basis of radioactivity loading [2.22 (n=3), 5.55 (n=4), 9.25 (n=4), 14.8 (n=3), 22.2 (n=3), 33.3 MBq (n=3)]. 103 Pd stent was implanted in one of the two iliac arteries of each rabbit and nonradioactive stent in the contralateral artery. The rabbits were fed with high fat diet. Treatment efficiency was assessed by angiography and quantitative histomorphometry of the stented iliac segments 28 d after the implantation. Results: Quantitative histomorphometry analysis indicated that 103 Pd stents induced a significant reduction in neointimal area and the percentage of stenosis within radioactive stents was lower compared with that in the control stents. Nevertheless, the suppression of neointima formation by 103 Pd stent implantation was not in a dose-dependent manner. Conclusions: Low-dose intravascular brachytherapy via a γ-particle-emitting 103 Pd radioactive stent potently inhibits neointimal hyperplasia and prevents the in-stent restenosis in rabbit iliac artery. 103 Pd stent implantation probably can be employed as a novel means to prevent in-stent restenosis
Placement of hemoparin-coated stents in the iliac arteries: Early experience and midterm results in 28 patients

Energy Technology Data Exchange (ETDEWEB)

Kalmar, Peter I., E-mail: peter.kalmar@medunigraz.at; Portugaller, Rupert H., E-mail: rupert.portugaller@medunigraz.at; Schedlbauer, Peter, E-mail: peter.schedlbauer@klinikum-graz.at; Bohlsen, Dennis, E-mail: dennis.bohlsen@medunigraz.at; Deutschmann, Hannes A., E-mail: hannes.deutschmann@medunigraz.at

2014-07-15

Purpose: Aim was to determine immediate results and mid-term outcome of the hemoparin-coated (HC) stainless-steel stent (camouflage coating) in the treatment of occlusive lesions of the iliac arteries. Materials and methods: Twenty-eight patients were prospectively treated with the use of a HC stent between January 2007 and March 2010. Clinical examination and color-doppler ultrasound were performed at 1, 3, 6 and 12 months, CT angiography (CTA) or MR angiography (MRA) at 12 months. Indication for treatment was a high-grade stenosis of the common iliac and/or external iliac artery. Results: Successful placement was achieved in all patients. Significant decrease in translesional pressure gradient (>10 mmHg) was measured in 27 patients (96%). In one patient, proximal dissection occurred without flow limitation. A minor complication (small access site hematoma) occurred in one patient (4%). Two patients (7%) were lost to follow-up. After 12 months, stent patency in CTA, MRA and ultrasound was 100%. 20 patients (77%) experienced an initial improvement of at least one clinical stage. In one patient (4%), mild intimal hyperplasia without significant stenosis was observed. In three patients (12%), proximal or distal stenosis occurred. A non-significant increase of mean ankle-brachial index (ABI) after treatment was measured (0.85 ± 0.27 vs. 0.75 ± 0.22, respectively; p = 0.328). Conclusions: The use of HC stents in patients with iliac artery occlusive disease may lead to a lower rate of intimal hyperplasia and thus to increased patency rates even in heavily calcified vessels. However, large-scale prospective trials have to be performed to evaluate the long-term patency rates of the HC coated stents.
Placement of hemoparin-coated stents in the iliac arteries: Early experience and midterm results in 28 patients

International Nuclear Information System (INIS)

Kalmar, Peter I.; Portugaller, Rupert H.; Schedlbauer, Peter; Bohlsen, Dennis; Deutschmann, Hannes A.

2014-01-01

Purpose: Aim was to determine immediate results and mid-term outcome of the hemoparin-coated (HC) stainless-steel stent (camouflage coating) in the treatment of occlusive lesions of the iliac arteries. Materials and methods: Twenty-eight patients were prospectively treated with the use of a HC stent between January 2007 and March 2010. Clinical examination and color-doppler ultrasound were performed at 1, 3, 6 and 12 months, CT angiography (CTA) or MR angiography (MRA) at 12 months. Indication for treatment was a high-grade stenosis of the common iliac and/or external iliac artery. Results: Successful placement was achieved in all patients. Significant decrease in translesional pressure gradient (>10 mmHg) was measured in 27 patients (96%). In one patient, proximal dissection occurred without flow limitation. A minor complication (small access site hematoma) occurred in one patient (4%). Two patients (7%) were lost to follow-up. After 12 months, stent patency in CTA, MRA and ultrasound was 100%. 20 patients (77%) experienced an initial improvement of at least one clinical stage. In one patient (4%), mild intimal hyperplasia without significant stenosis was observed. In three patients (12%), proximal or distal stenosis occurred. A non-significant increase of mean ankle-brachial index (ABI) after treatment was measured (0.85 ± 0.27 vs. 0.75 ± 0.22, respectively; p = 0.328). Conclusions: The use of HC stents in patients with iliac artery occlusive disease may lead to a lower rate of intimal hyperplasia and thus to increased patency rates even in heavily calcified vessels. However, large-scale prospective trials have to be performed to evaluate the long-term patency rates of the HC coated stents
[Early results with a monorail-stent-balloon device for endovascular treatment of renal artery stenosis].

Science.gov (United States)

Müller-Hülsbeck, S; Jahnke, T; Grimm, J; Behm, C; Hilbert, C; Frahm, C; Biederer, J; Brossmann, J; Heller, M

2002-03-01

To evaluate the technical feasibility of a new monorail-stent-balloon device for treatment of renal artery stenosis (RAS). During a study period of 18 months, 38 patients with proven RAS in 41 cases (hypertension n = 36, renal insufficiency n = 13) and indication for stenting (calicified ostial lesions n = 35, insufficient PTA n = 4, dissection n = 2) were enrolled into this prospective evaluation. Pre-mounted stents (Rx-Herculink(TM) 5 mm = 13, 6 mm = 34, 7 mm = 1) were implanted a transfemoral (n = 35) or transbrachial approach (n = 6). Mean grade and lengths of stenosis measured were 88 % plus minus 10 and 9 mm plus minus 5. Renal stent implantation was technically successful in all cases (100 %). In 7 cases a second stent had to be implanted to cover the entire lesion. The transstenotic pressure drop decreased from 88 mmHg plus minus 10 before to 1 mmHg plus minus 1.8 after the procedure. Remaining stenosis measured 0.7 % plus minus 4.2. Serum creatine levels decreased from 1.9 mm/dl to 1.5 mg/dl (n. s.), blood pressure decreased from 178/94 mmHg to 148/79 mmHg (p monorail-stend-balloon device a technically easy, secure and exact renal stent placement is guaranteed, patency rates are similar to those described in the current literature.
Stent-in-Stent Technique for the Treatment of Proximal Bronchial Restenosis after Insertion of Metallic Stents: A Report of Two Cases

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Benjamin Bondue

2016-01-01

Full Text Available Endoscopic treatment of a bronchial restenosis previously treated by insertion of a partially covered self-expandable metallic stent (SEMS can be difficult. Classically, after recanalization of the bronchus, the stent is removed and replaced by a more adapted one. We report on two cases of proximal bronchial restenosis treated by insertion of an additional stent inside the lumen of the previously inserted stent using the stent-in-stent (SIS technique. The indications for the initial stent were malignancy in Patient 1 and posttransplant bronchial stenosis in Patient 2. Restenosis occurred at the proximal end of the stent within months in both cases. Stent removal and insertion of a new stent were considered, but this option was discarded because of an excessive risk of bronchial perforation and preference towards an alternative approach. In both cases, a second customized SEMS was placed using the SIS technique after ablation of the proximal end stenosis of the stent by argon plasma coagulation and/or dilation with a balloon. Recanalization of the bronchus was achieved in both cases without complications. The SIS technique is a valuable alternative to removal of SEMS in case of proximal bronchial restenosis.
Endovascular AAA exclusion: will stents with hooks and barbs prevent stent-graft migration?

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Malina, M; Lindblad, B; Ivancev, K; Lindh, M; Malina, J; Brunkwall, J

1998-11-01

To investigate if stents with hooks and barbs will improve stent-graft fixation in the abdominal aorta. Sixteen- to 24-mm-diameter Dacron grafts were deployed inside cadaveric aortas. The grafts were anchored by stents as in endovascular abdominal aortic aneurysm repair. One hundred thirty-seven stent-graft deployments were carried out with modified self-expanding Z-stents with (A) no hooks and barbs (n = 75), (B) 4 5-mm-long hooks and barbs (n = 39), (C) 8 10-mm-long, strengthened hooks and barbs (n = 19), or (D) hooks only (n = 4). Increasing longitudinal traction was applied to determine the displacement force needed to extract the stent-grafts. The radial force of the stents was measured and correlated to the displacement force. The median (interquartile range) displacement force needed to extract grafts anchored by stent A was 2.5 N (2.0 to 3.4), stent B 7.8 N (7.4 to 10.8), and stent C 22.5 N (17.1 to 27.9), p barbs added anchoring strength. During traction, the weaker barbs were distorted or caused intimal tears. The stronger barbs engaged the entire aortic wall. The radial force of the stents had no impact on fixation, while aortic calcification and graft oversizing had marginal effects. Stent barbs and hooks increased the fixation of stent-grafts tenfold, while the radial force of stents had no impact. These data may prove important in future endograft development to prevent stent-graft migration after aneurysm exclusion.
PTA and Stenting of Benign Venous Stenoses in the Pelvis: Long-Term Results

International Nuclear Information System (INIS)

Wohlgemuth, Walter A.; Weber, Hermann; Loeprecht, Henning; Tietze, Wolfram; Bohndorf, Klaus

2000-01-01

Purpose: To provide follow-up data on endovascular intervention for venous stenoses in the pelvis.Methods: Between 1985 and 1995, 35 patients presented with 42 stenoses of the pelvic veins after operative thrombectomy and creation of an arteriovenous fistula, combined with intraoperative venous angioscopy. All patients underwent angioplasty and, if unsuccessful, percutaneous insertion of an endovascular stent (n = 7).Results: Angioplasty with and without endovascular stenting was technically successful in 34 of 35 patients (97%). Average length of the stenoses was 20.6 mm (range 10-90 mm), average diameter before dilation 4.1 mm (range 2-6 mm), and average diameter after dilation 10.1 mm (range 5-18 mm). Intraoperative angioscopy showed pathologic findings (intimal laceration or residual thrombotic material) in 14 patients. After an average follow-up period of 4.13 years, 24 (69%) patients had patent veins. The difference in the primary patency rate between patients with angioscopically abnormal veins (6 of 14 patients, corresponding to a patency rate of 43%) and patients with angioscopically normal veins after thrombectomy (18 of 21 patients, corresponding to a patency rate of 86%) was statistically significant (p < 0.01, log rank test).Conclusions: Percutaneous transluminal angioplasty and/or stenting are good treatment modalities for pelvic vein stenosis following surgical thrombectomy. Angioscopically abnormal veins have a poorer long-term patency, regardless of the type of intervention
Optimized intravenous flat detector CT for non-invasive visualization of intracranial stents: first results

International Nuclear Information System (INIS)

Struffert, Tobias; Kloska, Stephan; Engelhorn, Tobias; Ott, Sabine; Doelken, Marc; Saake, Marc; Doerfler, Arnd; Deuerling-Zheng, Yu.; Koehrmann, Martin

2011-01-01

As stents for treating intracranial atherosclerotic stenosis may develop in-stent re-stenosis (ISR) in up to 30%, follow-up imaging is mandatory. Residual stenosis (RS) is not rare. We evaluated an optimised Flat Detector CT protocol with intravenous contrast material application (i.v. FD-CTA) for non-invasive follow-up. In 12 patients with intracranial stents, follow-up imaging was performed using i.v. FD-CTA. MPR, subtracted MIP and VRT reconstructions were used to correlate to intra-arterial angiography (DSA). Two neuroradiologists evaluated the images in anonymous consensus reading and calculated the ISR or RS. Correlation coefficients and a Wilcoxon test were used for statistical analysis. In 4 patients, no stenosis was detected. In 6 patients RS and in two cases ISR by intima hyperplasia perfectly visible on MPR reconstructions of i.v. FD-CTA were detected. Wilcoxon's test showed no significant differences between the methods (p > 0.05). We found a high correlation with coefficients of the pairs DSA/ FD-CT MIP r = 0.91, DSA/ FD-CT MPR r = 0.82 and FD-CT MIP/ FD-CT MPR r = 0.8. Intravenous FD-CTA could clearly visualise the stent and the lumen, allowing ISR or RS to be recognised. FD-CTA provides a non-invasive depiction of intracranial stents and might replace DSA for non-invasive follow-up imaging. (orig.)
Expansion characteristics of coronary stents in focal stenoses

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Schmidt Wolfram

2017-09-01

Full Text Available The presented experimental in vitro approach was designed to assess the expansion behavior of stent systems in a resistant focal stenosis model with respect to a potential dog-boning effect. Five different stent systems (nominal diameter 3.0 mm were investigated. The focal stenosis was simulated by a stainless steel tube (ID ≤ 1.20 mm. Stent expansion was performed using a proprietary test device consisting of a test chamber with 37 °C water, 2-axis laser scanner and a pressure controller.
Comparison of Recanalization and In-Stent Stenosis Between the Low-Profile Visualized Intraluminal Support Stent and Enterprise Stent-Assisted Coiling for 254 Intracranial Aneurysms.

Science.gov (United States)

Feng, Xin; Qian, Zenghui; Liu, Peng; Zhang, Baorui; Wang, Luyao; Guo, Erkang; Wen, Xiaolong; Xu, Wenjuan; Jiang, Chuhan; Wu, Zhongxue; Li, Youxiang; Liu, Aihua

2018-01-01

To compare the rates of recanalization and in-stent stenosis between the Enterprise (EP) and low-profile visualized intraluminal support (LVIS) stent deployments for intracranial aneurysms (IAs), and the factors associated therein. Between June 2014 and July 2016, 142 patients with a total of 161 IAs were treated by LVIS stent-assisted coiling and 111 patients with a total of 142 IAs were treated by EP stent-assisted coiling at our institution. Procedure-related complications, angiographic follow-up results, and clinical outcomes were analyzed statistically. The rates of initially complete and near-complete IA occlusion immediately after the procedure were similar in the LVIS and EP groups (94.3% vs. 89.9%; P = 0.275). On follow-up, complete and near-complete occlusion rates and recanalization rates were also similar in the 2 groups (96.6% vs. 92.1%; P =0.330 and 8.0% vs. 13.5%; P = 0.245, respectively). On logistic regression analysis, a higher size ratio (SR) was significantly associated with the recanalization of aneurysms in the EP group, but not in the LVIS group. The rate of moderate to severe in-stent stenosis was lower in the LVIS group (10.2%) than in the EP group (16.8%), but the difference was not statistically significant (P = 0.198). Our data show acceptable rates of complete and near-complete occlusion with both the LVIS and EP stents. LVIS stents were associated with lower rates of recanalization and in-stent stenosis, but the difference was not significant. Higher SR (≥2) was a significant predictor of recanalization in IAs treated with EP stents, but not in those treated with LVIS stents. Copyright © 2017. Published by Elsevier Inc.

Clinical results of Intracoronary Brachytherapy (ICBT) for multiple in-stent restenosis

International Nuclear Information System (INIS)

Stadler, P.; Schaefer, C.; Chaber, S.; Putnik, K.; Treutwein, M.; Koelbl, O.; Muders, F.

2006-01-01

Background and purpose: treatment of in-stent restenosis (ISR) with percutaneous coronary intervention (PCI) alone is often followed by early re-restenosis. The present study focused on the effect of intracoronary brachytherapy (ICBT) on multiple in-stent restenosis (MISR) after repeated PCI. Patients and methods: 40 patients (27 male, 13 female, age: 66 ± 9 years) with MISR (two to six ISRs, median three ISRs) were retrospectively analyzed. All patients were treated by using the Novoste registered Beta-Cath trademark 3.5F System after PCI. The target vessel received 18.4-25.3 Gy of radiation at a depth of 2 mm from the center of the source. The restenosis-free survival and overall survival were calculated by Kaplan-Meier analysis (log-rank). The time interval between last PCI without ICBT and the consecutive recurrence was compared with the follow-up time after PCI with ICBT. Results: the 3-year overall survival rate after ICBT was 93%. The 0.5-, 1-, 2-, and 3-year ISR-free survival rates after PCI + ICBT were 81%, 72%, 52%, and 38%, respectively. After PCI alone, the 0.5-, 1-, and 2-year ISR-free survival rates were 30%, 13%, and 0%, respectively. This difference was highly significant (p < 0.0001). Patients with more than three ISRs before ICBT had a better outcome (3-year ISR-free survival: 80%) than patients with only two or three ISRs before ICBT (3-year ISR-free survival: 25%; p < 0.05). Conclusion: ICBT is highly effective and safe in patients with ISR. The results of this study are in accordance with the WRIST and BETA-WRIST data. After 6 months both studies revealed an ISR-free survival rate of 86% (WRIST) and 66% (BETA-WRIST), respectively. The ISR rates in the own control group (70%) were comparable to the placebo groups in WRIST (68%) and BETA-WRIST (72%). Interestingly, patients with more than three ISRs before ICBT had the lowest ISR rate after ICBT. (orig.)
Modelling and simulating in-stent restenosis with complex automata

NARCIS (Netherlands)

Hoekstra, A.G.; Lawford, P.; Hose, R.

2010-01-01

In-stent restenosis, the maladaptive response of a blood vessel to injury caused by the deployment of a stent, is a multiscale system involving a large number of biological and physical processes. We describe a Complex Automata Model for in-stent restenosis, coupling bulk flow, drug diffusion, and
Investigation Of Interaction Between Nitinol Stent And A Vascular Plaque Using Finite Element Method

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Recep Güneş

2012-06-01

Full Text Available In this study, the interaction between the Nitinol stent and the artery with plaque was investigated using finite element method. The occurring pressure values during the cardiac contraction (systolic and loosening (diastolic were applied as loading to the modeled system with Nitinol stent. In the light of the stress values, the suitability of the Nitinol stent in an artery with plaque was investigated. In the analysis, Nitinol stent was assumed to be shape memory alloy, and artery and plaque were assumed to behave linearly elastic. As a result, the stress and deformations in the plaque and artery due to the interference of Nitinol stent were discussed and concluded that the structure of artery with plaque can be expanded in accordance with Nitinol stent.
Acute ST-Elevation Myocardial Infarction after Coronary Stent Fracture.

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Rafighdust, Abbasali; Eshraghi, Ali

2015-10-27

The invention of the drug-eluting stent (DES) has brought about revolutionary changes in the field of interventional cardiology. In the DES era, in-stent restenosis has declined but new issues such as stent thrombosis have emerged. One of the emerging paradigms in the DES era is stent fracture. There are reports about stent fracture leading to in-stent restenosis or stent thrombosis. Most of these reports concern the Sirolimus-eluting stent. The present case is a representation of a Biolimus-eluting stent fracture. We introduce a 64-year-old male patient, for whom the BioMatrix stent was deployed in the right coronary artery. Five months after the implantation, he experienced acute myocardial infarction, with stent fracture leading to stent thrombosis being the causative mechanism. Another DES (Cypher) was used to manage this situation, and the final result was good.
Predictors of Long-Term Results After Treatment of Iliac Artery Obliteration by Transluminal Angioplasty and Stent Deployment

International Nuclear Information System (INIS)

Funovics, M.A.; Lackner, B.; Cejna, M.; Peloschek, P.; Sailer, J.; Philipp, M.O.; Maca, T.; Ahmadi, A.; Minar, E.; Lammer, J.

2002-01-01

Purpose: To investigate initial and long-term success rate after percutaneous treatment of iliac artery occlusion with angioplasty and stent deployment. To investigate the influence of vascular comorbidity, lesion length, stent placement and lesion coverage as possible predictors of outcome. Methods: Between January 1994 and December 1999, 80 iliac recanalizations were performed on 78 patients, median age 61.1 ±11.5 (SD) years. All patients were followed up by clinical examinations, duplex ultrasound and intravenous digital subtraction angiography. Mean follow-up time was 2.0 ± 1.53 (SD) years.Multivariate Cox regression analysis was used to determine the influence of cofactors on patency. Results: One, 2 and 4 years after recanalization, primary patency was 78.1%, 74.5% and 64.0%; secondary patency was 88.8%, 88.8% and 77.9%, respectively.Patients with shorter occlusions, complete lesion coverage and patent ipsilateral femoral arteries had significantly longer patency rates.Complications included inguinal hematoma (n=1), technical failure (n=3) aortic dissection (n=1), embolic occlusions (n=7), gluteal claudication (n=1) and genital necrosis after subsequent urethral surgery in one patient with contralateral occlusion and ipsilateral overstenting of the internal iliac artery with subsequent stenosis. Complications were of permanent clinical significance in seven of 78 (9%) of the patients. In 17 (22%) cases, percutaneous reintervention was performed with angioplasty in the stent (n=16) or deployment of a new stent (n=1). Conclusion: Endoluminal stent placement has its place in an interdisciplinary therapeutic approach as a viable therapeutic alternative to major transabdominal bypass surgery and can be performed with comparable complication rates. Patients with short occlusions, patent femoral arteries, and stents covering the entire occlusion have significant longer patency
Intravascular stent graft with polyurethane and metallic stent: experimental study

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Do, Young Soo; Lee, Won Jae; Kim, Boo Kyung Han; Park, Jae Hyung; Lee, Hak Jong; Lee, Sang Hyun; Kim, Sung Hyun; Kim, Jong Won; Ha, Jongwon

1997-01-01

To evaluate the usefulness of a new model of the stent graft, and of tissue response related to placement of the stent graft. The stent graft was constructed from polyurethane (Pellethane) graft and Hanaro stent(12mm in diameter, 45mm in length, 10 bends). A stent grafts was inserted into the lower thoracic aorta in each of six adult mongrel dogs(body weight, 12-16kg). At one, two, four, and six months, follow-up studies of angiography and spiral CT angiography were preformed to evaluate wascular patency, vascular stenosis, and thrombus formation. Two dogs were sacrificed at 1month, 2months, and 6months after insertion of the stent graft and macroscopic, light microscopic, and scanning electron microscopic examinations of the aortic segment including the stent graft were performed to evaluate intimal hyperplasia, endothelial growth to the graft, and thrombus formation. During follow-up at one, two, four, and six months, angiography or spiral CT angiography showed 20-100% luminal stenosis or occlusion of the lower thoracic aorta by the thrombus and perigraft leaks in three dogs(50%), and collateral vessels caused by occlusion of the aorta in two (33.3%). On gross examination, there were thrombi of 1-5mm thickness at the graft portions in all dogs, and this thickness gradually increased. The mean thickness of intimal hyperplasia at the stent portion gradually increased from 120μm to 227μm and the mean thickness of intimal hyperplasia at the graft portion from 93μm to 914μm. This thickness was greater at the graft portion than at the stent portion. Scanning electron microscopy showed elliptical endothelial lining on the neointimal surfaces at each end of the graft. Thrombi caused stenosis or occlusion of the stent graft. In order for such a graft to be ideal, further study is needed
Robot-Assisted Antegrade In-Situ Fenestrated Stent Grafting

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Riga, Celia V.; Bicknell, Colin D.; Wallace, Daniel; Hamady, Mohamad; Cheshire, Nicholas

2009-01-01

To determine the technical feasibility of a novel approach of in-situ fenestration of aortic stent grafts by using a remotely controlled robotic steerable catheter system in the porcine model. A 65-kg pig underwent robot-assisted bilateral antegrade in-situ renal fenestration of an abdominal aortic stent graft with subsequent successful deployment of a bare metal stent into the right renal artery. A 16-mm iliac extension covered stent served as the porcine aortic endograft. Under fluoroscopic guidance, the graft was punctured with a 20-G customized diathermy needle that was introduced and kept in place by the robotic arm. The needle was exchanged for a 4 x 20 mm cutting balloon before successful deployment of the renal stent. Robot-assisted antegrade in-situ fenestration is technically feasible in a large mammalian model. The robotic system enables precise manipulation, stable positioning, and minimum instrumentation of the aorta and its branches while minimizing radiation exposure.
A comparison of clinical efficacy between covered stent-grafts and bare stents in transjuglar in-trahepatic portosystemic shunt

International Nuclear Information System (INIS)

Jiang Yongbin; Zhang Xitong; Zhang Wei; Xia Yonghui; Liang Songnian; Xu Ke

2010-01-01

Objective: To compare the clinical efficacy between covered stent and uncovered stent in transjuglar in-trahepatic portosystemic shunt (TIPS). Methods: Thirty patients with liver cirrhosis (portal hypertension), who received TIPS, were retrospectively studied. All patients were divided into two groups covered-stent group (n=20) and uncovered-stent group (n=10). For each patient, portal pressure was measured before and after operation, and the patency of shunt was evaluated by color Doppler ultrasound after operation. The mortality, recurrent bleeding rate and incidence of hepatic encephalopathy were analyzed by Fisher exact probability test. Results: The TIPS treatment was successful in all patients, the portal pressure in the covered-stent group reduced from (3.78 ± 0.50)kPa to (2.13 ± 0.44) kPa and that of the uncovered-stent group reduced from (3.67 ± 0.48)kPA TO (2.13 ± 0.35)kPa. Twenty-six cases were postoperatively followed-up (17 cases in covered-stent group, 9 cases in uncovered-stent group). the follow-up period varied from 7 days to 62 months (median follow-up period was 23 months). Thirteen patients died of upper gastrointestinal bleeding and hepatic failure. The difference of mortality between covered-stent group (8/17) and uncovered-stent group (5/17) and the uncovered-stent group (3/9) was not different too (P>0.05). The incidence of hepatic encephalopathy in the covered-stent group (4/17) was not different from that of the uncovered-stent group (2/9) (P>0.05). The patency rates of 6 months and 12 months reached 100% in the covered-stent group, which were higher than those in the uncovered-stent group 77.8% (7/9) and 55.6%(5/9) (P<0.05). Conclusions: The patency rate of shunt at 12 months after TIPS was higher in the covered-stent group than the uncovered-stent group, while the mortality, recurrent bleeding rate and incidence of hepatic encephalopathy were not significantly different between the two groups. (authors)
Particle imaging velocimetry evaluation of intracranial stents in sidewall aneurysm: hemodynamic transition related to the stent design.

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Bouillot, Pierre; Brina, Olivier; Ouared, Rafik; Lovblad, Karl-Olof; Farhat, Mohamed; Pereira, Vitor Mendes

2014-01-01

We investigated the flow modifications induced by a large panel of commercial-off-the-shelf (COTS) intracranial stents in an idealized sidewall intracranial aneurysm (IA). Flow velocities in IA silicone model were assessed with and without stent implantation using particle imaging velocimetry (PIV). The use of the recently developed multi-time-lag method has allowed for uniform and precise measurements of both high and low velocities at IA neck and dome, respectively. Flow modification analysis of both regular (RSs) and flow diverter stents (FDSs) was subsequently correlated with relevant geometrical stent parameters. Flow reduction was found to be highly sensitive to stent porosity variations for regular stents RSs and moderately sensitive for FDSs. Consequently, two distinct IA flow change trends, with velocity reductions up to 50% and 90%, were identified for high-porosity RS and low-porosity FDS, respectively. The intermediate porosity (88%) regular braided stent provided the limit at which the transition in flow change trend occurred with a flow reduction of 84%. This transition occurred with decreasing stent porosity, as the driving force in IA neck changed from shear stress to differential pressure. Therefore, these results suggest that stents with intermediate porosities could possibly provide similar flow change patterns to FDS, favourable to curative thrombogenesis in IAs.
Preoperative biliary drainage by plastic or self-expandable metal stents in patients with periampullary tumors: results of a randomized clinical study

Science.gov (United States)

Olsson, Greger; Frozanpor, Farshad; Lundell, Lars; Enochsson, Lars; Ansorge, Christoph; Del Chiaro, Marco; Reuterwall-Hansson, Marcus; Shetye, Alysha; Arnelo, Urban

2017-01-01

Background and study aims Preoperative biliary drainage in patients with periampullary tumors and jaundice has been popularized to improve the quality of life and minimize the risks associated with subsequent radical surgery. The aim of this study was to investigate the possible superiority of self-expandable metal stents (SEMS) over plastic stents, by comparing the amount of bacteria in intraoperatively collected bile and using this variable as a proxy for the efficacy of the respective biliary drainage modalities. Patients and methods In this randomized clinical trial, 92 patients with obstructive jaundice were enrolled; 45 were allocated to the plastic stent group and 47 to the SEMS group. The primary outcome was the extent and magnitude of biliary bacterial growth at the time of surgical exploration. Secondary outcomes were: macroscopic grading of inflammation of the stented bile ducts, occurrence of adverse events after stenting, stent dysfunction, recognized surgical complexities, and incidence of postoperative complications. Results The patients were well matched regarding clinical and disease-specific characteristics. At surgery, there were no group differences in the bacterial amount and composition of the bile cultures or the perceived difficulty of surgical dissection. During the preoperative biliary drainage period, more instances of stent dysfunction requiring stent replacement were recorded in the plastic stent group (19 % vs. 0 %; P = 0.03). Postoperative complications in patients who underwent curative surgery were more common in patients with plastic stents (72 % vs. 52 %), among which clinically significant leakage from the pancreatic anastomoses seemed to predominate (12 % vs. 3.7 %); however, none of these differences in postoperative adverse events reached statistical significance. Conclusion This randomized clinical study was unable to demonstrate any superiority of SEMS in the efficacy of preoperative bile
Treatment of Visceral Aneurysm Using Multilayer Stent: Two-Year Follow-Up Results in Five Consecutive Patients

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Balderi, Alberto, E-mail: balders@libero.it; Antonietti, Alberto, E-mail: antonietti.a@ospedale.cuneo.it; Pedrazzini, Fulvio, E-mail: pedrazzini.f@ospedale.cuneo.it; Sortino, Davide, E-mail: davide.sortino@hotmail.it; Vinay, Claudia, E-mail: claudia.vinay@gmail.com; Grosso, Maurizio, E-mail: grosso.m@ospedale.cuneo.it [AO Santa Croce e Carle Hospital, Department of Radiology (Italy)

2013-10-15

Purpose: The present study was performed to analyze the midterm results (five consecutive patients, 2-year follow-up) of the endovascular management of visceral artery aneurysms using the Cardiatis Multilayer Flow Modulator (CMFM) (Cardiatis, Isnes, Belgium), a self-expandable stent. Materials and Methods: From August 2009 to January 2011, we implanted five CMFMs in five patients (all men; mean age 73 years) to treat two common hepatic artery aneurysms, one celiac trunk aneurysm, one splenic artery aneurysm, and one superior mesenteric artery aneurysm (diameter 25-81 mm). The primary end point was technical success. The secondary end point was stent patency, absence of aneurysm rupture or reperfusion, and shrinking of the sac at 6-, 12-, and 24-month follow-up using computed tomography angiography. Follow-up ranged from 24 to 48 months (mean 31.2). Results: Technical success was achieved in all patients. Complete exclusion of the aneurysm with sac shrinking was achieved in two patients. Two stents became occluded at 6- and 24-month follow-up, respectively; both patients were asymptomatic and were not retreated. One patient developed sac reperfusion due to incomplete aneurysm exclusion. Conclusion: Long-term results in a wider population are needed to validate the effectiveness of the CMFM.
A comparison of outcomes between a lumen-apposing metal stent with electrocautery-enhanced delivery system and a bi-flanged metal stent for drainage of walled-off pancreatic necrosis.

Science.gov (United States)

Bekkali, Noor L H; Nayar, Manu K; Leeds, John S; Charnley, Richard M; Huggett, Matthew T; Oppong, Kofi W

2017-12-01

Bi-flanged metal stents (BFMS) have shown promise in the drainage of walled-off pancreatic necrosis (WON), but their placement requires multiple steps and the use of other devices. More recently, a novel device consisting of a combined lumen-apposing metal stent (LAMS) and electrocautery-enhanced delivery system has been introduced. The aim of this study was to compare the placement and outcomes of the two devices. This was a retrospective review of consecutive patients undergoing endoscopic ultrasound-guided placement of BFMS or LAMS for drainage of symptomatic WON. Data from procedures between October 2012 and December 2016 were taken from a prospectively maintained database. We compared technical and clinical success, procedure time, costs, and composite end point of significant events (adverse events, stent migration, additional percutaneous drainage) between BFMS and LAMS. 72 consecutive patients underwent placement of BFMS (40 patients, 44 stents) or LAMS (32 patients, 33 stents). Technical success was 91 % for BFMS and 97 % for LAMS. Clinical success was 65 % vs. 78 %, respectively. Median in-room procedure time was significantly shorter in the LAMS group (45 minutes [range 30 - 80]) than in the BFMS group (62.5 minutes [range 35 - 135]; P comparable adverse events, success, and costs.
Low-profile stent placement with the monorail technique for treatment of renal artery stenosis: midterm results of a prospective trial.

Science.gov (United States)

Müller-Hülsbeck, Stefan; Frahm, Christian; Behm, Charlotte; Schäfer, Phillip Jobst; Bolte, Hendrik; Heller, Martin; Jahnke, Thomas

2005-07-01

To determine feasibility, safety, and midterm patency of a monorail balloon stent device for the treatment of renal artery stenosis (RAS). During a period of 30 months, 47 patients (with severe hypertension, n=45; renal insufficiency, n=20) with 50 cases of RAS and indications for stent implantation (calcified ostial lesion, n=41; insufficient percutaneous transluminal angioplasty, n=6; dissection, n=3) were enrolled into the prospective evaluation. After predilation, 59 stents (Rx-Herculink 4 mm, n=2; 5 mm, n=19; 6 mm, n=35; 7 mm, n=3) were implanted under manometer control with use of the long-sheath technique (5 F; 6 F for 7-mm stents) via a femoral (n=44) or transbrachial approach (n=6). Parameters of hypertension and renal insufficiency were determined before and after the procedure and for a maximum of 18 months. Restenosis rate was determined with color duplex ultrasonography. Renal artery stent placement (mean diameter, 5.7 mm; mean length, 16 mm) was technically successful in all cases (100%). Mean blood pressure and serum creatinine level decreased from 177/93 mm Hg to 145/78 mm Hg and from 1.8 mg/dL to 1.5 mg/dL, respectively. Within 48 hours after the implantation, acute occlusions occurred in two patients, supposedly triggered by cholesterol embolization. Primary and primary assisted patency rates were 87% and 92% at 6 months and 75% and 84% at 18 months. Renal artery stent placement with the rapid-exchange monorail system is a safe procedure with promising patency rates. In combination with the long-sheath technique, adequate control of stent deployment is guaranteed during the entire intervention. The low profile of the device facilitates the use of small sheaths (5 F) to minimize access-site complications.
Intraluminal Radioactive Stent Compared with Covered Stent Alone for the Treatment of Malignant Esophageal Stricture

International Nuclear Information System (INIS)

Wang Zhongmin; Huang Xunbo; Cao Jun; Huang Gang; Chen Kemin; LIu Yu; Liu Fenju

2012-01-01

Objective: This study was designed to compare the clinical effectiveness of intraluminal radioactive stent loaded with iodine-125 seeds implantation versus covered stent alone insertion in patients with malignant esophageal stricture. Methods: We studied two groups of patients with malignant esophageal stricture. Group A comprised 28 patients (19 men and 9 women) who underwent intraluminal radioactive stent loaded with iodine-125 seeds implantation and were followed prospectively. Group B comprised 30 patients (18 men and 12 women) who had previously received covered stent alone insertion; these patients were evaluated retrospectively. There was no crossover between the two groups during follow-up. Informed consent was obtained from each patient, and our institutional review board approved the study. The dysphagia score, overall survival rates, complication rates, and reintervention rates were compared in the two groups. Results: There were no significant differences between the two groups in terms of baseline characteristics. Stent placement was technically successful and well tolerated in all patients. The dysphagia score was improved in both groups after stent placement. The median survival was significantly longer in group A than in group B: 11 versus 4.9 months, respectively (P < 0.001). The complications of chest pain, esophageal reflux, and stent migration was more frequent in group B, but this difference did not reach statistical significance. There was no statistical difference in reintervention between two groups. Conclusions: Intraluminal radioactive stent loaded with iodine-125 seeds implantation was a feasible and practical management in treating malignant esophageal stricture and was superior to covered stent alone insertion, as measured by survival.
Spectral Analysis Related to Bare-Metal and Drug-Eluting Coronary Stent Implantation

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Silva, Rose Mary Ferreira Lisboa da, E-mail: roselisboa@cardiol.br [Faculdade de Medicina da UFMG, Divinópolis, MG (Brazil); Silva, Carlos Augusto Bueno [Faculdade de Medicina da UFMG, Divinópolis, MG (Brazil); Belo Horizonte, Hospital São João de Deus, Divinópolis, MG (Brazil); Greco, Otaviano José [Belo Horizonte, Hospital São João de Deus, Divinópolis, MG (Brazil); Moreira, Maria da Consolação Vieira [Faculdade de Medicina da UFMG, Divinópolis, MG (Brazil)

2014-08-15

The autonomic nervous system plays a central role in cardiovascular regulation; sympathetic activation occurs during myocardial ischemia. To assess the spectral analysis of heart rate variability during stent implantation, comparing the types of stent. This study assessed 61 patients (mean age, 64.0 years; 35 men) with ischemic heart disease and indication for stenting. Stent implantation was performed under Holter monitoring to record the spectral analysis of heart rate variability (Fourier transform), measuring the low-frequency (LF) and high-frequency (HF) components, and the LF/HF ratio before and during the procedure. Bare-metal stent was implanted in 34 patients, while the others received drug-eluting stents. The right coronary artery was approached in 21 patients, the left anterior descending, in 28, and the circumflex, in 9. As compared with the pre-stenting period, all patients showed an increase in LF and HF during stent implantation (658 versus 185 ms2, p = 0.00; 322 versus 121, p = 0.00, respectively), with no change in LF/HF. During stent implantation, LF was 864 ms2 in patients with bare-metal stents, and 398 ms2 in those with drug-eluting stents (p = 0.00). The spectral analysis of heart rate variability showed no association with diabetes mellitus, family history, clinical presentation, beta-blockers, age, and vessel or its segment. Stent implantation resulted in concomitant sympathetic and vagal activations. Diabetes mellitus, use of beta-blockers, and the vessel approached showed no influence on the spectral analysis of heart rate variability. Sympathetic activation was lower during the implantation of drug-eluting stents.
Magnetic stents retain nanoparticle-bound antirestenotic drugs transported by lipid microbubbles.

Science.gov (United States)

Räthel, T; Mannell, H; Pircher, J; Gleich, B; Pohl, U; Krötz, F

2012-05-01

Coating coronary stents with antirestenotic drugs revolutionized interventional cardiology. We developed a system for post-hoc drug delivery to uncoated stents. We coupled rapamycin or a chemically similar fluorescent dye to superparamagnetic nanoparticles. The antiproliferative activity of rapamycin coupled to nanoparticles was confirmed in vitro in primary porcine vascular cells. The particles were then incorporated into lipid based microbubbles. Commercially available stents were made magnetizable by nickel plating and used to induce strong field gradients in order to capture magnetic microbubbles from flowing liquids when placed in an external magnetic field. Nanoparticle bound Rapamycin dose dependently inhibited cell proliferation in vitro. Magnetic microcbubbles carrying coated nanoparticles were caught by magnets placed external to a flow-through tube. Plating commercial stents with nickel resulted in increased deposition at stent struts and allowed for widely increased distance of external magnets. Deposition depended on circulation time and velocity and distance of magnets. Deposited microbubbles were destroyed by ultrasound and delivered their cargo to targeted sites. Drugs can be incorporated into nanoparticle loaded microbubbles and thus be delivered to magnetizable stents from circulating fluids by applying external magnetic fields. This technology could allow for post-hoc drug coating of already implanted vascular stents.
Drug-eluting stents appear superior to bare metal stents for vein-graft PCI in vessels up to a stent diameter of 4 mm

Directory of Open Access Journals (Sweden)

Oliver P. Guttmann

2016-05-01

Full Text Available BackgroundResearch trials have shown improved short-term outcome with drug-eluting stents (DES over bare metal stents (BMS in saphenous vein graft (SVG percutaneous coronary intervention (PCI, primarily by reducing target vessel revascularization (TVR for in-stent restenosis. We compared the outcomes in patients undergoing SVG stent implantation treated with DES or BMS. In exploratory analyses we investigated the influence of stent generation and diameter.MethodsData were obtained from a prospective database of 657 patients who underwent PCI for SVG lesions between 2003 and 2011. A total of 344 patients had PCI with BMS and 313 with DES. Propensity scores were developed based on 15 observed baseline covariates in a logistic regression model with stent type as the dependent variable. The nearest-neighbour-matching algorithm with Greedy 5-1 Digit Matching was used to produce two patient cohorts of 313 patients each. We assessed major adverse cardiac events (MACE out to a median of 3.3 years (interquartile range: 2.1-4.1. MACE was defined as all-cause mortality, myocardial infarction (MI, TVR and stroke.ResultsThere was a significant difference in MACE between the two groups in favour of DES (17.9% DES vs. 31.2% BMS group; p = 0.0017 over the 5-year follow-up period. MACE was driven by increased TVR in the BMS group. There was no difference in death, MI or stroke. Adjusted Cox analysis confirmed a decreased risk of MACE for DES compared with BMS 0.75 (95% confidence interval (CI 0.52-0.94, with no difference in the hazard of all-cause mortality (hazard ratio: 1.08; 95% CI: 0.77-1.68. However, when looking at stent diameters greater than 4 mm, no difference was seen in MACE rates between BMS and DES.ConclusionsOverall in our cohort of patients who had PCI for SVG disease, DES use resulted in lower MACE rates compared with BMS over a 5-year follow-up period; however, for stent diameters over 4 mm no difference in MACE rates was seen.
Primary stent placement for recanalization of iliac artery occlusions: Using a self-expanding spiral stent

International Nuclear Information System (INIS)

Kim, Jae-Kyu; Kim, Yun-Hyeon; Chung, Sang-Yeung; Kang, Heoung-Keun

1999-01-01

Purpose: To report the clinical results for recanalizations of an occluded iliac artery by a self-expanding spiral stent.Methods: We attempted to recanalize 36 iliac artery occlusions in 34 patients [33 men, 1 woman, aged 51-75 years (average 61.6 years)]. The average lesion length was 6.92 cm (range 1-14 cm). The patients's chief complaints were intermittent claudication and resting pain. Fontaine classification was assigned before and after the procedure. Technical and clinical success were also analyzed.Results: Forty-five stents were successfully deployed in 34 patients. All 36 lesions (13 in the external iliac artery, 12 in the common iliac artery, and 11 in both) were patently recanalized on angiography. The follow-up period ranged from 6 months to 36 months (mean 11.9 months). Fourteen stents (39%) with incomplete expansion were dilated with a balloon catheter. Good technical (100%) and clinical (94%) results were obtained. The only complication was one hematoma at the puncture site. Reocclusions were noted in two lesions (5%) at 1 week and 15 months, respectively.Conclusion: A self-expanding spiral stent is a safe and effective device for recanalization of an iliac artery occlusion as the primary stent without any previous intervention.
Mechanisms and Patterns of Intravascular Ultrasound In-Stent Restenosis Among Bare Metal Stents and First- and Second-Generation Drug-Eluting Stents.

Science.gov (United States)

Goto, Kosaku; Zhao, Zhijing; Matsumura, Mitsuaki; Dohi, Tomotaka; Kobayashi, Nobuaki; Kirtane, Ajay J; Rabbani, LeRoy E; Collins, Michael B; Parikh, Manish A; Kodali, Susheel K; Leon, Martin B; Moses, Jeffrey W; Mintz, Gary S; Maehara, Akiko

2015-11-01

The most common causes of in-stent restenosis (ISR) are intimal hyperplasia and stent under expansion. The purpose of this study was to use intravascular ultrasound (IVUS) to compare the ISR mechanisms of bare metal stents (BMS), first-generation drug-eluting stents (DES), and second-generation DES. There were 298 ISR lesions including 52 BMS, 73 sirolimus-eluting stents, 52 paclitaxel-eluting stents, 16 zotarolimus-eluting stents, and 105 everolimus-eluting stent. Mean patient age was 66.6 ± 1.1 years, 74.2% were men, and 48.3% had diabetes mellitus. BMS restenosis presented later (70.0 ± 66.7 months) with more intimal hyperplasia compared with DES (BMS 58.6 ± 15.5%, first-generation DES 52.6 ± 20.9%, second-generation DES 48.2 ± 22.2%, p = 0.02). Although reference lumen areas were similar in BMS and first- and second-generation DES, restenotic DES were longer (BMS 21.8 ± 13.5 mm, first-generation DES 29.4 ± 16.1 mm, second-generation DES 32.1 ± 18.7 mm, p = 0.003), and stent areas were smaller (BMS 7.2 ± 2.4 mm(2), first-generation DES 6.1 ± 2.1 mm(2), second-generation DES 5.7 ± 2.0 mm(2), p Stent fracture was seen only in DES (first-generation DES 7 [5.0%], second-generation DES 8 [7.4%], p = 0.13). In conclusion, restenotic first- and second-generation DES were characterized by less neointimal hyperplasia, smaller stent areas, longer stent lengths, and more stent fractures than restenotic BMS. Copyright © 2015 Elsevier Inc. All rights reserved.
4D phase contrast flow imaging for in-stent flow visualization and assessment of stent patency in peripheral vascular stents--a phantom study.

Science.gov (United States)

Bunck, Alexander C; Jüttner, Alena; Kröger, Jan Robert; Burg, Matthias C; Kugel, Harald; Niederstadt, Thomas; Tiemann, Klaus; Schnackenburg, Bernhard; Crelier, Gerard R; Heindel, Walter; Maintz, David

2012-09-01

4D phase contrast flow imaging is increasingly used to study the hemodynamics in various vascular territories and pathologies. The aim of this study was to assess the feasibility and validity of MRI based 4D phase contrast flow imaging for the evaluation of in-stent blood flow in 17 commonly used peripheral stents. 17 different peripheral stents were implanted into a MR compatible flow phantom. In-stent visibility, maximal velocity and flow visualization were assessed and estimates of in-stent patency obtained from 4D phase contrast flow data sets were compared to a conventional 3D contrast-enhanced magnetic resonance angiography (CE-MRA) as well as 2D PC flow measurements. In all but 3 of the tested stents time-resolved 3D particle traces could be visualized inside the stent lumen. Quality of 4D flow visualization and CE-MRA images depended on stent type and stent orientation relative to the magnetic field. Compared to the visible lumen area determined by 3D CE-MRA, estimates of lumen patency derived from 4D flow measurements were significantly higher and less dependent on stent type. A higher number of stents could be assessed for in-stent patency by 4D phase contrast flow imaging (n=14) than by 2D phase contrast flow imaging (n=10). 4D phase contrast flow imaging in peripheral vascular stents is feasible and appears advantageous over conventional 3D contrast-enhanced MR angiography and 2D phase contrast flow imaging. It allows for in-stent flow visualization and flow quantification with varying quality depending on stent type. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

The Role Of Inflammation In Stent Restenosis More Than 1 Year Afetr Drug Eluting Stent Implantation

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Hasan Shemirani

2011-09-01

Full Text Available Background: In stent restenosis (ISR following endovascular interventions is the main limitation of their long-term success. Despite advances have been made during recent years to decrease restenosis, it remains a challenging clinical problem.The aim of this study was to evaluate the relationship between angiographic coronary in stent restenosis, inflammation after successful stent implantation. Methods: This study included 78 patients, 35year old and higher who underwent coronary angiography more than 1 year after drug-eluting stent (DES implantation because of symptoms suggestive ischemia. Patients were divided into ISR group (case and patent stent group (control according to angiography results. For all patients blood lipids and high sensitivity C-Reactive Protein (hsCRP were measured simultaneously. Results: Age, sex, hypertension, current smoking, and lipid profile other than High Density Lipoprotein (HDL-C of patients in the case and control groups were similar .However, HDL-C < 40mg/L was more prevalent with ISR (66.7% vs. 30.8%, p=0.002. The hsCRP level was 2.98±2.06 mg/L in the case group and 2.50±1.80 mg/L in the control group. There were no significant differences in mean hsCRP concentration between the two groups (p=0.14, however mean hsCRP level was significantly higher in men of case group than control group (3.35mg/L vs. 2.21mg/L, p<0.05. Conclusion: This study demonstrates that in men but not in women inflammation may be a predictor of in stent restenosis more than 1 year after drug eluting stent implantation. Also, high-density lipoprotein (HDL probably has protective effect against stent restenosis.
[Evaluation of Radiation Dose during Stent-graft Treatment Using a Hybrid Operating Room System].

Science.gov (United States)

Haga, Yoshihiro; Chida, Kouichi; Kaga, Yuji; Saitou, Kazuhisa; Arai, Takeshi; Suzuki, Shinichi; Iwaya, Yoshimi; Kumasaka, Eriko; Kataoka, Nozomi; Satou, Naoto; Abe, Mitsuya

2015-12-01

In recent years, aortic aneurysm treatment with stent graft grafting in the X-ray fluoroscopy is increasing. This is an endovascular therapy, because it is a treatment which includes the risk of radiation damage, having to deal with radiation damage, to know in advance is important. In this study, in order to grasp the trend of exposure stent graft implantation in a hybrid operating room (OR) system, focusing on clinical data (entrance skin dose and fluoroscopy time), was to count the total. In TEVAR and EVAR, fluoroscopy time became 13.40 ± 7.27 minutes, 23.67 ± 11.76 minutes, ESD became 0.87 ± 0.41 mGy, 1.11 ± 0.57 mGy. (fluoroscopy time of EVAR was 2.0 times than TEVAR. DAP of EVAR was 1.2 times than TEVAR.) When using the device, adapted lesions and usage are different. This means that care changes in exposure-related factors. In this study, exposure trends of the stent graft implantation was able to grasp. It can be a helpful way to reduce/optimize the radiation dose in a hybrid OR system.
Causes and prevention of in-stent restenosis of vertebral artery origin after stenting

International Nuclear Information System (INIS)

Zhao Huipin; Li Shenmao; Zhang Guangping

2010-01-01

Vertebral artery stenosis is an important cause of posterior circulation stroke. Vertebral artery stenosis most commonly occurs at its origin site. In recent years, balloon angioplasty and stent implantation have been widely employed in the treatment of vertebral artery origin stenosis. However, the long term outcome of stent implantation is affected by in-stent restenosis. Multiple contributory factors have been identified, but clear understanding of the overall underlying mechanism remains an enigma. With the development of pathophysiology, prevention and treatment methods of in-stent restenosis have been improved. In recent years, drug-eluting stents, radioactive stents and magnetic stents have been widely applied. To some extent, these stents and drug therapy can solve the problem of restenosis. This article aims to review the clinical application and the up-to-date research progresses in preventing and managing vertebral artery origin restenosis. (authors)
Metallic Stents for Tracheobronchial Pathology Treatment

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Serrano, Carolina; Laborda, Alicia; Lozano, Juan M.; Caballero, Hugo; Sebastián, Antonio; Lopera, Jorge; Gregorio, Miguel Ángel de

2013-01-01

Purpose: To present the 7-year experience of the treatment of benign and malignant tracheobronchial stenoses using metallic stents. Patients and Methods: One hundred twenty-three stents were inserted in 86 patients (74 benign and 12 malignant stenoses). Ninety-seven stents were placed in the trachea and 26 in the bronchi. The procedures were performed under fluoroscopic and flexible bronchoscopic guidance with the patient under light sedation. In cases of severe stenotic lesions or obstructions, laser resection was performed before stent placement. Clinical and functional pulmonary data were recorded before and 3 months after the procedure. Follow-up involved clinical data and radiographic techniques at 48 h and at 1-, 3-, 6-, and 12-month intervals. Results: The technical success was 100 %. Dyspnea disappearance, forced expiratory volume in the first second, and pulmonary functional data improvement was observed in all patients (p < 0.001). Complications were detected in 23 patients (26.7 %). Mean follow-up time was 6.3 ± 1.2 months in patients with malignant lesions and 76.2 ± 2.3 months patients with in benign lesions. By the end of the study, 100 % of patients with malignant pathology and 6.7 % of patients with benign lesions had died. Conclusion: Endoluminal treatment of tracheobronchial stenosis with metallic stents is a therapeutic alternative in patients who are poor candidates for surgery. In unresectable malignant lesions, the benefit of metallic stenting is unquestionable. In benign lesions, the results are satisfactory, but sometimes other interventions are required to treat complications. New stent technology may improve these results
Metallic Stents for Tracheobronchial Pathology Treatment

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Serrano, Carolina, E-mail: carolina.serrano@unizar.es [University of Zaragoza, Surgical Pathology Unit, Animal Pathology Department (Spain); Laborda, Alicia, E-mail: alaborda@unizar.es [University of Zaragoza, Minimally Invasive Techniques Research Group (GITMI) (Spain); Lozano, Juan M., E-mail: juamauloz@gmail.com [Marly Clinic, Radiology Department (Colombia); Caballero, Hugo, E-mail: hugocaballero2007@gmail.com [Marly Clinic, Pulmonology Department (Colombia); Sebastian, Antonio, E-mail: antonio.sebastian@ono.es [Lozano Blesa Clinical University Hospital, Pulmonology Department (Spain); Lopera, Jorge, E-mail: lopera@uthscsa.edu [Health Science Center, Interventional Radiology Deparment (United States); Gregorio, Miguel Angel de, E-mail: mgregori@unizar.es [University of Zaragoza, Minimally Invasive Techniques Research Group (GITMI) (Spain)

2013-12-15

Purpose: To present the 7-year experience of the treatment of benign and malignant tracheobronchial stenoses using metallic stents. Patients and Methods: One hundred twenty-three stents were inserted in 86 patients (74 benign and 12 malignant stenoses). Ninety-seven stents were placed in the trachea and 26 in the bronchi. The procedures were performed under fluoroscopic and flexible bronchoscopic guidance with the patient under light sedation. In cases of severe stenotic lesions or obstructions, laser resection was performed before stent placement. Clinical and functional pulmonary data were recorded before and 3 months after the procedure. Follow-up involved clinical data and radiographic techniques at 48 h and at 1-, 3-, 6-, and 12-month intervals. Results: The technical success was 100 %. Dyspnea disappearance, forced expiratory volume in the first second, and pulmonary functional data improvement was observed in all patients (p < 0.001). Complications were detected in 23 patients (26.7 %). Mean follow-up time was 6.3 {+-} 1.2 months in patients with malignant lesions and 76.2 {+-} 2.3 months patients with in benign lesions. By the end of the study, 100 % of patients with malignant pathology and 6.7 % of patients with benign lesions had died. Conclusion: Endoluminal treatment of tracheobronchial stenosis with metallic stents is a therapeutic alternative in patients who are poor candidates for surgery. In unresectable malignant lesions, the benefit of metallic stenting is unquestionable. In benign lesions, the results are satisfactory, but sometimes other interventions are required to treat complications. New stent technology may improve these results.
Experimental Study of Poly-l-Lactic Acid Biodegradable Stents in Normal Canine Bile Ducts

International Nuclear Information System (INIS)

Yamamoto, Kiyosei; Yoshioka, Tetsuya; Furuichi, Kinya; Sakaguchi, Hiroshi; Anai, Hiroshi; Tanaka, Toshihiro; Morimoto, Kengo; Uchida, Hideo; Kichikawa, Kimihiko

2011-01-01

Purpose: This study was designed to clarify the advantages of biodegradable stents in terms of mucosal reaction and biodegradation after placement. We designed a biodegradable stent and assessed stent degradation and changes in the normal bile ducts of dogs. Methods: The biodegradable stent is a balloon-expandable Z stent consisting of poly-l-lactic acid (PLLA) with a diameter of 6 mm and a length of 15 mm. We assessed four groups of three beagle dogs each at 1, 3, 6, and 9 months of follow-up. After evaluating stent migration by radiography and stent and bile duct patency by cholangiography, the dogs were sacrificed to remove the bile duct together with the stent. The bile duct lumen was examined macroscopically and histologically, and the stent degradation was examined macroscopically and by scanning electron microscopy (SEM). Results: Bile duct obstruction was absent and none of the stents migrated. Macroscopic evaluation showed moderate endothelial proliferation in the bile ducts at the implant sites at 3 and 6 months and a slight change at 9 months. Slight mononuclear cell infiltration was histologically identified at all time points and epithelial hyperplasia that was moderate at 3 months was reduced to slight at 6 and 9 months. Stent degradation was macroscopically evident in all animals at 9 months and was proven by SEM in two dogs at 6 months and in all of them at 9 months. Conclusions: Our results suggest that PLLA bioabsorbable stents seems to be useful for implantation in the biliary system with further investigation.
Outcomes of the single-stent versus kissing-stents technique in asymmetric complex aortoiliac bifurcation lesions.

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Suh, Yongsung; Ko, Young-Guk; Shin, Dong-Ho; Kim, Jung-Sun; Kim, Byeong-Keuk; Choi, Donghoon; Hong, Myeong-Ki; Jang, Yangsoo

2015-07-01

This study investigated the outcomes of single-stent vs kissing-stents techniques in asymmetric complex aortoiliac bifurcation (ACAB) lesions. We retrospectively investigated 80 consecutive patients (69 males, 66.6 ± 8.7 years) treated with a single stent and 30 patients (26 males, 67.1 ± 7.7 years) treated with kissing stents for ACAB between January 2005 and December 2012 from a single-center cohort. A ACAB lesion was defined as a symptomatic unilateral common iliac artery stenosis (>50%) combined with intermediate stenosis (30%-50%) in the contralateral common iliac artery ostium. The primary end point was the primary patency of the ACAB. The baseline clinical characteristics did not differ significantly between the single-stent and the kissing-stents group. Technical success was achieved in all patients. The single-stent group required fewer stents (1.3 ± 0.5 vs 2.3 ± 0.8; P stent group (3%) required bailout kissing stents because of plaque shift to the contralateral side. The major complication rates were 8% in single-stent vs 13% in the kissing-stent group, which was similar (P = .399). At 3 years, the single-stent and kissing-stents group had similar rates of primary patency (89% vs 87%; P = .916) and target lesion revascularization-free survival (93% vs 87%; P = .462). The single-stent technique in ACAB was safe and showed midterm outcomes comparable with those of kissing stents. Considering the benefits, such as fewer stents, less bilateral femoral access, and the availability of contralateral access for future intervention, the single-stent technique may be an advantageous treatment option in ACAB. Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.
Direct Stenting in Patients with Acute Lower Limb Arterial Occlusions: Immediate and Long-Term Results

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Galanakis, Nikolaos; Kontopodis, Nikolaos; Peteinarakis, Ioannis; Kehagias, Elias; Ioannou, Christos V.; Tsetis, Dimitrios

2017-01-01

PurposeThe purpose of this study is to accentuate the efficacy of direct stenting (stent placement without predilatation of the lesion) in patients with acute lower limb arterial ischemia (ALLI).Materials and MethodsBetween January 2010 and September 2015, 16 patients (11 men and 5 women) underwent direct stenting of acute arterial occlusions. All patients had contraindication for surgical revascularization or catheter-directed thrombolysis. According to SVS/ISCVS Classification, six patients had IIa and ten patients IIb ALLI. The occlusions were located in CIA, EIA, SFA, or popliteal artery. Mean follow-up time with clinical examination and color Duplex ultrasonography was 37.6 months (range 1–72). We analyzed the technical and clinical outcomes of the procedures, as well the complications and patency rates.ResultsTechnical success was achieved in all patients (16/16) and there was significant clinical improvement in 15 patients. There was neither distal embolization nor procedure-related complications. During the 6 years of follow-up, four patients died due to non-procedure-related causes and there were two minor and one major amputations. The primary patency rates and the amputation-free survival rates were 93.7 and 87% at 1 year, 75.2 and 71.2% at 3 years, and 75.2 and 62.3%, respectively, at 6 years.ConclusionsDirect stenting may be a valuable alternative procedure for acute arterial occlusions in selected cases with high technical success and significant clinical improvement.Level of EvidenceLevel 4, Case Series.
Direct Stenting in Patients with Acute Lower Limb Arterial Occlusions: Immediate and Long-Term Results

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Galanakis, Nikolaos [University of Crete Medical School, Interventional Radiology Unit, Department of Medical Imaging, University Hospital Heraklion (Greece); Kontopodis, Nikolaos [University of Crete Medical School, Vascular Surgery Unit, Department of Cardiothoracic and Vascular Surgery, University Hospital Heraklion (Greece); Peteinarakis, Ioannis; Kehagias, Elias [University of Crete Medical School, Interventional Radiology Unit, Department of Medical Imaging, University Hospital Heraklion (Greece); Ioannou, Christos V. [University of Crete Medical School, Vascular Surgery Unit, Department of Cardiothoracic and Vascular Surgery, University Hospital Heraklion (Greece); Tsetis, Dimitrios, E-mail: tsetis@med.uoc.gr [University of Crete Medical School, Interventional Radiology Unit, Department of Medical Imaging, University Hospital Heraklion (Greece)

2017-02-15

PurposeThe purpose of this study is to accentuate the efficacy of direct stenting (stent placement without predilatation of the lesion) in patients with acute lower limb arterial ischemia (ALLI).Materials and MethodsBetween January 2010 and September 2015, 16 patients (11 men and 5 women) underwent direct stenting of acute arterial occlusions. All patients had contraindication for surgical revascularization or catheter-directed thrombolysis. According to SVS/ISCVS Classification, six patients had IIa and ten patients IIb ALLI. The occlusions were located in CIA, EIA, SFA, or popliteal artery. Mean follow-up time with clinical examination and color Duplex ultrasonography was 37.6 months (range 1–72). We analyzed the technical and clinical outcomes of the procedures, as well the complications and patency rates.ResultsTechnical success was achieved in all patients (16/16) and there was significant clinical improvement in 15 patients. There was neither distal embolization nor procedure-related complications. During the 6 years of follow-up, four patients died due to non-procedure-related causes and there were two minor and one major amputations. The primary patency rates and the amputation-free survival rates were 93.7 and 87% at 1 year, 75.2 and 71.2% at 3 years, and 75.2 and 62.3%, respectively, at 6 years.ConclusionsDirect stenting may be a valuable alternative procedure for acute arterial occlusions in selected cases with high technical success and significant clinical improvement.Level of EvidenceLevel 4, Case Series.
Plastic Biliary Stent Migration During Multiple Stents Placement and Successful Endoscopic Removal Using Intra-Stent Balloon Inflation Technique: A Case Report and Literature Review.

Science.gov (United States)

Calcara, Calcedonio; Broglia, Laura; Comi, Giovanni; Balzarini, Marco

2016-02-05

Late migration of a plastic biliary stent after endoscopic placement is a well known complication, but there is little information regarding migration of a plastic stent during multiple stents placement. A white man was hospitalized for severe jaundice due to neoplastic hilar stenosis. Surgical eligibility appeared unclear on admission and endoscopy was carried out, but the first stent migrated proximally at the time of second stent insertion. After failed attempts with various devices, the migrated stent was removed successfully through cannulation with a dilation balloon. The migration of a plastic biliary stent during multiple stents placement is a possible complication. In this context, extraction can be very complicated. In our patient, cannulation of a stent with a dilation balloon was the only effective method.
Percutaneous Ureteral stent insertion

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Yoon, Yup; Sung, Dong Wook; Choi, Woo Suk; Lee, Dong Ho; Ko, Young Tae; Lee, Sun Wha; Lim, Jae Hoon [Kyung Hee University Hospital, Seoul (Korea, Republic of)

1990-10-15

Percutaneous ureteral stent insertion is a treatment of permanent or temporary urinary diversion to maintain continuity and function of the obstructed and injured ureter. We performed 31 cases of percutaneous double pig tall ureteral stent insertion in 21 patients, included 13 patients with malignant ureteral obstruction and eight patients with injured ureter as well as benign inflammatory stricture. Satisfactory resulted was obtained in all patients but one, who need percutaneous nephrostomy on week later for urinary diversion. No significant complication was encountered. The authors concluded that percutaneous ureteral stent insertion, an interventional procedure alternative to urologic retrograde method, is an effective method for urinary diversion.
Novel 3D-CT evaluation of carotid stent volume: greater chronological expansion of stents in patients with vulnerable plaques.

Science.gov (United States)

Itami, Hisakazu; Tokunaga, Koji; Okuma, Yu; Hishikawa, Tomohito; Sugiu, Kenji; Ida, Kentaro; Date, Isao

2013-09-01

Although self-expanding carotid stents may dilate gradually, the degrees of residual stenosis have been quantified by the NASCET criteria, which is too simple to reflect the configuration of the stented artery. We measured the volumes of the stent lumens chronologically by 3D-CT in patients after carotid artery stenting (CAS), and analyzed the correlations between the volume change and medical factors. Fourteen patients with carotid artery stenosis were treated using self-expanding, open-cell stents. All patients underwent preoperative plaque MRI (magnetization-prepared rapid acquisition gradient-echo, MPRAGE) and chronological 3D-CT examinations of their stents immediately after their placement and 1 day, 1 week, and 1 month after the procedure. The volume of the stent lumen was measured using a 3D workstation. The correlations between stent volume and various factors including the presence of underlying diseases, plaque characteristics, and the results of the CAS procedure were analyzed. Stent volume gradually increased in each case and had increased by 1.04-1.55 (mean, 1.25)-fold at 1 postoperative month. The presence of underlying medical diseases, plaque length, the degree of residual stenosis immediately after CAS, and plaque calcification did not have an impact on the change in stent volume. On the other hand, the stent volume increase was significantly larger in the patients with vulnerable plaques that demonstrated high MPRAGE signal intensity (P stent volume. Self-expanding stents in carotid arteries containing vulnerable plaques expand significantly more than those without such plaques in a follow-up period.
Extracranial Carotid Artery Stenting in Surgically High-Risk Patients Using the Carotid Wallstent Endoprosthesis:Midterm Clinical and Ultrasound Follow-Up Results

International Nuclear Information System (INIS)

Maleux, Geert; Bernaerts, Pauwel; Thijs, Vincent; Daenens, Kim; Vaninbroukx, Johan; Fourneau, Inge; Nevelsteen, Andre

2003-01-01

The purpose of this study was to evaluate the feasibility, safety and midterm outcome of elective implantation of the Carotid Wallstent (registered) in patients considered to be at high surgical risk. In a prospective study, 54 carotid artery stenoses in 51 patients were stented over a 24-month period. Three patients underwent bilateral carotid artery stenting. Institutional inclusion criteria for invasive treatment of carotid occlusive disease (carotid endarterectomy or carotid artery stenting) are patients presenting with a 70% or more symptomatic stenosis and those with an 80% or more asymptomatic stenosis having a life-expectancy of more than 1 year. All patients treated by carotid artery stenting were considered at high risk for carotid endarterectomy because of a hostile neck (17 patients-31.5%) or because of severe comorbidities (37 patients-68.5%). No cerebral protection device was used. Of the 54 lesions, 33 (61.1%) were symptomatic and 21 (38.8%) were asymptomatic. Follow-up was performed by physical examination and by duplex ultrasonography at 1 month, 6 months, 1 year and 2 years after the procedure. All 54 lesions could be stented successfully without periprocedural stroke. Advert events during follow-up (mean 13.9 ± 5.7 months) were non-stroke-related death in 6 patients (11.1%), minor stroke in 4 stented hemispheres(7.4%), transient ipsilateral facial pain in 1 patient (1.8%),infection of the stented surgical patch in 1 patient (1.8%) and asymptomatic in stent restenosis in 4 patients (7.4%). The percutaneous implantation of the Carotid Wallstent (registered) , even without cerebral protection device, appears to be a safe procedure with acceptable clinical and ultrasonographic follow-up results in patients at high surgical risk. But some late adverse events such as ipsilateral recurrence of non-disabling (minor) stroke or in stent restenosis still remain real challenging problems
Effect of Covered Metallic Stents Compared With Plastic Stents on Benign Biliary Stricture Resolution

Science.gov (United States)

Coté, Gregory A.; Slivka, Adam; Tarnasky, Paul; Mullady, Daniel K.; Elmunzer, B. Joseph; Elta, Grace; Fogel, Evan; Lehman, Glen; McHenry, Lee; Romagnuolo, Joseph; Menon, Shyam; Siddiqui, Uzma D.; Watkins, James; Lynch, Sheryl; Denski, Cheryl; Xu, Huiping; Sherman, Stuart

2017-01-01

IMPORTANCE Endoscopic placement of multiple plastic stents in parallel is the first-line treatment for most benign biliary strictures; it is possible that fully covered, self-expandable metallic stents (cSEMS) may require fewer endoscopic retrograde cholangiopancreatography procedures (ERCPs) to achieve resolution. OBJECTIVE To assess whether use of cSEMS is noninferior to plastic stents with respect to stricture resolution. DESIGN, SETTING, AND PARTICIPANTS Multicenter (8 endoscopic referral centers), open-label, parallel, randomized clinical trial involving patients with treatment-naive, benign biliary strictures (N = 112) due to orthotopic liver transplant (n = 73), chronic pancreatitis (n = 35), or postoperative injury (n = 4), who were enrolled between April 2011 and September 2014 (with follow-up ending October 2015). Patients with a bile duct diameter less than 6 mm and those with an intact gallbladder in whom the cystic duct would be overlapped by a cSEMS were excluded. INTERVENTIONS Patients (N = 112) were randomized to receive multiple plastic stents or a single cSEMS, stratified by stricture etiology and with endoscopic reassessment for resolution every 3 months (plastic stents) or every 6 months (cSEMS). Patients were followed up for 12 months after stricture resolution to assess for recurrence. MAIN OUTCOMES AND MEASURES Primary outcome was stricture resolution after no more than 12 months of endoscopic therapy. The sample size was estimated based on the noninferiority of cSEMS to plastic stents, with a noninferiority margin of −15%. RESULTS There were 55 patients in the plastic stent group (mean [SD] age, 57 [11] years; 17 women [31%]) and 57 patients in the cSEMS group (mean [SD] age, 55 [10] years; 19 women [33%]). Compared with plastic stents (41/48, 85.4%), the cSEMS resolution rate was 50 of 54 patients (92.6%), with a rate difference of 7.2% (1-sided 95% CI, −3.0% to ∞; P stents was rejected. The mean number of ERCPs to achieve resolution
Endovascular repair of arterial iliac vessel wall lesions with a self-expandable nitinol stent graft system.

Directory of Open Access Journals (Sweden)

Birger Mensel

Full Text Available To assess the therapeutic outcome after endovascular repair of iliac arterial lesions (IALs using a self-expandable Nitinol stent graft system.Between July 2006 and March 2013, 16 patients (13 males, mean age: 68 years with a self-expandable Nitinol stent graft. A total of 19 lesions were treated: nine true aneurysms, two anastomotic aneurysms, two dissections, one arteriovenous fistula, two type 1B endoleaks after endovascular aneurysm repair, one pseudoaneurysm, and two perforations after angioplasty. Pre-, intra-, and postinterventional imaging studies and the medical records were analyzed for technical and clinical success and postinterventional complications.The primary technical and clinical success rate was 81.3% (13/16 patients and 75.0% (12/16, respectively. Two patients had technical failure due to persistent type 1A endoleak and another patient due to acute stent graft thrombosis. One patient showed severe stent graft kinking on the first postinterventional day. In two patients, a second intervention was performed. The secondary technical and clinical success rate was 87.5% (14/16 and 93.8% (15/16. The minor complication rate was 6.3% (patient with painful hematoma at the access site. The major complication rate was 6.3% (patient with ipsilateral deep vein thrombosis. During median follow-up of 22.4 months, an infection of the aneurysm sac in one patient and a stent graft thrombosis in another patient were observed.Endovascular repair of various IALs with a self-expandable Nitinol stent graft is safe and effective.
Prospective Multicenter Study on the Challenges Inherent to Using Large Cell-Type Stents for Bilateral Stent-in-Stent Placement in Patients with Inoperable Malignant Hilar Biliary Obstruction.

Science.gov (United States)

Yang, Min Jae; Kim, Jin Hong; Hwang, Jae Chul; Yoo, Byung Moo; Lee, Sang Hyub; Ryu, Ji Kon; Kim, Yong-Tae; Woo, Sang Myung; Lee, Woo Jin; Jeong, Seok; Lee, Don Haeng

2018-06-22

Although endoscopic bilateral stent-in-stent placement is challenging, many recent studies have reported promising outcomes regarding technical success and endoscopic reintervention. This study aimed to evaluate the technical feasibility of stent-in-stent placement using large cell-type stents in patients with inoperable malignant hilar biliary obstruction. Forty-three patients with inoperable malignant hilar biliary obstruction from four academic centers were prospectively enrolled from March 2013 to June 2015. Bilateral stent-in-stent placement using two large cell-type stents was successfully performed in 88.4% of the patients (38/43). In four of the five cases with technical failure, the delivery sheath of the second stent became caught in the hook-cross-type vertex of the large cell of the first stent, and subsequent attempts to pass a guidewire and stent assembly through the mesh failed. Functional success was achieved in all cases with technical success. Stent occlusion occurred in 63.2% of patients (24/38), with a median patient survival of 300 days. The median stent patency was 198 days. The stent patency rate was 82.9%, 63.1%, and 32.1% at 3, 6, and 12 months, respectively. Endoscopic re-intervention was performed in 14 patients, whereas 10 underwent percutaneous drainage. Large cell-type stents for endoscopic bilateral stent-in-stent placement showed acceptable functional success and stent patency when technically successful. However, the technical difficulty associated with the entanglement of the second stent delivery sheath in the hook-cross-type vertex of the first stent may preclude large cell-type stents from being considered as a dedicated standard tool for stent-in-stent placement.
Effect of force-induced mechanical stress at the coronary artery bifurcation stenting: Relation to in-stent restenosis

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Lee, Cheng-Hung [Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Linkou, Chang Gung University College of Medicine, Tao-Yuan, Taiwan (China); Department of Mechanical Engineering, Chang Gung University, Tao-Yuan, Taiwan (China); Jhong, Guan-Heng [Graduate Institute of Medical Mechatronics, Chang Gung University, Tao-Yuan, Taiwan (China); Hsu, Ming-Yi; Wang, Chao-Jan [Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Tao-Yuan, Taiwan (China); Liu, Shih-Jung, E-mail: shihjung@mail.cgu.edu.tw [Department of Mechanical Engineering, Chang Gung University, Tao-Yuan, Taiwan (China); Hung, Kuo-Chun [Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Linkou, Chang Gung University College of Medicine, Tao-Yuan, Taiwan (China)

2014-05-28

The deployment of metallic stents during percutaneous coronary intervention has become common in the treatment of coronary bifurcation lesions. However, restenosis occurs mostly at the bifurcation area even in present era of drug-eluting stents. To achieve adequate deployment, physicians may unintentionally apply force to the strut of the stents through balloon, guiding catheters, or other devices. This force may deform the struts and impose excessive mechanical stresses on the arterial vessels, resulting in detrimental outcomes. This study investigated the relationship between the distribution of stress in a stent and bifurcation angle using finite element analysis. The unintentionally applied force following stent implantation was measured using a force sensor that was made in the laboratory. Geometrical information on the coronary arteries of 11 subjects was extracted from contrast-enhanced computed tomography scan data. The numerical results reveal that the application of force by physicians generated significantly higher mechanical stresses in the arterial bifurcation than in the proximal and distal parts of the stent (post hoc P < 0.01). The maximal stress on the vessels was significantly higher at bifurcation angle <70° than at angle ≧70° (P < 0.05). The maximal stress on the vessels was negatively correlated with bifurcation angle (P < 0.01). Stresses at the bifurcation ostium may cause arterial wall injury and restenosis, especially at small bifurcation angles. These finding highlight the effect of force-induced mechanical stress at coronary artery bifurcation stenting, and potential mechanisms of in-stent restenosis, along with their relationship with bifurcation angle.
Effect of force-induced mechanical stress at the coronary artery bifurcation stenting: Relation to in-stent restenosis

International Nuclear Information System (INIS)

Lee, Cheng-Hung; Jhong, Guan-Heng; Hsu, Ming-Yi; Wang, Chao-Jan; Liu, Shih-Jung; Hung, Kuo-Chun

2014-01-01

The deployment of metallic stents during percutaneous coronary intervention has become common in the treatment of coronary bifurcation lesions. However, restenosis occurs mostly at the bifurcation area even in present era of drug-eluting stents. To achieve adequate deployment, physicians may unintentionally apply force to the strut of the stents through balloon, guiding catheters, or other devices. This force may deform the struts and impose excessive mechanical stresses on the arterial vessels, resulting in detrimental outcomes. This study investigated the relationship between the distribution of stress in a stent and bifurcation angle using finite element analysis. The unintentionally applied force following stent implantation was measured using a force sensor that was made in the laboratory. Geometrical information on the coronary arteries of 11 subjects was extracted from contrast-enhanced computed tomography scan data. The numerical results reveal that the application of force by physicians generated significantly higher mechanical stresses in the arterial bifurcation than in the proximal and distal parts of the stent (post hoc P < 0.01). The maximal stress on the vessels was significantly higher at bifurcation angle <70° than at angle ≧70° (P < 0.05). The maximal stress on the vessels was negatively correlated with bifurcation angle (P < 0.01). Stresses at the bifurcation ostium may cause arterial wall injury and restenosis, especially at small bifurcation angles. These finding highlight the effect of force-induced mechanical stress at coronary artery bifurcation stenting, and potential mechanisms of in-stent restenosis, along with their relationship with bifurcation angle.
Renal PTA stenting

International Nuclear Information System (INIS)

Tsetis, D.

2012-01-01

Full text: Renal artery stenosis (RAS) is a common condition that may lead to hypertension, progressive renal dysfunction and cardiovascular morbidity. Catheter-based therapy for symptomatic, haemodynamically significant, RAS has become the preferred method of revascularization. Balloon angioplasty has been the traditional treatment of choice for fibromuscular dysplasia, however stents are increasingly used for the treatment of atheromatous lesions; in many cases-such as in ostial lesions-, direct stenting is strongly indicated. Despite the increased use of endovascular therapy for renal artery stenosis, there is still controversy regarding the optimal management and the net benefit of this treatment. Several randomized trials of balloon angioplasty or stenting for renal artery stenosis compared with medical therapy alone have been conducted, however these could not show definite advantage of endovascular therapy. Problems encountered with those trials include enrollment of small number of patients, frequent crossover from medical to interventional therapy compromising the intention-to-treat results, or selection of patients that are not expected to show clear benefit. The Angioplasty and Stenting for Renal Artery Lesions (ASTRAL) is the most important of these trials; however, it,s study design was faulty and therefore did not provide conclusive evidence to answer the question of whether angioplasty and stenting or medical therapy is the best treatment for haemodynamically significant RAS. All expectations are now focused on the Cardiovascular Outcomes in Renal Atherosclerotic Lesions (CORAL) trial which was designed to answer the same question, and its methodologies took into consideration the weaknesses of the ASTRAL trial. Regarding stent device itself, it seems that the optimal design is probably a stainless steel, laser cut, open-cells stent mounted on a rapid exchange delivery balloon catheter compatible with 0.014-in and 0.018-in guidewire. As a future
Direct stent puncture technique for intraluminal stent recanalization in the superficial femoral and popliteal arteries in-stent occlusion: Outcomes from a prospective clinical analysis of diabetics with critical limb ischemia

Energy Technology Data Exchange (ETDEWEB)

Palena, Luis Mariano, E-mail: marianopalena@hotmail.com; Manzi, Marco

2013-07-15

Purpose: To evaluate the efficacy and safety of “Direct Stent Puncture” technique for intraluminal stent recanalization in the femoro-popliteal segments. Methods and Materials: A cohort of diabetics who had symptomatic in-stent occlusion of the superficial femoral or popliteal arteries underwent endovascular recanalization. After antegrade failure, direct stent puncture technique was performed. The primary end-point was to efficacy assessment, intended as technical success and clinical improvement. The secondary end-point was safety assessment, intended as free of complication rate. Results: Fifty-four patients (37 men; 73.6 ± 8.5 years) underwent direct stent puncture technique, after several unsuccessful antegrade attempts to cross the occluded stent. Technical success for intraluminal stent recanalization was achieved in 53/54 (98.2%) of cases and failed in 1/54 (1.8%). Clinical improvement was obtained in 51/54 (94.4%) of cases, with regression of the clinical symptoms and improvement of the TcPO{sub 2}, from 3 ± 18 mmHg to 43 ± 11 mmHg after 15 days (p < 0.001). Free of complications rate was 92.5%. In 2/54 (3.7%) of cases distal embolization occurred, in 1/54 (1.9%) case a sudden vessel thrombosis was diagnosed after 12 hours and in 1/54 (1.9%) case hematoma at the stent puncture site was observed. Conclusions: Direct Stent Puncture technique is an efficacy and safety option for intraluminal stent recanalization in the femoro-popliteal segment in-stent occlusion.

R[iological interventions in central venous obstructions. Dilatation, stent-implantation and thrombolysis

International Nuclear Information System (INIS)

Mathias, K.; Jaeger, H.; Willaschek, J.; Theophil, B.

1998-01-01

Purpose: Venous congestion of the superior or inferior caval system has to be considered as a medical emergency. The results of various recanalization procedures and their utility are analyzed. Patients and methods: 176 patients with superior and 28 with inferior caval obstruction were treated with Gianturco-Z (n=39) and Wall Stents (n=207) respectively. Balloon venoplasty was performed prior to stent implanation. In 27 cases, local thrombolysis with urokinase was employed. Results: Interventional procedures were succesful in 198 and without success in 6 patients. In most patients, symptoms were relieved during or early after recanalization. No major complications were found. Discussion: Balloon angioplasty with stent placement and local thrombolysis are successful in the treatment of superior and inferior caval obstruction. Self-expanding Wallstents are superior to Gianturco-Z-stents. Oncologists should be m[e familiar with this type of treatment. (orig.) [de
Delayed cerebral infarction due to stent folding deformation following carotid artery stenting

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Seo, Kwon Duk; Lee, Kyung Yul; Suh, Sang Hyun [Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of); Kim, Byung Moon [Dept. of Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of)

2014-12-15

We report a case of delayed cerebral infarction due to stent longitudinal folding deformation following carotid artery stenting using a self-expandable stent with an open-cell design. The stented segment of the left common carotid artery was divided into two different lumens by this folding deformation, and the separated lumens became restricted with in-stent thrombosis. Although no established method of managing this rare complication exists, a conservative approach was taken with administration of anticoagulant and dual antiplatelet therapy. No neurological symptoms were observed during several months of clinical follow-up after discharge.
Dual-Source CT Angiography of Peripheral Arterial Stents: In Vitro Evaluation of 22 Different Stent Types

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Michael Köhler

2011-01-01

Full Text Available Purpose. To test different peripheral arterial stents using four image reconstruction approaches with respect to lumen visualization, lumen attenuation and image noise in dual-source multidetector row CT (DSCT in vitro. Methods and Materials. 22 stents (nitinol, steel, cobalt-alloy, tantalum, platinum alloy were examined in a vessel phantom. All stents were imaged in axial orientation with standard parameters. Image reconstructions were obtained with four different convolution kernels. To evaluate visualization characteristics of the stent, the lumen diameter, intraluminal density and noise were measured. Results. The mean percentage of the visible stent lumen diameter from the nominal stent diameter was 74.5% ± 5.7 for the medium-sharp kernel, 72.8% ± 6.4 for the medium, 70.8% ± 6.4 for the medium-smooth and 67.6% ± 6.6 for the smooth kernel. Mean values of lumen attenuation were 299.7HU ± 127 (medium-sharp, 273.9HU ± 68 (medium, 270.7HU ± 53 (medium-smooth and 265.8HU ± 43. Mean image noise was: 54.6 ± 6.3, 20.5 ± 1.7, 16.3 ± 1.7, 14.0 ± 2 respectively. Conclusion. Visible stent lumen diameter varies depending on stent type and scan parameters. Lumen diameter visibility increases with the sharpness of the reconstruction kernel. Smoother kernels provide more realistic density measurements inside the stent lumen and less image noise.
Nitinol Esophageal Stents: New Designs and Clinical Indications

International Nuclear Information System (INIS)

Strecker, Ernst-Peter; Boos, Irene; Vetter, Sylvia; Strohm, Michael; Domschke, Sigurd

1996-01-01

Purpose: To evaluate the clinical use of covered and noncovered, knitted nitinol stents in patients presenting new stent indications. Methods: Self-expandable, knitted nitinol stents were implanted in four patients for treatment of dysphagia. In two patients who had malignant strictures and had esophago-respiratory fistulae and in one patient with an esophagocutaneous fistula, polytetrafluoroethylene (PTFE)-covered stents were implanted. One patient received a noncovered stent, but a retrograde approach through a percutaneous endoscopic gastrostomy (PEG) fistula had to be chosen for recanalization of an esophageal occlusion. Two patients received stents for treatment of benign strictures. Results: Recanalization of the stricture and stent implantation were performed under fluoroscopic control without any procedure-related morbidity or mortality. Dysphagia improved in all patients and the esophageal fistulae could be sealed off by covered stents. During a maximum follow-up of 18 months, there was no stent migration or esophageal perforation. Complications observed were stent stenosis due to food impaction (1/4) and benign stent stenosis (2/2). Most complications could be treated by the interventional radiologist. Conclusion: Self-expandable, covered Nitinol stents provide an option for the treatment of dysphagia combined with esophageal fistulae. In combination with interventional radiology techniques, even complex strictures are accessible. For benign strictures, the value of stent treatment has not yet been proven
Role of metallic stents in benign esophageal stricture

Science.gov (United States)

Shim, Chan Sup

2012-10-01

Simple esophageal strictures, which are focal, straight, and large in diameter, usually require 1 - 3 dilation sessions to relieve symptoms. However, complex strictures, which are long, tortuous, or associated with a severely compromised luminal diameter, are usually more difficult to treat with conventional bougie or balloon dilation techniques, and often have high recurrence rates. Although the permanent placement of self-expandable metal stents (SEMS) has been used to manage refractory benign esophageal strictures, this procedure is associated with additional problems, such as stricture from tissue hyperplasia, stent migration, and fistula formation. Thus, several new types of stents have been developed, including temporary SEMS, self-expandable plastic stents (SEPS), and biodegradable stents. The use of these new products has produced varied results. Temporary SEMS that have been used to relieve benign esophageal conditions have caused granulation tissue at both ends of the stent because of contact between the mucosa and the exposed metal components of the stent, thus hindering stent removal. We examined the tissue response to two new types of SEMS, a flange-type and a straighttype, each coated with a silicone membrane on the outside of the metal mesh. These two SEMS were evaluated individually and compared with a conventional control stent in animal experiments. Although the newly designed stents resulted in reduced tissue hyperplasia, and were thus more easily separated from the esophageal tissue, some degree of tissue hyperplasia did occur. We suggest that newly designed DES (drug-eluting stents) may provide an alternative tool to manage refractory benign esophageal stricture.
Malignant gastric outlet obstruction managed by endoscopic stenting: a prospective single-centre study

DEFF Research Database (Denmark)

Havemann, Maria Cecilie; Adamsen, Sven; Wøjdemann, Morten

2008-01-01

-to-treat principle. All patients were offered endoscopic stenting. Oral intake before and after stenting was assessed using the gastric outlet obstruction score system (GOOSS). Various lengths of duodenal Hanaro(R) self-expanding nitinol stents were delivered through a therapeutic endoscope. Outcome criteria were......Objective. Endoscopic stenting for malignant gastric outlet obstruction was chosen as the primary strategy by which to palliate this complication, which is dominated by weight loss and anorexia. Advanced upper gastrointestinal tract cancers present late and life expectancy is limited. Only smaller...... multicentre studies point to endoscopic stenting as superior to surgery in terms of clinical outcome and cost. Material and methods. Forty-five consecutive patients with gastric outlet obstruction as a result of advanced upper GI-tract malignancy were enrolled in accordance with the intention...
Risk Factors and Clinical Evaluation of Superficial Femoral Artery Stent Fracture: Prote'ge'GPS Stent

International Nuclear Information System (INIS)

Lee, Da Un; Kim, Jae Kyu; Jung, Hye Doo; Huh, Tae Wook; Yim, Nam Yeol; Oh, Hyun jun; Choi, Soo Jin Na; Chang, Nam Kyu

2010-01-01

To evaluate the occurrence of superficial femoral artery stent fractures, the risk factors of stent fracture, and the relationship between fractures and clinical findings. Of the 38 patients who underwent treatment with Prote'ge'GPS stenting due to arterial occlusions on the superficial femoral artery, 17 also underwent a clinical analysis. Forty-three stents were inserted in the 17 superficial femoral arteries, ranging between 15 and 50 cm in length, with a mean treated length of 26.4 cm (15-50 cm). A fracture was evaluated by taking a PA and lateral simple radiography, as well as a follow-up evaluation accompanied with a CT angiography, DSA, and a color Doppler sonography. The examination involved the assessment of the difference between bone fractures due to length, placement, and frequency. Fractures occurred in 13 of 43 stents (30.2%). A total of 10 (71.4%) occurred in the upper third, compared to 4 (28.6%) in the lower third of the superficial femoral artery. In addition, 10 stents (71.4%) had a single strut fracture, whereas 4 (28.6%) had multiple strut fractures. A stent fracture occurred more frequently when the stents and lesions were longer (p=0.021, 0.012) and the stents were inserted near the joint. However, there was no significant relationship between stent numbers and the fractures (p=0.126). When the stents were inserted along the popliteal artery, a stent fracture occurred more frequently in the lower third of the artery. The stent fractures did not significantly influence the patency rate of the stented artery (p=0.44) Prote'ge'GPS stents in the superficial femoral artery revealed a considerable number of fractures and the fracture frequency showed a significant relationship with the length of stents and lesions. The closer stent insertion was to the joints, the more frequently fractures occurred. There were no evident significant relationships between the presence of stent fractures and the patency of the stented arteries
The Bolton Treovance abdominal stent-graft: European clinical trial design.

Science.gov (United States)

Chiesa, R; Riambau, V; Coppi, G; Zipfel, B; Llagostera, S; Marone, E M; Kahlberg, A

2012-10-01

Endovascular aortic repair (EVAR) has emerged as a promising, less invasive alternative to conventional open surgery for the treatment of infrarenal abdominal aortic aneurysms (AAAs). In the last 20 years, the application rate of EVAR and its clinical results have significantly improved thanks to the evolution of stent-grafts and endovascular delivery systems. However, further development is still needed to reduce the incidence of complications and secondary re-interventions. The Treovance abdominal aortic stent-graft (Bolton Medical, Barcelona, Spain) is a new-generation endovascular device, developed to increase flexibility, lower profile, improve deployment and sealing mechanisms. In particular, it is provided with some innovative features as a double layer of proximal barbs (suprarenal and infrarenal) for supplemental fixation, dull barbs between modules to avoid potential leg disconnections, detachable outer sheath provided with a new-design hemostatic valve, and a double improved mechanism (slow motion and "pin and pull") for precise stent-graft deployment. A European prospective, non-randomized, multi-institutional, "first-in-human" trial (the ADVANCE trial) was conducted from March to December 2011 to assess the safety and performance of the Treovance stent-graft system before commercialization. Thirty patients with anatomically suitable non-ruptured AAAs were enrolled at five clinical sites in Italy, Spain, and Germany. EVAR was completed successfully in all patients. The stent-graft was delivered and deployed safely even in heavily angulated or calcified anatomies. No 30-day device-related complications nor deaths were observed. Preliminary experience with the Treovance abdominal stent-graft within the ADVANCE trial was satisfactory with regard to technical success and perioperative clinical results. Follow-up data are needed to assess mid- and long-term clinical outcomes, along with durability of this new-generation endovascular device.
Enterprise stent for waffle-cone stent-assisted coil embolization of large wide-necked arterial bifurcation aneurysms.

Science.gov (United States)

Padalino, David J; Singla, Amit; Jacobsen, Walter; Deshaies, Eric M

2013-01-01

Large wide-necked arterial bifurcation aneurysms present a unique challenge for endovascular coil embolization treatment. One technique described in the literature deploys a Neuroform stent into the neck of the aneurysm in the shape of a waffle-cone, thereby acting as a scaffold for the coil mass. This case series presents four patients with large wide-necked bifurcation aneurysms treated with the closed-cell Enterprise stent using the waffle-cone technique. Four patients (59 ± 18 years of age) with large wide-necked arterial bifurcation aneurysms (three basilar apex and one MCA bifurcation) were treated with the waffle-cone technique using the Enterprise stent as a supporting device for stent-assisted coil embolization. Three of the patients presented with aneurysmal subarachnoid hemorrhage (Hunt-Hess 2-3; Fisher Grade 3-4). There was no procedural morbidity or mortality associated with treatment itself. One aneurysm was completely obliterated, and three had small residual necks. One patient developed an area of PCA infarct and visual field cut one month after the procedure and required recoiling of the residual neck. The flared ends of the Enterprise stent remodeled the aneurysm neck by conforming to the shape of the neck without any technical difficulty, resulting in a stable scaffold holding the coils into the aneurysm. The closed cell construction, flexibility, and flared ends of the Enterprise stent allow it to conform to the waffle-cone configuration and provide a stable scaffold for coil embolization of large wide-necked arterial bifurcation aneurysms. We have had excellent initial results using the Enterprise stent with the waffle-cone technique. However, this technique is higher risk than standard treatment methods and therefore should be reserved for large wide-necked bifurcation aneurysms where Y stenting is needed, but not possible, and surgical clip ligation is not an option.
Accelerated Recovery of Endothelium Function after Stent Implantation with the Use of a Novel Systemic Nanoparticle Curcumin

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Qi Lu

2015-01-01

Full Text Available Curcumin was reported to exhibit a wide range of pharmacological effects including antioxidant, anti-inflammatory, and antiproliferative activities and significantly prevent smooth muscle cells migration. In the present study, a novel kind of curcumin loaded nanoparticles (Cur-NP has been prepared and characterized with the aim of inhibiting inflammation formation and accelerating the healing process of the stented arteries. Cur-NP was administrated intravenously after stent implantation twice a week and detailed tissue responses were evaluated. The results demonstrated that intravenous administration of Cur-NP after stent implantation accelerated endothelial cells restoration and endothelium function recovery and may potentially be an effective therapeutic alternative to reduce adverse events for currently available drug eluting stents.
Long term follow-up of bifurcation aneurysms treated with braided stent assisted coiling and complex T- and Y- stent constructs.

Science.gov (United States)

Cheung, Nicholas K; Chiu, Albert Hy; Cheung, Andrew; Wenderoth, Jason D

2018-06-01

Stent assisted coil embolization (SACE) of bifurcation aneurysms is challenging. Heterogeneous results have been achieved to date, but largely for laser cut stents. While braided stents offer multiple technical advantages, their long term efficacy has yet to be validated. To report the first long term 18 month results for the durability of bifurcation aneurysms treated with braided stents. Over a 4 year period, 59 consecutive patients with 60 bifurcation aneurysms underwent elective braided SACE across three Australian neurovascular centers. 17 of these aneurysms underwent T- or Y-shaped stent constructs. All patients had immediate, 6 month and 18 month clinical and radiological follow-up. Radiological assessment was made on modified Raymond-Roy occlusion scores while clinical assessment was based on the modified Rankin Scale. Subgroup analysis of 17 aneurysms treated with multi-stent constructs was conducted. 6 month follow-up data were available for 59 aneurysms and 18 month follow-up data for 58 aneurysms. Satisfactory aneurysm occlusion was achieved in 97% at inception and at 6 months, and 98% at 18 months. Good neurological outcomes were achieved in 95% at 18 months. Similar satisfactory results were achieved with the multi-stent construct cohort. Intraprocedural thromboembolic events were recorded in 5% and delayed events in 2%. Technical complications were found in 5%. All complication rate was 13%. Braided SACE was safe, efficacious, and durable at the long term 18 month follow-up, including for multi-stent constructs. Preliminary results indicate favorable clinical and radiological outcomes compared with laser cut stents. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Manchester iStent study: early results from a prospective UK case series.

Science.gov (United States)

Patel, Ilesh; de Klerk, Timothy A; Au, Leon

2013-01-01

To evaluate the 6-month efficacy and safety of the iStent microtrabecular bypass stent in patients with open-angle glaucoma. A prospective, uncontrolled, interventional case series. Forty-four eyes with open-angle glaucoma were reported. All subjects underwent ab interno implantation of a single iStent together with (n = 40) or without (n = 4) cataract surgery. Patients were assessed at postoperative week 1, months 1 and 3, and quarterly, thereafter. Data collected included visual acuity, intraocular pressure measurement using Goldmann tonometry, number of glaucoma medications, and number and type of complications. The mean age of the sample was 76.8 years. The mean duration since glaucoma diagnosis was 5.3 years (standard deviation 2.9 years). The mean visual acuity was 0.53 logMAR at baseline that improved to 0.23 at 6 months postoperatively. The mean baseline intraocular pressure was 21.1 mmHg, and this decreased significantly to 16.7 mmHg at 6 months (P control. © 2013 The Authors. Clinical and Experimental Ophthalmology © 2013 Royal Australian and New Zealand College of Ophthalmologists.
Clinical application of hepatic vein percutaneous transluminal angioplasty and stent after stent placement in inferior vena cava

International Nuclear Information System (INIS)

Xu Hao; Zu Maoheng; Gu Yuming; Li Guojun; Zhang Qingqiao; Wei Ning; Xu Wei; Liu Hongtao

2005-01-01

Objective: To investigate the feasibility and effect of recanalization of hepatic vein with percutaneous transluminal angioplasty (PTA) and stent after stent placement in inferior vena cava (IVC). Methods: Eleven patients with Budd-Chiari syndrome (BCS)were once performed metal stent placement in IVC at other hospital, but ascites was not subsided in 9 patients after the stent placement and occurred again in 2 patients in 3 months after the procedure. PTA and metal stent placement were used to treat the occlusion of the hepatic vein (HV) via stent in IVC. Results: Recanalization of occlusive HV was successful in all 11 patients, and symptoms disappeared or were obviously improved. The mean blood pressure in HV dropped from pre-operation (45.12 ± 1.57) cm H 2 O (1 cm H 2 O=0.098 kPa) to post-operation (17.53 ± 0.68) cm H 2 O (P<0.01). In a period of 4-30 months (mean: 13.6 months) following-up, no patient reoccurred symptoms. Conclusion: Recanalization of HV via stent in IVC is a feasible and effective method for occlusive HV, but it is difficult. (authors)
Stenting of major airway constriction

International Nuclear Information System (INIS)

Wu Xiaomei

2002-01-01

Objective: To investigate the correlated issues in the stenting treatment of major airway constriction. Methods: Nineteen cases of major airway stenting procedure were studied retrospectively. The clinical choice of stents of different advantages or deficiencies were discussed. The importance of intravenous anesthesia supporting, life-parameters monitoring during the procedures and the prevention of complications were analysed. Results: Under intravenous and local anesthesia, 19 Wallstents had been successively placed and relieved 19 cases of major airway constrictions due to malignant or benign diseases (15 of tumors, 3 of tuberculosis, 1 of tracheomalacia). Intravenous anesthesia and life-parameters monitoring had made the procedures more safe and precise. Conclusions: Major airway stenting is an reliable method for relieving tracheobronchial stenosis; and intravenous anesthesia supporting and life-parameters monitoring guarantee the satisfactions of procedures
Coated stents to prevent restenosis in coronary heart disease

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Hagen, Anja

2005-11-01

Full Text Available Background: In-stent-restenosis (ISR is considered to be an essential limiting factor of stenting in coronary heart disease (CHD. The development of coated stents has raised expectations on substantial lowering restenosis after stenting with decreasing the rate of restenosis and a reduction in the rate of clinical events. Objectives: The present analysis addresses the questions on medical effectiveness and cost-effectiveness of the use of various coated stent types in CHD. Methods: The literature was searched in December 2004 in the most relevant medical and economic databases. The medical evaluation was conducted on the basis of published RCT. The data from the studies regarding various angiographic, sonographic and clinical endpoints were checked for methodical quality and summarised in meta-analyses. Within the scope of economic evaluation the primary studies were analysed and modelling was performed, applying clinical effect estimates from the meta-analyses of the medical evaluation and current estimates of German costs. Results: Medical evaluation: Ten different stenttypes were used in the included 26 RCT. The results for heparin, silicon-carbide, carbon and PTFE coated stenttypes could not reveal any significant differences between the medical effectiveness of coated and uncoated stents. The application of sirolimus, paclitaxel, everolimus and 7-hexanoyltaxol eluting stents showed a significant lower restenosis at 6-9 months with decrease in the rate of restenosis for polymer-based sirolimus, paclitaxel and 7-hexanoyltaxol eluting stents. In contrast, the use of gold-coated and actinomycin-D eluting stents was associated with a significantly higher restenosis. The polymer-based sirolimus and paclitaxel eluting stents also showed a significant and considerable reduction in the rate of repeated percutaneous revascularisations at 6-12 months (3.5% vs. 19.7%; p<0.0001, RR=0.19 [95%CI: 0.11; 0.33] and 3.5% vs. 12.2%; p<0.0001, RR=0.30 [95%CI: 0
Future developments in biliary stenting

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Hair CD

2013-06-01

Full Text Available Clark D Hair,1 Divyesh V Sejpal21Department of Medicine, Section of Gastroenterology and Hepatology, Baylor College of Medicine, Houston, TX, USA; 2Department of Medicine, Section of Gastroenterology, Hofstra North Shore-LIJ School of Medicine, North Shore University Hospital, Manhasset, NY, USAAbstract: Biliary stenting has evolved dramatically over the past 30 years. Advancements in stent design have led to prolonged patency and improved efficacy. However, biliary stenting is still affected by occlusion, migration, anatomical difficulties, and the need for repeat procedures. Multiple novel plastic biliary stent designs have recently been introduced with the primary goals of reduced migration and improved ease of placement. Self-expandable bioabsorbable stents are currently being investigated in animal models. Although not US Food and Drug Administration approved for benign disease, fully covered self-expandable metal stents are increasingly being used in a variety of benign biliary conditions. In malignant disease, developments are being made to improve ease of placement and stent patency for both hilar and distal biliary strictures. The purpose of this review is to describe recent developments and future directions of biliary stenting.Keywords: plastic stents, self-expandable metal stents, drug eluting stents, bioabsorbable stents, malignant biliary strictures, benign biliary strictures
Exclusion of Atherosclerotic Plaque from the Circulation Using Stent-Grafts: Alternative to Carotid Stenting with a Protection Device?

International Nuclear Information System (INIS)

Peynircioglu, Bora; Geyik, Serdar; Yavuz, Kivilcim; Cil, Barbaros E.; Saatci, Isil; Cekirge, Saruhan

2007-01-01

Purpose. To retrospectively assess the feasibility, safety, and clinical mid-term outcome of patients undergoing carotid artery stenting with stent-grafts. Methods. Over a 4 year period stent-grafts were used in the endovascular treatment of symptomatic internal carotid artery stenosis in 12 patients (2 women, 10 men, aged 47-83 (mean 64) years). Protection devices were not used. Possible microembolic complications were evaluated by magnetic resonance imaging (MRI) examinations of the brain before and the day after the procedure in all patients. Mean follow-up was 22 months (range 1-42 months), by Doppler ultrasonography and conventional angiography as well as clinical examination .Results. The technical success rate was 100%. A total of 13 coronary stent-grafts were used. The mean stenosis rate (in terms of diameter) was 85% and the mean length of stent-grafts used was 20.9 mm. The mean diameter to which the stent-grafts were dilated was 4.66 mm. In-hospital complications occurred in 1 patient who suffered a minor femoral access hematoma that did not require transfusion or surgical decompression. Post-stenting diffusion-weighted MRI revealed several ipsilateral silent microemboli in only 1 case, which was completely asymptomatic. Two patients had a major stroke after 2 years of follow-up. Restenosis was found in 2 patients who underwent successful balloon dilatation followed by placement of a self-expandable bare stent within the stent-grafts. Conclusions. Stent-grafts may prevent microembolic complications during stenting of atherosclerotic carotid lesions in selected cases, offering immediate exclusion of the atherosclerotic lesion from the circulation by pressing the plaque against the vessel wall. Comparative, randomized studies in larger series of patients are needed with carotid-dedicated stent-graft designs
Targeting In-Stent-Stenosis with RGD- and CXCL1-Coated Mini-Stents in Mice.

Science.gov (United States)

Simsekyilmaz, Sakine; Liehn, Elisa A; Weinandy, Stefan; Schreiber, Fabian; Megens, Remco T A; Theelen, Wendy; Smeets, Ralf; Jockenhövel, Stefan; Gries, Thomas; Möller, Martin; Klee, Doris; Weber, Christian; Zernecke, Alma

2016-01-01

Atherosclerotic lesions that critically narrow the artery can necessitate an angioplasty and stent implantation. Long-term therapeutic effects, however, are limited by excessive arterial remodeling. We here employed a miniaturized nitinol-stent coated with star-shaped polyethylenglycole (star-PEG), and evaluated its bio-functionalization with RGD and CXCL1 for improving in-stent stenosis after implantation into carotid arteries of mice. Nitinol foils or stents (bare metal) were coated with star-PEG, and bio-functionalized with RGD, or RGD/CXCL1. Cell adhesion to star-PEG-coated nitinol foils was unaltered or reduced, whereas bio-functionalization with RGD but foremost RGD/CXCL1 increased adhesion of early angiogenic outgrowth cells (EOCs) and endothelial cells but not smooth muscle cells when compared with bare metal foils. Stimulation of cells with RGD/CXCL1 furthermore increased the proliferation of EOCs. In vivo, bio-functionalization with RGD/CXCL1 significantly reduced neointima formation and thrombus formation, and increased re-endothelialization in apoE-/- carotid arteries compared with bare-metal nitinol stents, star-PEG-coated stents, and stents bio-functionalized with RGD only. Bio-functionalization of star-PEG-coated nitinol-stents with RGD/CXCL1 reduced in-stent neointima formation. By supporting the adhesion and proliferation of endothelial progenitor cells, RGD/CXCL1 coating of stents may help to accelerate endothelial repair after stent implantation, and thus may harbor the potential to limit the complication of in-stent restenosis in clinical approaches.
A novel, ring-connected stent versus conventional GI stents: comparative study of physical properties and migration rates in a canine colon obstruction model.

Science.gov (United States)

Park, Hong Suk; Choo, In Wook; Seo, Soowon; Hyun, Dongho; Lim, Sooyoun; Kim, Jae J; Hong, Saet-Byul; Min, Byung-Hoon; Do, Young Soo; Choo, Sung Wook; Shin, Sung Wook; Park, Kwang Bo; Cho, Sung Ki

2015-01-01

Migration of stents is one of the most common adverse events in covered stent placement in GI tract obstruction. To compare physical property and migration rates in a canine colon obstruction model among a novel stent and conventional stents. Comparative physical test and animal study. Medical device testing laboratory and animal laboratory. Mongrel dogs (N=26). Surgical colon obstruction followed by placement of a novel (n=13) or conventional (n=13) stent. Physical properties, migration, and adverse events. The novel stent showed better flexibility, as in a physical test of longitudinal compressibility and axial force, than did conventional stents, and it withstood the fatigue test for 10 days. In terms of radial force and tensile strength, the novel stent showed the same or better results than conventional stents. In a canine colon obstruction model, the migration rate of a novel stent was significantly lower than that of a conventional stent (2/13, 15.4% vs 8/13, 61.5%; P=.008). Animal study of limited size. The novel, ring-connected stent is more flexible and more resistant to migration than the conventional stents. Copyright © 2015 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.
An ovine in vivo framework for tracheobronchial stent analysis.

Science.gov (United States)

McGrath, Donnacha J; Thiebes, Anja Lena; Cornelissen, Christian G; O'Shea, Mary B; O'Brien, Barry; Jockenhoevel, Stefan; Bruzzi, Mark; McHugh, Peter E

2017-10-01

Tracheobronchial stents are most commonly used to restore patency to airways stenosed by tumour growth. Currently all tracheobronchial stents are associated with complications such as stent migration, granulation tissue formation, mucous plugging and stent strut fracture. The present work develops a computational framework to evaluate tracheobronchial stent designs in vivo. Pressurised computed tomography is used to create a biomechanical lung model which takes into account the in vivo stress state, global lung deformation and local loading from pressure variation. Stent interaction with the airway is then evaluated for a number of loading conditions including normal breathing, coughing and ventilation. Results of the analysis indicate that three of the major complications associated with tracheobronchial stents can potentially be analysed with this framework, which can be readily applied to the human case. Airway deformation caused by lung motion is shown to have a significant effect on stent mechanical performance, including implications for stent migration, granulation formation and stent fracture.

Are bio-absorbable stents the future of SFA treatment?

Science.gov (United States)

Peeters, P; Keirse, K; Verbist, J; Deloose, K; Bosiers, M

2010-02-01

Several limitations inherent to the implantation of a metallic device, such as the occurrence of in-stent re-stenosis, in an arterial lumen intuitively explain the interest for developing bio-absorbable stents. Two main types of bio-absorbable stents currently exist: polymer stents and metallic stents. To date, no studies with bio-absorbable stents have been conducted in the superficial femoral artery (SFA). Because of their strut thickness and lack of radial force, polymer stents are no good candidates for endovascular use. Absorbable metal stents (AMS) do have the potential to perform well for artery treatment, although current evidence from in-human coronary and infrapopliteal studies yield unsatisfactory results. Drastic technological improvements are mandatory before AMS can be considered for every day practice. Yet, it is our belief that further development of other metal and non-metal bio-absorbable stents, with or without drug-coating, may lead to the creation of the ultimate SFA stent.
Anchoring barbs and balloon expandable stents: what is the risk of perforation and failed stent deployment?

Science.gov (United States)

Bown, M J; Harrison, G J; How, T V; Brennan, J A; Fisher, R K; Vallabhaneni, S R; McWilliams, R G

2012-09-01

Balloon expandable stents may on occasion be deployed in close proximity to the anchoring barbs of endovascular grafts. The aim of this study was to determine the risk and effect of balloon perforation by anchoring barbs and to assess whether these risks are different if the balloon is protected by a covered stent mounted upon it. A bench-top model was developed to mimic the penetration of anchoring barbs into the lumen of medium sized blood vessels. The model allowed variation of angle and depth of vessel penetration. Both bare balloons and those with covered stents mounted upon them were tested in the model to determine whether there was a risk of perforation and which factors increased or decreased this risk. All combinations of barb angle and depth caused balloon perforation but this was most marked when the barb was placed perpendicular to the long axis of the balloon. When the deployment of covered stents was attempted balloon perforation occurred in some cases but full stent deployment was achieved in all cases where the perforation was in the portion of the balloon covered by the stent. The only situation in which stent deployment failed was where the barb was intentionally placed in the uncovered portion of the balloon. This resulted in only partial deployment of the stent. Balloon rupture is a distinct possibility when deploying balloon-expandable stents in close proximity to anchoring barbs. Care should be taken in this circumstance to ensure that the barb is well away from the uncovered portion of the balloon. Copyright © 2012 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.
No association between metal allergy and cardiac in-stent restenosis in patients with dermatitis-results from a linkage study

DEFF Research Database (Denmark)

Thyssen, Jacob P; Engkilde, Kåre; Menné, Torkil

2011-01-01

Background. Percutaneous coronary intervention (PCI) with implantation of a metal stent is a common procedure performed in patients with symptomatic ischaemic heart disease. Intracoronary stents typically have a backbone of stainless steel, which contains nickel, chromium, and molybdenum, and it ......Background. Percutaneous coronary intervention (PCI) with implantation of a metal stent is a common procedure performed in patients with symptomatic ischaemic heart disease. Intracoronary stents typically have a backbone of stainless steel, which contains nickel, chromium, and molybdenum......, and it remains unclear whether individuals who are allergic to these metals have an increased risk of restenosis after PCI with stent implantation. Objectives. To further evaluate whether dermatitis patients with nickel and/or chromium allergy had an increased risk of developing cardiac in-stent restenosis...... with stainless steel stents. Methods. An individual-level linkage study was performed to identify dermatitis patients who had been patch tested with the European baseline series between 1979 and 2007 at Gentofte University Hospital (N = 18794) and who had also undergone PCI at some point in a Danish hospital...
Results of a randomized clinical trial of external beam radiation to prevent restenosis after superficial femoral artery stenting.

Science.gov (United States)

Therasse, Eric; Donath, David; Elkouri, Stéphane; Lespérance, Jacques; Giroux, Marie-France; Oliva, Vincent L; Guertin, Marie-Claude; Bouchard, Louis; Perreault, Pierre; Gilbert, Patrick; Soulez, Gilles

2016-06-01

The objective of this study was to evaluate the safety and efficacy of external beam radiation (EBR) in preventing restenosis after superficial femoral artery (SFA) stenting in comparison with a control group treated with SFA stenting only. In this Institutional Review Board-approved study, patients who provided written informed consent were randomly assigned to 0 Gy or 14 Gy of EBR to the stent site 24 hours after SFA stenting. The primary end point was the angiographic binary restenosis rate 2 years after stenting. Categorical and continuous end points were respectively analyzed using logistic regression models and Wilcoxon tests. End points expressed as time to event were analyzed using a log-rank test. The study included 155 patients, 46 women and 109 men (mean age, 66 years; range, 45-85 years). In the 0 and 14 Gy groups, binary restenosis was present, respectively, in 44% (34/77) and 68% (52/76; P = .003) 2 years after stenting. Stent thrombosis occurred in 13% (10/78) of the 0 Gy group and in 33% (25/77) of the 14 Gy group (P = .003). Target lesion revascularization at 2 years was 26% (25/78) in the 0 Gy group and 30% (23/77) in the 14 Gy group (P = .56). There were no significant differences in total walking distances change from baseline to 2 years (46 ± 100 and 26 ± 79 m, respectively, in the 0 Gy and 14 Gy group; P = .25). There were no procedure-related deaths and no major amputations. A single 14 Gy dose of EBR to the SFA stenting site did not prevent in-stent restenosis. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.
Self-expandable metallic stents vs. plastic stents for endoscopic biliary drainage in hepatocellular carcinoma.

Science.gov (United States)

Chung, Kwang Hyun; Lee, Sang Hyub; Park, Jin Myung; Lee, Jae Min; Ahn, Dong-Won; Ryu, Ji Kon; Kim, Yong-Tae

2015-06-01

The patency of self-expandable metallic stents (SEMS) is known to be better than plastic stents in the palliation of malignant biliary obstruction. However, data are scarce for obstructive jaundice caused by hepatocellular carcinoma (HCC). This study aimed to compare SEMSs and plastic stents for the palliation of obstructive jaundice in unresectable HCC. A total of 96 patients who underwent endoscopic retrograde biliary drainage with SEMSs or plastic stents were included in this retrospective analysis. The rate of successful biliary drainage, adverse events, stent patency duration, and patient survival were compared between the SEMS (n = 36) and plastic stent (n = 60) groups. The rate of successful biliary drainage was similar between the SEMS and plastic stent groups (25/36 [69.4 %] vs. 39/60 [65.0 %]; P = 0.655). Adverse events occurred in 6 patients (16.7 %) in the SEMS group and 13 patients (21.7 %) in the plastic stent group (P = 0.552). The median patency duration was also similar between the two groups (60 vs. 68 days; P = 0.396). The median patient survival was longer in the plastic stent group than in the SEMS group (123 vs. 48 days; P = 0.005). SEMSs were not superior to plastic stents for the palliation of malignant biliary obstruction in HCC with regard to successful drainage, stent patency, and adverse events. Patient survival was better in the plastic stent group. Given the lower cost, plastic stents could be a favorable option for malignant biliary obstruction caused by HCC. © Georg Thieme Verlag KG Stuttgart · New York.
Comparison of diamond-like carbon-coated nitinol stents with or without polyethylene glycol grafting and uncoated nitinol stents in a canine iliac artery model

Science.gov (United States)

Kim, J H; Shin, J H; Shin, D H; Moon, M-W; Park, K; Kim, T-H; Shin, K M; Won, Y H; Han, D K; Lee, K-R

2011-01-01

Objective Neointimal hyperplasia is a major complication of endovascular stent placement with consequent in-stent restenosis or occlusion. Improvements in the biocompatibility of stent designs could reduce stent-associated thrombosis and in-stent restenosis. We hypothesised that the use of a diamond-like carbon (DLC)-coated nitinol stent or a polyethylene glycol (PEG)-DLC-coated nitinol stent could reduce the formation of neointimal hyperplasia, thereby improving stent patency with improved biocompatibility. Methods A total of 24 stents were implanted, under general anaesthesia, into the iliac arteries of six dogs (four stents in each dog) using the carotid artery approach. The experimental study dogs were divided into three groups: the uncoated nitinol stent group (n = 8), the DLC-nitinol stent group (n = 8) and the PEG-DLC-nitinol stent group (n = 8). Results The mean percentage of neointimal hyperplasia was significantly less in the DLC-nitinol stent group (26.7±7.6%) than in the nitinol stent group (40.0±20.3%) (p = 0.021). However, the mean percentage of neointimal hyperplasia was significantly greater in the PEG-DLC-nitinol stent group (58.7±24.7%) than in the nitinol stent group (40.0±20.3%) (p = 0.01). Conclusion Our findings indicate that DLC-coated nitinol stents might induce less neointimal hyperplasia than conventional nitinol stents following implantation in a canine iliac artery model; however, the DLC-coated nitinol stent surface when reformed with PEG induces more neointimal hyperplasia than either a conventional or DLC-coated nitinol stent. PMID:21325363
Mechanical properties of various z-stent designs: an endovascular stent-grafting perspective.

Science.gov (United States)

Bashar, Abul Hasan Muhammad; Kazui, Teruhisa; Washiyama, Naoki; Terada, Hitoshi; Yamashita, Katsushi; Haque, Mohammad E

2003-08-01

To comparatively assess the mechani-cal behavior of various clinically relevant Z-stent designs. A total of 16 Z-stents of original, biliary, spiral, and double-skirted designs (n=4 for each) were constructed using similar specifications for all. Stents were then evaluated for stiffness, snap opening force (SOF), flexibility, and displacement force using a novel tensiometer. Differences among the stents were determined using statistical methods. Stents explanted from dog aorta after a mean follow-up of 13 months were examined under a scanning electron microscope for surface defects. Forces required for about 50% reduction in diameter were 1.88 +/- 0.16 N, 3.81 +/- 0.21 N, 2.76 +/- 0.22 N, and 3.35 +/- 0.19 N for original, biliary, spiral, and skirted designs, respectively. Differences among the four designs were statistically significant at almost all points of measurement (P designs showed higher SOF values in the early measurements. Stents explanted from dog aorta after a mean duration of 13 months showed no obvious corrosion or breakage in the wire struts. Significant differences exist among the various Z-stent designs in terms of their mechanical properties. Understanding them should help to select the appropriate stent for a given lesion. 316L stainless steel shows a favorable long-term tissue interaction.
Stent thrombosis with drug-eluting and bare-metal stents: evidence from a comprehensive network meta-analysis.

Science.gov (United States)

Palmerini, Tullio; Biondi-Zoccai, Giuseppe; Della Riva, Diego; Stettler, Christoph; Sangiorgi, Diego; D'Ascenzo, Fabrizio; Kimura, Takeshi; Briguori, Carlo; Sabatè, Manel; Kim, Hyo-Soo; De Waha, Antoinette; Kedhi, Elvin; Smits, Pieter C; Kaiser, Christoph; Sardella, Gennaro; Marullo, Antonino; Kirtane, Ajay J; Leon, Martin B; Stone, Gregg W

2012-04-14

The relative safety of drug-eluting stents and bare-metal stents, especially with respect to stent thrombosis, continues to be debated. In view of the overall low frequency of stent thrombosis, large sample sizes are needed to accurately estimate treatment differences between stents. We compared the risk of thrombosis between bare-metal and drug-eluting stents. For this network meta-analysis, randomised controlled trials comparing different drug-eluting stents or drug-eluting with bare-metal stents currently approved in the USA were identified through Medline, Embase, Cochrane databases, and proceedings of international meetings. Information about study design, inclusion and exclusion criteria, sample characteristics, and clinical outcomes was extracted. 49 trials including 50,844 patients randomly assigned to treatment groups were analysed. 1-year definite stent thrombosis was significantly lower with cobalt-chromium everolimus eluting stents (CoCr-EES) than with bare-metal stents (odds ratio [OR] 0·23, 95% CI 0·13-0·41). The significant difference in stent thrombosis between CoCr-EES and bare-metal stents was evident as early as 30 days (OR 0·21, 95% CI 0·11-0·42) and was also significant between 31 days and 1 year (OR 0·27, 95% CI 0·08-0·74). CoCr-EES were also associated with significantly lower rates of 1-year definite stent thrombosis compared with paclitaxel-eluting stents (OR 0·28, 95% CI 0·16-0·48), permanent polymer-based sirolimus-eluting stents (OR 0·41, 95% CI 0·24-0·70), phosphorylcholine-based zotarolimus-eluting stents (OR 0·21, 95% CI 0·10-0·44), and Resolute zotarolimus-eluting stents (OR 0·14, 95% CI 0·03-0·47). At 2-year follow-up, CoCr-EES were still associated with significantly lower rates of definite stent thrombosis than were bare-metal (OR 0·35, 95% CI 0·17-0·69) and paclitaxel-eluting stents (OR 0·34, 95% CI 0·19-0·62). No other drug-eluting stent had lower definite thrombosis rates compared with bare
Comparison of a New Polytetrafluoroethylene-Covered Metallic Stent to a Noncovered Stent in Canine Ureters

International Nuclear Information System (INIS)

Chung, Hwan-Hoon; Lee, Seung Hwa; Cho, Sung Bum; Park, Hong Suk; Kim, Young Sik; Kang, Byung Chul; Frisoli, Joan K.; Razavi, Mahmood K.

2008-01-01

The aim of this study was to determine the feasibility of using a newly designed polytetrafluoroethylene (PTFE)-covered metallic stent in the ureter by comparing its effectiveness with that of the noncovered stent in a canine model. We placed 14 stents in the ureters of seven mongrel dogs that weighed 30-40 kg each. The covered and noncovered stents were deployed in the right and left ureters, respectively, of six dogs. In the seventh dog, a covered stent and a double-J catheter were inserted in the right ureter, and a covered stent only was inserted in the left ureter. The first six dogs were sacrificed at 5, 10, and 15 weeks after deployment of the stents (two for each follow-up period), and the seventh dog was sacrificed at 30 weeks. There was no migration or poor expansion of any of the stents observed on plain radiography. On intravenous pyelogram and retrograde pyelogram, all of the covered stents at each follow-up period had patent lumens at the stented segments without hydronephrosis, and the passage of contrast material through it was well preserved. The noncovered stents in the dogs sacrificed at 5 and 10 weeks and one of the two dogs sacrificed at 15 weeks showed near-complete occlusion of the stent lumen due to ingrowth of the soft tissue, and severe hydronephrosis was also noted. The noncovered stent in the other dog sacrificed at 15 weeks showed the passage of contrast material without hydronephrosis, but the lumen of the stent was still nearly occluded by the soft tissue. There was no evidence of hydronephrosis or passage disturbance of the contrast material in both ureters of the dog sacrificed at 30 weeks. We conclude that the newly designed PTFE-covered stent effectively prevented the luminal occlusion caused by urothelial hyperplasia compared to the near-total occlusion of the noncovered stents, and no migration of the covered stents was noted
Treatment of Post-Stent Gastroesophageal Reflux by Anti-Reflux Z-Stent

International Nuclear Information System (INIS)

Davies, Roger Philip; Kew, Jacqueline; Byrne, Peter D.

2000-01-01

Severe symptoms of heartburn and retrosternal pain consistent with gastro-esophageal reflux (GER) developed in a patient following placement of a conventional self-expanding 16-24-mm-diameter x 12-cm-long esophageal stent across the gastroesophageal junction to treat an obstructing esophageal carcinoma. A second 18-mm-diameter x 10-cm-long esophageal stent with anti-reflux valve was deployed coaxially and reduced symptomatic GER immediately. Improvement was sustained at 4-month follow-up. An anti-reflux stent can be successfully used to treat significant symptomatic GER after conventional stenting
Impact of stent strut design in metallic stents and biodegradable scaffolds.

Science.gov (United States)

Foin, Nicolas; Lee, Renick D; Torii, Ryo; Guitierrez-Chico, Juan Luis; Mattesini, Alessio; Nijjer, Sukhjinder; Sen, Sayan; Petraco, Ricardo; Davies, Justin E; Di Mario, Carlo; Joner, Michael; Virmani, Renu; Wong, Philip

2014-12-20

Advances in the understanding of healing mechanisms after stent implantation have led to the recognition of stent strut thickness as an essential factor affecting re-endothelialization and overall long term vessel healing response after Percutaneous Coronary Interventions (PCI). Emergence of Drug-eluting stents (DESs) with anti-proliferative coating has contributed to reducing the incidence of restenosis and Target Lesion Revascularization (TVR), while progress and innovations in stent materials have in the meantime facilitated the design of newer platforms with more conformability and thinner struts, producing lesser injury and improving integration into the vessel wall. Recent advances in biodegradable metal and polymer materials now also allow for the design of fully biodegradable platforms, which are aimed at scaffolding the vessel only temporarily to prevent recoil and constrictive remodeling of the vessel during the initial period required, and are then progressively resorbed thereby avoiding the drawback of leaving an unnecessary implant permanently in the vessel. The aim of this article is to review recent evolution in stent material and stent strut design while understanding their impact on PCI outcomes. The article describes the different metallic alloys and biodegradable material properties and how these have impacted the evolution of stent strut thickness and ultimately outcomes in patients. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
Treatment of ureterovaginal fistula using a Memokath stent

DEFF Research Database (Denmark)

Mohammad, Wael; Fode, Mikkel Mejlgaard; Azawi, Nessn Htum

2014-01-01

results in non-radiated patients. Meanwhile, conservative treatment using ureteral stents in selected patients has resulted in reported success rates of 71%. We present the case of a 24-year-old woman with UVF due to surgery and radiotherapy for cervix cancer. The patient has been successfully treated...... with the insertion of a Memokath 051 stent (PNN Medical A/S, Denmark), which is a thermoexpandable, nickel-titanium alloy stent. The patient has been totally continent during a follow-up period of 3 years. The Memokath stent has been changed twice within this period due to dysfunction....
Metallic stents for tracheobronchial pathology treatment.

Science.gov (United States)

Serrano, Carolina; Laborda, Alicia; Lozano, Juan M; Caballero, Hugo; Sebastián, Antonio; Lopera, Jorge; de Gregorio, Miguel Ángel

2013-12-01

To present the 7-year experience of the treatment of benign and malignant tracheobronchial stenoses using metallic stents. One hundred twenty-three stents were inserted in 86 patients (74 benign and 12 malignant stenoses). Ninety-seven stents were placed in the trachea and 26 in the bronchi. The procedures were performed under fluoroscopic and flexible bronchoscopic guidance with the patient under light sedation. In cases of severe stenotic lesions or obstructions, laser resection was performed before stent placement. Clinical and functional pulmonary data were recorded before and 3 months after the procedure. Follow-up involved clinical data and radiographic techniques at 48 h and at 1-, 3-, 6-, and 12-month intervals. The technical success was 100 %. Dyspnea disappearance, forced expiratory volume in the first second, and pulmonary functional data improvement was observed in all patients (p < 0.001). Complications were detected in 23 patients (26.7 %). Mean follow-up time was 6.3 ± 1.2 months in patients with malignant lesions and 76.2 ± 2.3 months patients with in benign lesions. By the end of the study, 100 % of patients with malignant pathology and 6.7 % of patients with benign lesions had died. Endoluminal treatment of tracheobronchial stenosis with metallic stents is a therapeutic alternative in patients who are poor candidates for surgery. In unresectable malignant lesions, the benefit of metallic stenting is unquestionable. In benign lesions, the results are satisfactory, but sometimes other interventions are required to treat complications. New stent technology may improve these results.
Delayed colonic perforation following stent placement for colorectal obstruction: a description of two cases with stent palliation.

Directory of Open Access Journals (Sweden)

Jalal Vahedian Ardakani

2013-10-01

Full Text Available Bowel stent insertion has a variety of complications one major of which is colonic perforation. The purpose of this article is to reveal two cases with delayed colonic perforation after stent placement to relieve bowel obstruction caused by rectal cancer. The first patient was a 55 year-old man who was a candidate for stent placement to avoid palliative surgery and relieve his bowel obstruction. Although the procedure resulted in complete relief of patient symptoms, but he returned with signs of peritonitis 10 days after the stent placement. A perforation was found at rectosigmoid junction on laparotomy. The second patient was a 60 year-old man who underwent a successful stent placement and returned 3 months later with a complaint of abdominal pain that showed up to be due to a rectal perforation on investigations. In conclusion, bowel perforation following stent placement can be a major complication, so close follow-up is necessary to detect it as soon as possible and prevent it from becoming an irreparable complication.
Crossing Y-stent technique with dual open-cell stents for coiling of wide-necked bifurcation aneurysms.

Science.gov (United States)

Ko, Jun Kyeung; Han, In Ho; Cho, Won Ho; Choi, Byung Kwan; Cha, Seung Heon; Choi, Chang Hwa; Lee, Sang Weon; Lee, Tae Hong

2015-05-01

Double stenting in a Y-configuration is a promising therapeutic option for wide-necked cerebral aneurysms not amenable to reconstruction with a single stent. We retrospectively evaluated the efficacy and safety of the crossing Y-stent technique for coiling of wide-necked bifurcation aneurysms. By collecting clinical and radiological data we evaluated from January 2007 through December 2013, 20 wide-necked bifurcation aneurysms. Twelve unruptured and eight ruptured aneurysms in 20 patients were treated with crossing Y-stent-assisted coiling. Aneurysm size and neck size ranged from 3.2 to 28.2mm (mean 7.5mm) and from 1.9 to 9.1mm (mean 4.5mm). A Y-configuration was established successfully in all 20 patients. All aneurysms were treated with a pair of Neuroform stents. The immediate angiographic results were total occlusion in 17 aneurysms, residual neck in two, and residual sac in one. Peri-operative morbidity was only 5%. Fifteen of 18 surviving patients underwent follow-up conventional angiography (mean, 10.9 months). The result showed stable occlusion in all 15 aneurysms and asymptomatic in-stent occlusion in one branch artery. At the end of the observation period (mean, 33.5 months), all 12 patients without subarachnoid hemorrhage had excellent clinical outcomes (mRS 0), except one (mRS 2). Of eight patients with subarachnoid hemorrhage, four remained symptom free (mRS 0), while the other four had were dependent or dead (mRS score, 3-6). In this report on 20 patients, crossing Y-stent technique for coiling of wide-necked bifurcation aneurysms showed a good technical safety and favorable clinical and angiographic outcome. Copyright © 2015. Published by Elsevier B.V.
Self-expandable metalic endotracheal stent

International Nuclear Information System (INIS)

Do, Young Soo; Cho, Dae Soon; Cho, Kyung Ja; Lee, Young Soo; Lee, Mi Jae

1993-01-01

Six bare stents and six covered stents were inserted in the trachea of 12 dogs under general anesthesia. After 1-10 weeks of observation, the dogs were killed, and the trachea and lung were examined grossly and histologically. Pneumonia and stent migration were observed more frequently at covered stent group. Inflammatory change of the trachea was more severe at covered stent group. In conclusion, we believe that it is inadequate to insert silicone covered stent in the tracheobronchial tree. (Author)
Self-expandable metalic endotracheal stent

Energy Technology Data Exchange (ETDEWEB)

Do, Young Soo; Cho, Dae Soon; Cho, Kyung Ja; Lee, Young Soo; Lee, Mi Jae [Korea Cancer Center Hospital, Seoul (Korea, Republic of)

1993-01-01

Six bare stents and six covered stents were inserted in the trachea of 12 dogs under general anesthesia. After 1-10 weeks of observation, the dogs were killed, and the trachea and lung were examined grossly and histologically. Pneumonia and stent migration were observed more frequently at covered stent group. Inflammatory change of the trachea was more severe at covered stent group. In conclusion, we believe that it is inadequate to insert silicone covered stent in the tracheobronchial tree. (Author).
Stenting plus coiling: dangerous or helpful?; Stenting plus Coiling bei akut rupturierten intrakraniellen Aneurysmen

Energy Technology Data Exchange (ETDEWEB)

Wanke, I.; Gizewski, E.; Doerfler, A.; Stolke, D.; Forsting, M. [Essen Univ. (Germany). Inst. fuer Radiologie und Neuroradiologie

2005-09-01

Purpose: the purpose of this study was to evaluate the procedural risk of treating acute ruptured aneurysms with a stentcoil combination. Material and methods: between August 2001 and January 2004 we treated nine acute subarachnoid hemorrhage (SAH) patients with a combination of stents and platinum coils. Results: six aneurysms were 100% eliminated; the residual three aneurysms had a 95% to 99% occlusion. A transient thrombosis in the stent in one patient could be recanalized by intravenous application of ReoPro {sup registered}. In another patient an occlusive vasospasm at the distal end of the stent was successfully treated with intraarterial Nimotop {sup registered}. Neurological complications occurred in none of the patients. Conclusion: in broad-based aneurysms which cannot be clipped or in which any neurosurgical treatment presents an unacceptably high risk (posterior circulation and paraophthalmic aneurysms), treatment using a combination of stent and platinum coils might be an option even in the acute phase of an SAH. Platelet aggregation can be treated with Aspirin registered and Plavix {sup registered} after placement of the first coil, vasospasms with intraarterial Nimotop {sup registered}, and acute stent thrombosis with GP IIa/IIIb-antagonists. (orig.)
Physical properties of a new type of self-expandable nitinol stent

Energy Technology Data Exchange (ETDEWEB)

Park, Sang Soo [Seoul Health College, Seoul (Korea, Republic of); Kim, Tae Hyung; Song, Sang Woo; Kang, Seong Gwon; Huh, Soo Jin; Song, Ho Young [Ulsan Univ. College of Medicine, Seoul (Korea, Republic of); Kim, Eun Sang [Stentech, Inc., Seoul (Korea, Republic of); Kim, Cheol Saeng [Solco Surgical Instruments Co., Ltd, Seoul (Korea, Republic of)

1999-08-01

To study the new physical properties including hoop strength and flexibility of a newly developed nitinol stent. The new stent was made of a single nitinol wire 0.15 - 0.25 mm in diameter. This was wound around a cylindrical metallic jig with a constant angle to the longitudinal direction, and stents which winding were constructed. Hoop strength of the stents was measured with a spring gauge and compared with that of Wallstent and Hanaro stents. The flexibility of the new stent was evaluated on the basis of changes in stent diameter when bent in the direction of 180 deg Hoop strength of the new nitinol stent was proportional to 3.8 ({+-}0.3)-th power of the wire thickness. A greater number of wires on a lateral cut surface or a greater number of longitudinal windings also resulted in increased strength. However, the former caused an increase in total wire area and the latter resulted increased stent length when compressed. Hoop strength of the new nitinol stent was superior to that of Wallstent and Hanaro stents, and stent diameter did not decrease when the stent was bent in the direction of 180 degrees. Hoop strength of the new nitinol stent was most significantly affected by wire thickness. The stent was very flexible and thus seemed suitable for an angled lumen.
Atrial septal stenting - How I do it?

Directory of Open Access Journals (Sweden)

Kothandam Sivakumar

2015-01-01

Full Text Available A wide atrial communication is important to maintain hemodynamics in certain forms of congenital and acquired heart defects. In comparison to balloon septostomy or blade septostomy, atrial septal stenting provides a controlled, predictable, and long-lasting atrial communication. It often needs a prior Brockenbrough needle septal puncture to obtain a stable stent position. A stent deployed across a previously dilated and stretched oval foramen or tunnel form of oval foramen carries higher risk of embolization. This review provides technical tips to achieve a safe atrial septal stenting. Even though this is a "How to do it article," an initial discussion about the indications for atrial septal stenting is vital as the resultant size of the atrial septal communication should be tailored for each indication.

Classic crush and DK crush stenting techniques.

Science.gov (United States)

Zhang, Jun-Jie; Chen, Shao-Liang

2015-01-01

Clinical data have supported the advantages of the double kissing (DK) crush technique, which consists of stenting the side branch (SB), balloon crush, first kissing, stenting the main vessel (MV) and final kissing balloon inflation, for complex coronary bifurcation lesions compared to other stenting techniques. Careful rewiring from the proximal cell of the MV stent to make sure the wire is in the true lumen of the SB stent is key to acquiring optimal angiographic results. Balloon anchoring from the MV, alternative inflation and each kissing inflation using large enough non-compliant balloons at high pressure, and the proximal optimisation technique are mandatory to improve both angiographic and clinical outcomes. Stratification of a given bifurcation lesion is recommended before decision making.
Predictive factors for the failure of endoscopic stent-in-stent self-expandable metallic stent placement to treat malignant hilar biliary obstruction.

Science.gov (United States)

Sugimoto, Mitsuru; Takagi, Tadayuki; Suzuki, Rei; Konno, Naoki; Asama, Hiroyuki; Watanabe, Ko; Nakamura, Jun; Kikuchi, Hitomi; Waragai, Yuichi; Takasumi, Mika; Sato, Yuki; Hikichi, Takuto; Ohira, Hiromasa

2017-09-14

To investigate the factors predictive of failure when placing a second biliary self-expandable metallic stents (SEMSs). This study evaluated 65 patients with an unresectable malignant hilar biliary obstruction who were examined in our hospital. Sixty-two of these patients were recruited to the study and divided into two groups: the success group, which consisted of patients in whom a stent-in-stent SEMS had been placed successfully, and the failure group, which consisted of patients in whom the stent-in-stent SEMS had not been placed successfully. We compared the characteristics of the patients, the stricture state of their biliary ducts, and the implemented endoscopic retrograde cholangiopancreatography (ERCP) procedures between the two groups. The angle between the target biliary duct stricture and the first implanted SEMS was significantly larger in the failure group than in the success group. There were significantly fewer wire or dilation devices (ERCP catheter, dilator, or balloon catheter) passing the first SEMS cell in the failure group than in the success group. The cut-off value of the angle predicting stent-in-stent SEMS placement failure was 49.7 degrees according to the ROC curve (sensitivity 91.7%, specificity 61.2%). Furthermore, the angle was significantly smaller in patients with wire or dilation devices passing the first SEMS cell than in patients without wire or dilation devices passing the first SEMS cell. A large angle was identified as a predictive factor for failure of stent-in-stent SEMS placement.
Future developments in biliary stenting

Science.gov (United States)

Hair, Clark D; Sejpal, Divyesh V

2013-01-01

Biliary stenting has evolved dramatically over the past 30 years. Advancements in stent design have led to prolonged patency and improved efficacy. However, biliary stenting is still affected by occlusion, migration, anatomical difficulties, and the need for repeat procedures. Multiple novel plastic biliary stent designs have recently been introduced with the primary goals of reduced migration and improved ease of placement. Self-expandable bioabsorbable stents are currently being investigated in animal models. Although not US Food and Drug Administration approved for benign disease, fully covered self-expandable metal stents are increasingly being used in a variety of benign biliary conditions. In malignant disease, developments are being made to improve ease of placement and stent patency for both hilar and distal biliary strictures. The purpose of this review is to describe recent developments and future directions of biliary stenting. PMID:23837001
The effect of stent structure changes on the hemodynamics and the formation of in-stent restenosis

International Nuclear Information System (INIS)

Wu Xia; Xu Ke; Xiao Liang; Zhang Xitong; Su Hongying; Feng Bo

2009-01-01

Objective: To investigate the effect of stent structure changes on the formation of in-stent restenosis by studying the influence of these changes on the shear force to the vascular wall, on the velocity of flow and on the flow pattern. Methods: Five stent models were established by using Pro/engineer wildfire 3.0. Model A was regarded as control structure. On the base structure of model A, transverse link component was added to form model B, and vertical link component was added to form model C. The thickness of model D was twice than that of model A, and the meshes density of model E was twice than that of model A. Fluid models were built up by importing these stent models into computational fluid dynamics (CFD) software ansys11.0-CFX, then, CFD analysis was proceeded to study the effect of stent structure on hemodynamics. Results: After the stents were implanted, the percentage of low wall shear stress on the surface of model A, B, C, D and E was 7.78%, 6.65%, 1.48%, 16.52% and 12.12%, respectively. The percentage of D and E was obviously larger than that of A, while the percentage of B was markedly smaller than that of A. The velocity vector on the cross-sectional planes showed that the low velocity and eddy areas in D and E were much larger than that in A, while this area in C was smaller than that in A. Conclusion: The stent structure changes can cause obvious changes in hemodynamics in the implanted vessels. The increase in the thickness and meshes density of the stent is the main factor that induces the formation of low wall shear stress, which will precipitate the development of in-stent restenosis. The added vertical link component will reduce the area of low wall shear stress as well as the occurrence of in-stent restenosis. (authors)
Percutaneous Transhepatic Biliary Metal Stent for Malignant Hilar Obstruction: Results and Predictive Factors for Efficacy in 159 Patients from a Single Center

Energy Technology Data Exchange (ETDEWEB)

Li, Mingwu, E-mail: lmw-jack@china.com.cn; Bai, Ming, E-mail: mingbai1983@gmail.com; Qi, Xingshun, E-mail: qixingshun19840717@126.com; Li, Kai, E-mail: lkiscoming@163.com; Yin, Zhanxin, E-mail: yinzhanxin@sina.com [Fourth Military Medical University, Department of Digestive Interventional Radiology, Xijing Hospital of Digestive Diseases (China); Wang, Jianhong, E-mail: 54526844@qq.com [Fourth Military Medical University, Department of Ultrasound, Xijing Hospital of Digestive Diseases (China); Wu, Wenbing, E-mail: wuwb211@126.com; Zhen, Luanluan, E-mail: zll2007101@163.com; He, Chuangye, E-mail: sxhechuangye@126.com [Fourth Military Medical University, Department of Digestive Interventional Radiology, Xijing Hospital of Digestive Diseases (China); Fan, Daiming, E-mail: fandaim@fmmu.edu.cn [Fourth Military Medical University, State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases (China); Zhang, Zhuoli, E-mail: Zhuoli-Zhang@northwestern.edu [Northwestern University, Department of Radiology (United States); Han, Guohong, E-mail: hangh2009@gmail.com, E-mail: Hangh@fmmu.edu.cn [Fourth Military Medical University, Department of Digestive Interventional Radiology, Xijing Hospital of Digestive Diseases (China)

2015-06-15

AimTo investigate and compare the efficacy and safety of percutaneous transhepatic biliary stenting (PTBS) using a one- or two-stage procedure and determine the predictive factors for the efficacious treatment of malignant hilar obstruction (MHO).Methods159 consecutive patients with MHO who underwent PTBS were enrolled between January 2010 and June 2013. Patients were classified into one- or two-stage groups. Independent predictors of therapeutic success were evaluated using a logistic regression model.Results108 patients were treated with one-stage PTBS and 51 patients were treated with two-stage PTBS. The stents were technically successful in all patients. Successful drainage was achieved in 114 patients (71.4 %). A total of 42 early major complications were observed. Re-interventions were attempted in 23 patients during follow-up. The cumulative primary patency rates at 3, 6, and 12 months were 88, 71, and 48 %, respectively. Stent placement using a one- or two-stage procedure did not significantly affect therapeutic success, early major complications, median stent patency, or survival. A stent placed across the duodenal papilla was an independent predictor of therapeutic success (odds ratio = 0.262, 95 % confidence interval [0.107–0.642]). Patients with stents across papilla had a lower rate of cholangitis compared with patients who had a stent above papilla (7.1 vs. 20.3 %, respectively, p = 0.03).ConclusionsThe majority of patients with MHO who underwent one-stage PTBS showed similar efficacy and safety outcomes compared with those who underwent two-stage PTBS. Stent placement across the duodenal papilla was associated with a higher therapeutic success rate.
Self-Expanding Nitinol Renal Artery Stents: Comparison of Safety and Efficacy of Bare Versus Polyzene-F Nanocoated Stents in a Porcine Model

International Nuclear Information System (INIS)

Kurz, P.; Stampfl, U.; Christoph, P.; Henn, C.; Satzl, S.; Radeleff, B.; Berger, I.; Richter, G. M.

2011-01-01

Objective: To investigate the safety and efficacy of a Polyzene-F nanocoat on new low-profile self-expandable nitinol stents in minipig renal arteries. Materials and Methods: Ten bare nitinol stents (BNS) and 10 stents coated with a 50 nm-thin Polyzene-F coating were randomly implanted into renal arteries of 10 minipigs (4- and 12-week follow-up, 5 animals/group). Thrombogenicity, on-stent surface endothelialization, vessel wall injury, late in-stent stenosis, and peristrut vessel wall inflammation were determined by quantitative angiography and postmortem histomorphometry. Results: In 6 of 10 BNS, >50% stenosis was found, but no stenosis was found in stents with a nanothin Polyzene-F coating. Histomorphometry showed a statistically significant (p < 0.05) different average maximum luminal loss of 55.16% ± 8.43% at 12 weeks in BNS versus 39.77% ± 7.41% in stents with a nanothin Polyzene-F coating. Stents with a nanothin Polyzene-F coating had a significantly (p < 0.05) lower inflammation score after 12 weeks, 1.31 ± 1.17 versus 2.17 ± 0.85 in BNS. The results for vessel wall injury (0.6 ± 0.58 for Polyzene-F-coated stents; 0.72 ± 0.98 for BNS) and re-endothelialization, (1.16 ± 0.43 and 1.23 ± 0.54, respectively) were not statistically significant at 12-week follow-up. No thrombus deposition was observed on the stents at either follow-up time point. Conclusion: Nitinol stents with a nanothin Polyzene-F coating successfully decreased in-stent stenosis and vessel wall inflammation compared with BNS. Endothelialization and vessel wall injury were found to be equal. These studies warrant long-term pig studies (≥120 days) because 12 weeks may not be sufficient time for complete healing; thereafter, human studies may be warranted.
Shrinking the Supply Chain for Implantable Coronary Stent Devices.

Science.gov (United States)

Moore, Sean S; O'Sullivan, Kevin J; Verdecchia, Francesco

2016-02-01

Stenting treatments for the management of disease in the heart, arterial and venous systems, biliary ducts, urethras, ureters, oesophageal tract and prostate have made enormous technical advances since their introduction into clinical use. The progression from metallic to polymer based bio-absorbable stents, coupled with the advances in additive manufacturing techniques, present a unique opportunity to completely re-envision the design, manufacture, and supply chain of stents. This paper looks at current stenting trends and proposes a future where the stent supply chain is condensed from ~150 days to ~20 min. The Cardiologist therefore has the opportunity to become a designer, manufacturer and user with patients receiving custom stents specific to their unique pathology that will be generated, delivered and deployed in the Cath-lab. The paper will outline this potentially revolutionary development and consider the technical challenges that will need to be overcome in order to achieve these ambitious goals. A high level overview of the generating eluting stents in situ program-GENESIS-is outlined including some early experimental work.
Endoscopic stent suture fixation for prevention of esophageal stent migration during prolonged dilatation for achalasia treatment.

Science.gov (United States)

Rieder, E; Asari, R; Paireder, M; Lenglinger, J; Schoppmann, S F

2017-04-01

The aim of this study is to compare endoscopic stent suture fixation with endoscopic clip attachment or the use of partially covered stents (PCS) regarding their capability to prevent stent migration during prolonged dilatation in achalasia. Large-diameter self-expanding metal stents (30 mm × 80 mm) were placed across the gastroesophageal junction in 11 patients with achalasia. Stent removal was scheduled after 4 to 7 days. To prevent stent dislocation, endoscopic clip attachment, endoscopic stent suture fixation, or PCS were used. The Eckardt score was evaluated before and 6 months after prolonged dilatation. After endoscopic stent suture fixation, no (0/4) sutured stent migrated. When endoscopic clips were used, 80% (4/5) clipped stents migrated (p = 0.02). Of two PCS (n = 2), one migrated and one became embedded leading to difficult stent removal. Technical adverse events were not seen in endoscopic stent suture fixation but were significantly correlated with the use of clips or PCS (r = 0.828, p = 0.02). Overall, 72% of patients were in remission regarding their achalasia symptoms 6 months after prolonged dilatation. Endoscopic suture fixation of esophageal stents but not clip attachment appears to be the best method of preventing early migration of esophageal stents placed at difficult locations such as at the naive gastroesophageal junction. © The Authors 2017. Published by Oxford University Press on behalf of International Society for Diseases of the Esophagus. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Numerical investigations of the mechanical properties of braided vascular stents.

Science.gov (United States)

Fu, Wenyu; Xia, Qixiao; Yan, Ruobing; Qiao, Aike

2018-01-01

Braided stents, such as Pipeline Embolization Device (PED; ev3 Neurovascular, Irvine, CA, USA), are commonly used to treat cerebral aneurysms. However, little information is available on the compression and bending characteristics of such stents. This paper investigates how geometrical parameters of braided stents influence their radial compression and bending characteristics. Six groups of braided stent models with different braiding angles, numbers of wires and wire diameters are constructed. Parametric analyses of these models are conducted using Abaqus/Explicit software. The numerical results of a finite element analysis are validated by comparison with data of theoretical analysis. The results show that the radial stiffness is not uniform along the longitudinal direction of the stent. When the braiding angle increases from 30° to 75°, the minimum radial deformation decreases from 0.85 mm to 0.0325 mm (at a pressure of 500 Pa, for 24 braided wires). When the wire diameter increases from 0.026 mm to 0.052 mm, the minimum radial deformation decreases from 0.65 mm to 0.055 mm (at a pressure of 500 Pa and a braiding angle of 60°, for 24 braided wires). Frictions don't affect stent diameter and its axial length when braided stent is crimping, but the friction must be considered when it is related to the radial pressure required for compression the braided stent. Compared with commonly used intracranial stents, a braided stent with geometrical parameters close to PED stent has a smaller radial stiffness but a considerably greater longitudinal flexibility. The results of this analysis of braided stents can help in the design and selection of flow diverter stents for clinical treatment of cerebral aneurysms.
Esophageal stent migration can lead to intestinal obstruction

Science.gov (United States)

Karatepe, Oguzhan; Acet, Ersin; Altiok, Merih; Battal, Muharrem; Adas, Gokhan; Karahan, Servet

2009-01-01

Background: Self-expanding metallic stents are the devices of choice in the treatment of malign or benign strictures of the esophagus. Stent migration is a well-known complication of this procedure. Aims: We report a case of intestinal obstruction caused by esophageal stent migration, in which surgical intervention was used. Methods: A 65-year-old woman, who had a medical history of gastric cancer operations and esophageal stent applications, was admitted to our emergency department with a 48-hour history of abdominal pain, nausea and vomiting. An emergency laparotomy was performed and the migrated stent causing intestinal obstruction was removed. Results: The patient recovered without incident and was discharged on postoperative day 3. Conclusion: This case illustrates that esophageal stent migration has to be considered as a potential life-threatening complication. PMID:22666672
Wingspan stent for symptomatic M1 stenosis of middle cerebral artery

International Nuclear Information System (INIS)

Guo Xinbin; Ma Nan; Hu Xiaobo; Guan Sheng; Fan Yimu

2011-01-01

Objective: Stent placement for intracranial atherosclerotic stenosis has become an alternative treatment technique; however, stent placement for middle cerebral artery (MCA) stenosis remains a technical and clinical challenge. Our purpose was to assess the safety and feasibility of Wingspan stent for patients with symptomatic M1 stenosis, and its initial effect on prevention of ischemic events. Methods: Fifty-three cases with recurrent symptomatic MCA stenosis resistant to medical therapy treated by self-expanding stent were reviewed retrospectively (average 58 ± 18.5 years old, 19 women). All patients underwent angioplasty and stenting with the Gateway balloon–Wingspan stent system, and advised follow-up with DSA or TCD at 6th month. Results: Patients had an average stenosis ratio of 76.5 ± 15.4% prior to the treatment. Of the 53 patients, the technical success rate was 98.1% as a whole (52/53). The mean degree of stenosis reduced from (76.5 ± 15.4)% to (18.2 ± 11.3)%. Complications associated with the procedure include subarachnoid hemorrhage (1.89%) and occlusion (3.78%) occurred. During a follow-up of 6 months, there was no recurrence of transient ischemic attack or stroke in 52 cases with successful stenting. Cerebral hemodynamics of MCA using transcranial Doppler monitoring were at normal level (<120 cm/s) in 41 follow-up patients. The follow up angiography at 6 month post-procedure was conducted in 32 patients and showed good patency in stented vessels. Conclusions: Wingspan stent for symptomatic stenosis of middle cerebral artery is a safe and feasible procedure. It improves clinical outcome in the intermediate follow up, but its long-term effect remains to be further evaluated.
Drug-eluting stents and bare metal stents in patients with NSTE-ACS

DEFF Research Database (Denmark)

Pedersen, Sune Haahr; Pfisterer, Matthias; Kaiser, Christoph

2014-01-01

the randomised BASKET-PROVE trial (sirolimus-eluting stent vs. everolimus-eluting stent vs. bare metal stent in large-vessel stenting). The primary endpoint was the combined two-year rate of cardiovascular death or non-fatal myocardial infarction (MI). Secondary endpoints were each component of the primary...... implantation in large vessels was associated with a reduction in both TVR and the combined endpoint consisting of cardiovascular death/MI. Thus, DES use improves both efficacy and safety. These findings support the use of DES in NSTE-ACS patients....
Biodegradable stents in benign stenosis of the esophagus

International Nuclear Information System (INIS)

Manova, G.

2013-01-01

Full text: Introduction: Benign stenosis of the esophagus can be postcorrosion peptic or postoperative. The treatment is difficult and traditionally consists of multiple dilatations. In refractory stenosis the placement of metal self-expanding stents is disputed because requiring their subsequent removal. New experience for therapeutic decision is self- degradable stents. Manipulation is a single and not requires their removal. What you will learn: Patients indicated for the treatment with self- degradable stents are with benign stenosis not suitable for balloon dilatation or bougienage dilation. The main groups are those with postcorrosion stenosis, peptic stenosis due to untreated gastroesophageal reflux disease with different prescription as well as post-surgical and post-radiation stenosis. Self-expanding stents made by monofilament polymer of polydioxanone, whose integrity and radial force remain 6-8 weeks depending on the gastric pH are used. Stents are applied in hard guide placed in the stenosis through the working channel of gastroscopy, and they are released under X-ray control. Putting is preceded by balloon dilatation due to the large diameter of the mounted stent. During the manipulations, several difficulties are encountered, which are missing in self-expanding metal stents. Discussion: Short-term results are satisfactory - Dysphagia in the patients is overcome and they recover their normal diet. The patients reported no pain. The control inspection of the 1st month showed partial degradation of the stents. On 3rd month it is set the complete degradation. Term follow-up shows resumption of dysphagia. Conclusion: Good short-term results make the use of self-degradable stents possible alternative for the treatment of the esophagus refractory stenosis. Long-term results are contradictory, still missing long enough randomized studies on this topic
Risk factors for technical failure of endoscopic double self-expandable metallic stent placement by partial stent-in-stent method.

Science.gov (United States)

Kawakubo, Kazumichi; Kawakami, Hiroshi; Toyokawa, Yoshihide; Otani, Koichi; Kuwatani, Masaki; Abe, Yoko; Kawahata, Shuhei; Kubo, Kimitoshi; Kubota, Yoshimasa; Sakamoto, Naoya

2015-01-01

Endoscopic double self-expandable metallic stent (SEMS) placement by the partial stent-in-stent (PSIS) method has been reported to be useful for the management of unresectable hilar malignant biliary obstruction. However, it is technically challenging, and the optimal SEMS for the procedure remains unknown. The aim of this study was to identify the risk factors for technical failure of endoscopic double SEMS placement for unresectable malignant hilar biliary obstruction (MHBO). Between December 2009 and May 2013, 50 consecutive patients with MHBO underwent endoscopic double SEMS placement by the PSIS method. We retrospectively evaluated the rate of successful double SEMS placement and identified the risk factors for technical failure. The technical success rate for double SEMS placement was 82.0% (95% confidence interval [CI]: 69.2-90.2). On univariate analysis, the rate of technical failure was high in patients with metastatic disease and unilateral placement. Multivariate analysis revealed that metastatic disease was a significant risk factor for technical failure (odds ratio: 9.63, 95% CI: 1.11-105.5). The subgroup analysis after double guidewire insertion showed that the rate of technical success was higher in the laser-cut type SEMS with a large mesh and thick delivery system than in the braided type SEMS with a small mesh and thick delivery system. Metastatic disease was a significant risk factor for technical failure of double SEMS placement for unresectable MHBO. The laser-cut type SEMS with a large mesh and thin delivery system might be preferable for the PSIS procedure. © 2014 Japanese Society of Hepato-Biliary-Pancreatic Surgery.
Prospective, multi-center evaluation of a silicon carbide coated cobalt chromium bare metal stent for percutaneous coronary interventions: Two-year results of the ENERGY Registry

International Nuclear Information System (INIS)

Erbel, Raimund; Eggebrecht, Holger; Roguin, Ariel; Schroeder, Erwin; Philipp, Sebastian; Heitzer, Thomas; Schwacke, Harald; Ayzenberg, Oded; Serra, Antonio; Delarche, Nicolas; Luchner, Andreas; Slagboom, Ton

2014-01-01

Background: Novel bare metal stents with improved stent design may become a viable alternative to drug-eluting stents in certain patient groups, particularly, when long-term dual antiplatelet therapy should be avoided. Purpose: The ENERGY registry aimed to assess the safety and benefits of a cobalt–chromium thin strut bare metal stent with a passive coating in a large series of patients under real-world conditions. Methods and materials: This prospective registry recruited 1016 patients with 1074 lesions in 48 centers from April to November 2010. The primary endpoint was the rate of major adverse cardiac events (MACEs), a composite of cardiac death, myocardial infarction and clinically driven target lesion revascularization. Results: More than half of the lesions (61.0%) were type A/B1 lesions, mean lesion length was 14.5 ± 6.5 mm and mean reference vessel diameter 3.2 ± 0.5 mm. MACE rates at 6, 12 and 24 months were 4.9%, 8.1% and 9.4%, target lesion revascularization rates 2.8%, 4.9% and 5.4% and definite stent thrombosis rates 0.5%, 0.6% and 0.6%. Subgroups showed significant differences in baseline and procedural characteristics which did not translate into significantly different clinical outcomes. Specifically, MACE rates at 24 months were 13.5% in diabetics, 8.6% in small stents and 9.6% in acute coronary syndrome patients. Conclusion: The population of ENERGY reflects real-world conditions with bare metal stents being mainly used in simple lesions. In this setting, percutaneous coronary intervention using a cobalt–chromium thin strut bare metal stent with a passive coating showed very good results up to 24 months. (ClinicalTrials.gov:NCT01056120) Summary for annotated table of contents: The ENERGY international registry evaluated the safety and benefits of a cobalt–chromium thin strut bare metal stent with passive coating in 1016 patients under real-world conditions until 2 years. Results were encouraging with a low composite rate of cardiac death
Prospective, multi-center evaluation of a silicon carbide coated cobalt chromium bare metal stent for percutaneous coronary interventions: Two-year results of the ENERGY Registry

Energy Technology Data Exchange (ETDEWEB)

Erbel, Raimund, E-mail: erbel@uk-essen.de [Department of Cardiology, University of Duisburg-Essen, Essen (Germany); Eggebrecht, Holger [Cardioangiological Center Bethanien (CCB), Frankfurt (Germany); Roguin, Ariel [Department of Cardiology, Rambam Medical Center, Haifa (Israel); Schroeder, Erwin [Division of Cardiovascular Medicine, Cliniques Universitaires de Mont-Godinne, Yvoir (Belgium); Philipp, Sebastian [Department Internal Medicine/Cardiology, Elbe Klinikum Stade, Stade (Germany); Heitzer, Thomas [Department of Cardiology, Heart Center Dortmund, Dortmund (Germany); Schwacke, Harald [Department of Internal Medicine, Diakonissen-Stiftungs- Krankenhaus Speyer (Germany); Ayzenberg, Oded [The Heart Institute, Kaplan Medical Center, Rehovot (Israel); Serra, Antonio [Servicio de Cardiología, Hospital de la Santa Creu i Sant Pau, Barcelona, España (Spain); Delarche, Nicolas [Cardiology unit, Pau General Hospital, Pau (France); Luchner, Andreas [Department of Internal Medicine/Cardiology, Universitätsklinikum Regensburg (Germany); Slagboom, Ton [Department of Cardiology, Onze Lieve Vrouwe Gasthuis, Amsterdam (Netherlands)

2014-11-15

Background: Novel bare metal stents with improved stent design may become a viable alternative to drug-eluting stents in certain patient groups, particularly, when long-term dual antiplatelet therapy should be avoided. Purpose: The ENERGY registry aimed to assess the safety and benefits of a cobalt–chromium thin strut bare metal stent with a passive coating in a large series of patients under real-world conditions. Methods and materials: This prospective registry recruited 1016 patients with 1074 lesions in 48 centers from April to November 2010. The primary endpoint was the rate of major adverse cardiac events (MACEs), a composite of cardiac death, myocardial infarction and clinically driven target lesion revascularization. Results: More than half of the lesions (61.0%) were type A/B1 lesions, mean lesion length was 14.5 ± 6.5 mm and mean reference vessel diameter 3.2 ± 0.5 mm. MACE rates at 6, 12 and 24 months were 4.9%, 8.1% and 9.4%, target lesion revascularization rates 2.8%, 4.9% and 5.4% and definite stent thrombosis rates 0.5%, 0.6% and 0.6%. Subgroups showed significant differences in baseline and procedural characteristics which did not translate into significantly different clinical outcomes. Specifically, MACE rates at 24 months were 13.5% in diabetics, 8.6% in small stents and 9.6% in acute coronary syndrome patients. Conclusion: The population of ENERGY reflects real-world conditions with bare metal stents being mainly used in simple lesions. In this setting, percutaneous coronary intervention using a cobalt–chromium thin strut bare metal stent with a passive coating showed very good results up to 24 months. (ClinicalTrials.gov:NCT01056120) Summary for annotated table of contents: The ENERGY international registry evaluated the safety and benefits of a cobalt–chromium thin strut bare metal stent with passive coating in 1016 patients under real-world conditions until 2 years. Results were encouraging with a low composite rate of cardiac death
Percutaneous placement of ureteral stent

Energy Technology Data Exchange (ETDEWEB)

Kim, Seung Hyup; Park, Jae Hyung; Han, Joon Koo; Han, Man Chung [Seoul National University College of Medicine, Seoul (Korea, Republic of)

1990-12-15

Antegrade placement of ureteral stents has successfully achieved in 41 of 46 ureters. When it was difficult to advance ureteral stents through the lesion, it was facilitated by retrograde guide-wire snare technique through urethra. Complications associated with the procedure were non-function of ureteral stent by occlusion, upward migration,and spontaneous fracture of ureteral stent. These complications were managed by percutaneous nephrostomy and removal of ureteral stents by guide-wire snare technique and insertion of a new ureteral stent. While blood cell in urine was markedly increased in about 50% of patients following the procedure.
Chest pain following oesophageal stenting for malignant dysphagia

Energy Technology Data Exchange (ETDEWEB)

Golder, Mark; Tekkis, Paris P.; Kennedy, Colette; Lath, Sadaf; Toye, Rosemary; Steger, Adrian C

2001-03-01

AIM: The palliative use of self-expanding metallic stents has been widely reported to relieve dysphagia in cases of oesophageal carcinoma. Little has been documented on the severity of chest pain following oesophageal stenting. The aim of this study was to investigate the association of pain with oesophageal stenting for malignant dysphagia. METHODS: Fifty-two patients with inoperable oesophageal carcinoma underwent stent placement between 1995-1999. Daily opioid analgesic requirements (mg of morphine equivalent doses) were monitored for 3 days before and 7 days after stenting. The degree of palliation was expressed as a dysphagia score (0-3). Hospital stay, readmission days, stent complications and patient survival time were also recorded. RESULTS: Twenty-six patients (50%) required opioid analgesia for chest pain (median dose: 80 mg morphine/day) within 48 h of the procedure compared to 11 (21.2%) patients before stenting (P = 0.0041). A significant increase was evident in the analgesic consumption following stent deployment (P < 0.001). The dysphagia score improved by a median value of 1 (CI 0.25)P < 0.001, with a re-intervention rate of 11.5%. The median survival time was 40 days post stenting (range 1-120). CONCLUSION: A significant proportion of patients developed chest pain after oesophageal stenting, requiring high dose opioid analgesia. As the origin of the pain is still unknown, pre-emptive analgesia may a play role in reducing stent-related morbidity and possibly in-hospital stay. Golder, M. et al. (2001)
Chest pain following oesophageal stenting for malignant dysphagia

International Nuclear Information System (INIS)

Golder, Mark; Tekkis, Paris P.; Kennedy, Colette; Lath, Sadaf; Toye, Rosemary; Steger, Adrian C.

2001-01-01

AIM: The palliative use of self-expanding metallic stents has been widely reported to relieve dysphagia in cases of oesophageal carcinoma. Little has been documented on the severity of chest pain following oesophageal stenting. The aim of this study was to investigate the association of pain with oesophageal stenting for malignant dysphagia. METHODS: Fifty-two patients with inoperable oesophageal carcinoma underwent stent placement between 1995-1999. Daily opioid analgesic requirements (mg of morphine equivalent doses) were monitored for 3 days before and 7 days after stenting. The degree of palliation was expressed as a dysphagia score (0-3). Hospital stay, readmission days, stent complications and patient survival time were also recorded. RESULTS: Twenty-six patients (50%) required opioid analgesia for chest pain (median dose: 80 mg morphine/day) within 48 h of the procedure compared to 11 (21.2%) patients before stenting (P = 0.0041). A significant increase was evident in the analgesic consumption following stent deployment (P < 0.001). The dysphagia score improved by a median value of 1 (CI 0.25)P < 0.001, with a re-intervention rate of 11.5%. The median survival time was 40 days post stenting (range 1-120). CONCLUSION: A significant proportion of patients developed chest pain after oesophageal stenting, requiring high dose opioid analgesia. As the origin of the pain is still unknown, pre-emptive analgesia may a play role in reducing stent-related morbidity and possibly in-hospital stay. Golder, M. et al. (2001)
Long-term outcome in patients treated with sirolimus-eluting stents in complex coronary artery lesions: 3-year results of the SCANDSTENT (Stenting Coronary Arteries in Non-Stress/Benestent Disease) trial

DEFF Research Database (Denmark)

Kelbaek, H.; Klovgaard, L.; Helqvist, S.

2008-01-01

data of the long-term outcome of patients with complex coronary artery lesions. METHODS: We randomly assigned 322 patients with total coronary occlusions or lesions located in bifurcations, ostial, or angulated segments of the coronary arteries to have SES or BMS implanted. RESULTS: At 3 years, major...... performed between 1 and 3 years after the index treatment (p = NS). According to revised definitions, stent thrombosis occurred in 5 patients (3.1%) in the SES group and in 7 patients (4.4%) in the BMS group (p = NS); very late stent thrombosis was observed in 4 versus 1 patient. CONCLUSIONS: A continued...

Excellent long-term results with iliac stenting in local anesthesia for post-thrombotic syndrome

DEFF Research Database (Denmark)

Klitfod, Lotte; Just, Sven; Foegh, Pia

2015-01-01

BACKGROUND: Only 20% of iliac veins will recanalize on anticoagulation (AC) treatment alone and may, therefore, develop venous obstruction after iliofemoral deep venous thrombosis (DVT). A considerable number of these patients will suffer from post-thrombotic syndrome (PTS) leading to impaired qu...... stent was 89% (17/19) and 16 patients (84 %) had almost or total symptom relief at follow-up. CONCLUSION: Endovascular stenting of iliac obstruction in local anesthesia is minimally invasive and shows excellent long-term outcomes for patients suffering from PTS....
Evolution of patency rates of self-expandable bare metal stents for endovascular treatment of femoro-popliteal arterial occlusive disease: Does stent design matter?

Science.gov (United States)

Treitl, Karla Maria; Woerner, Benedikt; Schinner, Regina; Czihal, Michael; Notohamiprodjo, Susan; Hoffmann, Ulrich; Treitl, Marcus

2017-09-01

To analyse the patency rates of femoro-popliteal stenting with different self-expandable Nitinol stent-designs. Two hundred and twenty-two patients (142 (64%) male; age 72.4 ± 11.6 years) with symptomatic femoro-popliteal peripheral arterial occlusive disease (PAOD) underwent percutaneous transluminal angioplasty (PTA) and stenting with three different Nitinol stents (interwoven IW: n = 70; closed-cell CC: n = 85; open-cell OC: n = 67). One-year post-procedural target lesion revascularization (TLR_12M) rates were investigated with regard to co-morbidities: diabetes (DBM), hyperlipidaemia (HLP), hypertension (RR), coronary artery disease (CAD) and degree of calcification. Twelve-month follow-up data were available for 60, 69 and 50 patients in the IW, OC and CC groups (179 patients in total). The cumulative patency (IW: 52 (86.7%); OC: 50 (72.5%); CC: 23 (46.0%); P stent and the highest TLR_12M for the CC stent. The interwoven stent-design was superior to the standard open- and closed-cell stent-designs in endovascular treatment of femoro-popliteal PAOD in a follow-up period of 12 months. • Results of femoro-popliteal stenting are still unsatisfactory. • Comparative studies for currently available different Nitinol stent-designs are lacking. • This is a first comparative study on long-term patency of different Nitinol stent-designs. • Interwoven stent-design leads to improved long-term patency. • Interwoven stent-design leads to lower TLR than other stent-designs.
Many particle magnetic dipole-dipole and hydrodynamic interactions in magnetizable stent assisted magnetic drug targeting

International Nuclear Information System (INIS)

Cregg, P.J.; Murphy, Kieran; Mardinoglu, Adil; Prina-Mello, Adriele

2010-01-01

The implant assisted magnetic targeted drug delivery system of Aviles, Ebner and Ritter is considered both experimentally (in vitro) and theoretically. The results of a 2D mathematical model are compared with 3D experimental results for a magnetizable wire stent. In this experiment a ferromagnetic, coiled wire stent is implanted to aid collection of particles which consist of single domain magnetic nanoparticles (radius ∼10nm). In order to model the agglomeration of particles known to occur in this system, the magnetic dipole-dipole and hydrodynamic interactions for multiple particles are included. Simulations based on this mathematical model were performed using open source C++ code. Different initial positions are considered and the system performance is assessed in terms of collection efficiency. The results of this model show closer agreement with the measured in vitro experimental results and with the literature. The implications in nanotechnology and nanomedicine are based on the prediction of the particle efficiency, in conjunction with the magnetizable stent, for targeted drug delivery.
Successful percutaneous stenting of a right gastroepiploic coronary bypass graft using monorail delivery system: a case report.

Science.gov (United States)

Alam, M; Safi, A M; Mandawat, M K; Anderson, J E; Kwan, T; Feit, A; Clark, L T

2000-02-01

The right gastroepiploic artery (RGEA) is being successfully used as an arterial conduit in a selected group of patients undergoing coronary artery bypass graft surgery. However, myocardial ischemia may result due to spasm, occlusion, and stenosis of this graft. The anastamosis site at distal right coronary artery (RCA) or posterior descending artery (PDA) is the most common location for stenosis of an in situ gastroepiploic coronary bypass graft. Balloon angioplasty of such stenoses has been reported with optimal short-term results. Stent deployment would decrease the restenosis rate, so that repeat procedures could be minimized for these technically challenging lesions. We describe a case of successful deployment of a stent with monorail delivery system at the anastamotic site stenosis of an in situ gastroepiploic right coronary artery bypass graft. This percutaneous coronary intervention could prevent redo coronary artery bypass graft surgery. Cathet. Cardiovasc. Intervent. 49:197-199, 2000. Copyright 2000 Wiley-Liss, Inc.
A scanning electron microscopic study of biliary stent materials

NARCIS (Netherlands)

van Berkel, A. M.; van Marle, J.; van Veen, H.; Groen, A. K.; Huibregtse, K.

2000-01-01

Clogging of biliary stents remains an important problem. In vitro studies have shown less sludge formation in Teflon stents. Recently, clinical studies with Teflon stents have produced contradictory results. The aim of this study was to investigate whether the surface properties of the
A Fast Placement Technique for Covered Tracheobronchial Stents in Patients with Complicated Esophagorespiratory Fistulas

International Nuclear Information System (INIS)

Kishi, Kazushi; Nakao, Taisei; Goto, Hironobu; Kimura, Masashi; Sonomura, Tetsuo; Yamanaka, Noboru; Nanjo, Kishio; Sato, Morio

2005-01-01

Purpose. To test an endotracheal placement procedure for malignant esophagorespiratory fistula when endoesophageal placement is inapplicable. Methods. We report on patients with malignant esophagorespiratory fistula to which endoesophageal approaches were complicated with a complete obstruction of the hypopharynx, a collapsible tracheobronchus, or a previously placed endoesophageal stents. Gore-Tex membrane-covered Z-stents were deployed in the trachea using a coaxial introducer system in three patients. A Dumon tube was deployed in the bronchus over the bronchofiberscope in one patient. Results. All fistula were completely sealed by the endotracheal or endobronchial stenting. Symptomatic and clinical improvements were immediate obtained. Conclusion. Endotracheal or endobronchial covered stent placement is thought to be an effective alternative method for sealing esophagorespiratory fistula
Iliocaval Confluence Stenting for Chronic Venous Obstructions

Energy Technology Data Exchange (ETDEWEB)

Graaf, Rick de, E-mail: r.de.graaf@mumc.nl [Maastricht University Medical Centre (MUMC), Department of Radiology (Netherlands); Wolf, Mark de, E-mail: markthewolf@gmail.com [Maastricht University Medical Centre (MUMC), Department of Surgery (Netherlands); Sailer, Anna M., E-mail: anni.sailer@mumc.nl [Maastricht University Medical Centre (MUMC), Department of Radiology (Netherlands); Laanen, Jorinde van, E-mail: jorinde.van.laanen@mumc.nl; Wittens, Cees, E-mail: c.wittens@me.com [Maastricht University Medical Centre (MUMC), Department of Surgery (Netherlands); Jalaie, Houman, E-mail: hjalaie@ukaachen.de [University Hospital Aachen, Department of Surgery (Germany)

2015-10-15

PurposeDifferent techniques have been described for stenting of venous obstructions. We report our experience with two different confluence stenting techniques to treat chronic bi-iliocaval obstructions.Materials and MethodsBetween 11/2009 and 08/2014 we treated 40 patients for chronic total bi-iliocaval obstructions. Pre-operative magnetic resonance venography showed bilateral extensive post-thrombotic scarring in common and external iliac veins as well as obstruction of the inferior vena cava (IVC). Stenting of the IVC was performed with large self-expandable stents down to the level of the iliocaval confluence. To bridge the confluence, either self-expandable stents were placed inside the IVC stent (24 patients, SECS group) or high radial force balloon-expandable stents were placed at the same level (16 patients, BECS group). In both cases, bilateral iliac extensions were performed using nitinol stents.ResultsRecanalization was achieved for all patients. In 15 (38 %) patients, a hybrid procedure with endophlebectomy and arteriovenous fistula creation needed to be performed because of significant involvement of inflow vessels below the inguinal ligament. Mean follow-up was 443 ± 438 days (range 7–1683 days). For all patients, primary, assisted-primary, and secondary patency rate at 36 months were 70, 73, and 78 %, respectively. Twelve-month patency rates in the SECS group were 85, 85, and 95 % for primary, assisted-primary, and secondary patency. In the BECS group, primary patency was 100 % during a mean follow-up period of 134 ± 118 (range 29–337) days.ConclusionStenting of chronic bi-iliocaval obstruction shows relatively high patency rates at medium follow-up. Short-term patency seems to favor confluence stenting with balloon-expandable stents.
Covered duodenal self-expandable metal stents prolong biliary stent patency in double stenting: The largest series of bilioduodenal obstruction.

Science.gov (United States)

Hori, Yasuki; Naitoh, Itaru; Hayashi, Kazuki; Kondo, Hiromu; Yoshida, Michihiro; Shimizu, Shuya; Hirano, Atsuyuki; Okumura, Fumihiro; Ando, Tomoaki; Jinno, Naruomi; Takada, Hiroki; Togawa, Shozo; Joh, Takashi

2018-03-01

Endoscopic biliary and duodenal stenting (DS; double stenting) is widely accepted as a palliation therapy for malignant bilioduodenal obstruction. The aim of the current study was to investigate the patency and adverse events of duodenal and biliary stents in patients with DS. Patients who underwent DS from April 2004 to March 2017 were analyzed retrospectively with regard to clinical outcomes and predictive factors of recurrent biliary and duodenal obstruction (recurrent biliary obstruction [RBO] and recurrent duodenal obstruction [RDO]). A total of 109 consecutive patients was enrolled. Technical success of DS was achieved in 108 patients (99.1%). Symptoms due to biliary and duodenal obstruction were improved in 89 patients (81.7%). RBO occurred in 25 patients (22.9%) and RDO in 13 (11.9%). The median times to RBO and RDO from DS were 87 and 76 days, respectively. Placement of a duodenal uncovered self-expandable metal stent (U-SEMS) was significantly associated with RBO in the multivariable analysis (P = 0.007). Time to RBO was significantly longer in the duodenal covered self-expandable metal stent group than in the U-SEMS group (P = 0.003). No predictive factors of RDO were detected, and duodenal stent type was not associated with the time to RDO (P = 0.724). Double stenting was safe and effective for malignant bilioduodenal obstruction. Duodenal U-SEMS is a risk factor for RBO. The covered self-expandable metal stent is the preferred type of duodenal SEMS in patients with DS (Clinical trial registration number: UMIN000027606). © 2017 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.
The implantation of separating aortic stent-graft into the canine thoracic aorta: an experimental study

International Nuclear Information System (INIS)

Xia Jinguo; Shi Haibin; Yang Zhengqiang; Li Chao; Liu Sheng; Zu Qingquan; Li Linsun

2011-01-01

Objective: to assess the technical feasibility of implanting separating stent-graft into the canine thoracic aorta and to study its biocompatibility. Methods: Twelve adult dogs were randomly and equally divided into three groups. The right femoral artery was cut open, through which the separating stent-graft was inserted and deployed in the canine thoracic aorta, with the proximal end of the graft being quite close to the origin of the left subclavian artery. the technical feasibility of the deployment process was assessed. Angiography was performed at 4, 8 and 12 weeks after stent-graft placement to evaluate the position and patency of the stent-graft. Then the dogs were sacrificed and the specimens were collected for pathologic study. Both gross and microscopic examinations were made to evaluate the fixation of the stent-graft with the vessel wall, the endothelialization of stent-graft surface and the pathologic changes of the vascular wall. Results: A total of ten separating stent-grafts were successfully deployed in the canine thoracic aorta, no migration or deformation occurred. One dog died of massive bleeding due to the rupture of the right femoral artery which occurred when the delivery system containing the inner bare stent was inserted through the right femoral artery. Death occurred in another dog as a result of the ascending aorta rupture caused by the migration of outer-layer stent-graft. Angiography was conducted at 4, 8 and 12 weeks after stent-graft placement. No migration, deformation, rupture or stenosis of the implanted stent-grafts were observed. The formation of intima on the inner surface of the bare stent appeared at 4 weeks, which became more and more obvious with the time passing, and at 12 weeks complete endothelialization of stent-graft surface was observed. Conclusion: Technically, it is feasible to deploy the separating aortic stent-graft into the canine thoracic aorta. Moreover, the separating aortic stent-graft carries excellent
[Cost-effectiveness trial of self-expandable metal stents and plastic biliary stents in malignant biliary obstruction].

Science.gov (United States)

Daróczi, Tímea; Bor, Renáta; Fábián, Anna; Szabó, Ella; Farkas, Klaudia; Bálint, Anita; Czakó, László; Rutka, Mariann; Szűcs, Mónika; Milassin, Ágnes; Molnár, Tamás; Szepes, Zoltán

2016-02-14

Self-expandable metal and plastic stents can be applied in the palliative endoscopic treatment of patients with unresectable malignant biliary obstruction. The use of metal stentsis recommended if the patient's life expectancy is more than four months. To compare the therapeutic efficacy and cost-effectiveness of metal and plastic stents in the treatment of malignant biliary obstruction. The authors retrospectively enrolled patients who received metal (37 patients) or plastic stent (37 patients). The complication rate, stent patency and cumulative cost of treatment were assessed in the two groups. The complication rate of metal stents was lower (37.84% vs. 56.76%), but the stent patency was higher compared with plastic stents (19.11 vs. 8.29 weeks; p = 0.0041). In the plastic stent group the frequency of hospitalization of patients in context with stent complications (1.18 vs. 2.32; p = 0.05) and the necessity of reintervention for stent dysfunction (17 vs. 27; p = 0.033) were substantially higher. In this group multiple stent implantation raised the stent patency from 7.68 to 10.75 weeks. There was no difference in the total cost of treatment of malignant biliary obstruction between the two groups (p = 0.848). Considering the cost of treatment and the burden of patients the authors recommend self-expandable metal sten timplantation if the life expectancy of patients is more than two months. In short survival cases multiple plastic stent implantation is recommended.
Percutaneous transhepatic self-expanding metal stents for palliation ...

African Journals Online (AJOL)

Stent occlusion occurred in 4 patients (8%) within a week as result of stent migration (n=3) or presumed biliary sludge (n=1); 2 (4%) stents occluded between 7 days and 1 month. Four patients (8%) died during hospital admission due to pre-existing biliary sepsis (n=3) and pneumonia (n=1). Nine patients developed ...
Safety and efficacy of everolimus-eluting stents compared with first-generation drug-eluting stents in patients undergoing primary percutaneous coronary intervention

Energy Technology Data Exchange (ETDEWEB)

Escárcega, Ricardo O.; Baker, Nevin C.; Magalhaes, Marco A.; Lipinski, Michael J.; Minha, Sa’ar; Torguson, Rebecca; Satler, Lowell F.; Pichard, Augusto D.; Suddath, William O.; Waksman, Ron, E-mail: ron.waksman@medstar.net

2014-09-15

Objective: To assess the safety and efficacy everolimus-eluting stents (EES) compared with first-generation drug-eluting stents (DES) in patients with acute myocardial infarction (MI) undergoing primary percutaneous coronary intervention (PCI). Background: EES have been associated with improved clinical outcomes compared to paclitaxel-eluting stents (PES) and with similar outcomes compared to sirolimus-eluting stents (SES). Methods: A total of 520 patients who presented with ST-elevation myocardial infarction (STEMI) from 2003 to 2013, who underwent primary PCI with DES, were retrospectively analyzed. Of these, 247 received SES, 136 PES, and 137 EES. Patients were followed up to 2 years for major adverse cardiac events (MACE). Univariate and multivariate models detected correlates to outcome. Results: EES implantation, compared with PES and SES, resulted in comparable rates of MACE (8.8% vs. 16.2%, p = 0.06 and 8.8% vs. 12.6%, respectively, p = 0.26), stent thrombosis, MI, and target lesion revascularization. Patients who received EES had lower rates of all-cause mortality (3.7% vs. 12.6% vs. 9.4%, p = 0.03) at 1-year follow up. However, in the univariate and multivariate analyses, stent type was not independently associated with the primary outcome or with all-cause mortality. Diabetes mellitus and number of stents implanted were independently associated with the primary outcome. Conclusion: While EES seem to be associated with better outcome when compared to PES, the main correlates of STEMI patients are the presence of diabetes and number of stents implanted, and not the type of stent used for intervention.
Gastric and Duodenal Stents: Follow-Up and Complications

International Nuclear Information System (INIS)

Pinto Pabon, Isabel Teresa; Paul Diaz, Laura; Ruiz de Adana, Juan Carlos; Lopez Herrero, Julio

2001-01-01

Purpose: To assess the efficacy of self-expanding metallic stents in treating inoperable gastric and duodenal stenoses during follow-up and to evaluate the complications encountered.Methods: A total of 31 patients suffering from gastroduodenal obstruction (29 malignant, 2 benign) were treated with a self-expanding metallic stent (Wallstent). In 24 cases insertion was by the peroral route, in seven cases via gastrostomy.Results: All the strictures were successfully negotiated under fluoroscopic guidance without having to resort to endoscopy. A total of 27 patients (87%) were able to resume a regular diet, a soft diet, or a liquid diet orally. Complications included one case of stent malpositioning, one case of leakage of ascitic fluid through the gastrostomy orifice, one case of perforation and fistula to the biliary tree, and two cases of hematemesis. In two patients (6%) additional stents were implanted to improve patency. In all patients follow-up was maintained until death. Recurrence of symptoms immediately before death occurred in seven cases (23%). Mean survival time of patients was 13.3 weeks (SE ± 4.6).Conclusions: The deployment of gastroduodenal stents resulted in good palliation of inoperable gastric and duodenal stenoses. Certain technical aspects, e.g., adaptation of stents to bowel morphology, is critical to proper stent function and avoidance of complications
An argument for the use of multiple segment stents in curved arteries.

Science.gov (United States)

Kasiri, Saeid; Kelly, Daniel J

2011-08-01

Stenting of curved arteries is generally perceived to be more challenging than straight vessels. Conceptually implanting multiple shorter stents rather than a single longer stent into such a curved artery represents a promising concept, but little is known about the impact of such an approach. The objective of this study is to evaluate the effectiveness of using a multiple segment stent rather than a single long stent to dilate a curved artery using the finite element method. A double segment stent (DSS) and a single segment stent (SSS) were modeled. The stents were compared when expanded into a model of a curved artery. The model predicts that the DSS provides higher flexibility, more conformity, and lower recoil in comparison to the SSS. The volume of arterial tissue experiencing high levels of stress due to stent implantation is also reduced for the DSS. It is suggested that a multiple segment stenting system is a potential solution to the problem of higher rates of in-stent restenosis in curved arteries and mechanically challenging environments.
Experimental absorbable stent permits airway remodeling.

Science.gov (United States)

Liu, Kuo-Sheng; Liu, Yun-Hen; Peng, Yi-Jie; Liu, Shih-Jung

2011-02-01

Despite metallic and silicone stents being effective in treating various airway lesions, many concerns still remain. A bioresorbable stent that scaffolds the airway lumen and dissolves after the remodeling process is completed has advantages over metallic and silicone stents. We designed and fabricated a new mesh-type bioresorbable stent with a backbone of polycaprolactone (PCL), and evaluated its safety and biocompatibility in a rabbit trachea model. The PCL stent was fabricated by a laboratory-made microinjection molding machine. In vitro mechanical strength of the PCL stents was tested and compared to that of commercial silicone stents. The bioresorbable stents were surgically implanted into the cervical trachea of New Zealand white rabbits (n=6). Animals received bronchoscopic examination at 1, 2, 4, 8, and 12 weeks after surgery. Histological examination was completed to evaluate the biocompatibility of the stents. No animals died during the period of study. Distal stent migration was noted in 1 rabbit. In-stent secretion accumulation was found in 2 rabbits. Histological examination showed intact ciliated epithelium and marked leukocyte infiltration in the submucosa of the stented area at 10 and 28 weeks. Stent degradation was minimal, and the mechanical strength was well preserved at the end of 33 weeks. These preliminary findings showed good safety and biocompatibility of the new PCL stent when used in the airway remodeling. PCL could be a promising bioresorbable material for stent design if prolonged degradation time is required. Copyright Â© 2011 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.
Protein losing enteropathy secondary to a pulmonary artery stent

Directory of Open Access Journals (Sweden)

Narayanswami Sreeram

2012-01-01

Full Text Available A 2-year-old patient with hypoplastic left heart syndrome presented 6 months following Fontan completion with protein-losing enteropathy (PLE. He had undergone stent implantation in the left pulmonary artery after the Norwood procedure, followed by redilation of the stent prior to Fontan completion. Combined bronchoscopic and catheterization studies during spontaneous breathing confirmed left bronchial stenosis behind the stent, and diastolic systemic ventricular pressure during expiration of 25 mm Hg. We postulate that the stent acts as a valve, against which the patient generates high expiratory pressures, which are reflected in the ventricular diastolic pressure. This may be the cause of PLE.
Self-made Palmaz stent: an experimental swine model study

International Nuclear Information System (INIS)

He Shicheng; Teng Gaojun; Guo Jinhe; Fang Wen

2000-01-01

Objective: To investigate the histologic changes and physicochemical stability of self-made Palmaz stent placed in swine arteries. Methods: The self-made Palmaz stent was made of 316L stainless steel wire. Nine stents were respectively placed within internal carotid, renal and iliac arteries of six pigs. Pigs were euthanized at intervals of 0.5, 1 and 3 months respectively and angiography were performed. Immediately followed by light and electro scanning microscopy for the stent zones. Results: All stents were successfully implanted in the target arteries and were patent shown in the angiographic examination immediately after the stent placement. Eight stents (8/9) remained patent at the time before euthanasia. No migration of stent were shown in the follow-up angiography. Light and electron scanning microscopy showed that the surface of the stents was covered by a thin layer of endothelial cells 2 weeks after the procedure and completely covered after 4 weeks. No inflammation occurred. Conclusions: The self-made Palmaz stent has good physicochemical stability and histocompatibility with easy placement, rather long term patency, histopathologic stability and thus the promising for clinical application
TACE Combined with Implantation of Irradiation Stent Versus TACE Combine with Bare Stent for HCC Complicated by IVCTT

Energy Technology Data Exchange (ETDEWEB)

Yang, Qing-hui; Zhang, Wen; Liu, Qing-xin; Liu, Ling-xiao [Fudan University, Department of Interventional Radiology, Zhongshan Hospital (China); Wu, Lin-lin [Tengzhou Central People’s Hospital, Department of Oncology (China); Wang, Jian-hua; Yan, Zhi-ping, E-mail: 798373254@qq.com; Luo, Jian-jun, E-mail: 12211210022@fudan.edu.cn [Fudan University, Department of Interventional Radiology, Zhongshan Hospital (China)

2016-09-15

PurposeThis study was designed to evaluate the safety and efficacy of transarterial chemoembolization (TACE) combined with intra-IVC implantation of an irradiation stent for the treatment of hepatocellular carcinoma (HCC) complicated by inferior vena cava tumor thrombosis (IVCTT).MethodsSixty-one consecutive patients with HCC complicated by IVCTT treated by TACE combined with IVC stenting were retrospectively analysed. IVC stenting was performed using a stent loaded with {sup 125}I seeds strands (the irradiation stent) in 33 patients (Group A) and 28 patients with a bare stent (Group B). Propensity score matching eliminated the baseline differences. Overall survival, oedema related to IVC obstruction remission rate and procedure-related adverse events were compared between the two groups.ResultsThe adverse effect rate was similar for both Group A and Group B patients, and complications were adequately handled by medical treatment. TACE combined with implantation of an irradiation stent showed a significant median survival benefit over TACE combined with a bare stent, with a median survival time of 203.0 ± 28.135 days versus 93.0 ± 24.341 days (p = 0.006). The propensity score-matched (24 pairs) cohort analyses (200 ± 31.231 days vs. 66 ± 23.270 days, p = 0.019). The oedema remission rate was 97.0 % in group A patients and 96.4 % in group B, respectively. TACE-irradiation stent and object tumor response were the independent prognostic factors of favorable survival.ConclusionsTACE combined with irradiation stent implantation is a safe and effective treatment modality for patients with HCC complicated by IVCTT and may extend their survival time.
Insertion of a self-expandable metallic stent in canine lacrimal Sac : a long-term evaluation

Energy Technology Data Exchange (ETDEWEB)

Song, Ho Young; Sung, Kyu Bo; Yoon, Hyun Ki [Univ. of Ulsan, Ulsan (Korea, Republic of). College of Medicine; Kwon, Soon Tae [Chungnam National Univ., Taejon (Korea, Republic of). Medical School; Lee, Ho Jung; Lee, In Chul; Kim, Tae Hyung; Park, Sang Soo; Huh, Soo Jin [Univ. of Ulsan, Ulsan (Korea, Republic of). College of Medicine

1998-01-01

To evaluate the feasibility and long-term outcome of the use of self-expandable metallic Z-stents in the canine lacrimal sac. Stent placement was technically successful and well tolerated in all but one lacrimal sac, in which the stent was misplaced. At three and six months after stent placement, stent wires were not encased by epithelium, but at nine months, and one, two and three years after placement, six of the 12 stents had become encased in a proliferation of this where the stent wires contacted the lacrimal sac wall. In no lacrimal system in which stent placement had been successful was migration, stenosis or obstruction of the lacrimal system observed. One misplaced stent caused obstruction of the lacrimal sac, however . In 11 of 12 case (92%), fluoroscopic placement of an expandable metallic stent in the canine lacrimal sac was successful: in 6 of 8 cases (75%), the stent wires became encased by a proliferation of mucosa, but during long-term follow-up of 9 months to 3 years, no obstruction was observed. (author). 20 refs., 1 tab., 5 figs.
Insertion of a self-expandable metallic stent in canine lacrimal Sac : a long-term evaluation

International Nuclear Information System (INIS)

Song, Ho Young; Sung, Kyu Bo; Yoon, Hyun Ki; Kwon, Soon Tae; Lee, Ho Jung; Lee, In Chul; Kim, Tae Hyung; Park, Sang Soo; Huh, Soo Jin

1998-01-01

To evaluate the feasibility and long-term outcome of the use of self-expandable metallic Z-stents in the canine lacrimal sac. Stent placement was technically successful and well tolerated in all but one lacrimal sac, in which the stent was misplaced. At three and six months after stent placement, stent wires were not encased by epithelium, but at nine months, and one, two and three years after placement, six of the 12 stents had become encased in a proliferation of this where the stent wires contacted the lacrimal sac wall. In no lacrimal system in which stent placement had been successful was migration, stenosis or obstruction of the lacrimal system observed. One misplaced stent caused obstruction of the lacrimal sac, however . In 11 of 12 case (92%), fluoroscopic placement of an expandable metallic stent in the canine lacrimal sac was successful: in 6 of 8 cases (75%), the stent wires became encased by a proliferation of mucosa, but during long-term follow-up of 9 months to 3 years, no obstruction was observed. (author). 20 refs., 1 tab., 5 figs

A review on biodegradable materials for cardiovascular stent application

Science.gov (United States)

Hou, Li-Da; Li, Zhen; Pan, Yu; Sabir, MuhammadIqbal; Zheng, Yu-Feng; Li, Li

2016-09-01

A stent is a medical device designed to serve as a temporary or permanent internal scaffold to maintain or increase the lumen of a body conduit. The researchers and engineers diverted to investigate biodegradable materials due to the limitation of metallic materials in stent application such as stent restenosis which requires prolonged anti platelet therapy, often result in smaller lumen after implantation and obstruct re-stenting treatments. Biomedical implants with temporary function for the vascular intervention are extensively studied in recent years. The rationale for biodegradable stent is to provide the support for the vessel in predicted period of time and then degrading into biocompatible constituent. The degradation of stent makes the re-stenting possible after several months and also ameliorates the vessel wall quality. The present article focuses on the biodegradable materials for the cardiovascular stent. The objective of this review is to describe the possible biodegradable materials for stent and their properties such as design criteria, degradation behavior, drawbacks and advantages with their recent clinical and preclinical trials.
Stent implantation influence wall shear stress evolution

Science.gov (United States)

Bernad, S. I.; Totorean, A. F.; Bosioc, A. I.; Petre, I.; Bernad, E. S.

2016-06-01

Local hemodynamic factors are known affect the natural history of the restenosis critically after coronary stenting of atherosclerosis. Stent-induced flows disturbance magnitude dependent directly on the strut design. The impact of flow alterations around struts vary as the strut geometrical parameters change. Our results provide data regarding the hemodynamic parameters for the blood flow in both stenosed and stented coronary artery under physiological conditions, namely wall shear stress and pressure drop.
Management of stent dislodgment in coarctoplasty of aorta with three overlapping self-expandable nitinol stents.

Science.gov (United States)

Ghazi, Payam; Haji-Zeinali, Ali-Mohammad

2010-01-01

We describe a case of native coarctation of aorta managed with three self-expandable nitinol stents. After balloon pre-dilation, the first and second stents were dislodged. The coarcted area was successfully treated with the third stent overlapped with the previous stents. During follow up (30 months), the patient was free of complications. It seems that implantation of multiple overlapping self-expandable stents in aortic coarctation patients, if needed, is safe and possible.
Temporary placement of covered retrievable expandable nitinol stents with barbs in high-risk surgical patients with benign prostatic hyperplasia: work in progress.

Science.gov (United States)

Kim, Choung-Soo; Song, Ho-Young; Jeong, In Gab; Yeo, Hyun Jin; Kim, Eun-Young; Park, Jung-Hoon; Yoon, Chang Jin; Paick, Sung Hyun; Park, Sang Woo; Bae, Jae-Ik; Won, Je Hwan

2011-10-01

To report the use of a newly constructed, covered, retrievable, expandable nitinol stent with barbs to overcome the problem of stent migration associated with conventional covered prostatic expandable stents and to evaluate prospectively the technical feasibility and clinical effectiveness of the stents in patients with benign prostatic hyperplasia (BPH). A covered retrievable expandable nitinol stent with four barbs was placed with use of an 18-F stent delivery system in seven consecutive patients with symptomatic BPH who had high operative risks. Age range of patients was 62-83 years (mean 74 years). In cases in which the stent migrated, it was replaced with a stent with eight barbs. The stents were routinely removed 4 months after placement using a 21-F stent removal set. Stent placement was technically successful and well tolerated in six of the seven patients. The remaining patient needed a second stent placement after removal of the first stent. The stent with four barbs migrated into the urinary bladder in four patients (57%); three of these patients received a second stent with eight barbs with good results, and the fourth patient did not need further treatment because his symptoms improved. Routine removal of the stent 4 months after placement was performed in three of the seven patients with good results. Retrievable stents with eight barbs seem to overcome the problem of stent migration associated with conventional prostatic expandable stents. Preliminary results suggest that stents with barbs are both feasible and effective in patients with BPH. Copyright © 2011 SIR. Published by Elsevier Inc. All rights reserved.
Temporary metallic stent placement in the treatment of refractory benign esophageal strictures: results and factors associated with outcome in 55 patients

Energy Technology Data Exchange (ETDEWEB)

Kim, Jin Hyoung; Kim, Kyung Rae; Shin, Ji Hoon; Lim, Jin-Oh [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea); Song, Ho-Young [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea)]|[University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology, Seoul (Korea); Choi, Eugene K. [Weill Medical College of Cornell University, New York, NY (United States)

2009-02-15

The purpose of this study was to evaluate the effectiveness of temporary metallic stenting in 55 patients with treatment-resistant benign esophageal strictures and to identify factors associated with clinical outcomes. Under fluoroscopic guidance, covered retrievable stents were placed in 55 patients with benign esophageal strictures and were removed with retrieval hook 1 week to 6 months after placement. Stent placement was successful in all patients, and the mean dysphagia score was reduced from 2.8 to 1.3 (p<0.001). The most common complications were tissue hyperproliferation (31%), severe pain (24%), and stent migration (25%). During follow-up (mean: 38 months), recurrence of the stricture necessitating balloon dilation was seen in 38 (69%) of 55 patients. Maintained patency rates after temporary stenting at 1, 3, and 6 months and 1, 2, and 4 years were 58%, 43%, 38%, 33%, 26%, and 21%, respectively. In multivariate analysis, length (p=0.003) of the stricture was the only significant factor associated with maintained patency after temporary stenting. In conclusion, temporary metallic stenting for refractory benign esophageal strictures may be effective during the period of stent placement, but is disadvantaged by the high recurrence rates after stent removal, particularly in patients with a long length of stricture (>7cm). (orig.)
Complication rate in unprotected carotid artery stenting with closed-cell stents

International Nuclear Information System (INIS)

Tietke, Marc W.K.; Kerby, Tina; Alfke, Karsten; Riedel, Christian; Rohr, Axel; Jensen, Ulf; Jansen, Olaf; Zimmermann, Phillip; Stingele, Robert

2010-01-01

The discussion on the use of protection devices (PDs) in carotid artery stenting (CAS) is gaining an increasing role in lowering the periprocedural complication rates. While many reviews and reports with retrospective data analysis do promote the use of PDs the most recent multi-centre trials are showing advantages for unprotected CAS combined with closed-cell stent designs. We retrospectively analysed 358 unprotected CAS procedures performed from January 2003 to June 2009 in our clinic. Male/female ratio was 2.68/1. The average age was 69.3 years. Seventy-three percent (261/358) showed initial neurological symptoms. All patients were treated on a standardised interventional protocol. A closed and small-sized cell designed stent was implanted in most cases (85.2%). One hundred seventy-one (47.8%) were controlled by Doppler ultrasonography usually at first in a 3-month and later in 6-month intervals. The peri-interventional and 30-day mortality/stroke rate was 4.19% (15/358). These events included three deaths, five hyperperfusion syndromes (comprising one death by a secondary fatal intracranial haemorrhage), one subarachnoid haemorrhage and seven ischaemic strokes. Only 20% (3/15) of all complications occurred directly peri-interventional. The overall peri-interventional complication rate was 0.8% (3/358). Most complications occurred in initial symptomatic patients (5.36%). The in-stent restenosis rate for more than 70% was 7% (12/171) detected at an average of 9.8 month. Our clinical outcome demonstrates that unprotected CAS with small cell designed stents results in a very low procedural complication rate, which makes the use of a protection device dispensable. (orig.)
Antegrade Ureteral Stenting is a Good Alternative for the Retrograde Approach.

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van der Meer, Rutger W; Weltings, Saskia; van Erkel, Arian R; Roshani, Hossain; Elzevier, Henk W; van Dijk, Lukas C; van Overhagen, Hans

2017-07-01

Double J (JJ) stents for treating obstructive ureteral pathology are generally inserted through a retrograde route with cystoscopic guidance. Antegrade percutaneous insertion using fluoroscopy can be performed alternatively but is less known. Indications, success rate and complications of antegrade ureteral stenting were evaluated. Data of consecutive patients in which antegrade ureteral stenting was performed were retrospectively analysed using the radiology information system and patient records. Patient characteristics, details of the antegrade JJ stent insertion procedure and registered complications were collected. Furthermore, it was investigated if prior to the antegrade procedure a retrograde attempt for JJ stent insertion was performed. Total 130 attempts for antegrade JJ stent insertion were performed in 100 patients. A percutaneous nephrostomy catheter had already been placed in the majority of kidneys (n = 109) for initial treatment of hydronephrosis. Most prevelant indication for a JJ stent was obstructive ureteral pathology due to malignancy (n = 63). A JJ stent was successfully inserted in 125 of 130 procedures. In 21 cases, previous retrograde ureteral stenting had failed but, subsequent antegrade ureteral stenting was successful. There were 8 procedure related complications; 6 infections, 1 false tract and 1 malposition. Antegrade percutaneous insertion of a JJ stent is a good alternative for retrograde insertion.
Carotid Stenting with Distal Protection in High-Surgical-Risk Patients: One-Year Results of the ASTI Trial

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Bosiers, Marc, E-mail: marc.bosiers@telenet.be [A.Z. Sint-Blasius, Department of Vascular Surgery (Belgium); Scheinert, Dierk, E-mail: dierk.scheinert@gmx.de [Park Hospital, Center for Vascular Medicine-Angiology and Vascular Surgery (Germany); Mathias, Klaus, E-mail: k.mathias@asklepios.com [Klinikum Dortmund GmbH (Germany); Langhoff, Ralf, E-mail: ralf.langhoff@sankt-gertrauden.de [Sankt Gertrauden-Krankenhaus (Germany); Mudra, Harald, E-mail: haraldmudra@aol.com [Klinikum Neuperlach (Germany); Diaz-Cartelle, Juan, E-mail: juan.diazcartelle@bostonscientific.com [One Boston Scientific Place, Boston Scientific Corporation (United States)

2015-04-15

PurposeThis prospective, multicenter, nonrandomized study evaluated the periprocedural and 1-year outcomes in high-surgical-risk patients with carotid artery stenosis treated with the Adapt Carotid Stent plus FilterWire EZ distal protection catheter (Boston Scientific Corporation, Natick, MA).Materials and MethodsThe study enrolled 100 patients (32 symptomatic, 63 asymptomatic, 5 unknown) at high risk for carotid endarterectomy due to prespecified anatomical criteria and/or medical comorbidities. Thirty-day and 1-year follow-up included clinical evaluation, carotid duplex ultrasound, and independent neurologic and NIH stroke scale assessments. One-year endpoints included the composite rate of major adverse events (MAE), defined as death, stroke, and myocardial infarction (MI) and the rates of late ipsilateral stroke (31–365 days), target lesion revascularization, and in-stent restenosis.ResultsOf the 100 enrolled patients, technical success was achieved in 90.9 % (90/99). The 30-day MAE rate (5.1 %) consisted of major stroke (2.0 %) and minor stroke (3.1 %); no deaths or MIs occurred. The 1-year MAE rate (12.2 %) consisted of death, MI, and stroke rates of 4.4, 3.3, and 8.9 %, respectively. Late ipsilateral stroke (31–365 days) rate was 1.1 %. Symptomatic patients had higher rates of death (11.1 vs. 1.7 %) and MI (7.4 vs. 1.7 %), but lower rates of major (7.4 vs. 10.0 %) and minor stroke (0.0 vs. 6.7 %), compared with asymptomatic patients.ConclusionResults through 1 year postprocedure demonstrated that carotid artery stenting with Adapt Carotid Stent and FilterWire EZ is safe and effective in high-risk-surgical patients.
Carotid Stenting with Distal Protection in High-Surgical-Risk Patients: One-Year Results of the ASTI Trial

International Nuclear Information System (INIS)

Bosiers, Marc; Scheinert, Dierk; Mathias, Klaus; Langhoff, Ralf; Mudra, Harald; Diaz-Cartelle, Juan

2015-01-01

PurposeThis prospective, multicenter, nonrandomized study evaluated the periprocedural and 1-year outcomes in high-surgical-risk patients with carotid artery stenosis treated with the Adapt Carotid Stent plus FilterWire EZ distal protection catheter (Boston Scientific Corporation, Natick, MA).Materials and MethodsThe study enrolled 100 patients (32 symptomatic, 63 asymptomatic, 5 unknown) at high risk for carotid endarterectomy due to prespecified anatomical criteria and/or medical comorbidities. Thirty-day and 1-year follow-up included clinical evaluation, carotid duplex ultrasound, and independent neurologic and NIH stroke scale assessments. One-year endpoints included the composite rate of major adverse events (MAE), defined as death, stroke, and myocardial infarction (MI) and the rates of late ipsilateral stroke (31–365 days), target lesion revascularization, and in-stent restenosis.ResultsOf the 100 enrolled patients, technical success was achieved in 90.9 % (90/99). The 30-day MAE rate (5.1 %) consisted of major stroke (2.0 %) and minor stroke (3.1 %); no deaths or MIs occurred. The 1-year MAE rate (12.2 %) consisted of death, MI, and stroke rates of 4.4, 3.3, and 8.9 %, respectively. Late ipsilateral stroke (31–365 days) rate was 1.1 %. Symptomatic patients had higher rates of death (11.1 vs. 1.7 %) and MI (7.4 vs. 1.7 %), but lower rates of major (7.4 vs. 10.0 %) and minor stroke (0.0 vs. 6.7 %), compared with asymptomatic patients.ConclusionResults through 1 year postprocedure demonstrated that carotid artery stenting with Adapt Carotid Stent and FilterWire EZ is safe and effective in high-risk-surgical patients
Assessment Of Coronary Arterial Stents By Multislice-CT Angiography

International Nuclear Information System (INIS)

Maintz, D.; Fallenberg, E. M.; Heindel, W.; Fischbach, R.; Grude, M.

2003-01-01

Purpose: To assess patency and lumen visibility of coronary artery stents by multislice-CT angiography (MSCTA) in comparison with conventional coronary angiography as the standard of reference. Material and Methods: 47 stents of 13 different types were evaluated in 29 patients. MSCTA was performed on a 4-slice scanner with a standard coronary protocol (detector collimation 4 x 1 mm; table feed 1.5 mm/rotation, 400 mAs, 120 kV). Image evaluation was performed by two readers who were blinded to the reports from the catheter angiography. MIP reconstructions were evaluated for image quality on a 4-point scale (1 = poor, 4 = excellent) and stent patency (contrast distal to the stent as an indirect patency sign). Axial images and multiplanar reformations through the stents were used for assessment of stent lumen visibility (measurement of the visible stent lumen diameter) and detection of relevant in-stent stenosis (50%). Results: Image quality was fair to good on average (score 2.64 ± 1.0) and depended on the heart rate (heart rate 45-60: average score 3.2, heart rate 61-70: average score 2.8, heart rate >71: average score 1.4). Thirty-seven stents were correctly classified as patent, 1 was correctly classified as occluded and 9 stents were not assessable due to insufficient image quality because of triggering artifacts. Parts of the stent lumen could be visualized in 30 cases. On average, 20-40% of the stent lumen diameter was visible. Twenty-five stents were correctly classified as having no stenosis, 1 was falsely classified as stenosed, 1 was correctly classified as occluded. In 20 stents lumen visibility was not sufficient for stenosis evaluation. Conclusion: Although the stent lumen may be partly visualized in most stents, a reliable evaluation of in-stent stenoses does not seem practical by 4-slice MSCT. Nevertheless, for stent patency evaluation, MS-CTA might provide valuable clinical information. With submillimeter MSCT (e.g. 16-slice scanners) and more
[Magnetic resonance compatibility research for coronary mental stents].

Science.gov (United States)

Wang, Ying; Liu, Li; Wang, Shuo; Shang, Ruyao; Wang, Chunren

2015-01-01

The objective of this article is to research magnetic resonance compatibility for coronary mental stents, and to evaluate the magnetic resonance compatibility based on laboratory testing results. Coronary stents magnetic resonance compatibility test includes magnetically induced displacement force test, magnetically induced torque test, radio frequency induced heating and evaluation of MR image. By magnetic displacement force and torque values, temperature, and image distortion values to determine metal coronary stent demagnetization effect. The methods can be applied to test magnetic resonance compatibility for coronary mental stents and evaluate its demagnetization effect.
Revisiting the tethered ureteral stents in children: a novel modification.

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Kajbafzadeh, Abdol-Mohammad; Nabavizadeh, Behnam; Keihani, Sorena; Hosseini Sharifi, Seyed Hossein

2015-06-01

To propose a simple noninvasive method for ureteral stent retrieval using an extraction string sutured to the skin in children. A retrospective chart review was performed to gather relevant data from December 2005 to February 2013. After the surgeries, if indicated, a tethered double-J stent was placed in the ureter. A 5-0 non-absorbable Prolene stitch was used as an extraction string passing through the urethra and was sutured to subcoronal skin in boys or inner surface of labia majora in girls. For stent removal, a small amount of 2 % lidocaine jelly was pushed into the urethra 5 min before the procedure. The string was then pulled by continuous and gentle force until the entire stent was out. The suture was then cut to release the stent. No sedation or anesthesia was needed. A total of 378 double-J stents with extraction strings were inserted for a total of 325 patients (61.2 % male). Of the 53 patients with bilateral ureteral stents, one male patient (1.88 %) experienced early stent protrusion from urethral meatus. Two of 272 patients (0.73 %) with unilateral ureteral stent (one male and one female) encountered the same problem. All other stents were extracted successfully using the extraction string without any complications. No upward stent migration or suture site reaction was encountered. This method is a safe, easy-to-use, feasible and noninvasive alternative for cystoscopic stent removal with high success rate and minimal complications. This can lead to considerable saving in time and costs for patients, families and healthcare system.
Risk Factors for Migration, Fracture, and Dislocation of Pancreatic Stents

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Yoshiaki Kawaguchi

2015-01-01

Full Text Available Aim. To analyze the risk factors for pancreatic stent migration, dislocation, and fracture in chronic pancreatitis patients with pancreatic strictures. Materials and Methods. Endoscopic stent placements (total 386 times were performed in 99 chronic pancreatitis patients with pancreatic duct stenosis at our institution between April 2006 and June 2014. We retrospectively examined the frequency of stent migration, dislocation, and fracture and analyzed the patient factors and stent factors. We also investigated the retrieval methods for migrated and fractured stents and their success rates. Results. The frequencies of stent migration, dislocation, and fracture were 1.5% (5/396, 0.8% (3/396, and 1.2% (4/396, respectively. No significant differences in the rates of migration, dislocation, or fracture were noted on the patient factors (etiology, cases undergoing endoscopic pancreatic sphincterotomy, location of pancreatic duct stenosis, existence of pancreatic stone, and approach from the main or minor papilla and stent factors (duration of stent placement, numbers of stent placements, stent shape, diameter, and length. Stent retrieval was successful in all cases of migration. In cases of fractured stents, retrieval was successful in 2 of 4 cases. Conclusion. Stent migration, fracture, and dislocation are relatively rare, but possible complications. A good understanding of retrieval techniques is necessary.
Compliance Study of Endovascular Stent Grafts Incorporated with Polyester and Polyurethane Graft Materials in both Stented and Unstented Zones

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Ying Guan

2016-08-01

Full Text Available Compliance mismatch between stent graft and host artery may induce complications and blood flow disorders. However, few studies have been reported on stent graft compliance. This study aims to explore the deformation and compliance of stent graft in stented and unstented zones under three pressure ranges. Compliance of two stent grafts incorporated with polyurethane graft (nitinol-PU and polyester graft (nitinol-PET materials respectively were tested; the stents used in the two stent grafts were identical. For the circumferential deformation of the stent grafts under each pressure range, the nitinol-PET stent graft was uniform in both zones. The nitinol-PU stent graft was circumferentially uniform in the stented zone, however, it was nonuniform in the unstented zone. The compliance of the PU graft material was 15 times higher than that of the PET graft. No significant difference in compliance was observed between stented and unstented zones of the nitinol-PET stent graft regardless of the applied pressure range. However, for the nitinol-PU stent graft, compliance of the unstented PU region was approximately twice that of the stented region; thus, compliance along the length of the nitinol-PU stent graft was not constant and different from that of the nitinol-PET stent graft.
Safety of Early Carotid Artery Stenting after Systemic Thrombolysis: A Single Center Experience

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Fabrizio Sallustio

2012-01-01

Full Text Available Background. Patients with acute ischemic stroke due to internal carotid artery (ICA disease are at high risk of early stroke recurrence. A combination of IV thrombolysis and early carotid artery stenting (CAS may result in more effective secondary stroke prevention. Objective. We tested safety and durability of early CAS following IV thrombolysis in stroke patients with residual stenosis in the symptomatic ICA. Methods. Of consecutive patients treated with IV rtPA, those with residual ICA stenosis ≥70% or 24 hours. The protocol included pre-rtPA MRI and MR angiography, and post-rtPA carotid ultrasound and CT angiography. Stroke severity was assessed by the NIH Stroke Scale (NIHSS. Three- and twelve-month stent patency was assessed by ultrasound. Twelve-month functional outcome was assessed by the modified Rankin Scale (mRS. Results. Of 145 consecutive IV rtPA-treated patients, 6 (4% underwent early CAS. Median age was 76 (range 67–78 years, median NIHSS at stroke onset was 12 (range 9–16 and 7 (range 7-8 before CAS. Median onset-to-CAS time was 48 (range 30–94 hours. A single self-expandable stent was implanted to cover the entire lesion in all patients. The procedure was uneventful in all patients. After 12 months, all patients had stent patency, and the functional outcome was favourable (mRS ≤ 2 in all but 1 patient experiencing a recurrent stroke for new-onset atrial fibrillation. Conclusion. This small case series of a single centre suggests that early CAS may be considered a safe alternative to CEA after IV rtPA administration in selected patients at high risk of stroke recurrence.
Transient coronary aneurysm formation after Nevo™ stent implantation versus persistent coronary aneurysm after Cypher Select™ stent implantation

DEFF Research Database (Denmark)

Christiansen, Evald Høj; Lassen, Jens Flensted; Jensen, Lisette Okkels

2011-01-01

We implanted a Cypher Select™ coronary stent and two months later a Nevo™ sirolimus-eluting coronary stent in another vessel. At a prescheduled angiographic follow-up, coronary aneurysms were seen in the two stented segments, 6 and 8 months after stent implantation, respectively. Six months later......, the aneurysm had healed in the Nevo, but was still present in the Cypher stented segment. We hypothesize that aneurysm formation was induced by sirolimus and the polymer of the implanted stents, and that subsequent healing was possible in the Nevo stent after degradation of the polymer....
The study of metal stents for effect to the radiation therapy

International Nuclear Information System (INIS)

Gao Li; Feng Ningyuan; Zhai Renyou; Yang Weizhi; Xu Guozhen; Wang Yafei

2001-01-01

Objective: To confirm whether the metal stents affect the radiation beam. Methods: The transmission factors from the national self-expanding esophagus stent, stainless self-expanding bile duct stent, and balloon-expanded vascular stent was supervised under 192 Ir irradiation in the air. Results: The transmission factors from the 3 kinds of metal stents were 0.993, 0.988, and 0.997, which meant that the attenuation of the stents to the radiation was 0.7%, 1.2%, and 0.3%, respectively (mean: 0.7%). Conclusion: The effect of the metal stents to the radiation was less than 1.2% and that meant there was no clinical significant effect on the patients irradiated following stent implantation or to perform the intra-stents brachytherapy
Mechanical design of an intracranial stent for treating cerebral aneurysms.

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Shobayashi, Yasuhiro; Tanoue, Tetsuya; Tateshima, Satoshi; Tanishita, Kazuo

2010-11-01

Endovascular treatment of cerebral aneurysms using stents has advanced markedly in recent years. Mechanically, a cerebrovascular stent must be very flexible longitudinally and have low radial stiffness. However, no study has examined the stress distribution and deformation of cerebrovascular stents using the finite element method (FEM) and experiments. Stents can have open- and closed-cell structures, and open-cell stents are used clinically in the cerebrovasculature because of their high flexibility. However, the open-cell structure confers a risk of in-stent stenosis due to protrusion of stent struts into the normal parent artery. Therefore, a flexible stent with a closed-cell structure is required. To design a clinically useful, highly flexible, closed-cell stent, one must examine the mechanical properties of the closed-cell structure. In this study, we investigated the relationship between mesh patterns and the mechanical properties of closed-cell stents. Several mesh patterns were designed and their characteristics were studied using numerical simulation. The results showed that the bending stiffness of a closed-cell stent depends on the geometric configuration of the stent cell. It decreases when the stent cell is stretched in the circumferential direction. Mechanical flexibility equal to an open-cell structure was obtained in a closed-cell structure by varying the geometric configuration of the stent cell. Copyright © 2010 IPEM. Published by Elsevier Ltd. All rights reserved.
Ureteral stent discomfort: Etiology and management

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Ricardo Miyaoka

2009-01-01

Full Text Available Objectives : To review the evidence-based literature on the causes, characteristics, and options to manage double J stent-related symptoms. Methods : We performed a Medline database assessment on papers that investigated the prevalence, mechanisms, risk factors, bothersome and management of double-J stent-related symptoms. Articles in English were reviewed and summarized. Results : Stent-related symptoms have a high prevalence and may affect over 80% of patients. They include irritative voiding symptoms including frequency, urgency, dysuria, incomplete emptying; flank and suprapubic pain; incontinence, and hematuria. Assessment tools are important to determine their intensity and allow for comparisons between different points in the timeline. The Urinary Stent Symptom Questionnaire (USSQ is the most proper tool used for this purpose. Management should be focused on the prevention and management of symptoms. In this sense, research has focused on new materials and stent designs that would be more compatible to the physiologic properties of the urinary tract and medications that can ameliorate the sensitivity and motor response of the bladder. Conclusions : Stent-related symptoms are very common in the Urological clinical setting. It is of major importance for the urologist to understand their physiopathology and to be familiar with ways to avoid or manage them.
Complications related to conventional self-expandable metal stent insertion and internal irradiation stent insertion in patients with advanced esophageal carcinoma: an analysis of 32 cases

International Nuclear Information System (INIS)

Xu Xingwen; Di Haiting; Zhu Jun; Shi Jian

2011-01-01

Objective: To compare the occurrence of complications between conventional self-expandable metal stent and internal irradiation stent insertion in treating patients with advanced esophageal carcinomas. Methods: A total of 32 patients with advanced esophageal carcinoma were randomly divided into irradiation stent group (n=15) and conventional stent group (n=17). Internal irradiation stent loaded with 125 I seeds was employed in patients of irradiation stent group, while conventional self-expandable metal stent was used in patients of conventional stent group. After the treatment, clinical follow-up was regularly conducted. Postoperative complications such as fever, severe chest pain, cough, esophageal perforation, pneumonia, hemorrhage, stent migration and restenosis, etc. were observed. Results: No significant difference in the occurrence of fever, severe chest pain, esophageal perforation and hemorrhage existed between the two groups (P>0.05). The difference in the occurrence of long-term complications such as stent migration or restenosis between the two groups was out statistically significant (P>0.05). However, the restenosis in irradiation stent group occurred obviously much later than that in conventional stent group. Conclusion: For the treatment of advanced esophageal carcinomas, the insertion of internal irradiation esophageal stent is safe. It dose not increase the incidence of postoperative complications. Therefore, it is worth popularizing this technique in clinical practice. (authors)

Renal artery stent angioplasty for renovascular hypertension

International Nuclear Information System (INIS)

Li Gang; Li Haiqing; Wang Lin

2005-01-01

Objective: To evaluate the therapeutic results of expandable stent for treatment of atherosclerotic renovascular obstructive disease. Methods: 15 patients (10 men and 5 women, 41-75 years old; mean age, 52 years) with renal arterial hypertension underwent renal stent angioplasty including renal arterial stenosis 89%(n=13) and fully obstruction without function in 2, of which 2 patients had bilateral involvement. The stenotic range of all arterial segments showed 60% to 90% width of the normal arterial diameter. 16 stents were implanted under the guidance of fluoroscopy. The most of stents implanted were Palmaz (n=12, 75%) with regular clinical and angiographic follow up. Results: Technical success (residual stenosis <30%) was achieved in all patients without serious complication. During the follow-up (6-15 months; mean, 8 ± 4 months), hypertension was improved in 9 patients and cured in 4 patients with a total benefit of 86% and no efficacy in 2(13%). The average systolic blood pressure decreased from 27.12 ± 3.09 kPa to 18.62 ± 3.12 kPa and the average diastolic blood pressure decreased from 17.73 ± 1.92 kPa to 11.12 ± 2.43 kPa after stent treatment (P<0.05). Serum creatinine remained stable in 60% (n=9) patients with improvement in 33% (n=5) and worsened in 6% (n=1) patients. Follow-up angiography was performed in all patients with 1 case of a restenosis. 6 months after expanding through stent by using balloon, the two follow up angiographies showed a stable restenosis about 20%. Conclusions: Percutaneous transluminal stent placement is highly beneficial for patients who had renal arterial obstructive disease. The success of stent angioplasty of complete obstructive renal arteries reveals wide prospects for interventional method. (authors)
Favorable Outcomes after Implantation of Biodegradable Polymer Coated Sirolimus-Eluting Stents in Diabetic Population: Results from INDOLIMUS-G Diabetic Registry

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Anurag Polavarapu

2015-01-01

Full Text Available Objective. The main aim is to evaluate safety, efficacy, and clinical performance of the Indolimus (Sahajanand Medical Technologies Pvt. Ltd., Surat, India sirolimus-eluting stent in high-risk diabetic population with complex lesions. Methods. It was a multicentre, retrospective, non-randomized, single-arm study, which enrolled 372 diabetic patients treated with Indolimus. The primary endpoint of the study was major adverse cardiac events (MACE, which is a composite of cardiac death, target lesion revascularization (TLR, target vessel revascularization (TVR, myocardial infarction (MI, and stent thrombosis (ST. The clinical follow-ups were scheduled at 30 days, 6 months, and 9 months. Results. The mean age of the enrolled patients was 53.4 ± 10.2 years. A total of 437 lesions were intervened successfully with 483 stents (1.1 ± 0.3 per lesion. There were 256 (68.8% male patients. Hypertension and totally occluded lesions were found in 202 (54.3% and 45 (10.3% patients, respectively. The incidence of MACE at 30 days, 6 months and 9 months was 0 (0%, 6 (1.6%, and 8 (2.2%, respectively. The event-free survival at 9-month follow-up by Kaplan Meier method was found to be 97.8%. Conclusion. The use of biodegradable polymer coated sirolimus-eluting stent is associated with favorable outcomes. The results demonstrated in our study depict its safety and efficacy in diabetic population.
Metallic Limus-Eluting Stents Abluminally Coated with Biodegradable Polymers: Angiographic and Clinical Comparison of a Novel Ultra-Thin Sirolimus Stent Versus Biolimus Stent in the DESTINY Randomized Trial.

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Lemos, Pedro A; Abizaid, Alexandre A C; Meireles, George C; Sarmento-Leite, Rogério; Prudente, Mauricio; Cantarelli, Marcelo; Dourado, Adriano D; Mariani, Jose; Perin, Marco A; Costantini, Costantino; Costa, Ricardo A; Costa, José Ribamar; Chamie, Daniel; Campos, Carlos A; Ribeiro, Expedito

2015-12-01

To evaluate the outcomes of patients treated with a new drug-eluting stent formulation with low doses of sirolimus, built in an ultra-thin-strut platform coated with biodegradable abluminal coating. This study is a randomized trial that tested the main hypothesis that the angiographic late lumen loss of the novel sirolimus-eluting stent is noninferior compared with commercially available biolimus-eluting stent. A final study population comprising 170 patients with one or two de novo lesions was randomized in the ratio 2:1 for sirolimus-eluting stent or biolimus-eluting stent, respectively. The primary endpoint was 9-month angiographic in-stent late lumen loss. Adverse clinical events were prospectively collected for 1 year. After 9 months, the novel sirolimus-eluting stent was shown noninferior compared with the biolimus stent for the primary endpoint (angiographic in-stent late lumen loss: 0.20 ± 0.29 mm vs. 0.15 ± 0.20 mm, respectively; P value for noninferiority <0.001). The 1-year incidence of death, myocardial infarction, repeat revascularization, and stent thrombosis remained low and not significantly different between the groups. The present randomized trial demonstrates that the tested novel sirolimus-eluting stent was angiographically noninferior in comparison with a last-generation biolimus-eluting stent. © 2015 John Wiley & Sons Ltd.
Evaluation of Silicone as an Endovascular Stent Membrane: In Vivo Canine Studies

International Nuclear Information System (INIS)

Fontaine, Arthur B.; Borsa, John J.; Hoffer, Eric; Bloch, Robert; So, Corali

2001-01-01

Purpose: Comparative evaluation of the biological effects of a silicone-covered stent versus a bare-metal stent, in an animal model.Methods: Twelve stent implants were placed in the iliac arteries of six adult dogs. Each animal received one 8-mm x 20-mm silicone-covered stent (Permalume; Boston Scientific Vascular, Watertown, MA, USA), in the right iliac artery and one Wallstent (Boston Scientific Vascular) of the same diameter and length in the left iliac artery, during systemic anticoagulation. Angiography was performed before and after implantations. Animals were then allowed to recover and no platelet suppression was given during a 6-week interval, after which the animals were euthanized. The stented arteries were isolated and pressure-fixed in situ with 10% buffered formalin at a pressure of approximately 100 mmHg for a period of 1 hr. Two of 12 stented specimens were opened lengthwise and the luminal surfaces were photographed. Ten of 12 stented arterial segments were encased in methacrylate, then stained with hematoxylin and eosin. Neointimal thickness was quantified on histologic cross-section, for both bare and covered stents. The mean neointimal thicknesses were compared for significant difference using a student t-test.Results: All implants were widely patent at 6-week follow-up angiography. Histologic analysis showed bare metal stents covered by a thin uniform lining of neointima composed of smooth muscle cells in a hyaline matrix (mean thickness of 189 ± 47 μm). Silicone covered stents were devoid of neointima. There was no chronic thrombus or mature endothelium noted anywhere upon the internal silicone surfaces of any of the specimens. There was no foreign body reaction to the silicone cover.Conclusion: Short-term implantation of a silicone-lined Wallstent in canine iliac arteries is well tolerated. Silicone appears to be inert at 6 weeks in this experimental application
Development of biodegradable magnesium alloy stents with coating

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Lorenza Petrini

2014-07-01

Full Text Available Biodegradable stents are attracting the attention of many researchers in biomedical and materials research fields since they can absolve their specific function for the expected period of time and then gradually disappear. This feature allows avoiding the risk of long-term complications such as restenosis or mechanical instability of the device when the vessel grows in size in pediatric patients. Up to now biodegradable stents made of polymers or magnesium alloys have been proposed. However, both the solutions have limitations. The polymers have low mechanical properties, which lead to devices that cannot withstand the natural contraction of the blood vessel: the restenosis appears just after the implant, and can be ascribed to the compliance of the stent. The magnesium alloys have much higher mechanical properties, but they dissolve too fast in the human body. In this work we present some results of an ongoing study aiming to the development of biodegradable stents made of a magnesium alloy that is coated with a polymer having a high corrosion resistance. The mechanical action on the blood vessel is given by the magnesium stent for the desired period, being the stent protected against fast corrosion by the coating. The coating will dissolve in a longer term, thus delaying the exposition of the magnesium stent to the corrosive environment. We dealt with the problem exploiting the potentialities of a combined approach of experimental and computational methods (both standard and ad-hoc developed for designing magnesium alloy, coating and scaffold geometry from different points of views. Our study required the following steps: i selection of a Mg alloy suitable for stent production, having sufficient strength and elongation capability; ii computational optimization of the stent geometry to minimize stress and strain after stent deployment, improve scaffolding ability and corrosion resistance; iii development of a numerical model for studying stent
Endoscopically placed nitinol stents for pediatric tracheal obstruction.

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Prasad, Mukesh; Bent, John P; Ward, Robert F; April, Max M

2002-11-11

To provide preliminary clinical data regarding endoscopically placed nitinol stents for children with tracheal obstruction as a temporizing measure to allow for trach tube decannulation while awaiting growth to allow for tracheal resection. This case series describes the experiences of two children (ages 5 and 15) who were dependent upon tracheotomy because of acquired tracheal obstruction. Both patients had combined tracheomalacia and tracheal stenosis. After failing tracheoplasty with rib graft augmentation both patients suffered from extensive tracheal disease, which was too long to allow for immediate tracheal resection. Endoscopic placement of nitinol stents in the obstructed tracheal segment using fluoroscopic guidance. All tracheotomy tubes were removed immediately after successful stent deployment with the patient still under general anesthesia. Four stents were placed in total. The first patient's initial stent was too narrow and was, therefore, removed and replaced at a later date with a larger diameter stent. The second patient experienced distal migration of his initial stent requiring stent removal and replacement at a later date. Both patients remain successfully decannulated (follow-up, 25 and 26 months) and are currently living more normal lives as they grow and await tracheal resection. Preliminary use of nitinol stents for pediatric tracheal obstruction has enabled successful decannulation in two children with complicated airways. Our results with this series of patients suggest that nitinol stents can be safely used in children as a temporizing measure until tracheal resection can be safely performed. With this approach children can live free from the hassles of trach care, social isolation and peer ridicule. Limited pediatric experience exists in the literature about nitinol stents. Thus, our experience with stent selection and placement will help others avoid problems encountered in this initial series. Copyright 2002 Elsevier Science Ireland
[The Predictive Factors of Stent Failure in the Treatment of Malignant Extrinsc Ureteral Obstruction Using Internal Ureteral Stents].

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Matsuura, Hiroshi; Arase, Shigeki; Hori, Yasuhide; Tochigi, Hiromi

2017-12-01

In this study, we retrospectively reviewed the experiences at our single institute in the treatment of malignant extrinsic ureteral obstruction (MUO) using ureteral stents to investigate the clinical outcomes and the predictive factors of stent failure. In 52 ureters of 38 patients who had radiologically significant hydronephrosis due to MUO, internal ureteral stents (The BARD(R) INLAY(TM) ureteral stent set) were inserted. The median follow-up interval after the initial stent insertion was 124.5 days (4-1,120). Stent failure occurred in 8 ureters (15.4%) of the 7 patients. The median interval from the first stent insertion to stent failure was 88 days (1-468). A Cox regression multivariate analysis showed that the significant predictors of stent failure were bladder invasion. Based on the possibility of stent failure, the adaptation of the internal ureteral stent placement should be considered especially in a patient with MUO combined with bladder invasion.
A novel balloon assisted two-stents telescoping technique for repositioning an embolized stent in the pulmonary conduit.

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Kobayashi, Daisuke; Gowda, Srinath T; Forbes, Thomas J

2014-08-01

A 9-year-old male, with history of pulmonary atresia and ventricular septal defect, status post complete repair with a 16 mm pulmonary homograft in the right ventricular outflow tract (RVOT) underwent 3110 Palmaz stent placement for conduit stenosis. Following deployment the stent embolized proximally into the right ventricle (RV). We undertook the choice of repositioning the embolized stent into the conduit with a transcatheter approach. Using a second venous access, the embolized stent was carefully maneuvered into the proximal part of conduit with an inflated Tyshak balloon catheter. A second Palmaz 4010 stent was deployed in the distal conduit telescoping through the embolized stent. The Tyshak balloon catheter was kept inflated in the RV to stabilize the embolized stent in the proximal conduit until it was successfully latched up against the conduit with the deployment of the overlapping second stent. One year later, he underwent Melody valve implantation in the pre-stented conduit relieving conduit insufficiency. This novel balloon assisted two-stents telescoping technique is a feasible transcatheter option to secure an embolized stent from the RV to the RVOT. © 2014 Wiley Periodicals, Inc.
Endoscopic stenting for hilar cholangiocarcinoma: efficacy of unilateral and bilateral placement of plastic and metal stents in a retrospective review of 480 patients

Science.gov (United States)

2012-01-01

Background Endoscopic biliary drainage of hilar cholangiocarcinoma is controversial with respect to the optimal types of stents and the extent of drainage. This study evaluated endoscopic palliation in patients with hilar cholangiocarcinoma using self-expandable metallic stents (SEMS) and plastic stents (PS).We also compared unilateral and bilateral stent placement according to the Bismuth classification. Methods Data on 480 patients receiving endoscopic biliary drainage for hilar cholangiocarcinoma between September 1995 and December 2010 were retrospectively reviewed to evaluate the following outcome parameters: technical success (TS), functional success (FS), early and late complications, stent patency and survival. Patients were followed from stent insertion until death or stent occlusion. Patients were divided into 3 groups according to the Bismuth classification (Group 1, type I; Group 2, type II; Group 3, type > III). Results The initial stent insertion was successful in 450 (93.8%) patients. TS was achieved in 204 (88.3%) patients treated with PS and in 246 (98.8%) patients palliated with SEMS (p stent patency in weeks (w) were as follows: 20 w in patients palliated with PS and 27 w in patients treated with SEMS (p stent patency. Conclusions SEMS insertion for the palliation of hilar cholangiocarcinoma offers higher technical and clinical success rates in the ITT analysis as well as lower complication rates and a superior cumulative stent patency when compared with PS placement in all Bismuth classifications. The cumulative patency of bilateral SEMS or PS stents was significantly higher than that of unilateral SEMS or PS stents, with lower occlusion rates in Bismuth II patients. PMID:22873816
A new self-expanding nitinol stent (Enterprise) for the treatment of wide-necked intracranial aneurysms: initial clinical and angiographic results in 31 aneurysms

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Weber, Werner; Kuehne, Dietmar [Alfried Krupp Hospital, Department of Radiology and Neuroradiology, Essen (Germany); Bendszus, Martin; Solymosi, Laszlo [University of Wuerzburg, Department of Neuroradiology, Wuerzburg (Germany); Kis, Bernhard [University of Duisburg-Essen, Research Unit, Rheinische Kliniken Essen, Department of Psychiatry and Psychotherapy, Essen (Germany); Boulanger, Thierry [Centre Hospitalier of Luxembourg, Service of Neuroradiology, Luxembourg (Luxembourg)

2007-07-15

We report the results of a prospective clinical study using a new self-expanding nitinol stent (Enterprise) designed for the treatment of wide-necked intracranial aneurysms. We treated 31 saccular, wide-necked intracranial aneurysms in 30 patients. Ten aneurysms had recanalized after prior endovascular treatment without a stent, and 21 aneurysms had not been treated before. Stent deployment was successful in all procedures. Additional coil embolization was performed in all aneurysms. Initial complete angiographic occlusion was achieved in 6 aneurysms, a neck remnant was left in 18 aneurysms and there were 7 residual aneurysms. Angiographic follow-up examinations of 30 lesions after 6 months demonstrated 15 complete occlusions, 8 neck remnants and 7 residual aneurysms. One patient refused the 6-month angiographic follow-up. Spontaneous occlusion of the aneurysm had occurred in 14 patients, and 6 aneurysms showed recanalization. Four of these residual aneurysms were retreated. At the 6-month follow-up, 29 parent arteries were unaffected, whereas two parent vessels demonstrated minor asymptomatic narrowing at the stent site. Two patients experienced one or more possible or probable device-related serious adverse events during the 6-month follow-up period. There was no procedural morbidity or mortality at 6 months after the procedure. The reported results demonstrated the safety and feasibility of the Cordis Neurovascular Enterprise stent in the treatment of wide-necked intracranial aneurysms. Initial clinical and angiographic results are favorable. (orig.)
Current state of the absorbable metallic (magnesium) stent.

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Waksman, Ron

2009-12-15

BIOTRONIK's absorbable metal stent technology is based ona magnesium alloy that offers superior stent mechanics and biocompatibility. The first generation (AMS-1) showed promising results regarding mechanical properties as well as feasibility and safety in several human applications (150 cases). The second generation (AMS-2.1) shows improved scaffolding and efficacy in animals due to a more slowly degrading magnesium alloy and an optimised stent design. The preclinical results of the drug-eluting AMS-3 are encouraging and the clinical investigational program will resume in 2010.
Differences in Endothelial Injury After Balloon Angioplasty, Insertion of Balloon-Expanded Stents or Release of Self-Expanding Stents: An Electron Microscopic Experimental Study

International Nuclear Information System (INIS)

Harnek, Jan; Zoucas, Evita; Carlemalm, Erik; Cwikiel, Wojciech

1999-01-01

Purpose: To evaluate which of six different commonly available stents inserted into an artery without percutaneous transluminal angioplasty (PTA) causes the least endothelial damage. To compare the degree of endothelial injury after insertion of such a stent with injury caused by PTA. Methods: Twelve healthy pigs were used in the experiments. In the first part of the study six different types of stents were inserted into the common iliac arteries. In the second part of the study self-expanding stents with large spaces between the wires were used. PTA was performed in the contralateral iliac artery. The pigs were killed immediately after the procedure and resected specimens examined after fixation, using scanning electron microscopy. Results: All procedures but two were accomplished successfully. More endothelium was preserved after insertion of self-expanding stents with large spaces between the wires, compared with stents with small spaces and balloon-expanded stents. After insertion of self-expanding stents with large spaces, 50.1% ± 16.4% of the endothelium remained intact, compared with only 5.6% ± 7.7% after PTA. The difference was statistically significant (p < 0.001). Conclusion: Self-expanding stents with large spaces between the wires, inserted without PTA, cause less damage to the endothelium than other stents and significantly less damage than PTA
Air cholangiography in endoscopic bilateral stent-in-stent placement of metallic stents for malignant hilar biliary obstruction.

Science.gov (United States)

Lee, Jae Min; Lee, Sang Hyub; Jang, Dong Kee; Chung, Kwang Hyun; Park, Jin Myung; Paik, Woo Hyun; Lee, Jun Kyu; Ryu, Ji Kon; Kim, Yong-Tae

2016-03-01

Although endoscopic bilateral stent-in-stent (SIS) placement of self-expandable metallic stents (SEMS) is one of the major palliative treatments for unresectable malignant hilar biliary obstruction, post-endoscopic retrograde cholangiopancreatography (ERCP) cholangitis can occur frequently due to inadequate drainage, especially after contrast injection into the biliary tree. The aim of this study is to evaluate the efficacy and safety of air cholangiography-assisted stenting. This study included 47 patients with malignant hilar biliary obstruction who underwent endoscopic bilateral SEMS placement using the SIS technique. They were divided into two groups, air (n = 23) or iodine contrast (n = 24) cholangiography. We retrospectively compared comprehensive clinical and laboratory data of both groups. There were no significant differences found between the two groups with respect to technical success (87% versus 87.5%, air versus contrast group, respectively), functional success (95% versus 95.2%), 30-day mortality (8.3% versus 8.7%) and stent patency. Post-ERCP adverse events occurred in 5 (21.7%) of the patients in the air group and 8 (33.3%) of the patients in the contrast group. Among these, the rate of cholangitis was significantly lower in the air group (4.8% versus 29.2%, p = 0.048). In multivariate analysis, air cholangiography, technical success and a shorter procedure time were significantly associated with a lower incidence of post-ERCP cholangitis. Air cholangiography-assisted stenting can be a safe and effective method for endoscopic bilateral SIS placement of SEMS in patients with malignant hilar biliary obstruction.
Reproducibility of haemodynamical simulations in a subject-specific stented aneurysm model--a report on the Virtual Intracranial Stenting Challenge 2007.

Science.gov (United States)

Radaelli, A G; Augsburger, L; Cebral, J R; Ohta, M; Rüfenacht, D A; Balossino, R; Benndorf, G; Hose, D R; Marzo, A; Metcalfe, R; Mortier, P; Mut, F; Reymond, P; Socci, L; Verhegghe, B; Frangi, A F

2008-07-19

This paper presents the results of the Virtual Intracranial Stenting Challenge (VISC) 2007, an international initiative whose aim was to establish the reproducibility of state-of-the-art haemodynamical simulation techniques in subject-specific stented models of intracranial aneurysms (IAs). IAs are pathological dilatations of the cerebral artery walls, which are associated with high mortality and morbidity rates due to subarachnoid haemorrhage following rupture. The deployment of a stent as flow diverter has recently been indicated as a promising treatment option, which has the potential to protect the aneurysm by reducing the action of haemodynamical forces and facilitating aneurysm thrombosis. The direct assessment of changes in aneurysm haemodynamics after stent deployment is hampered by limitations in existing imaging techniques and currently requires resorting to numerical simulations. Numerical simulations also have the potential to assist in the personalized selection of an optimal stent design prior to intervention. However, from the current literature it is difficult to assess the level of technological advancement and the reproducibility of haemodynamical predictions in stented patient-specific models. The VISC 2007 initiative engaged in the development of a multicentre-controlled benchmark to analyse differences induced by diverse grid generation and computational fluid dynamics (CFD) technologies. The challenge also represented an opportunity to provide a survey of available technologies currently adopted by international teams from both academic and industrial institutions for constructing computational models of stented aneurysms. The results demonstrate the ability of current strategies in consistently quantifying the performance of three commercial intracranial stents, and contribute to reinforce the confidence in haemodynamical simulation, thus taking a step forward towards the introduction of simulation tools to support diagnostics and
Applying value stream mapping techniques to eliminate non-value-added waste for the procurement of endovascular stents

International Nuclear Information System (INIS)

Teichgräber, Ulf K.; Bucourt, Maximilian de

2012-01-01

Objectives: To eliminate non-value-adding (NVA) waste for the procurement of endovascular stents in interventional radiology services by applying value stream mapping (VSM). Materials and methods: The Lean manufacturing technique was used to analyze the process of material and information flow currently required to direct endovascular stents from external suppliers to patients. Based on a decision point analysis for the procurement of stents in the hospital, a present state VSM was drawn. After assessment of the current status VSM and progressive elimination of unnecessary NVA waste, a future state VSM was drawn. Results: The current state VSM demonstrated that out of 13 processes for the procurement of stents only 2 processes were value-adding. Out of the NVA processes 5 processes were unnecessary NVA activities, which could be eliminated. The decision point analysis demonstrated that the procurement of stents was mainly a forecast driven push system. The future state VSM applies a pull inventory control system to trigger the movement of a unit after withdrawal by using a consignment stock. Conclusion: VSM is a visualization tool for the supply chain and value stream, based on the Toyota Production System and greatly assists in successfully implementing a Lean system.
Metallic stents for management of malignant biliary obstruction

International Nuclear Information System (INIS)

Lee, Byung Hee; Do, Young Soo; Byun, Hong Sik; Kim, Kie Hwan; Chin, Soo Yil

1992-01-01

In patients with inoperable malignant biliary obstruction, percutaneous transhepatic biliary drainage (PTBD) has been the method of choice for palliative treatment. All patients except three had undergone PTBD, and the stents were placed 5-7 days after the initial drainage procedure. Three patients underwent stent placement on the same day of PTBD. External drainage catheter is converted to various types of tube endoprostheses with associated physiologic and psychologic benefits. Tube stents, however, have some problems such as migration, occlusion, and traumatic implantation procedure. We report our experiences and clinical results of percutaneous placement of metallic stents in 40 patients with malignant biliary obstruction
Metallic stents for management of malignant biliary obstruction

Energy Technology Data Exchange (ETDEWEB)

Lee, Byung Hee; Do, Young Soo; Byun, Hong Sik; Kim, Kie Hwan; Chin, Soo Yil [Korea Cancer Center Hospital, Seoul (Korea, Republic of)

1992-11-15

In patients with inoperable malignant biliary obstruction, percutaneous transhepatic biliary drainage (PTBD) has been the method of choice for palliative treatment. All patients except three had undergone PTBD, and the stents were placed 5-7 days after the initial drainage procedure. Three patients underwent stent placement on the same day of PTBD. External drainage catheter is converted to various types of tube endoprostheses with associated physiologic and psychologic benefits. Tube stents, however, have some problems such as migration, occlusion, and traumatic implantation procedure. We report our experiences and clinical results of percutaneous placement of metallic stents in 40 patients with malignant biliary obstruction.
French experience of silicone tracheobronchial stenting in children.

Science.gov (United States)

Fayon, Michael; Donato, Lionel; de Blic, Jacques; Labbé, André; Becmeur, François; Mely, Laurent; Dutau, Hervé

2005-01-01

Silicone stents were inserted into the trachea or left main-stem bronchus in 14 children aged 2-69 months (median, 7 months). Indications were as follows: tracheomalacia or airway kinking (7 cases), vascular compression (5 cases), and surgically corrected congenital tracheal stenoses (2 cases). The best results were obtained in tracheomalacia. Overall, 6 cases out of 14 (43%) were considered successful, with a stent placement duration of 3-15 months (median, 7 months). Two cases were considered a technical success, although they were clinical failures. Five cases were considered failures primarily due to stent migration. A retrospective analysis of failures suggests that most of these could have been avoided by the use of larger stents. One patient died of stent obstruction. No wall erosion was observed, and the development of granulation tissue was infrequent. Endoscopic removal of the prostheses was uneventful. The biocompatibility of silicone stents appears to be better than what is reported for metal ones, although the stability of the former is less satisfactory. The present study shows the feasibility of silicone stent placement in infants. These stents should be considered as a possible therapeutic option in certain types of childhood airway disorders, although further studies are required.
Metallic stent and stereotactic conformal radiotherapy for hilar cholangiocarcinoma

International Nuclear Information System (INIS)

Li Yu; Wang Ning; Tian Qihe; Guo Zhanwen; Zhang Haibo; Song Liyan

2005-01-01

Objective: To evaluate the effect of metallic stent combined with stereotactic conformal radiotherapy (SCRT) for hilar cholangiocarcinoma. Methods: Fifty-four patients with hilar cholangiocarcinoma were analyzed, including 31 treated with stent plus stereotactic conformal radiotherapy (combined group) and 23 with metallic stent alone (control group). Results: The mean survival time of combined group was 11.1 ± 4.6 months, compared with 5.1 ± 2.8 months of the control group, giving a significant difference between the two groups (P<0.01). Conclusion: The combination of metallic stent and stereotactic conformal radiotherapy is more effective than metallic stent alone for unresectable hilar cholangiocarcinoma. (authors)
Coronary In-Stent Restenosis: Assessment with Corrected Coronary Opacification Difference across Coronary Stents Measured with CT Angiography.

Science.gov (United States)

Gao, Yang; Lu, Bin; Hou, Zhi Hui; Yu, Fang Fang; Yin, Wei Hua; Wang, Zhi Qiang; Wu, Yong Jian; Mu, Chao Wei; Meinel, Felix G; McQuiston, Andrew D; Schoepf, U Joseph

2015-05-01

To determine whether changes in coronary opacification normalized to the aorta (corrected coronary opacification [CCO]) across stents can help identify in-stent restenosis (ISR) severity with use of invasive coronary angiography as the standard of reference. This study was approved by the institutional review board, and the requirement to obtain informed consent was waived. The authors retrospectively analyzed 106 patients (88 men, 18 women; mean age, 59.6 years ± 10.4; age range, 36-84 years) who had previously undergone stent implantation within 3 months of coronary computed tomographic (CT) angiography. Attenuation values in the coronary lumen were measured proximal and distal to the stents and normalized to the descending aorta. The CCO difference across the stent was compared with the severity of ISR. One-way analysis of variance least significant difference was used for comparison. A total of 141 stents were assessed. Seventy-six stents were normally patent, 18 had ISR of less than 50%, 28 had ISR of 50%-99%, and 19 were fully occluded. The median CCO differences in the four groups were 0.078, 0.163, 0.346, and 0.606, respectively. There was no significant difference between stents with an ISR of at least 50% and those with total occlusion (P = .056), although the other groups had significant differences at pairwise comparison (P stents smaller than 3 mm in diameter, the median CCO differences in the four groups were 0.086, 0.136, 0.390, and 0.471, respectively. The CCO differences across normal stents and stents with ISR of less than 50% were significantly less than those across stents with an ISR of at least 50% and those with total occlusion (P stents with no ISR and those with an ISR of less than 50% (P = .821) and between stents with an ISR of at least 50% and those with an ISR of 100% (P = .836). The CCO difference across coronary stents is related to ISR severity in obstructive ISR in stents smaller than 3 mm in diameter. © RSNA, 2014.

Absorbable stent: focus on clinical applications and benefits

Directory of Open Access Journals (Sweden)

Gonzalo N

2012-02-01

Full Text Available Nieves Gonzalo, Carlos MacayaInterventional Cardiology, Cardiovascular Institute. Hospital Clinico San Carlos, Instituto de Investigación Sanitaria del Hospital Clinico San Carlos, Madrid, SpainAbstract: Coronary stents have improved very significantly the immediate and long-term results of percutaneous coronary interventions. However, once the vessel has healed, the scaffolding function of the stent is no longer needed, and the presence of a permanent metallic prosthesis poses important disadvantages. This has led to the idea of creating new devices that are able to provide mechanical support for a determined period and then disappear from the vessel, allowing its natural healing and avoiding the risks associated with having a permanent metallic cage, such as stent thrombosis. Absorbable stents currently appear as one of the most promising fields in interventional cardiology. The present article will review the available clinical evidence regarding these devices at present and their future perspectives.Keywords: absorbable stent, bioresorbable stent, absorb, percutaneous coronary intervention
Transluminal endovascular stent-graft for the treatment of aortic aneurysms

Energy Technology Data Exchange (ETDEWEB)

Lee, Do Yun; Chang, Byung Chul; Shim, Won Heum; Cho, Seung Yun; Chung, Nam Sik; Kwon, Hyuk Moon; Lee, Young Joon; Lee, Jong Tae [Yonsei University College of Medicine, Seoul (Korea, Republic of)

1995-09-15

The standard treatment for aortic aneurysms is surgical replacement with a prosthetic graft. Currently there is great interest in endoluminal intervention for treatment of aortic aneurysm. The purpose of this study was to evaluate the safety and effectiveness of endoluminally placed Stent-graft for the treatment of aortic aneurysms. Transluminal endovascular Stent-graft placements were attempted in 9 patients with infra-renal aortic aneurysms(n 6), thoracic aortic aneurysm(n = 1), and aortic dissection(n = 2). The endovascular Stent-grafts were custom-designed for each patient and were constructed of self-expandable modified Gianturco Stents covered with polytetrafluroethylene. The Stent-grafts were introduced through a 16-18 French sheath and expanded to 17-30 mm in diameter. The endovascular therapy was performed using a common femoral artery cutdown with local anesthesia. The endovascular Stent-graft deployment was achieved in 7 of 9 patients. Two cases failed deployment of the Stent-graft due to iliac artery stenosis and tortousity. There were complete thrombosis of the thoracic and infra-renal aortic aneurysm surround the Stent-graft in 3 patients, and persistent leak with partial thrombosis in 2. Two patients with aortic dissection were successfully treated by obliteration of entry tears. There were no major complication associated with Stent-graft placement. These preliminary results show that transluminal endovascular Stent-grafts offer great promise and good results. Further investigation is needed to establish its long-term safety and efficacy.
Transluminal endovascular stent-graft for the treatment of aortic aneurysms

International Nuclear Information System (INIS)

Lee, Do Yun; Chang, Byung Chul; Shim, Won Heum; Cho, Seung Yun; Chung, Nam Sik; Kwon, Hyuk Moon; Lee, Young Joon; Lee, Jong Tae

1995-01-01

The standard treatment for aortic aneurysms is surgical replacement with a prosthetic graft. Currently there is great interest in endoluminal intervention for treatment of aortic aneurysm. The purpose of this study was to evaluate the safety and effectiveness of endoluminally placed Stent-graft for the treatment of aortic aneurysms. Transluminal endovascular Stent-graft placements were attempted in 9 patients with infra-renal aortic aneurysms(n 6), thoracic aortic aneurysm(n = 1), and aortic dissection(n = 2). The endovascular Stent-grafts were custom-designed for each patient and were constructed of self-expandable modified Gianturco Stents covered with polytetrafluroethylene. The Stent-grafts were introduced through a 16-18 French sheath and expanded to 17-30 mm in diameter. The endovascular therapy was performed using a common femoral artery cutdown with local anesthesia. The endovascular Stent-graft deployment was achieved in 7 of 9 patients. Two cases failed deployment of the Stent-graft due to iliac artery stenosis and tortousity. There were complete thrombosis of the thoracic and infra-renal aortic aneurysm surround the Stent-graft in 3 patients, and persistent leak with partial thrombosis in 2. Two patients with aortic dissection were successfully treated by obliteration of entry tears. There were no major complication associated with Stent-graft placement. These preliminary results show that transluminal endovascular Stent-grafts offer great promise and good results. Further investigation is needed to establish its long-term safety and efficacy
Treatment of hilar cholangiocarcinoma with inserting biliary double stents

International Nuclear Information System (INIS)

Jia Guangzhi; Zhang Zidong; Wang Xuejing; Yin Hua; Li Jianming

2004-01-01

Objective: To investigate the inserting technique of biliary double stents in treating hilar cholangiocarcinoma. Methods: 6 patients with hilar cholangiocarcinoma (Bismuth IV) were treated by percutaneous transhepatic insertion of biliary stents. Double stents were inserted in each patient. Different inserting methods were adopted according to the branch angles formed by left and right hepatic ducts. Results: The jaundice of all patients alleviated or disappeared obviously after stent implantation. The average difference between post-and pre-operation in the serum total bilirubin level was (104 ± 29) μmol/L (P<0.01). Stent obstruction was found in 2 cases after 4 and 6 months respectively. Conclusion: Double stents implantation is effective for the treatment of hilar cholangiocarcinoma. Beware of the angulation between main hepatic duct and adopting different inserting methods. (authors)
Post-biliary sphincterotomy bleeding despite covered metallic stent deployment

Directory of Open Access Journals (Sweden)

Gianfranco Donatelli

2016-05-01

Full Text Available Objectives: Several endoscopic techniques have been proposed for the management of post-sphincterotomy bleeding. Lately, self-expandable metal stents deployment has gained popularity especially as a rescue therapy when other endoscopic techniques fail. Methods-results: We report the case report of a massive post-sphincterotomy bleeding in a patient with a self-expandable metal stent in the biliary tree. Despite the presence of a correctly positioned self-expandable metal stent, a new endoscopic session was required to control the bleeding. Conclusions: Self-expandable metal stent may be useful to manage post-endoscopic sphincterotomy bleeding. However, up to now there is no specifically designed self-expandable metal stent for such complication. Large new designed self-expandable metal stent may be a useful tool for biliary endoscopist.
Optimization of cardiovascular stent against restenosis: factorial design-based statistical analysis of polymer coating conditions.

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Gayathri Acharya

Full Text Available The objective of this study was to optimize the physicodynamic conditions of polymeric system as a coating substrate for drug eluting stents against restenosis. As Nitric Oxide (NO has multifunctional activities, such as regulating blood flow and pressure, and influencing thrombus formation, a continuous and spatiotemporal delivery of NO loaded in the polymer based nanoparticles could be a viable option to reduce and prevent restenosis. To identify the most suitable carrier for S-Nitrosoglutathione (GSNO, a NO prodrug, stents were coated with various polymers, such as poly (lactic-co-glycolic acid (PLGA, polyethylene glycol (PEG and polycaprolactone (PCL, using solvent evaporation technique. Full factorial design was used to evaluate the effects of the formulation variables in polymer-based stent coatings on the GSNO release rate and weight loss rate. The least square regression model was used for data analysis in the optimization process. The polymer-coated stents were further assessed with Differential scanning calorimetry (DSC, Fourier transform infrared spectroscopy analysis (FTIR, Scanning electron microscopy (SEM images and platelet adhesion studies. Stents coated with PCL matrix displayed more sustained and controlled drug release profiles than those coated with PLGA and PEG. Stents coated with PCL matrix showed the least platelet adhesion rate. Subsequently, stents coated with PCL matrix were subjected to the further optimization processes for improvement of surface morphology and enhancement of the drug release duration. The results of this study demonstrated that PCL matrix containing GSNO is a promising system for stent surface coating against restenosis.
In-situ investigation of stress conditions during expansion of bare metal stents and PLLA-coated stents using the XRD sin(2)ψ-technique.

Science.gov (United States)

Kowalski, Wolfgang; Dammer, Markus; Bakczewitz, Frank; Schmitz, Klaus-Peter; Grabow, Niels; Kessler, Olaf

2015-09-01

Drug eluting stents (DES) consist of platform, coating and drug. The platform often is a balloon-expandable bare metal stent made of the CoCr alloy L-605 or stainless steel 316 L. The function of the coating, typically a permanent polymer, is to hold and release the drug, which should improve therapeutic outcome. Before implantation, DES are compressed (crimped) to allow implantation in the human body. During implantation, DES are expanded by balloon inflation. Crimping, as well as expansion, causes high stresses and high strains locally in the DES struts, as well as in the polymer coating. These stresses and strains are important design criteria of DES. Usually, they are calculated numerically by finite element analysis (FEA), but experimental results for validation are hardly available. In this work, the X-ray diffraction (XRD) sin(2)ψ-technique is applied to in-situ determination of stress conditions of bare metal L-605 stents, and Poly-(L-lactide) (PLLA) coated stents. This provides a realistic characterization of the near-surface stress state and a validation option of the numerical FEA. XRD-results from terminal stent struts of the bare metal stent show an increasing compressive load stress in tangential direction with increasing stent expansion. These findings correlate with numerical FEA results. The PLLA-coating also bears increasing compressive load stress during expansion. Copyright © 2015 Elsevier Ltd. All rights reserved.
PulmoStent : In Vitro to In Vivo Evaluation of a Tissue Engineered Endobronchial Stent

NARCIS (Netherlands)

Thiebes, Anja Lena; Kelly, Nicola; Sweeney, Caoimhe A.; McGrath, Donnacha J.; Clauser, Johanna; Kurtenbach, Kathrin; Gesche, Valentine N.; Chen, Weiluan; Kok, Robbert Jan; Steinseifer, Ulrich; Bruzzi, Mark; O’Brien, Barry J.; McHugh, Peter E.; Jockenhoevel, Stefan; Cornelissen, Christian G.

Currently, there is no optimal treatment available for end stage tumour patients with airway stenosis. The PulmoStent concept aims on overcoming current hurdles in airway stenting by combining a nitinol stent with a nutrient-permeable membrane, which prevents tumour ingrowth. Respiratory epithelial
Stent migration after right ventricular outflow tract stenting in the severe cyanotic Tetralogy of Fallot case

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Tamaki Hayashi

2017-01-01

Full Text Available We report our experience with a stent migration after right ventricle outflow tract stenting and converted to patent ductus arteriosus stenting in Tetralogy of Fallot (TOF with severe infundibular stenosis. Finally, the patient achieved to TOF repair, and the migrated stent was removed without any complication.
The Erasme Study: A Multicenter Study on the Safety and Technical Results of the Palmaz Stent Used for the Treatment of Atherosclerotic Ostial Renal Artery Stenosis

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Bakker, Jeannette; Goffette, Pierre P.; Henry, Michel; Mali, Willem P.T.M.; Melki, Jean-Pierre; Moss, Jon G.; Rabbia, Claudio; Therasse, Eric; Thomson, Kenneth R.; Thurnher, Siegfried; Vignali, Claudio

1999-01-01

Purpose: To assess, in a multicenter setting, safety, technical results, and restenosis rate of the Palmaz stent for treatment of atherosclerotic ostial renal artery stenosis. Methods: Ten centers enrolled 106 patients (120 treated renal artery stenoses) in the study. Patient selection was based on unsuccessful percutaneous transluminal renal angioplasty (residual stenosis ≥ 20%) performed for treatment of ostial stenosis ≥ 50%, in patients with hypertension and/or impaired renal function. Safety was assessed by means of the complication rate, and technical results by the number of successful stent placements and occurrence of restenosis (>50%) at intraarterial angiographic follow-up. Results: Stent placement was successful (n = 112) or partially successful (n = 5) in 117 (98%) arteries. Complications occurred in 19 procedures; seven were of serious clinical significance. Angiographic follow-up was performed in 89 of 117 (76%) cases, at a mean of 8 months (range 2.5-18 months). Fifteen stents (16.9%) showed restenosis (at a mean of 8.5 months), of which 10 were successfully redilated. Conclusion: Renal artery stenting has a high technical success rate, a complication rate comparable to percutaneous transluminal renal angioplasty, and a low rate of restenosis at 8 months angiographic follow-up
Steerable antegrade stenting: a new trick of the trade

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Udo Nagele

2007-06-01

Full Text Available INTRODUCTION: Whereas a retrograde attempt to insert an indwelling stent is performed in lithotomy position, usually renal access is gained in a prone position. To overcome the time loss of patient repositioning, a renal puncture can be performed in a modified lithotomy position with torqued truncus and slightly elevated flank. There is a two-fold advantage of this position: transurethral and transrenal access can be obtained using a combined approach. In the present study, this simple technique is used to position a floppy guide wire through a modified needle directly through the renal pelvis into the ureter. MATERIALS AND METHODS: The kidney is punctured in the modified lithotomy position under sonographic control using an initial three-part puncture needle. A floppy tip guide-wire is inserted into the collecting system via the needle after retrieving the stylet. The retracted needle is bent at the tip while the guide-wire is secured in the needle and the collecting system. The use of the floppy tip guide-wire helps to insert the curved needle back into the kidney pelvis, which becomes the precise guidance for the now steerable wire. The desired steerable stent is positioned under radiographic control in a retrograde fashion over the endoscopically harbored tip of the guide-wire. Two patient cohorts (newly described method and conventional method were compared. RESULTS: The presented steering procedure saves 16.5 mean minutes compared to the conventional antegrade stenting and 79.5 Euros compared to the control group. CONCLUSION: The described combined antegrade-retrograde stent placement through a bent three-part puncture needle results in both clinical superiority (OR time, success rate and financial benefits.
The role of airway stenting in pediatric tracheobronchial obstruction.

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Antón-Pacheco, Juan L; Cabezalí, Daniel; Tejedor, Raquel; López, María; Luna, Carmen; Comas, Juan V; de Miguel, Eduardo

2008-06-01

Tracheobronchial obstruction is infrequent in the pediatric age group but it is associated with significant morbidity and mortality. The purpose of this study is to review the results of a single institution experience with endoscopic stent placement in children with benign tracheobronchial obstruction, and with special concern on safety and clinical effectiveness. Twenty-one patients with severe airway stenosing disease in which stent placement was performed between 1993 and 2006. Inclusion criteria according to the clinical status were: failure to wean from ventilation, episode of apnea, frequent respiratory infections (>3 pneumonia/year), and severe respiratory distress. Additional criteria for stent placement were: failure of surgical treatment, bronchomalacia, and tracheomalacia refractory to previous tracheostomy. Selection of the type of stent depended on the site of the lesion, the patient's age, and the stent availability when time of presentation. The following variables were retrospectively evaluated: age, type of obstruction, associated malformations, stent properties, technical and clinical success, complications and related reinterventions, outcome and follow-up period. Thirty-three stents were placed in the trachea (n=18) and/or bronchi (n=15) of 21 patients with a median age of 6 months (range, 9 days-19 years). Etiology of the airway obstruction included severe tracheomalacia and/or bronchomalacia in 19 cases (90%), and postoperative tracheal stenosis in two. Twelve children had a total of 20 balloon-expandable metallic stents placed, and 10 had 13 silicone-type stents (one patient had both). In nine patients (42%) more than one device was placed. Stent positioning was technically successful in all but one patient. Clinical improvement was observed in 18 patients (85%) but complications occurred in five of them (27%). Eight patients died during follow-up but only in one case it was related to airway stenting. Thirteen patients (62%) are alive and
Sensor to detect endothelialization on an active coronary stent

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Coffey Arthur C

2010-11-01

Full Text Available Abstract Background A serious complication with drug-eluting coronary stents is late thrombosis, caused by exposed stent struts not covered by endothelial cells in the healing process. Real-time detection of this healing process could guide physicians for more individualized anti-platelet therapy. Here we present work towards developing a sensor to detect this healing process. Sensors on several stent struts could give information about the heterogeneity of healing across the stent. Methods A piezoelectric microcantilever was insulated with parylene and demonstrated as an endothelialization detector for incorporation within an active coronary stent. After initial characterization, endothelial cells were plated onto the cantilever surface. After they attached to the surface, they caused an increase in mass, and thus a decrease in the resonant frequencies of the cantilever. This shift was then detected electrically with an LCR meter. The self-sensing, self-actuating cantilever does not require an external, optical detection system, thus allowing for implanted applications. Results A cell density of 1300 cells/mm2 on the cantilever surface is detected. Conclusions We have developed a self-actuating, self-sensing device for detecting the presence of endothelial cells on a surface. The device is biocompatible and functions reliably in ionic liquids, making it appropriate for implantable applications. This sensor can be placed along the struts of a coronary stent to detect when the struts have been covered with a layer of endothelial cells and are no longer available surfaces for clot formation. Anti-platelet therapy can be adjusted in real-time with respect to a patient's level of healing and hemorrhaging risks.
Limited Role for Biliary Stent as Surrogate Fiducial Marker in Pancreatic Cancer: Stent and Intratumoral Fiducials Compared

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Horst, Astrid van der, E-mail: a.vanderhorst@amc.uva.nl [Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Lens, Eelco; Wognum, Silvia; Jong, Rianne de [Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Hooft, Jeanin E. van [Department of Gastroenterology and Hepatology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Tienhoven, Geertjan van; Bel, Arjan [Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands)

2014-07-01

Purpose: Because of low soft-tissue contrast of cone beam computed tomography (CBCT), fiducial markers are often used for radiation therapy patient setup verification. For pancreatic cancer patients, biliary stents have been suggested as surrogate fiducials. Using intratumoral fiducials as standard for tumor position, this study aims to quantify the suitability of biliary stents for measuring interfractional and respiratory-induced position variations of pancreatic tumors. Methods and Materials: Eleven pancreatic cancer patients with intratumoral fiducials and a biliary stent were included in this study. Daily CBCT scans (243 in total) were registered with a reference CT scan, based on bony anatomy, on fiducial markers, and on the biliary stent, respectively. We analyzed the differences in tumor position (ie, markers center-of-mass position) among these 3 registrations. In addition, we measured for 9 patients the magnitude of respiratory-induced motion (MM) of the markers and of the stent on 4-dimensional CT (4DCT) and determined the difference between these 2 magnitudes (ΔMM). Results: The stent indicated tumor position better than bony anatomy in 67% of fractions; the absolute difference between the markers and stent registration was >5 mm in 46% of fractions and >10 mm in 20% of fractions. Large PTV margins (superior-inferior direction, >19 mm) would be needed to account for this interfractional position variability. On 4DCT, we found in superior-inferior direction a mean ΔMM of 0.5 mm (range, –2.6 to 4.2 mm). Conclusions: For respiratory-induced motion, the mean ΔMM is small, but for individual patients the absolute difference can be >4 mm. For interfractional position variations, a stent is, on average, a better surrogate fiducial than bony anatomy, but large PTV margins would still be required. Therefore, intratumoral fiducials are recommended for online setup verification for all pancreatic patients scheduled for radiation therapy, including
Impact of an endothelial progenitor cell capturing stent on coronary microvascular function: comparison with drug-eluting stents.

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Choi, Woong Gil; Kim, Soo Hyun; Yoon, Hyung Seok; Lee, Eun Joo; Kim, Dong Woon

2015-01-01

Although drug-eluting stents (DESs) effectively reduce restenosis following percutaneous coronary intervention (PCI), they also delay re-endothelialization and impair microvascular function, resulting in adverse clinical outcomes. Endothelial progenitor cell (EPC) capturing stents, by providing a functional endothelial layer on the stent, have beneficial effects on microvascular function. However, data on coronary microvascular function in patients with EPC stents versus DESs are lacking. Seventy-four patients who previously underwent PCI were enrolled in this study. Microvascular function was evaluated 6 months after PCI based on the index of microvascular resistance (IMR) and the coronary flow reserve (CFR). IMR was calculated as the ratio of the mean distal coronary pressure at maximal hyperemia to the inverse of the hyperemic mean transit time (hTmn). The CFR was calculated by dividing the hTmn by the baseline mean transit time. Twenty-one patients (age, 67.2 ± 9.6 years; male:female, 15:6) with an EPC stent and 53 patients (age, 61.5 ± 14.7 years; male:female, 40:13) with second-generation DESs were included in the study. There were no significant differences in the baseline clinical and angiographic characteristics of the two groups. Angiography performed 6 months postoperatively did not show significant differences in their CFR values. However, patients with the EPC stent had a significantly lower IMR than patients with second-generation DESs (median, 25.5 [interquartile range, 12.85 to 28.18] vs. 29.0 [interquartile range, 15.42 to 39.23]; p = 0.043). Microvascular dysfunction was significantly improved after 6 months in patients with EPC stents compared to those with DESs. The complete re-endothelialization achieved with the EPC stent may provide clinical benefits over DESs, especially in patients with microvascular dysfunction.
Radiologic placement of metallic esophageal stents: preliminary experience

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Good, S.; Asch, M.R.; Jaffer, N.; Casson, A.G.

1997-01-01

To assess the usefulness of covered, self expanding metallic stents for alleviating stricture associated with malignant esophageal lesions. Patients and methods: Self-expanding metallic stents were placed in 10 patients with dysphagia related to stricture caused by malignant esophageal lesions. The stents were placed fluoroscopically with local anesthesia, and patency of the esophageal lumen was assessed by barium study after the procedure. The patients were then followed clinically. Results: In all 10 cases patency of the lumen was renewed after stent placement. After the procedure 9 of the patients could tolerate a normal or near-normal diet; in the other patient esophageal perforation occurred, and clinical deterioration prevented oral intake of food. In one patient, 2 stents were needed because of the length of the stricture. Two patients experienced reflux after placement of the stent across the gastro-esophageal junction. Another patient had asymptomatic aspiration after stent placement in the proximal esophagus. In 2 patients, symptoms associated with tracheoesophageal fistula were relieved after placement of the stents. Six of the 10 patients died; mean survival after the procedure was 12 (range 1 to 56) weeks. The other 4 patients were alive at the time of writing, having survived for a mean of 7.5 (range 2 to 13) weeks; all of these patients tolerated a near-normal diet. Conclusions: The placement of covered, self-expanding metallic stents is a quick, effective method of palliating dysphagia related to stricture caused by malignant esophageal lesions. (author)
Endoscopic stenting for hilar cholangiocarcinoma: efficacy of unilateral and bilateral placement of plastic and metal stents in a retrospective review of 480 patients

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Liberato Manuel José

2012-08-01

Full Text Available Abstract Background Endoscopic biliary drainage of hilar cholangiocarcinoma is controversial with respect to the optimal types of stents and the extent of drainage. This study evaluated endoscopic palliation in patients with hilar cholangiocarcinoma using self-expandable metallic stents (SEMS and plastic stents (PS.We also compared unilateral and bilateral stent placement according to the Bismuth classification. Methods Data on 480 patients receiving endoscopic biliary drainage for hilar cholangiocarcinoma between September 1995 and December 2010 were retrospectively reviewed to evaluate the following outcome parameters: technical success (TS, functional success (FS, early and late complications, stent patency and survival. Patients were followed from stent insertion until death or stent occlusion. Patients were divided into 3 groups according to the Bismuth classification (Group 1, type I; Group 2, type II; Group 3, type > III. Results The initial stent insertion was successful in 450 (93.8% patients. TS was achieved in 204 (88.3% patients treated with PS and in 246 (98.8% patients palliated with SEMS (p P P Conclusions SEMS insertion for the palliation of hilar cholangiocarcinoma offers higher technical and clinical success rates in the ITT analysis as well as lower complication rates and a superior cumulative stent patency when compared with PS placement in all Bismuth classifications. The cumulative patency of bilateral SEMS or PS stents was significantly higher than that of unilateral SEMS or PS stents, with lower occlusion rates in Bismuth II patients.
Direct implantation of rapamycin-eluting stents with bioresorbable drug carrier technology utilising the Svelte coronary stent-on-a-wire: the DIRECT II study.

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Verheye, Stefan; Khattab, Ahmed A; Carrie, Didier; Stella, Pieter; Slagboom, Ton; Bartunek, Jozef; Onuma, Yoshinobu; Serruys, Patrick W

2016-08-05

Our aim was to demonstrate the safety and efficacy of the Svelte sirolimus-eluting coronary stent-on-a-wire Integrated Delivery System (IDS) with bioresorbable drug coating compared to the Resolute Integrity zotarolimus-eluting stent with durable polymer in patients with de novo coronary artery lesions. Direct stenting, particularly in conjunction with transradial intervention (TRI), has been associated with reduced bleeding complications, procedure time, radiation exposure and contrast administration compared to conventional stenting with wiring and predilatation. The low-profile Svelte IDS is designed to facilitate TRI and direct stenting, reducing the number of procedural steps, time and cost associated with coronary stenting. DIRECT II was a prospective, multicentre trial which enrolled 159 patients to establish non-inferiority of the Svelte IDS versus Resolute Integrity using a 2:1 randomisation. The primary endpoint was angiographic in-stent late lumen loss (LLL) at six months. Target vessel failure (TVF), as well as secondary clinical endpoints, will be assessed annually up to five years. At six months, in-stent LLL was 0.09±0.31 mm in the Svelte IDS group compared to 0.13±0.27 mm in the Resolute Integrity group (p<0.001 for non-inferiority). TVF at one year was similar across the Svelte IDS and Resolute Integrity groups (6.5% vs. 9.8%, respectively). DIRECT II demonstrated the non-inferiority of the Svelte IDS to Resolute Integrity with respect to in-stent LLL at six months. Clinical outcomes at one year were comparable between the two groups.
Theoretical modelling of physiologically stretched vessel in magnetisable stent assisted magnetic drug targeting application

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Mardinoglu, Adil; Cregg, P.J.; Murphy, Kieran; Curtin, Maurice; Prina-Mello, Adriele

2011-01-01

The magnetisable stent assisted magnetic targeted drug delivery system in a physiologically stretched vessel is considered theoretically. The changes in the mechanical behaviour of the vessel are analysed under the influence of mechanical forces generated by blood pressure. In this 2D mathematical model a ferromagnetic, coiled wire stent is implanted to aid collection of magnetic drug carrier particles in an elastic tube, which has similar mechanical properties to the blood vessel. A cyclic mechanical force is applied to the elastic tube to mimic the mechanical stress and strain of both the stent and vessel while in the body due to pulsatile blood circulation. The magnetic dipole-dipole and hydrodynamic interactions for multiple particles are included and agglomeration of particles is also modelled. The resulting collection efficiency of the mathematical model shows that the system performance can decrease by as much as 10% due to the effects of the pulsatile blood circulation. - Research highlights: →Theoretical modelling of magnetic drug targeting on a physiologically stretched stent-vessel system. →Cyclic mechanical force applied to mimic the mechanical stress and strain of both stent and vessel. →The magnetic dipole-dipole and hydrodynamic interactions for multiple particles is modelled. →Collection efficiency of the mathematical model is calculated for different physiological blood flow and magnetic field strength.
Reintervention for stent occlusion after bilateral self-expandable metallic stent placement for malignant hilar biliary obstruction.

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Inoue, Tadahisa; Naitoh, Itaru; Okumura, Fumihiro; Ozeki, Takanori; Anbe, Kaiki; Iwasaki, Hiroyasu; Nishie, Hirotada; Mizushima, Takashi; Sano, Hitoshi; Nakazawa, Takahiro; Yoneda, Masashi; Joh, Takashi

2016-11-01

Endoscopic reintervention for stent occlusions following bilateral self-expandable metallic stent (SEMS) placement for malignant hilar biliary obstruction (MHBO) is challenging, and time to recurrent biliary obstruction (RBO) of the revisionary stent remains unclear. We aimed to clarify a suitable reintervention method for stent occlusions following bilateral SEMS placement for MHBO. Between 2002 and 2014, 52 consecutive patients with MHBO who underwent endoscopic reintervention for stent occlusion after bilateral SEMS placement were enrolled at two university hospitals and one tertiary care referral center. We retrospectively evaluated the technical and functional success rates of the reinterventions, and the time to RBO of the revisionary stents. Technical and functional success rates of the reinterventions were 92% (48/52) and 90% (43/48), respectively. Univariate analysis did not determine any significant predictive factors for technical and functional failures. Median time to RBO of the revisionary stents was 68 days. Median time to RBO was significantly longer for revisionary SEMS placement than for plastic stent placement (131 days vs 47 days, respectively; log-rank test, P = 0.005). Revisionary SEMS placement was the only independent factor that was significantly associated with a longer time to RBO of the revisionary stent in the multivariate Cox proportional hazards analysis (hazard ratio 0.37; 95% confidence interval 0.14-0.95; P = 0.039). Revisionary SEMS placement is a suitable endoscopic reintervention method for stent occlusion following bilateral SEMS placement from the perspective of time to RBO of the revisionary stent. © 2016 Japan Gastroenterological Endoscopy Society.

Successful Treatment of Bronchoesophageal Fistula With Esophageal and Bronchial Stenting

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Cheng-Yi Wang

2011-04-01

Full Text Available Bronchoesophageal fistula is reported in 5-10% of patients with esophageal cancer. In most of these cases, the insertion of a single stent, either a tracheobronchial or an esophageal stent, is sufficient to seal off the fistula. In this case we describe a 67-year-old man with esophageal cancer and complications of bronchoesophageal fistula, which resulted in repeated pneumonia and acute respiratory failure. Initially, two expandable metallic membranous esophageal stents were placed to cover the fistula. However, the esophageal stent failed to stop the air leak and dislodged into the stomach. Thereafter, a bronchial stent was placed at the right intermediate bronchus and successfully stopped the air leak. The patient was then weaned from the ventilator 1 week after the insertion of a bronchial stent. In conclusion, stenting in both the esophagus and airways should be considered when both are severely invaded by malignancy, when the airway is compressed, or when the fistula is insufficiently sealed by an esophageal stent.
Time-dependent 3D simulations of the hemodynamics in a stented coronary artery

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Faik, Isam; Mongrain, Rosaire; Leask, Richard L; Rodes-Cabau, Josep; Larose, Eric; Bertrand, Olivier

2007-01-01

Stenting is becoming the major interventional cardiology procedure worldwide. However restenosis remains a major limitation to the effectiveness of stents. Alterations to the local hemodynamics in the stented segment of the artery could be a potential factor in the development of in-stent restenosis. The characterization of wall shear stress and of blood flow patterns in a stented artery is therefore necessary for a good understanding of the role of hemodynamics in the development of in-stent restenosis. We have used a time-dependent 3D numerical model of a stented coronary artery to study the characteristics of the blood flow and the shear stress distribution. Our results show that the presence of the stent produces significant secondary flow that is limited to an annulus in the near wall region. Low shear stress zones were localized in the vicinity of the struts while the tips of the struts exhibited high values of shear stress. These results support the hypothesis that local hemodynamics may affect the development of in-stent restenosis and could influence the choice of stent geometries for future stent designs
Stenting of the SFA - indications, techniques,

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Rieger, J.; Treitl, M.; Reiser, M.; Ruppert, V.

2006-01-01

Aggressive risk factor modification, change of eating habits, exercise programs, and forceful antiplatelet therapy are the most important tools for the treatment of PAOD in symptomatic patients suffering from intermittent claudication. There are however no guidelines for revascularization at this stage. Endovascular treatment has been increasingly utilized over the last decade and increasingly displaced vascular surgery. Amongst numerous endovascular techniques beside PTA, stents meanwhile play the most important role due to constant technical progress. Results regarding the rate of restenosis or patency rates still remain worse compared to other vascular beds. This paper gives a review over recent results, currently available stent techniques, and possible indications for the endovascular therapy of an artery, which has turned out to be the biggest ordeal for material and construction of stents. (orig.) [de
Clinical experience in coronary stenting with the Vivant Z Stent.

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Chee, K H; Siaw, F S; Chan, C G; Chong, W P; Imran, Z A; Haizal, H K; Azman, W; Tan, K H

2005-06-01

This single centre study was designed to demonstrate feasibility, safety and efficacy of the Vivant Z stent (PFM AG, Cologne, Germany). Patients with de novo lesion were recruited. Coronary angioplasty was performed with either direct stenting or after balloon predilatation. Repeated angiogram was performed 6 months later or earlier if clinically indicated. Between January to June 2003, a total of 50 patients were recruited (mean age 55.8 +/- 9 years). A total of 52 lesions were stented successfully. Mean reference diameter was 2.77 mm (+/-0.59 SD, range 2.05-4.39 mm) with mean target lesion stenosis of 65.5% (+/-11.6 SD, range 50.1-93.3%). Forty-six lesions (88.5%) were American College of Cardiologist/American Heart Association class B/C types. Direct stenting was performed in 18 (34.6%) lesions. Mean stent diameter was 3.18 mm (+/-0.41 SD, range 2.5-4 mm), and mean stent length was 14.86 mm (+/-2.72 SD, range 9-18 mm). The procedure was complicated in only one case which involved the loss of side branch with no clinical sequelae. All treated lesions achieved Thrombolysis In Myocardial Infarction 3 flow. Mean residual diameter stenosis was 12.2% (+/-7.55 SD, range 0-22.6%) with acute gain of 1.72 mm (+/-0.50 SD, range 0.5-2.8). At 6 months, there was no major adverse cardiovascular event. Repeated angiography after 6 months showed a restenosis rate of 17% (defined as >50% diameter restenosis). Mean late loss was 0.96 mm (+/-0.48 SD) with loss index of 0.61 (+/-0.38 SD). The restenosis rate of those lesions less than 3.0 mm in diameter was 22.2% compared with 6.25% in those lesions more than 3.0 mm in diameter. The Vivant Z stent was shown to be safe and efficacious with low restenosis rate in de novo coronary artery lesion.
Orbital atherectomy as an adjunct to debulk difficult calcified lesions prior to mesenteric artery stenting.

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Manunga, Jesse M; Oderich, Gustavo S

2012-08-01

To describe a technique in which percutaneous orbital atherectomy is used to debulk heavily calcified superior mesenteric artery (SMA) occlusions as an adjunct in patients undergoing angioplasty and stenting. The technique is demonstrated in a 62-year-old woman with a replaced right hepatic artery originating from an SMA occluded by densely calcified lesions. Via a left transbrachial approach, a 7-F MPA guide catheter was used to engage the ostium of the SMA, which was crossed using a catheter and guidewire. The calcified lesion was debulked using the 2-mm Diamondback 360° orbital atherectomy system. The wire was exchanged for a 0.014-inch filter wire and 0.018-inch guidewire. Using a 2-guidewire technique, the SMA was stented with a self-expanding stent for the distal lesion that crossed side branches and a balloon-expandable stent at the ostium. A 0.014-inch guidewire was placed into the replaced hepatic artery through a cell of the self-expanding stent, followed by deployment of a small balloon-expandable stent to address the residual lesion. The use of orbital atherectomy to debulk occluded and heavily calcified SMA lesions may optimize the technical results with angioplasty and stenting.
Fully covered stents versus partially covered stents for palliative treatment of esophageal cancer: Is there a difference?

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Alonso Lárraga, J O; Flores Carmona, D Y; Hernández Guerrero, A; Ramírez Solís, M E; de la Mora Levy, J G; Sánchez Del Monte, J C

2018-02-26

Malignant dysphagia is difficulty swallowing resulting from esophageal obstruction due to cancer. The goal of palliative treatment is to reduce the dysphagia and improve oral dietary intake. Self-expandable metallic stents are the current treatment of choice, given that they enable the immediate restoration of oral intake. The aim of the present study was to describe the results of using totally covered and partially covered esophageal stents for palliating esophageal cancer. A retrospective study was conducted on patients with inoperable esophageal cancer treated with self-expandable metallic stents. The 2 groups formed were: group A, which consisted of patients with a fully covered self-expandable stent (SX-ELLA ® ), and group B, which was made up of patients with a partially covered self-expandable stent (Ultraflex ® ). Of the 69-patient total, 50 were included in the study. Group A had 19 men and 2 women and their mean age was 63.6 years (range 41-84). Technical success was achieved in 100% (n=21) of the cases and clinical success in 90.4% (n=19). Group B had 24 men and 5 women and their mean age was 67.5 years (range 43-92). Technical success was achieved in 100% (n=29) of the cases and clinical success in 89.6% (n=26). Complications were similar in both groups (33.3 vs. 51.7%). There was no difference between the 2 types of stent for the palliative treatment of esophageal cancer with respect to technical success, clinical success, or complications. Copyright © 2018 Asociación Mexicana de Gastroenterología. Publicado por Masson Doyma México S.A. All rights reserved.
Bronchoscopic guidance of endovascular stenting limits airway compression.

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Ebrahim, Mohammad; Hagood, James; Moore, John; El-Said, Howaida

2015-04-01

Bronchial compression as a result of pulmonary artery and aortic arch stenting may cause significant respiratory distress. We set out to limit airway narrowing by endovascular stenting, by using simultaneous flexible bronchoscopy and graduated balloon stent dilatation, or balloon angioplasty to determine maximum safe stent diameter. Between August 2010 and August 2013, patients with suspected airway compression by adjacent vascular structures, underwent CT or a 3D rotational angiogram to evaluate the relationship between the airway and the blood vessels. If these studies showed close proximity of the stenosed vessel and the airway, simultaneous bronchoscopy and graduated stent re-dilation or graduated balloon angioplasty were performed. Five simultaneous bronchoscopy and interventional catheterization procedures were performed in four patients. Median age/weight was 33 (range 9-49) months and 14 (range 7.6-24) kg, respectively. Three had hypoplastic left heart syndrome, and one had coarctation of the aorta (CoA). All had confirmed or suspected left main stem bronchial compression. In three procedures, serial balloon dilatation of a previously placed stent in the CoA was performed and bronchoscopy was used to determine the safest largest diameter. In the other two procedures, balloon testing with simultaneous bronchoscopy was performed to determine the stent size that would limit compression of the adjacent airway. In all cases, simultaneous bronchoscopy allowed selection of an ideal caliber of the stent that optimized vessel diameter while minimizing compression of the adjacent airway. In cases at risk for airway compromise, flexible bronchoscopy is a useful tool to guide endovascular stenting. Maximum safe stent diameter can be determined without risking catastrophic airway compression. © 2014 Wiley Periodicals, Inc.
The interventional treatment with two stents in malignant hilar obstruction

International Nuclear Information System (INIS)

Gao Kun; Dai Dingke; Zhao Renyou; Qian Xiaojun

2006-01-01

Objective: To evaluate the methodology of interventional treatment with two stents in malignant hilar obstructions. Methods: Retrospectively analyzing the two stents, interventional management of unresectable malignant hilar obstruction in 22 patients included unilateral and bilateral puncture routes for placing 'T' shape stent set and 'Y' shape stent set, respectively; together with recording the related complications. Results: The overall technical success rate was 100%, without severe complication. The total serum bilirubin reduced from (337.9 + 81.7) μmol/L before procedure to (129.1 + 51.1) μmol/L after the stent placement. Stent obstruction was found in 8 cases at 6 months; 5 cases by the time of 6-12 months and only 2 cases after 1 year. Conclusion: The method of two stents interventional treatment is a safe and useful management for malignant hilar obstructions. (authors)
Plastic strains during stent deployment have a critical influence on the rate of corrosion in absorbable magnesium stents.

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Galvin, Emmet; Cummins, Christy; Yoshihara, Shoichiro; Mac Donald, Bryan J; Lally, Caitríona

2017-08-01

Magnesium stents are a promising candidate in the emerging field of absorbable metallic stents (AMSs). In this study, the mechanical and corrosion performance of dog-bone specimens and a specific stent design of a magnesium alloy, WE43, are assessed experimentally in terms of their corrosion behaviour and mechanical integrity. It is shown that plastic strains that are induced in the struts of the stent during stent deployment have a critical influence in directing subsequent corrosion behaviour within the material. In addition, the deployment and scaffolding characteristics of the magnesium stent are elucidated and contrasted with those of a commercial stainless steel stent. The magnesium stent is found to support higher levels of cyclic strain amplitude than the stainless steel stent, even prior to degradation, and this may play a role in reducing in-stent restenosis. This study provides new insights into the experimental performance of a current AMS design and material whilst demonstrating the critical influence of plastic strain on the corrosion performance and scaffolding ability of an AMS.
Treatment of malignant gastric outlet obstruction with stents: An evaluation of the reported variables for clinical outcome

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Medhus Asle W

2009-06-01

Full Text Available Abstract Background Malignant gastric outlet obstruction (GOO is commonly seen in patients with advanced gastric-, pancreatic-, duodenal, hepatobiliary or metastatic malignancies. Ten to 25% of patients with pancreatic cancer will develop duodenal obstruction during the course of the disease. Duodenal stenting with self-expandable metal stents is an alternative treatment to surgical bypass procedures. Our aim was to review the published literature regarding treatment of malignant GOO with stents to reveal whether the information provided is sufficient to evaluate the clinical effects of this treatment Methods A literature search from 2000 – 2007 was conducted in Pub Med, Embase, and Cochrane library, combining the following search terms: duodenal stent, malignant duodenal obstruction, gastric outlet obstruction, SEMS, and gastroenteroanastomosis. All publications presenting data with ≥ 15 patients and only articles written in English were included and a review focusing on the following parameters were conducted: 1 The use of graded scoring systems evaluating clinical success; 2 Assessment of Quality of life (QoL before and after treatment; 3 Information on stent-patency; 4 The use of objective criteria to evaluate the stent effect. Results 41 original papers in English were found; no RCT's. 16 out of 41 studies used some sort of graded scoring system. No studies had objectively evaluated QoL before or after stent treatment, using standardized QoL-questionnaires, 32/41 studies reported on stent patency and 9/41 performed an oral contrast examination after stent placement. Objective quantitative tests of gastric emptying had not been performed. Conclusion Available reports do not provide sufficient relevant information of the clinical outcome of duodenal stenting. In future studies, these relevant issues should be addressed to allow improved evaluation of the effect of stent treatment.
Impact of stent length on clinical outcomes of first-generation and new-generation drug-eluting stents.

Science.gov (United States)

Konishi, Hirokazu; Miyauchi, Katsumi; Dohi, Tomotaka; Tsuboi, Shuta; Ogita, Manabu; Naito, Ryo; Kasai, Takatoshi; Tamura, Hiroshi; Okazaki, Shinya; Isoda, Kikuo; Daida, Hiroyuki

2016-04-01

The aim of this study is to compare first- and new-generation drug-eluting stents (DESs) which are implanted in long lesion. Stent length is known to be a predictor of adverse events after percutaneous coronary intervention (PCI), even with the first-generation DESs. The introduction of new-generation DESs has reduced the rates of adverse clinical events. However, the impact of stent length on long-term clinical outcomes is not well known. A total of 1181 consecutive patients who underwent PCI using either a first-generation DES (n = 885) or a new-generation DES (n = 296) between 2004 and 2011 were investigated. In each of the stent groups, the patients were divided into two groups by stent length (>32 and ≤32 mm) and compared. During the follow-up period, the incidence of major adverse cardiac events (MACEs) was significantly higher for patients with long stents implanted than with short stents (P stent groups in the new-generation DES group (P = 0.24; log-rank test). On multivariate Cox regression analysis, stent length was not associated with adverse events in the new-generation DES groups [hazard ratio (HR) 0.87; 95 % confidence interval (95 % CI) 0.71-1.04; P = 0.14]. Implanted stent length was significantly associated with a higher risk of MACEs in patients who received first-generation DESs, but not in patients who received the new-generation DESs.
Evaluation of a novel stent technology: the Genous EPC capturing stent

NARCIS (Netherlands)

Klomp, M.

2012-01-01

Tegenwoordig gebruiken ziekenhuizen een nieuwe stent bij dotterbehandelingen van kransslagadervernauwingen. Deze Genous-stent heeft een laag met antistoffen waardoor het behandelde bloedvat snel bedekt raakt met lichaamseigen cellen. Zo wordt tegengegaan dat er opnieuw een vernauwing optreedt of dat
Brachytherapy using holmium-166 liquid balloon system for in-stent restenosis: 6 months clinical and angiographic follow-up

Energy Technology Data Exchange (ETDEWEB)

Kim, M. H.; Kim, S. K.; Cha, K. S.; Kim, Y. D.; Lee, H. S.; Kang, D. Y. [Donga University College of Medicine, Busan (Korea, Republic of)

2002-07-01

In western country, 3 systems of brachytherapy using commercial radioactive source has been established. However, brachytherapy using holmium-166 liquid balloon system (HLBS) for the patient with stent restenosis has not been studied enough. 30 patients (male 23, mean age 58.9 7.7) were enrolled. Target dose was 15 Gy at 1 mm distance from the intimal surface. Clinical diagnoses of the study patients included stable angina 10 and unstable angina 20 patients. Target lesion included LAD 19, LCx 5 and RCA 6 arteries. Pre-brachytherapy treatment included cutting balloon angioplasty in 25, rotational atherectomy in 5 patients. Fractionation and stepping was done in 6 patients each. Follow-up angiography was done in 19 patients. Of them, 4 cases developed angiographic restenosis (21%) including 3 cases of total occlusion. 6 month MACE (major adverse cardiac event) occurred in 5 patients including one sudden cardiac death in a patient with 80 year-old, triple-vessel diseased patient. Vascular brachytherapy using HLBS is a safe and effective treatment modality for in-stent restenosis showing acceptable angiographic and clinical result.
Stent thrombosis, myocardial infarction, and death after drug-eluting and bare-metal stent coronary interventions

DEFF Research Database (Denmark)

Jensen, Lisette Okkels; Maeng, Michael; Kaltoft, Anne

2007-01-01

OBJECTIVES: The aim of the study was to examine outcomes subsequent to implantation of drug-eluting stents (DES) and bare-metal stents (BMS). BACKGROUND: Use of DES might be associated with increased risk of stent thrombosis (ST), myocardial infarction (MI), and death. METHODS: From January 2002...... through June 2005, data from all percutaneous coronary interventions in western Denmark were prospectively recorded in the Western Denmark Heart Registry; 12,395 consecutive patients (17,152 lesions) treated with stent implantation were followed for 15 months. Data on death and MI were ascertained from...... within 15 months after implantation of DES seems unlikely to outweigh the benefit of these stents. Udgivelsesdato: 2007-Jul-31...
Flow Characteristics Near to Stent Strut Configurations on Femoropopliteal Artery

Science.gov (United States)

Paisal, Muhammad Sufyan Amir; Fadhil Syed Adnan, Syed; Taib, Ishkrizat; Ismail, Al Emran; Kamil Abdullah, Mohammad; Nordin, Normayati; Seri, Suzairin Md; Darlis, Nofrizalidris

2017-08-01

Femoropopiteal artery stenting is a common procedure suggested by medical expert especially for patient who is diagnosed with severe stenosis. Many researchers reported that the growth of stenosis is significantly related to the geometry of stent strut configuration. The different shapes of stent geometry are presenting the different flow pattern and re-circulation in stented femoropopliteal artery. The blood flow characteristics near to the stent geometry are predicted for the possibility of thrombosis and atherosclerosis to be formed as well as increase the growth of stenosis. Thus, this study aims to determine the flow characteristic near to stent strut configuration based on different hemodynamic parameters. Three dimensional models of stent and simplified femoropopliteal artery are modelled using computer aided design (CAD) software. Three different models of stent shapes; hexagon, circle and rectangle are simulated using computational fluid dynamic (CFD) method. Then, parametric study is implemented to predict the performance of stent due to hemodynamic differences. The hemodynamic parameters considered are pressure, velocity, low wall shear stress (WSSlow) and wall shear stress (WSS). From the observation, flow re-circulation has been formed for all simulated stent models which the proximal region shown the severe vortices. However, rectangular shape of stent strut (Type P3) shows the lowest WSSlow and the highest WSS between the range of 4 dyne/cm2 and 70 dyne/cm2. Stent Type P3 also shows the best hemodynamic stent performance as compare to others. In conclusion, Type P3 has a favourable result in hemodynamic stent performance that predicted less probability of thrombosis and atherosclerosis to be formed as well as reduces the growth of restenosis.
Development and application of stent-based image guided navigation system for oral and maxillofacial surgery

Energy Technology Data Exchange (ETDEWEB)

Lee, Woo Jin; Kim, Dae Seung [Interdisciplinary Program in Radiation Applied Life Science, Dental Research Institute and BK21, College of Medicine, Seoul National University, Seoul (Korea, Republic of); Yi, Won Jin; Lee, Sam Sun; Choi, Soon Chul; Heo, Min Suk; Huh, Kyung Hoe; Kim, Myung Jin; Lee, Jee Ho [Department of Oral and Maxillofacial Surgery, Dental Research Institute, School of Dentistry, Seoul National University, Seoul (Korea, Republic of)

2009-09-15

The purpose of this study was to develop a stent-based image guided surgery system and to apply it to oral and maxillofacial surgeries for anatomically complex sites. We devised a patient-specific stent for patient-to-image registration and navigation. Three dimensional positions of the reference probe and the tool probe were tracked by an optical camera system and the relative position of the handpiece drill tip to the reference probe was monitored continuously on the monitor of a PC. Using 8 landmarks for measuring accuracy, the spatial discrepancy between CT image coordinate and physical coordinate was calculated for testing the normality. The accuracy over 8 anatomical landmarks showed an overall mean of 0.56 {+-} 0.16 mm. The developed system was applied to a surgery for a vertical alveolar bone augmentation in right mandibular posterior area and possible interior alveolar nerve injury case of an impacted third molar. The developed system provided continuous monitoring of invisible anatomical structures during operation and 3D information for operation sites. The clinical challenge showed sufficient accuracy and availability of anatomically complex operation sites. The developed system showed sufficient accuracy and availability in oral and maxillofacial surgeries for anatomically complex sites.
Tracheal obstruction caused by an expandable metallic stent: a case of successful removal of the stent.

Science.gov (United States)

Okuyama, Hiroomi; Kubota, Akio; Kawahara, Hisayoshi; Oue, Takaharu; Nose, Satoko; Ihara, Toshiyuki

2005-07-01

We report a case of tracheal obstruction caused by an expandable metallic stent. A 3-month-old girl with severe tracheomalacia had a placement of a Palmaz stent. At 3 years of age, she developed progressive dyspnea. The CT scan showed tracheal obstruction caused by granulation tissue over the stent. At operation, the stent was found to have penetrated the posterior tracheal wall. Under partial cardiopulmonary bypass, the stent was removed along with the membranous wall of the trachea, and the trachea was reconstructed using slide tracheoplasty. Tracheal obstruction is one of the serious complications caused by an expandable metallic stent. Direct open approach to the trachea under cardiopulmonary bypass is thought to be a safe way to manage this problem.
Outcomes of Temporary Partially Covered Stent Placement for Benign Tracheobronchial Stenosis

International Nuclear Information System (INIS)

Ma, Ji; Han, Xinwei; Wu, Gang; Jiao, Dechao; Ren, Kewei; Bi, Yonghua

2016-01-01

PurposeTo evaluate the intermediate outcomes of temporary partially covered tracheobronchial stenting in patients with benign tracheobronchial stenosis.Materials and MethodsWe conducted a retrospective study of patients with benign tracheobronchial stenosis who underwent stent placement. All stents were removed approximately 3 months after placement. Respiratory function was assessed using the visual analogue scale (VAS) and Karnofsky performance status scale (KPS) before and after stent placement. The lumen diameters of the stenotic lesions were measured using chest computed tomography (CT) and compared between before stent placement and after stent removal.ResultsA total of 51 stents were successfully placed in consecutive 51 patients with benign tracheobronchial stenosis. No serious complications occurred. The mean VAS and KPS scores significantly improved after stent removal (6.291 ± 0.495 and 25.352 ± 10.533, respectively) compared with those before stent placement (1.493 ± 0.504 and 60.140 ± 16.344, respectively; P 0.05).ConclusionTemporary partially covered stenting may be a safe and effective treatment for benign tracheobronchial stenosis.
Covered stent to exclude intravascular thrombus.

Science.gov (United States)

Liistro, Francesco; Stankovic, Goran; Di Mario, Carlo; Montorfano, Matteo; Briguori, Carlo; Colombo, Antonio

2002-04-01

To describe the utility of stent-graft implantation to avoid distal embolization from a large thrombus-containing lesion. A 67-year-old man was evaluated for recent onset of disabling left leg claudication. Angiography disclosed a mobile lobular mass occluding the left common iliac artery; irregular staining suggested an atherothrombotic lesion. Through a percutaneous ipsilateral access and an 8-F sheath, a balloon-expandable Jostent peripheral stent-graft was positioned with the distal edge immediately proximal to the internal iliac artery ostium. A prominent "waist" at the center of the balloon confirmed entrapment of the thrombotic mass. Completion angiography showed an optimal result with no residual stenosis or evidence of distal embolization. At 6-month follow-up, the patient was asymptomatic with angiographically documented luminal patency and no evidence of in-stent stenosis. Stent-graft implantation appears a viable treatment alternative for thrombus-containing lesions, particularly when the thrombotic material is localized or is in a large vessel.
Fenestrated Stent Graft Repair of Abdominal Aortic Aneurysm: Hemodynamic Analysis of the Effect of Fenestrated Stents on the Renal Arteries

Energy Technology Data Exchange (ETDEWEB)

Sun, Zhonghua; Chaichana, Thanapong [Curtin University of Technology, Perth (Australia)

2010-02-15

We wanted to investigate the hemodynamic effect of fenestrated stents on the renal arteries with using a fluid structure interaction method. Two representative patients who each had abdominal aortic aneurysm that was treated with fenestrated stent grafts were selected for the study. 3D realistic aorta models for the main artery branches and aneurysm were generated based on the multislice CT scans from two patients with different aortic geometries. The simulated fenestrated stents were designed and modelled based on the 3D intraluminal appearance, and these were placed inside the renal artery with an intra-aortic protrusion of 5.0-7.0 mm to reflect the actual patients' treatment. The stent wire thickness was simulated with a diameter of 0.4 mm and hemodynamic analysis was performed at different cardiac cycles. Our results showed that the effect of the fenestrated stent wires on the renal blood flow was minimal because the flow velocity was not significantly affected when compared to that calculated at pre-stent graft implantation, and this was despite the presence of recirculation patterns at the proximal part of the renal arteries. The wall pressure was found to be significantly decreased after fenestration, yet no significant change of the wall shear stress was noticed at post-fenestration, although the wall shear stress was shown to decrease slightly at the proximal aneurysm necks. Our analysis demonstrates that the hemodynamic effect of fenestrated renal stents on the renal arteries is insignificant. Further studies are needed to investigate the effect of different lengths of stent protrusion with variable stent thicknesses on the renal blood flow, and this is valuable for understanding the long-term outcomes of fenestrated repair.

Fenestrated Stent Graft Repair of Abdominal Aortic Aneurysm: Hemodynamic Analysis of the Effect of Fenestrated Stents on the Renal Arteries

International Nuclear Information System (INIS)

Sun, Zhonghua; Chaichana, Thanapong

2010-01-01

We wanted to investigate the hemodynamic effect of fenestrated stents on the renal arteries with using a fluid structure interaction method. Two representative patients who each had abdominal aortic aneurysm that was treated with fenestrated stent grafts were selected for the study. 3D realistic aorta models for the main artery branches and aneurysm were generated based on the multislice CT scans from two patients with different aortic geometries. The simulated fenestrated stents were designed and modelled based on the 3D intraluminal appearance, and these were placed inside the renal artery with an intra-aortic protrusion of 5.0-7.0 mm to reflect the actual patients' treatment. The stent wire thickness was simulated with a diameter of 0.4 mm and hemodynamic analysis was performed at different cardiac cycles. Our results showed that the effect of the fenestrated stent wires on the renal blood flow was minimal because the flow velocity was not significantly affected when compared to that calculated at pre-stent graft implantation, and this was despite the presence of recirculation patterns at the proximal part of the renal arteries. The wall pressure was found to be significantly decreased after fenestration, yet no significant change of the wall shear stress was noticed at post-fenestration, although the wall shear stress was shown to decrease slightly at the proximal aneurysm necks. Our analysis demonstrates that the hemodynamic effect of fenestrated renal stents on the renal arteries is insignificant. Further studies are needed to investigate the effect of different lengths of stent protrusion with variable stent thicknesses on the renal blood flow, and this is valuable for understanding the long-term outcomes of fenestrated repair
Prospective Evaluation of Two iStent® Trabecular Stents, One iStent Supra® Suprachoroidal Stent, and Postoperative Prostaglandin in Refractory Glaucoma: 4-year Outcomes.

Science.gov (United States)

Myers, Jonathan S; Masood, Imran; Hornbeak, Dana M; Belda, Jose I; Auffarth, Gerd; Jünemann, Anselm; Giamporcaro, Jane Ellen; Martinez-de-la-Casa, Jose M; Ahmed, Iqbal Ike K; Voskanyan, Lilit; Katz, L Jay

2018-03-01

This study evaluates long-term outcomes of two trabecular micro-bypass stents, one suprachoroidal stent, and postoperative prostaglandin in eyes with refractory open angle glaucoma (OAG). Prospective ongoing 5-year study of 80 eligible subjects (70 with 4-year follow-up) with OAG and IOP ≥ 18 mmHg after prior trabeculectomy and while taking 1-3 glaucoma medications. Subjects received two iStent ® trabecular micro-bypass stents, one iStent Supra ® suprachoroidal stent, and postoperative travoprost. Postoperative IOP was measured with medication and annually following medication washouts. Performance was measured by the proportion of eyes with ≥ 20% IOP reduction on one medication (the protocol-specified prostaglandin) versus preoperative medicated IOP (primary outcome); and the proportion of eyes with postoperative IOP ≤ 15 and ≤ 18 mmHg on one medication (secondary outcome). Additional clinical and safety data included medications, visual field, pachymetry, gonioscopy, adverse events, visual acuity, and slit-lamp and fundus examinations. Preoperatively, mean medicated IOP was 22.0 ± 3.1 mmHg on 1.2 ± 0.4 medications, and mean unmedicated IOP was 26.4 ± 2.4 mmHg. Postoperatively, among eyes without later cataract surgery, mean medicated IOP at all visits through 48 months was ≤ 13.7 mmHg (≥ 37% reduction), and annual unmedicated IOP was ≤ 18.4 mmHg (reductions of ≥ 30% vs. preoperative unmedicated IOP and ≥ 16% vs. preoperative medicated IOP). At all postoperative visits among eyes without additional surgery or medication, ≥ 91% of eyes had ≥ 20% IOP reduction on one medication versus preoperative medicated IOP. At month 48, 97 and 98% of eyes achieved IOP ≤ 15 and ≤ 18 mmHg, respectively, on one medication. Six eyes required additional medication, no eyes required additional glaucoma surgery, and safety measurements were favorable throughout follow-up. IOP control was achieved safely with two
[Coronary stents: 30 years of medical progress].

Science.gov (United States)

Silvain, Johanne; Cayla, Guillaume; Collet, Jean-Philippe; Fargeot, Catherine; Montalescot, Gilles

2014-03-01

The history of interventional cardiology has been marked by several technologic revolutions since the late 1970s. The first key step was the use of inflatable balloon angioplasty as an alternative to CABG surgery for coronary revascularization, followed by intracoronary delivery of bare metal stent (BMS) and drug eluting stents (DES) to drastically reduce intracoronary restenosis observed with BMS. Improved stents platforms and polymers (absorbable or biocompatible) led to a dramatic reduction in the rate of late stent thrombosis. Self-expanding stents are now available to improve stent a position especially in acute myocardial infarction. The emergence of new fully bioabsorbable stents that can be combined with antiproliferative drugs is the ongoing revolution. A new generation of stents is continuously improving and likely to become the ideal stent for coronary revascularization in the near future. © 2014 médecine/sciences – Inserm.
Endoscopic management of unresectable malignant gastroduodenal obstruction with a nitinol uncovered metal stent: A prospective Japanese multicenter study

Science.gov (United States)

Sasaki, Reina; Sakai, Yuji; Tsuyuguchi, Toshio; Nishikawa, Takao; Fujimoto, Tatsuya; Mikami, Shigeru; Sugiyama, Harutoshi; Yokosuka, Osamu

2016-01-01

AIM: To determine the safety and efficacy of endoscopic duodenal stent placement in patients with malignant gastric outlet obstruction. METHODS: This prospective, observational, multicenter study included 39 consecutive patients with malignant gastric outlet obstruction. All patients underwent endoscopic placement of a nitinol, uncovered, self-expandable metal stent. The primary outcome was clinical success at 2 wk after stent placement that was defined as improvement in the Gastric Outlet Obstruction Scoring System score relative to the baseline. RESULTS: Technical success was achieved in all duodenal stent procedures. Procedure-related complications occurred in 4 patients (10.3%) in the form of mild pneumonitis. No other morbidities or mortalities were observed. The clinical success rate was 92.3%. The mean survival period after stent placement was 103 d. The mean period of stent patency was 149 d and the patency remained acceptable for the survival period. Stent dysfunction occurred in 3 patients (7.7%) on account of tumor growth. CONCLUSION: Endoscopic management using duodenal stents for patients with incurable malignant gastric outlet obstruction is safe and improved patients’ quality of life. PMID:27076769
Cost analysis of prophylactic intraoperative cystoscopic ureteral stents in gynecologic surgery.

Science.gov (United States)

Fanning, James; Fenton, Bradford; Jean, Geraldine Marie; Chae, Clara

2011-12-01

Prophylactic intraoperative ureteral stent placement is performed to decrease operative ureteric injury, though few data are available on the effectiveness of this procedure, and no data are available on its cost. To analyze the cost of prophylactic intraoperative cystoscopic ureteral stents in gynecologic surgery. All cases of prophylactic ureteral stent placement performed in gynecologic surgery during a 1-year period were identified and retrospectively reviewed through the electronic medical records database of Summa Health System. Costs were obtained through the Healthcare Cost Accounting System. The principles of cost-effective analysis were used (ie, explicit and detailed descriptions of costs and cost-effectiveness statistics). Importantly, we evaluated cost and not charges or financial model estimates. In addition, we obtained the contribution margins (ie, the hospital's net profit or loss) for prophylactic ureteral stent placement. Other gynecologic procedures were also analyzed. Among 792 major inpatient gynecologic procedures, 18 cases of prophylactic intraoperative ureteral stents were identified. Median costs were as follows: additional cost of prophylactic intraoperative ureteral stenting, $1580; additional cost of surgical resources, $770; cost of ureteral catheters, $427; cost of surgeons, $383. The contribution margins per case for various gynecologic surgical procedures were as follows: oophorectomy, $2804 profit; abdominal hysterectomy, $2649 profit; laparoscopically assisted vaginal hysterectomy (LAVH), $1760 profit. When intraoperative ureteral stenting was added, the contribution margins changed to the following: oophorectomy, $782 profit; abdominal hysterectomy, $627 profit; LAVH, $262 loss. Overall, the contribution margin profit was decreased by about 85%, from $2400 to $380. Prophylactic intraoperative ureteral stenting in gynecologic surgery decreases a hospital's contribution margin. Because of the expense of this procedure, as well as
Nitinol memmo-alloy stents for benign and malignant tracheal stensis

International Nuclear Information System (INIS)

Wang Zhongmin; Wu Chaoxian; Gong Ju; Zheng Yunfeng; Gu Xuezhang

2005-01-01

Objective: To observe the therapeutic and side effects of tracheal stents in tracheal stenosis caused by tracheal malacia and malignant tumours. Methods: Twenty-five patients treated with tracheal stents were retrospectively analyzed. Results: Tracheal stents have been implanted successfully in twenty-five patients through fiberbronchoscope or tracheal intubation, and dyspnoea improved greatly after the procedure. Conclusions: Tracheal stents can relieve symptoms and improve the life quality in patients with tracheal stenosis caused by malignant tumors or tracheal malacia. (authors)
Transanal stent in anterior resection does not prevent anastomotic leakage

DEFF Research Database (Denmark)

Bülow, Steffen; Bulut, O; Christensen, Ib Jarle

2006-01-01

OBJECTIVE: A defunctioning transanal stent may theoretically reduce the leakage rate after anterior rectal resection. We present a randomized open study with the aim of comparing the leakage rate after anterior resection with a loop ileostomy, a transanal stent, both or neither. PATIENTS...... completion of the operation the patients were randomized in two groups with and without a transanal stent. RESULTS: A clinically significant leakage was diagnosed in 25 patients (13%). No significant difference was found 17 of 98 patients with a stent and 8 of 96 without (P = 0.09), or in 9 of 44 ileostomy...... patients with a stent and in 3 of 45 without (P = 0.07). Several leaks over a short time led to an interim analysis after inclusion of 194 of 448 planned patients. The analysis showed no significant protective effect of the stent, and more leakages in the stent group, although not statistically significant...
Three-year patient-related and stent-related outcomes of second-generation everolimus-eluting Xience V stents versus zotarolimus-eluting resolute stents in real-world practice (from the Multicenter Prospective EXCELLENT and RESOLUTE-Korea Registries).

Science.gov (United States)

Lee, Joo Myung; Park, Kyung Woo; Han, Jung-Kyu; Yang, Han-Mo; Kang, Hyun-Jae; Koo, Bon-Kwon; Bae, Jang-Whan; Woo, Sung-Il; Park, Jin Sik; Jin, Dong-Kyu; Jeon, Dong Woon; Oh, Seok Kyu; Park, Jong-Seon; Kim, Doo-Il; Hyon, Min Su; Jeon, Hui-Kyung; Lim, Do-Sun; Kim, Myeong-Gon; Rha, Seung-Woon; Her, Sung-Ho; Hwang, Jin-Yong; Kim, Sanghyun; Choi, Young Jin; Kang, Jin Ho; Moon, Keon-Woong; Jang, Yangsoo; Kim, Hyo-Soo

2014-11-01

Long-term outcomes are imperative to confirm safety of drug-eluting stents. There have been 2 randomized controlled trials comparing everolimus-eluting stents (EESs) and Resolute zotarolimus-eluting stents (ZES-Rs). To date, long-term clinical outcomes of these stents were limited to only 1 report, which has recently reported 4-year comparisons of these stents. Therefore, more evidence is needed regarding long-term clinical outcomes of the second-generation stents. This study compared the long-term clinical outcomes of EES with ZES-R in "all-comer" cohorts up to 3-year follow-up. The EXCELLENT and RESOLUTE-Korea registries prospectively enrolled 3,056 patients treated with EES and 1,998 with ZES-R, respectively, without exclusions. Stent-related composite outcomes (target lesion failure) and patient-related composite events up to 3-year follow-up were compared in crude and propensity score-matched analyses. Of 5,054 patients, 3,830 patients (75.8%) had off-label indication (2,217 treated with EES and 1,613 treated with ZES-R). The stent-related outcome (189 [6.2%] vs 127 [6.4%], p = 0.812) and the patient-related outcome (420 [13.7%] vs 250 [12.5%], p = 0.581) did not differ between EES and ZES-R, respectively, at 3 years, which was corroborated by similar results from the propensity score-matched cohort (hazard ratio [HR] 0.92, 95% confidence interval [CI] 0.70 to 1.20, p = 0.523 and 0.85, 95% CI 0.70 to 1.02, p = 0.081, for stent- and patient-related outcomes, respectively). The rate of definite or probable stent thrombosis up to 3 years (22 [0.7%] vs 10 [0.5%], p = 0.370) was also similar. The rate of very late definite or probable stent thrombosis was very low and comparable between the 2 stents (3 [0.1%] vs 1 [0.1%], p = 0.657). In multivariate analysis, chronic renal failure (adjusted HR 3.615, 95% CI 2.440 to 5.354, p stents showed comparable safety and efficacy at 3-year follow-up in this robust real-world registry with unrestricted use of EES and
High-resolution 3D X-ray imaging of intracranial nitinol stents

International Nuclear Information System (INIS)

Snoeren, Rudolph M.; With, Peter H.N. de; Soederman, Michael; Kroon, Johannes N.; Roijers, Ruben B.; Babic, Drazenko

2012-01-01

To assess an optimized 3D imaging protocol for intracranial nitinol stents in 3D C-arm flat detector imaging. For this purpose, an image quality simulation and an in vitro study was carried out. Nitinol stents of various brands were placed inside an anthropomorphic head phantom, using iodine contrast. Experiments with objects were preceded by image quality and dose simulations. We varied X-ray imaging parameters in a commercially interventional X-ray system to set 3D image quality in the contrast-noise-sharpness space. Beam quality was varied to evaluate contrast of the stents while keeping absorbed dose below recommended values. Two detector formats were used, paired with an appropriate pixel size and X-ray focus size. Zoomed reconstructions were carried out and snapshot images acquired. High contrast spatial resolution was assessed with a CT phantom. We found an optimal protocol for imaging intracranial nitinol stents. Contrast resolution was optimized for nickel-titanium-containing stents. A high spatial resolution larger than 2.1 lp/mm allows struts to be visualized. We obtained images of stents of various brands and a representative set of images is shown. Independent of the make, struts can be imaged with virtually continuous strokes. Measured absorbed doses are shown to be lower than 50 mGy Computed Tomography Dose Index (CTDI). By balancing the modulation transfer of the imaging components and tuning the high-contrast imaging capabilities, we have shown that thin nitinol stent wires can be reconstructed with high contrast-to-noise ratio and good detail, while keeping radiation doses within recommended values. Experimental results compare well with imaging simulations. (orig.)
[Evaluation of stents in treating childhood benign esophageal strictures].

Science.gov (United States)

Reinshagen, K; Kähler, G; Manegold, B C; Waag, K-L

2009-01-01

Esophageal stenting is a popular of treatment of esophageal strictures in adults. It has also been described for children with benign strictures who did not respond to standard dilatation therapy. The aim of the study was to evaluate weather esophageal stents could be used safely and effectively in the treatment of benign esophageal strictures in children. From 1993 to 2005 stenting therapy was performed in 12 children with complicated esophageal strictures. Etiologies of the strictures were caustic burns in 9 patients, postoperative strictures due to complicated esophageal atresia in 2 patients and iatrogenic esophageal injury in 1 patient. Esophageal silicon tubi, covered retrievable expandable nitinol and plastic stents were placed endoscopically. The clinical course and the long term follow up were evaluated retrospectively The stents and tubi were placed in all patients without complications and were later removed successfully. 6 patients were treated with a self expanding plastic stent. The plastic stents showed a distinct tendency to migrate but in 5/6 patients esophageal stricture was treated successfully. 3 patients were treated by a covered self expanding nitinol stent. No migration occurred. One patient was asymptomatic after therapy, one required further dilatation therapy and the third had esophageal resection. 3 patients were treated by esophageal tubi. 2 patients required surgery in the follow up, one patient is asymptomatic. The use of stenting devices in children to treat benign esophageal strictures is safe and efficient. The self expanding plastic stents had the best long term results but required high compliance of parents and children due to the tendency of stent migration. Self expanding nitinol stents are more traumatic at the extraction procedure and are useful in patients with low compliance. Recurrence of strictures occurred most often after esophageal tubi possibly due to the lack of radial expansion.
Initial experience with a new biodegradable airway stent in children: Is this the stent we were waiting for?

Science.gov (United States)

Antón-Pacheco, Juan L; Luna, Carmen; García, Enrique; López, María; Morante, Rocío; Tordable, Cristina; Palacios, Alba; de Miguel, Mónica; Benavent, Isabel; Gómez, Andrés

2016-06-01

To report our experience with a new type of biodegradable airway stent in the setting of severe tracheobronchial obstruction in children. We conducted a retrospective and prospective (since June 2014) study of pediatric patients with severe airway obstruction treated with biodegradable stents in our institution between 2012 and 2015. The following data were collected: demographics, indication for stenting, bronchoscopic findings, insertion technique complications, clinical outcome, stent related complications, re-stenting, and time of follow-up. Thirteen custom-made polydioxanone stents were placed in four infants (mean age, 4 months) with severe tracheobronchial obstruction: tracheomalacia (two patients), bronchomalacia (1), and diffuse tracheal stenosis (1). All the stents were bronchoscopically inserted uneventfully. Immediate and maintained clinical improvement was observed in every case. No major stent related complications have occurred and only mild or moderate granulation tissue was observed during surveillance bronchoscopy. Two patients required repeated stenting as expected. All the patients are alive and in a good respiratory condition with a follow-up ranging from 5 to 40 months. Biodegradable airway stents seem to be safe, effective, and cause fewer complications than other types of stents. They can be an alternative to the classic metallic or plastic stents for severe tracheal stenosis or malacia in small children. More experience is needed in order to establish the definite clinical criteria for their use in pediatric patients. Pediatr Pulmonol. 2016;51:607-612. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.
Stent Fracture and Reocclusion After Placement of a Single Self-Expanding Stent in the Common Iliac Artery and Endovascular Treatment

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Higashiura, Wataru; Sakaguchi, Shoji; Morimoto, Kengo; Kichikawa, Kimihiko

2008-01-01

We present a case of fracture of a single self-expanding stent placed in the common iliac artery (CIA). An 80-year-old woman underwent placement of a self-expanding stent for CIA occlusion. Stent fracture and reocclusion were detected after 18 months. Successful revascularization was achieved using a stent-in-stent maneuver. The possibility of stent fracture with reocclusion should be considered following treatment with a single self-expanding stent for CIA occlusion.
Management of acute cholangitis as a result of occlusion from a self-expandable metallic stent in patients with malignant distal and hilar biliary obstructions.

Science.gov (United States)

Shiomi, Hideyuki; Matsumoto, Kazuya; Isayama, Hiroyuki

2017-04-01

Acute cholangitis as a result of common bile duct stones can be managed; however, cholangitis caused by occlusion with a biliary self-expandable metallic stent (SEMS) in patients with an unresectable malignant biliary obstruction has not been fully discussed. The acute cholangitis clinical guidelines (Tokyo Guidelines 2013) recommend following the same procedure as that used for cholangitis; however, the patient's condition, including performance status, tumor extension or staging, and prognosis must be considered. Most physicians manage cholangitis from a SEMS occlusion using a two-step procedure. They insert endoscopic drainage with a plastic stent or insert a nasobiliary drainage tube, which does not exacerbate sepsis. Addition or replacement of a biliary SEMS is required in many cases depending on the cause of the occlusion. Tumor ingrowth through the stent mesh is common in uncovered SEMS and requires placement of another stent in an in-stent method. However, covered SEMS tends to be occluded by sludge, so it must be replaced because of the bacterial biofilm that forms on the covering membrane. The location of the biliary stricture (hilar or distal) should also be considered. Strategies for managing cholangitis as a result of occlusion by a biliary SEMS remain controversial, so prospective clinical trials are needed. © 2017 The Authors. Digestive Endoscopy © 2017 Japan Gastroenterological Endoscopy Society.
Current global status of carotid artery stent placement.

Science.gov (United States)

Wholey, M H; Wholey, M; Bergeron, P; Diethrich, E B; Henry, M; Laborde, J C; Mathias, K; Myla, S; Roubin, G S; Shawl, F; Theron, J G; Yadav, J S; Dorros, G; Guimaraens, J; Higashida, R; Kumar, V; Leon, M; Lim, M; Londero, H; Mesa, J; Ramee, S; Rodriguez, A; Rosenfield, K; Teitelbaum, G; Vozzi, C

1998-05-01

Our purpose was to review the current status of carotid artery stent placement throughout the world. Surveys were sent to major interventional centers in Europe, North and South America, and Asia. Information from peer-reviewed journals was also included and supplemented the survey. The survey asked various questions regarding the patients enrolled, procedure techniques, and results of carotid stenting, including complications and restenosis. Of the centers which were sent surveys, 24 responded. The total number of endovascular carotid stent procedures that have been performed worldwide to date included 2,048 cases, with a technical success of 98.6%. Complications that occurred during carotid stent placement or within a 30-day period following placement were recorded. Overall, there were 63 minor strokes, with a rate of occurrence of 3.08%. The total number of major strokes was 27, for a rate of 1.32%. There were 28 deaths within a 30-day postprocedure period, resulting in a mortality rate of 1.37%. Restenosis rates of carotid stenting have been 4.80% at 6 mo. Endovascular stent treatment of carotid artery atherosclerotic disease is growing as an alternative to vascular surgery, especially for patients that are at high risk for standard carotid endarterectomy. The periprocedural risks for major and minor strokes and death are generally acceptable at this early stage of development.
The Incidence and Risk Factors of In-Stent Restenosis for Vertebrobasilar Artery Stenting.

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Zheng, Dai; Mingyue, Zhu; Wei, Shi; Min, Li; Wanhong, Chen; Qiliang, Dai; Yongjun, Jiang; Xinfeng, Liu

2018-02-01

In-stent restenosis (ISR) remains a challenge for vertebrobasilar artery stenting (VBAS). We aimed to investigate the incidence and risk factors of ISR. This was a retrospective study. From July 28, 2005, to July 30, 2015, patients who received VBAS with an angiographic follow-up time of 6 to 12 months after surgery were enrolled. The clinical and angiographic issues were recorded and analyzed. In total, 283 patients with 335 stents were incorporated into the study. Vertebral ostial lesions accounted for 73.4% (246/335) of the lesions. During the follow-up period, 58 patients with 60 stents experienced ISR (>50%). Stepwise logistic regression analysis showed that the degree of residual stenosis, stent diameter, and alcohol consumption were independent predictors of ISR. Our study demonstrated the incidence and risk factors of ISR after VBAS. This retrospective study with the largest cohort to date provided insight into the occurrence of ISR after VBAS. Copyright © 2017 Elsevier Inc. All rights reserved.
Stent placement of gastroenteric anastomoses formed by magnetic compression.

Science.gov (United States)

Cope, C; Clark, T W; Ginsberg, G; Habecker, P

1999-01-01

To evaluate the use of stents for prolonging the patency of gastroenteric anastomoses (GEA) induced by magnet compression. Rare earth magnets were inserted perorally and serially in 15 dogs so as to mate across the gastric and jejunal walls. After magnet excretion, the resulting GEA was identified endoscopically, dilated (n = 1), and stented with bare (n = 2) or partially covered (n = 6) flared 10-mm or 12-mm Z stents. The GEA was followed at 2-4-week intervals for patency; malfunctioning shunts were irrigated, or dilated with angioplasty balloons. Gross and histologic examination of the anastomotic tissues was performed in 14 animals. Magnet pairs were excreted in 5-7 days. Of the 19 magnet placements in 15 animals, stent placement was not possible because of early GEA closure (n = 6), failure to locate (n = 2), pancreatic abscess (n = 1), and magnet perforation with peritonitis (n = 1). Estimated duration of GEA patency was 19 days after balloon dilation, 40-64 days with bare Z stents, and 58-147 days (mean, 90 days) with partially covered Z stents. Shunt function was commonly hindered by bezoars. Stent narrowing or occlusion was caused by tissue overgrowth through bare stents (n = 2), between covered stent struts and through partially detached membrane (n = 2). Serious morbidity (n = 2) was due to malpositioned magnets across the pancreas in one animal and gastric perforation in the other. One dog was euthanized because of unsuspected kidney infection. Partially covered stents significantly extend the anatomic patency rate of magnetic GEA to 7 weeks or more. Functional patency is frequently impaired by bezoars. Ongoing improvements in covered stent design should provide longer-term GEA patency.
Covered stent placement for the treatment of malignant superior vena cava syndrome: Is unilateral covered stenting and effective?

International Nuclear Information System (INIS)

Cho, Young Hoon; Gwon, Dong Il; Ko, Gi Young; Ko, Heung Kyu; Kim, Jin Hyoung; Shin, Ji Hoon; Yoon, Hyun Ki; Sung, Kyu Bo

2014-01-01

To evaluate the safety and efficacy of unilateral covered stent placement in patients with malignant superior vena cava (SVC) syndrome. Between October 2008 and November 2012, expanded polytetrafluoroethylene-covered stent placement for malignant SVC syndrome was performed in 40 consecutive patients (35 men and five women; mean age, 61.4 years; range, 35-81 years). All covered stents were unilaterally placed within the SVC or across the venous confluence when needed to relieve venous obstruction and prevent tumor overgrowth, regardless of patency of contralateral brachiocephalic veins. Stent placement was technically successful in all patients. There were no major complications. Of the 37 patients symptomatic prior to stent placement, 34 (92%) experienced complete symptomatic relief 1-8 days after stent placement. Of the 29 patients who underwent covered stent placement across the venous confluence, nine patients had patent contralateral brachiocephalic veins prior to stent placement. However, no sign of SVC obstruction or contralateral upper extremity venous thrombosis was observed during the follow-up period. Kaplan-Meier analysis revealed median patient survival of 163 days. Stent occlusion occurred in four (10%) of 40 patents. Cumulative stent patency rates at 1, 3, 6, and 12 months were 95%, 92%, 86%, and 86%, respectively. Unilateral covered stent placement appears to be a safe and effective method for treating malignant SVC syndrome, despite the location of SVC occlusion.
Covered stent placement for the treatment of malignant superior vena cava syndrome: Is unilateral covered stenting and effective?

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Cho, Young Hoon; Gwon, Dong Il; Ko, Gi Young; Ko, Heung Kyu; Kim, Jin Hyoung; Shin, Ji Hoon; Yoon, Hyun Ki; Sung, Kyu Bo [Dept. of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of)

2014-02-15

To evaluate the safety and efficacy of unilateral covered stent placement in patients with malignant superior vena cava (SVC) syndrome. Between October 2008 and November 2012, expanded polytetrafluoroethylene-covered stent placement for malignant SVC syndrome was performed in 40 consecutive patients (35 men and five women; mean age, 61.4 years; range, 35-81 years). All covered stents were unilaterally placed within the SVC or across the venous confluence when needed to relieve venous obstruction and prevent tumor overgrowth, regardless of patency of contralateral brachiocephalic veins. Stent placement was technically successful in all patients. There were no major complications. Of the 37 patients symptomatic prior to stent placement, 34 (92%) experienced complete symptomatic relief 1-8 days after stent placement. Of the 29 patients who underwent covered stent placement across the venous confluence, nine patients had patent contralateral brachiocephalic veins prior to stent placement. However, no sign of SVC obstruction or contralateral upper extremity venous thrombosis was observed during the follow-up period. Kaplan-Meier analysis revealed median patient survival of 163 days. Stent occlusion occurred in four (10%) of 40 patents. Cumulative stent patency rates at 1, 3, 6, and 12 months were 95%, 92%, 86%, and 86%, respectively. Unilateral covered stent placement appears to be a safe and effective method for treating malignant SVC syndrome, despite the location of SVC occlusion.
Ureteral stent retrieval using the crochet hook technique in females.

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Takashi Kawahara

Full Text Available INTRODUCTION: We developed a method for ureteral stent removal in female patients that requires no cystoscopy or fluoroscopic guidance using a crochet hook. In addition, we also investigated the success rate, complications and pain associated with this procedure. METHODS: A total of 40 female patients (56 stents underwent the removal of ureteral stents. All procedures were carried out with the patients either under anesthesia, conscious sedation, or analgesic suppositories as deemed appropriate for each procedure including Shock Wave Lithotripsy (SWL, Ureteroscopy (URS, Percutaneous Nephrolithotomy (PCNL, and ureteral stent removal. At the time of these procedures, fluoroscopy and/or cystoscopy were prepared, but they were not used unless we failed to successfully remove the ureteral stent using the crochet hook. In addition, matched controls (comprising 50 stents which were removed by standard ureteral stent removal using cystoscopy were used for comparison purposes. RESULTS: A total of 47 of the 56 stents (83.9% were successfully removed. In addition, 47 of 52 (90.4% were successfully removed except for two migrated stents and two heavily encrusted stents which could not be removed using cystoscopy. Ureteral stent removal using the crochet hook technique was unsuccessful in nine patients, including two encrustations and two migrations. Concerning pain, ureteral stent removal using the crochet hook technique showed a lower visual analogue pain scale (VAPS score than for the standard technique using cystoscopy. CONCLUSIONS: Ureteral stent removal using a crochet hook is considered to be easy, safe, and cost effective. This technique is also easy to learn and is therefore considered to be suitable for use on an outpatient basis.
”Missing clot” during mechanical thrombectomy in acute stroke using Solitaire stent retrieval system

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Vikram Huded

2016-01-01

Full Text Available Stent retrieval system is an established treatment modality in acute ischemic stroke with large vessel occlusion. Here, we describe a complication which occurred during mechanical thrombectomy in three cases where the clot dislodged during retrieval. There was a possibility of the clot getting reinjected into the artery with possible dire consequences.

Flow Velocities After Carotid Artery Stenting: Impact of Stent Design. A Fluid Dynamics Study in a Carotid Artery Model with Laser Doppler Anemometry

International Nuclear Information System (INIS)

Greil, Oliver; Kleinschmidt, Thomas; Weiss, Wolfgang; Wolf, Oliver; Heider, Peter; Schaffner, Silvio; Gianotti, Marc; Schmid, Thomas; Liepsch, Dieter; Berger, Hermann

2005-01-01

Purpose. To study the influence of a newly developed membrane stent design on flow patterns in a physiologic carotid artery model. Methods. Three different stents were positioned in silicone models of the carotid artery: a stainless steel stent (Wall-stent), a nitinol stent (SelfX), and a nitinol stent with a semipermeable membrane (MembraX). To increase the contact area of the membrane with the vessel wall, another MembranX model was modified at the outflow tract. The membrane consists of a biocompatible silicone-polyurethane copolymer (Elast-Eon) with a pore size of 100 μm. All stents were deployed across the bifurcation and the external carotid artery origin. Flow velocity measurements were performed with laser Doppler anemometry (LDA), using pulsatile flow conditions (Re = 220; flow 0.39 l/min; flow rate ratio ICA:ECA = 70:30) in hemodynamically relevant cross-sections. The hemodynamic changes were analyzed by comparing velocity fluctuations of corresponding flow profiles. Results. The flow rate ratio ICA:ECA shifted significantly from 70/30 to 73.9/26.1 in the MembraX and remained nearly unchanged in the SelfX and Wallstent. There were no changes in the flow patterns at the inflow proximal to the stents. In the stent no relevant changes were found in the SelfX. In the Wallstent the separation zone shifted from the orifice of the ICA to the distal end of the stent. Four millimeters distal to the SelfX and the Wallstent the flow profile returned to normal. In the MembraX an increase in the central slipstreams was found with creation of a flow separation distal to the stent. With a modification of the membrane this flow separation vanished. In the ECA flow disturbances were seen at the inner wall distal to the stent struts in the SelfX and the Wallstent. With the MembraX a calming of flow could be observed in the ECA with a slight loss of flow volume. Conclusions. Stent placement across the carotid artery bifurcation induces alterations of the physiologic flow
Long-Term Type 1 Diabetes Enhances In-Stent Restenosis after Aortic Stenting in Diabetes-Prone BB Rats

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Geanina Onuta

2011-01-01

Full Text Available Type 1 diabetic patients have increased risk of developing in-stent restenosis following endovascular stenting. Underlying pathogenetic mechanisms are not fully understood partly due to the lack of a relevant animal model to study the effect(s of long-term autoimmune diabetes on development of in-stent restenosis. We here describe the development of in-stent restenosis in long-term (~7 months spontaneously diabetic and age-matched, thymectomized, nondiabetic Diabetes Prone BioBreeding (BBDP rats (n=6-7 in each group. Diabetes was suboptimally treated with insulin and was characterized by significant hyperglycaemia, polyuria, proteinuria, and increased HbA1c levels. Stented abdominal aortas were harvested 28 days after stenting. Computerized morphometric analysis revealed significantly increased neointima formation in long-term diabetic rats compared with nondiabetic controls. In conclusion, long-term autoimmune diabetes in BBDP rats enhances in-stent restenosis. This model can be used to study the underlying pathogenetic mechanisms of diabetes-enhanced in-stent restenosis as well as to test new therapeutic modalities.
Usefulness of flexible covered stent in malignant colorectal obstruction

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Kang, Jee Hee; Kang, Sung Gwon; Kim, Hyung Jin; Noh, Hong Gi; Woo, Jae Hong; Suh, Chang Hae [Inha Univ. Hospital, Inchon (Korea, Republic of)

1998-07-01

To evaluate the usefulness of flexible covered stent in the treatment of acute colorectal obstruction secondary to colorectal carcinoma. Materials and Methods : Flexible covered stents were placed in 11 patients with clinical and radiologic signs of acute colonic obstruction secondary to colorectal carcinoma. The purposes of stent insertion were pre-operative bowel preparation in seven patients and palliative treatment in four. A fistula was present in two;in one this was between the proximal jejunum and colon, and the other was rectovaginal. The usefulness of stent insertion for the purpose of preoperative bowel preparation was evaluated according to the feasibility and status of bowel preparation, as decided by the operator. Palliative treatment for the relief of symptoms of acute bowel obstruction was evaluated according to the number and amount of defecation,bowel dilatation in simple abdomen radiography, and the presence of complications. Results : Bowel preparation for the purpose of preoperative bowel cleansing was easy in seven patients;the fecal materials remaining in the colon presented no problems during surgery. In one of four patients palliative treatment involved a colostomy;this was due to recurrent stent obstruction by fecal materials after three months, and in two other patients there was stent obstruction after two and five months, respectively. The stent in one of four patients who underwent palliative treatment was removed because of stent migration three days after insertion;the stents in two patients with fistulas covered the fistulas successfully. Complications after stent insertion were anal pain in three patients, anal bleeding in three and stent migration in one. Conclusion : The flexible covered stent was an effective device for the relief of acute colonic obstruction secondary to malignant rectosigmoid neoplasia. It allowed for single-stage operation and covered the fistula. We believe however that for further evaluation of the
Endotracheal expandable metallic stent placement in dogs

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Sawada, S; Tanabe, Y; Fujiwara, Y; Koyama, T; Tanigawa, N; Kobayashi, M; Katsube, Y; Nakamura, H [Tottori Univ. School of Medicine, Yonago (Japan). Dept. of Radiology Research Inst. for Microbial Diseases, Osaka (Japan). Dept. of Radiology

1991-01-01

Various types of Gianturco zig-zag wire stent were implanted into the tracheas of 4 dogs to define the suitable characteristics of the endotracheal wire stent in these animals. These stents were constructed of 0.45, and 0.33 mm stainless steel wire. The diameter of the fully expanded stents was 3 cm and their lengths were 2, 3, and 4 cm. The 2 cm stent constructed of 0.33 mm wire showed minimum pathologic changes of the trachea of the dog compared to the other stents, and at the same time had a complete covering of ciliated columnar epithelium over the stent surface. (orig.).
Colorectal Stenting in Malignant Large Bowel Obstruction: The Learning Curve

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D. Williams

2011-01-01

Full Text Available Aim. Self-expanding metal stents (SEMSs are increasingly used for the palliation of metastatic colorectal cancer and as a bridge to surgery for obstructing tumours. This case series analyses the learning curve and changes in practice of colorectal stenting over a three year period. Methods. A study of 40 patients who underwent placement of SEMS for the management of colorectal cancer. Patients spanned the learning curve of a single surgeon endoscopist. Results. Technical success rates increased from 82% initially, using an average of 1.7 stents per procedure, to a 94% success rate where all patients were stented using a single stent. There has been a change in practice from elective palliative stenting toward emergency preoperative stenting. Conclusion. There is a steep learning curve for the use of SEMS in the management of malignant colorectal bowel obstruction. We suggest that at least 20 cases are required for an operator to be considered experienced.
Percutaneous coronary intervention with second-generation paclitaxel-eluting stents versus everolimus-eluting stents in United States contemporary practice (REWARDS TLX Trial).

Science.gov (United States)

Waksman, Ron; Ghali, Magdi; Goodroe, Randy; Ryan, Thomas; Turco, Mark; Ring, Michael; McGarry, Thomas; Dobies, David; Shammas, Nicolas; Steinberg, Daniel H; Swymelar, Stacy; Kaneshige, Kimberly; Torguson, Rebecca

2012-10-15

Registry Experience at the Washington Hospital Center, DES - Taxus Liberte Versus Xience V (REWARDS TLX) is a physician-initiated, retrospective, real-world, multicenter, observational study for all patients >18 years of age subjected to percutaneous coronary intervention with everolimus-eluting stents (EESs) or paclitaxel-eluting stents (PESs). Outcomes of patients receiving a TAXUS Liberté or XIENCE V drug-eluting stent were compared. Baseline clinical, procedural, and follow-up data at 12 months were collected from 10 clinical centers by an electronic data capture system. The study's primary end point was major adverse cardiac events: a composite of all-cause death, Q-wave myocardial infarction, target vessel revascularization, and stent thrombosis. The trial is registered with http://www.clinicaltrials.gov (NCT01134159). Data were entered for 1,195 patients (PES, n = 595; EES, n = 600). Baseline clinical characteristics were similar except for higher dyslipidemia, systemic hypertension, and family history of coronary artery disease in the EES group. In-hospital outcome was similar between groups, with an overall in-hospital stent thrombosis rate of 0.2%. The primary end point at 12 months was similar (EES 7.8% vs 10.8%, p = 0.082). Overall stent thrombosis rate was lower in the EES group (0.3% vs 1.2%, respectively, p = 0.107); however, target lesion revascularization was similar (PES, hazard ratio 1.46, 95% confidence interval 0.98 to 2.19, p = 0.064). There was no difference in overall mortality between groups. In conclusion, second-generation EESs and PESs demonstrated similar efficacy and safety profiles for broadened patient and lesion subsets compared to a selected population from the pivotal trials. However, for composite efficacy and safety end points, EESs outperformed second-generation PESs. Copyright © 2012 Elsevier Inc. All rights reserved.
Covered metal stent or multiple plastic stents for refractory pancreatic ductal strictures in chronic pancreatitis: a systematic review.

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Shen, Yonghua; Liu, Mingdong; Chen, Min; Li, Yunhong; Lu, Ying; Zou, Xiaoping

2014-01-01

Refractory chronic pancreatitis has been proposed as a challenge for endoscopists following routine single plastic stenting. However, data on the efficacy and safety of further endoscopic stenting are still controversial. The current systematic review aimed to assess the efficacy and safety of placement of fully covered self-expandable metal stent (FCSEMS) and multiple plastic stents. Databases including MEDLINE, EMBASE, the Cochrane Library, CBM, CNKI, VIP, and WANFANG Database were used to search relevant trials. Published studies were assessed by using well-defined inclusion and exclusion criteria. The process was independently performed by two investigators. A total of 5 studies provided data of 80 patients. Forest plots and publication bias were not carried out because few studies were relevant and screened studies were all case series. The technical success rate was 100% both in placement of FCSEMS and multiple plastic stents. The functional success rate after placement of FCSEMS was 100%, followed by multiple plastic stents (94.7%). Complications occurred 26.2% after FCSEMS placement, which was not described in detail in multiple plastic stents. The stent migration rate was 8.2% for FCSEMS and 10.5% for multiple plastic stents. Reintervention rate was 9.8% for FCSEMS and 15.8% for multiple plastic stents. Pain improvement rate was 85.2% for FCSEMS and 84.2% for multiple plastic stents. FCSEMS appeared to be no significant difference with multiple plastic stents in treatment of refractory chronic pancreatitis. We need to develop more investigations. Copyright © 2014 IAP and EPC. Published by Elsevier B.V. All rights reserved.
Endoscopic ultrasound-guided biliary drainage using a newly designed metal stent with a thin delivery system: a preclinical study in phantom and porcine models.

Science.gov (United States)

Minaga, Kosuke; Kitano, Masayuki; Itonaga, Masahiro; Imai, Hajime; Miyata, Takeshi; Yamao, Kentaro; Tamura, Takashi; Nuta, Junya; Warigaya, Kenji; Kudo, Masatoshi

2017-12-08

This study was designed to evaluate the feasibility and safety of a newly designed self-expandable metal stent for endoscopic ultrasound-guided biliary drainage (EUS-BD) when it was delivered via three different stent delivery systems: a 7.5Fr delivery catheter with a bullet-shaped tip (7.5Fr-bullet), a 7Fr catheter with a bullet-shaped tip (7Fr-bullet), or a 7Fr catheter with a tee-shaped tip (7Fr-tee). This experimental study utilized a porcine model of biliary dilatation involving ten pigs. In the animal study, technical feasibility and clinical outcomes of the stent when placed with each of the delivery systems were examined. In addition, a phantom model was used to measure the resistance of these delivery systems to advancement. Phantom experiments showed that, compared with 7Fr-bullet, 7Fr-tee had less resistance force to the advancement of the stent delivery system. EUS-BD was technically successful in all ten pigs. Fistulous tract dilation was necessary in 100% (2/2), 75% (3/4), and 0% (0/4) of the pigs that underwent EUS-BD using 7.5Fr-bullet, 7Fr-bullet, and 7Fr-tee, respectively. There were no procedure-related complications. Our newly designed metal stent may be feasible and safe for EUS-BD, particularly when delivered by 7Fr-tee, because it eliminates the need for fistulous tract dilation.
The application of DynaCT in performing the placement of intracranial stent

International Nuclear Information System (INIS)

Shen Hui; Wang Yongchun; Wang Minjie; Ding Hailing; Qin Yashan; Mao Yaqin; Li Songhua; Mao Yanjun; Hao Qiang

2011-01-01

Objective: To evaluate the clinical application of DynaCT technique in performing intracranial stent implantation. Methods: Thirty-nine patients who were planed to receive intracranial stent implantation were involved in this study. During the procedure DynaCT scanning was employed to monitor the real-time situation of stent implantation. Results: A total of 47 stents were implanted in intracranial vessels in the 39 patients. By using conventional angiography during operation the position of these stents was observed and was assured to be in the proper position. The adherence of these stents to the vascular wall was demonstrated with DynaCT multi-planar reconstruction images and the stent adherence in good condition was ensured. Conclusion: DynaCT applied during and after intracranial stent implantation is very helpful for displaying the contours of the stents as well as the vascular lumen and for providing a detail picture of the relationship between the stent and the surrounding anatomy. Therefore, DynaCT scanning is of great clinical significance for performing the intracranial stent implantation. (authors)
Fabrication of hydrophobic structures on coronary stent surface based on direct three-beam laser interference lithography

Science.gov (United States)

Gao, Long-yue; Zhou, Wei-qi; Wang, Yuan-bo; Wang, Si-qi; Bai, Chong; Li, Shi-ming; Liu, Bin; Wang, Jun-nan; Cui, Cheng-kun; Li, Yong-liang

2016-05-01

To solve the problems with coronary stent implantation, coronary artery stent surface was directly modified by three-beam laser interference lithography through imitating the water-repellent surface of lotus leaf, and uniform micro-nano structures with the controllable period were fabricated. The morphological properties and contact angle (CA) of the microstructure were measured by scanning electron microscope (SEM) and CA system. The water repellency of stent was also evaluated by the contact and then separation between the water drop and the stent. The results show that the close-packed concave structure with the period of about 12 μm can be fabricated on the stent surface with special parameters (incident angle of 3°, laser energy density of 2.2 J·cm-2 and exposure time of 80 s) by using the three-beam laser at 1 064 nm, and the structure has good water repellency with CA of 120°.
Design and modeling balloon-expandable coronary stent for manufacturability

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Suryawan, D.; Suyitno

2017-02-01

Coronary artery disease (CAD) is a disease that caused by narrowing of the coronary artery. The narrowing coronary artery is usually caused by cholesterol-containing deposit (plaque) which can cause a heart attack. CAD is the most common cause mortality in Indonesia. The commonly CAD treatment use the stent to opens or alleviate the narrowing coronary artery. In this study, the stent design is optimized for the manufacturability. Modeling is used to determine the free stent expansion due to applied pressure in the inner surface of the stent. The stress distribution, outer diameter change, and dogboning phenomena are investigated in the simulation. The result of modeling and simulating was analyzed and used to optimize the stent design before it is manufactured using EDM (Electric Discharge Machine) in the next research.
Palliative metallic stent placement for managing esophageal cancer of the aging

International Nuclear Information System (INIS)

Li Qnqi; Yin Huabin; Yue Wei; Ji Chengzhou; Yang Yufeng

2000-01-01

Objective: To evaluate the effectiveness of self-expanding metallic stent in the treatment of the old patients with malignant esophageal stricture. Methods: 32 old patients with malignant esophageal stricture were treated with covered self-expandable metallic stents, 32 stents were placed by X-TV guiding, without pre-dilatation of the stenosis by balloon catheter. Results: All 32 stents were successfully placed, the successful rate was 100%. All of the patients obtained the improvement of the food intake ability. No fatal stent-related complications occurred. The average survival time was 6.5 months. Conclusions: The covered self-expandable metallic stent is effective in the palliative management of malignant esophageal stricture of the aging
Thrombosis of second-generation drug-eluting stents in real practice results from the multicenter Spanish registry ESTROFA-2 (Estudio Español Sobre Trombosis de Stents Farmacoactivos de Segunda Generacion-2).

Science.gov (United States)

de la Torre Hernández, José M; Alfonso, Fernando; Gimeno, Federico; Diarte, Jose A; Lopez-Palop, Ramón; Pérez de Prado, Armando; Rivero, Fernando; Sanchis, Juan; Larman, Mariano; Diaz, Jose F; Elizaga, Jaime; Moreiras, Javier Martín; Gomez Jaume, Alfredo; Hernández, José M; Mauri, Josepa; Recalde, Angel Sánchez; Bullones, Juan A; Rumoroso, Jose R; Del Blanco, Bruno García; Baz, Jose A; Bosa, Francisco; Botas, Javier; Hernández, Felipe

2010-09-01

This study sought to evaluate second-generation drug-eluting stent (DES) thrombosis in clinical practice. First-generation DES are associated with a significant incidence of late thrombosis. There is paucity of data regarding real practice late thrombosis incidence and predictors with second-generation DES, zotarolimus-eluting stent (ZES), and everolimus-eluting stents (EES). A prospective, large-scale, non-industry-linked multicenter registry was designed. Complete clinical-procedural data and systematic follow-up of all patients treated with these stents was reported in a dedicated registry supported by the Spanish Working Group on Interventional Cardiology. From 2005 to 2008, 4,768 patients were included in 34 centers: 2,549 treated with ZES, and 2,219 with EES. The cumulative incidence of definite/probable thrombosis for ZES was 1.3% at 1 year and 1.7% at 2 years and for EES 1.4% at 1 year and 1.7% at 2 years (p = 0.8). The increment of definite thrombosis between the first and second year was 0.2% and 0.25%, respectively. In a propensity score analysis, the incidence remained very similar. Ejection fraction (adjusted hazard ratio [HR]: 0.97; 95% confidence interval [CI]: 0.95 to -0.99; p = 0.008), stent diameter (adjusted HR: 0.37; 95% CI: 0.17to 0.81; p = 0.01) and bifurcations (adjusted HR: 2.1; 95% CI: 1.14 to 3.7; p = 0.02) emerged as independent predictors of thrombosis. In the subgroup of patients with bifurcations, the use of ZES was independently associated with a higher thrombosis rate (adjusted HR: 4; 95% CI: 1.1 to 13; p = 0.03). In a real practice setting, the incidence of thrombosis at 2 years with ZES and EES was low and quite similar. The incidence of very late thrombosis resulted lower than was reported in registries of first-generation DES. In the subset of bifurcations, the use of ZES significantly increased the risk of thrombosis. Copyright © 2010 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
Peri-stent aneurysm formation following a stent implant for stenotic intracranial vertebral artery dissection: a technical report of two cases successfully treated with coil embolization.

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Ishimaru, Hideki; Nakashima, Kazuaki; Takahata, Hideaki; Matsuoka, Yohjiro

2013-02-01

Although stenting for stenotic vertebral artery dissection (VAD) improves compromised blood flow, subsequent peri-stent aneurysm (PSA) formation is not well-known. We report two cases with PSA successfully treated with coil embolization. Three patients with stenotic intracranial VAD underwent endovascular angioplasty at our institution because they had acute infarction in posterior circulation territory and clinical evidence of hemodynamic insufficiency. In two of three patients balloon angioplasty at first session failed to relieve the stenosis, and a coronary stent was implanted. Angiography immediately after stenting showed no abnormality in case 1 and minimal slit-like projection at proximal portion of the stent in case 2. Angiography obtained 16 months after the stenting revealed PSA in case 1. In case 2, angiography performed 3 months later showed that the projection at proximal portion enlarged and formed an aneurysm outside the stent. Because follow-up angiographies showed growth of the aneurysm in both cases, endovascular aneurysmal embolization was performed. We advanced a microcatheter into the aneurysm through the strut of existing stent and delivered detachable coils into the aneurysm lumen successfully in both cases. The post-procedural course was uneventful, and complete obliteration of aneurysm was confirmed on angiography in both cases. Stenting for stenotic intracranial VAD may result in delayed PSA; therefore, follow-up angiographies would be necessary after stenting for stenotic intracranial arterial dissection. Coil embolization through the stent strut would be a solution for enlarging PSA.
Self-expandable metal stents for obstructing colonic and extracolonic cancer

DEFF Research Database (Denmark)

van Hooft, Jeanin E; van Halsema, Emo E; Vanbiervliet, Geoffroy

2014-01-01

as a bridge to elective surgery is not recommended as a standard treatment of symptomatic left-sided malignant colonic obstruction (strong recommendation, high quality evidence). 3 For patients with potentially curable but obstructing left-sided colonic cancer, stent placement may be considered......, and Evaluation (GRADE) system was adopted to define the strength of recommendations and the quality of evidence. Main recommendations The following recommendations should only be applied after a thorough diagnostic evaluation including a contrast-enhanced computed tomography (CT) scan. 1 Prophylactic colonic...... stent placement is not recommended. Colonic stenting should be reserved for patients with clinical symptoms and imaging evidence of malignant large-bowel obstruction, without signs of perforation (strong recommendation, low quality evidence). 2 Colonic self-expandable metal stent (SEMS) placement...
Percutaneous Biliary Drainage Using Open Cell Stents for Malignant Biliary Hilar Obstruction

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Ahn, Sun Jun; Bae, Jae Ik; Han, Tae Sun; Won, Je Hwan; Kim, Ji Dae; Kwack, Kyu Sung; Lee, Jae Hee; Kim, Young Chul [Dept. of Radiology, Ajou University School of Medicine, Suwon (Korea, Republic of)

2012-11-15

To evaluate the feasibility, safety and the effectiveness of the complex assembly of open cell nitinol stents for biliary hilar malignancy. During the 10 month period between January and October 2007, 26 consecutive patients with malignant biliary hilar obstruction underwent percutaneous insertion of open cell design nitinol stents. Four types of stent placement methods were used according to the patients' ductal anatomy of the hilum. We evaluated the technical feasibility of stent placement, complications, patient survival, and the duration of stent patency. Bilobar biliary stent placement was conducted in 26 patients with malignant biliary obstruction-T (n = 9), Y (n 7), crisscross (n = 6) and multiple intersecting types (n = 4). Primary technical success was obtained in 24 of 26 (93%) patients. The crushing of the 1st stent during insertion of the 2nd stent occurred in two cases. Major complications occurred in 2 of 26 patients (7.7%). One case of active bleeding from hepatic segmental artery and one case of sepsis after procedure occurred. Clinical success was achieved in 21 of 24 (87.5%) patients, who were followed for a mean of 141.5 days (range 25-354 days). The mean primary stent patency period was 191.8 days and the mean patient survival period was 299 days. Applying an open cell stent in the biliary system is feasible, and can be effective, especially in multiple intersecting stent insertions in the hepatic hilum.
Percutaneous Biliary Drainage Using Open Cell Stents for Malignant Biliary Hilar Obstruction

International Nuclear Information System (INIS)

Ahn, Sun Jun; Bae, Jae Ik; Han, Tae Sun; Won, Je Hwan; Kim, Ji Dae; Kwack, Kyu Sung; Lee, Jae Hee; Kim, Young Chul

2012-01-01

To evaluate the feasibility, safety and the effectiveness of the complex assembly of open cell nitinol stents for biliary hilar malignancy. During the 10 month period between January and October 2007, 26 consecutive patients with malignant biliary hilar obstruction underwent percutaneous insertion of open cell design nitinol stents. Four types of stent placement methods were used according to the patients' ductal anatomy of the hilum. We evaluated the technical feasibility of stent placement, complications, patient survival, and the duration of stent patency. Bilobar biliary stent placement was conducted in 26 patients with malignant biliary obstruction-T (n = 9), Y (n 7), crisscross (n = 6) and multiple intersecting types (n = 4). Primary technical success was obtained in 24 of 26 (93%) patients. The crushing of the 1st stent during insertion of the 2nd stent occurred in two cases. Major complications occurred in 2 of 26 patients (7.7%). One case of active bleeding from hepatic segmental artery and one case of sepsis after procedure occurred. Clinical success was achieved in 21 of 24 (87.5%) patients, who were followed for a mean of 141.5 days (range 25-354 days). The mean primary stent patency period was 191.8 days and the mean patient survival period was 299 days. Applying an open cell stent in the biliary system is feasible, and can be effective, especially in multiple intersecting stent insertions in the hepatic hilum.
Covered Balloon-Expanding Stents in Airway Stenosis.

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Majid, Adnan; Kheir, Fayez; Chung, Jey; Alape, Daniel; Husta, Bryan; Oh, Scott; Folch, Erik

2017-04-01

The balloon-expanding stents are widely available but rarely described for use within the tracheobronchial tree. This report describes our experience with these stents in airway stenosis particularly as a lobar salvage therapy. This was a retrospective review of all records in which the balloon-expanding stents were used at a tertiary medical center. Ages, sex, location of stenosis, etiology of stenosis, stent size, duration of stent placement and associated interventions for airway stenosis were recorded. Patient's self-reported respiratory symptoms, dyspnea scale, and radiographic imaging at baseline and after stent placement were also reported. Twenty-one Atrium iCAST stents were inserted in 18 patients with malignant and benign airway disease. The median age was 69.5 years (interquartile range, 53.5 to 74). Most stents (n=20, 95%) were deployed in the lobar airways. There was a significant improvement in the modified Medical Research Council dyspnea scale from median of 3 to 2 (Pstent placement was achieved in 15 patients (83%). No deaths were related to airway stenting complications. Adverse events related to stents included migration (n=2, 9.5%), granulation tissue formation (n=2, 9.5%) and mucus plugging (n=1, 4.8%). Lobar stenting with balloon-expanding metallic stents appears feasible, safe and improves symptoms as well as radiographic atelectasis in patients with lobar airway stenosis in this small case series. Larger studies are needed to confirm this observation and to address long-term safety.
Fluoroscopically guided placement of self-expandable metallic stents and stent-grafts in the treatment of acute malignant colorectal obstruction.

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Kim, Honsoul; Kim, Seung Hyoung; Choi, Sun Young; Lee, Kwang-Hun; Won, Jong Yoon; Lee, Do Yun; Lee, Jong Tae

2008-12-01

To evaluate the technical feasibility and clinical effectiveness of fluoroscopically guided placement of self-expandable metallic stents and stent-grafts for acute malignant colorectal obstruction. Radiologic images and clinical reports of 42 patients (22 men, 20 women; age range, 28-93 years; median age, 65.5 years) who underwent fluoroscopically guided colorectal stent insertion without endoscopic assistance for acute malignant obstruction were reviewed retrospectively. Eighteen patients received bare stents as a bridge to surgery. Twenty-four patients received 27 insertions of either a bare stent (n = 15) or a stent-graft (n = 12) for palliation. The obstruction was located in the rectum (n = 8), sigmoid (n = 17), descending colon (n = 8), splenic flexure (n = 3), and transverse colon (n = 6). Clinical success, defined as more than 50% dilatation of the stent with subsequent symptomatic improvement, was achieved in 41 of the 42 patients (98%). No major procedure-related complications occurred. Minor complications occurred in eight of the 45 procedures (18%). No perioperative mortalities occurred within 1 month after surgery. In the palliative group, the median stent patency was 62 days (range, 0-1,014 days). There was no statistically significant difference in stent patency between the bare stents (range, 0-855 days; median, 68 days) and stent-grafts (range, 1-1,014 days; median, 81 days). Fluoroscopically guided placement of self-expandable metallic stents and stent-grafts for the relief of acute malignant colorectal obstruction was technically feasible without endoscopic assistance-even in lesions proximal to the splenic flexure and transverse colon-and clinically effective in both bridge to surgery and palliative management.
Absorbable stent: focus on clinical applications and benefits.

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Gonzalo, Nieves; Macaya, Carlos

2012-01-01

Coronary stents have improved very significantly the immediate and long-term results of percutaneous coronary interventions. However, once the vessel has healed, the scaffolding function of the stent is no longer needed, and the presence of a permanent metallic prosthesis poses important disadvantages. This has led to the idea of creating new devices that are able to provide mechanical support for a determined period and then disappear from the vessel, allowing its natural healing and avoiding the risks associated with having a permanent metallic cage, such as stent thrombosis. Absorbable stents currently appear as one of the most promising fields in interventional cardiology. The present article will review the available clinical evidence regarding these devices at present and their future perspectives.

Outcomes of Endovascular Aneurysm Repair using the Ovation Stent Graft System in Adverse Anatomy.

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Greaves, Nicholas S; Moore, Aiden; Seriki, Dare; Ghosh, Jonathan

2018-04-01

The aim was the evaluation of mid-term efficacy and safety outcome measures for the Ovation (Endologix, Santa Rosa, CA, USA) stent graft system in the management of infrarenal abdominal aortic aneurysms (iAAA) with adverse anatomy. A retrospective observational study of all patients undergoing elective iAAA repair was carried out from 2012 to 2017 using Ovation Prime or iX stent grafts with a minimum of 3 months follow-up at a single UK vascular centre. Post-operative surveillance involved computed tomography scans at 3 months and 1 year, with duplex ultrasound yearly thereafter. Outcome measures were established with retrospective analysis of pre- and post-operative imaging, and included peri-operative mortality, major adverse events, limb complications, aneurysm diameter change, and endoleak rates. All patients were within Ovation instructions for use (IFU), and assessment was made to determine whether aneurysms had anatomical features considered adverse for other commonly used stent graft platforms. Ovation stent grafts were implanted in 52 patients (79% male, mean age 75.7 years) with a mean aneurysm diameter of 62.5 mm (range 55-107 mm). There was 100% technical deployment success. The 30 day mortality was 0% and there was no aneurysm related mortality during follow-up (median 24 months, range 3-48 months). There were no type I or III endoleaks, but 19% developed type II endoleaks with one patient requiring re-intervention. No iliac limb occlusions were identified but one case required relining for limb kinking. All 52 cases were within the IFU for Ovation but only 12% met the IFU criteria for the Cook and Medtronic devices. The mid-term experience with Ovation demonstrates safe, durable treatment of iAAAs, including those with unfavourable anatomy, frequently off IFU for other commonly used devices. Copyright © 2017 European Society for Vascular Surgery. Published by Elsevier B.V. All rights reserved.
Changes in the mechanical environment of stenotic arteries during interaction with stents: computational assessment of parametric stent designs.

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Holzapfel, Gerhard A; Stadler, Michael; Gasser, Thomas C

2005-02-01

Clinical studies have identified factors such as the stent design and the deployment technique that are one cause for the success or failure of angioplasty treatments. In addition, the success rate may also depend on the stenosis type. Hence, for a particular stenotic artery, the optimal intervention can only be identified by studying the influence of factors such as stent type, strut thickness, geometry of the stent cell, and stent-artery radial mismatch with the wall. We propose a methodology that allows a set of stent parameters to be varied, with the aim of evaluating the difference in the mechanical environment within the wall before and after angioplasty with stenting. Novel scalar quantities attempt to characterize the wall changes inform of the contact pressure caused by the stent struts, and the stresses within the individual components of the wall caused by the stent. These quantities are derived numerically and serve as indicators, which allow the determination of the correct size and type of the stent for each individual stenosis. In addition, the luminal change due to angioplasty may be computed as well. The methodology is demonstrated by using a full three-dimensional geometrical model of a postmortem specimen of a human iliac artery with a stenosis using imaging data. To describe the material behavior of the artery, we considered mechanical data of eight different vascular tissues, which formed the stenosis. The constitutive models for the tissue components capture the typical anisotropic, nonlinear and dissipative characteristics under supra-physiological loading conditions. Three-dimensional stent models were parametrized in such a way as to enable new designs to be generated simply with regard to variations in their geometric structure. For the three-dimensional stent-artery interaction we use a contact algorithm based on smooth contact surfaces of at least C-continuity, which prevents numerical problems known from standard facet-based contact
Retreatment of recanalized aneurysms after Y-stent-assisted coil embolization with double enterprise stents: case report and systematic review of the literature.

Science.gov (United States)

Kono, Kenichi; Shintani, Aki; Terada, Tomoaki

2014-01-01

It is necessary to consider possibility of recanalization and retreatment after coil embolization for cerebral aneurysms. There is concern that retreatment for recanalized aneurysms after Y-stent-assisted coil embolization may be difficult because of double stents, especially in Y-stents with double closed-cell stents owing to narrowed structures. However, no detailed reports of retreatment after Y-stent have been reported. Between July 2010 and June 2013, we treated four aneurysms with Y-stent-assisted coil embolization using Enterprise closed-cell stents. Recanalization occurred in one case (25%), and retreatment was performed. We easily navigated a microcatheter into the target portions of the aneurysm through the Y-stent and occluded the aneurysm with coils. Additionally, by systematically searching in PubMed, we found 105 cases of Y-stent-assisted coil embolization using Enterprise stents or Neuroform stents with more than 6 months of follow-up. Among them, retreatment was performed in 10 cases (9.5%). There were no significant differences in retreatment rates among different stent combinations (P=0.91; Fisher's exact test). In conclusion, navigation of a microcatheter into the aneurysm through the Y-stent with double Enterprise stents was feasible, and retreatment rates after Y-stent-assisted coiling may not depend on stent combinations.
Oversizing and Restenosis with Self-Expanding Stents in Iliofemoral Arteries

International Nuclear Information System (INIS)

Saguner, Ardan M.; Traupe, Tobias; Räber, Lorenz; Hess, Nina; Banz, Yara; Saguner, Arhan R.; Diehm, Nicolas; Hess, Otto M.

2012-01-01

Purpose: Uncoated self-expanding nitinol stents (NS) are commonly oversized in peripheral arteries. In current practice, 1-mm oversizing is recommended. Yet, oversizing of NS may be associated with increased restenosis. To provide further evidence, NS were implanted in porcine iliofemoral arteries with a stent-to-artery-ratio between 1.0 and 2.3. Besides conventional uncoated NS, a novel self-expanding NS with an antiproliferative titanium-nitride-oxide (TiNOX) coating was tested for safety and efficacy. Methods: Ten uncoated NS and six TiNOX-coated NS (5–6 mm) were implanted randomly in the iliofemoral artery of six mini-pigs. After implantation, quantitative angiography (QA) was performed for calculation of artery and minimal luminal diameter. Follow-up was performed by QA and histomorphometry after 5 months. Results: Stent migration, stent fracture, or thrombus formation were not observed. All stents were patent at follow-up. Based on the location of the stent (iliac/femoral) and the stent-to-artery-ratio, stent segments were divided into “normal-sized” (stent-to-artery-ratio < 1.4, n = 12) and “oversized” (stent-to-artery-ratio ≥ 1.4, n = 9). All stent segments expanded to their near nominal diameter during follow-up. Normal-sized stent segments increased their diameter by 6% and oversized segments by 29%. A significant correlation between oversizing and restenosis by both angiography and histomorphometry was observed. Restenosis rates were similar for uncoated NS and TiNOX-coated NS. Conclusions: TiNOX-coated NS are as safe and effective as uncoated NS in the porcine iliofemoral artery. All stents further expand to near their nominal diameter during follow-up. Oversizing is linearly and positively correlated with neointimal proliferation and restenosis, which may not be reduced by TiNOX-coating.
Treatment of carotid artery aneurysms with covered stents; Aneurysmabehandlung der Arteria carotis interna mit gecoverten Stents

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Rohr, A.; Alfke, K.; Doerner, L.; Jansen, O. [UKSH Kiel (Germany). Neurochirurgie Neuroradiologie; Bartsch, T.; Stingele, R. [UKSH Kiel (Germany). Neurologie

2007-10-15

Purpose: Evaluation of the use of covered stents in treating pseudoaneurysms of the cervical and intracranial/extradural carotid artery and determination of the periprocedural and short- to mid-term complication rate. Materials and Methods: 8 patients with 9 spontaneous dissecting aneurysms of the cervical carotid artery - 5 of which were symptomatic - plus one patient with ofthalmoplegia due to an aneurysm of the cavernous carotid artery were studied. While the latter was treated with a PTFE-covered balloon-mounted stainless steel stent (Jostent/Graftmaster), a self-expanding PTFE-covered Nitonol Stent (Symbiot) was used in all other cases. Intervention was performed with local anesthesia. Aspirin and Clopidogrel were both used as antiplatelet drugs. Clinical signs and symptoms and vascular imaging with DS, MR, CT angiography and ultrasound were recorded during patient follow-up, with a mean follow-up period of 14.6 months (4 - 30). Results: We were able to treat 8 out of 10 aneurysms (80 %) using covered stents. The aneurysms were immediately occluded and the associated stenoses of the parent vessel were eliminated. No clinically relevant complications occurred during the procedure or in the follow-up interval. In two cases, elongation of the carotid artery prevented the stent from being positioned over the aneurysm neck. These cases were shown to be stable with the use of antiplatelet drugs. Conclusion: Covered stents can be used in the treatment of pseudoaneurysms of the carotid artery as an alternative to long-term antithrombotic medication or surgery. In our study treatment was effective (80 %) and free of complications in the short- and mid-term follow-up. Possible indications, technique and the use of imaging modalities for patient follow-up are discussed. (orig.)
Risk factors for in-stent restenosis of vertebral artery origin after stent implantation: a Meta-analysis

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Fang-fang HAO

2018-01-01

Full Text Available Objective To systematically review the risk factors for in-stent restenosis (ISR of vertebral artery origin after sent implantation to provide theoretical foundation for clinical prevention and treatment. Methods Taking vertebral artery, vertebrobasilar insufficiency, stents, drug-eluting stents, self expandable metallic stents in English and Chinese as key words, retrospective clinical studies about risk factors for ISR of vertebral artery origin were searched by using PubMed, EMBASE/SCOPUS, Cochrane Library, China Biology Medicine (CBM, China National Knowledge Infrastructure (CNKI, Wanfang Data and VIP database from January 1, 1966 to March 30, 2017. Quality assessment and Meta-analysis were made by using Newcastle-Ottawa Scale (NOS and Stata 12.0 software. Results The research enrolled 3468 articles in all, from which 11 studies were chosen after excluding duplicates and those not meeting the inclusion criteria. A total number of 1352 patients were divided into ISR group (N = 440 and non-ISR group (N = 912. The ISR incidence rate of smokers was significantly higher than non-smokers (OR = 2.179, 95%CI: 1.373-3.458; P = 0.001. The differences of bare metal stents (BMS utilization rate (OR = 2.072, 95% CI: 1.560-2.753; P = 0.000 and drug-eluting stents (DES utilization rate (OR = 0.483, 95% CI: 0.363-0.641; P = 0.000 between ISR group and non-ISR group were statistically significant. Conclusions Smoking and using BMS are risk factors for ISR of vertebral artery origin, and using DES is protective factor. Due to limited study quality, more high-quality studies are needed to verify this conclusion. DOI: 10.3969/j.issn.1672-6731.2017.12.004
Long-Term Safety of Drug-Eluting and Bare-Metal Stents

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Palmerini, Tullio; Benedetto, Umberto; Biondi-Zoccai, Giuseppe

2015-01-01

BACKGROUND: Previous meta-analyses have investigated the relative safety and efficacy profiles of different types of drug-eluting stents (DES) and bare-metal stents (BMS); however, most prior trials in these meta-analyses reported follow-up to only 1 year, and as such, the relative long-term safety....... RESULTS: Fifty-one trials that included a total of 52,158 randomized patients with follow-up duration ≥3 years were analyzed. At a median follow-up of 3.8 years, cobalt-chromium everolimus-eluting stents (EES) were associated with lower rates of mortality, definite stent thrombosis (ST), and myocardial...... infarction than BMS, paclitaxel-eluting stents (PES), and sirolimus-eluting stents (SES) and less ST than BES. Phosphorylcholine-based zotarolimus-eluting stents had lower rates of definite ST than SES and lower rates of myocardial infarction than BMS and PES. The late rates of target...
Angioplasty and stent placement - carotid artery

Science.gov (United States)

... medlineplus.gov/ency/article/002953.htm Angioplasty and stent placement - carotid artery To use the sharing features ... to remove plaque buildup ( endarterectomy ) Carotid angioplasty with stent placement Description Carotid angioplasty and stenting (CAS) is ...
Comparison of in vivo acute stent recoil between the bioabsorbable everolimus-eluting coronary stent and the everolimus-eluting cobalt chromium coronary stent: insights from the ABSORB and SPIRIT trials

DEFF Research Database (Denmark)

Tanimoto, Shuzou; Serruys, Patrick W; Thuesen, Leif

2007-01-01

OBJECTIVES: This study sought to evaluate and compare in vivo acute stent recoil of a novel bioabsorbable stent and a metallic stent. BACKGROUND: The bioabsorbable everolimus-eluting coronary stent (BVS) is composed of a poly-L-lactic acid backbone, coated with a bioabsorbable polymer containing...... the antiproliferative drug, everolimus, and expected to be totally metabolized and absorbed in the human body. Because the BVS is made from polymer, it may have more acute recoil than metallic stents in vivo. METHODS: A total of 54 patients, who underwent elective stent implantation for single de novo native coronary...... artery lesions, were enrolled: 27 patients treated with the BVS and 27 patients treated with the everolimus-eluting cobalt chromium stent (EES). Acute absolute recoil, assessed by quantitative coronary angiography, was defined as the difference between mean diameter of the last inflated balloon...
Endobronchial Occlusion Stent: A Preliminary Experimental Study

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Choi, Yo Won; Jeong, Woo Kyoung; Lee, Seoung Hoon; Heo, Jeong Nam; Jeon, Seok Chol [Hanyang University College of Medicine, Seoul (Korea, Republic of); Ko, Gi Young; Song, Ho Young [University of Ulsan College of Medicine, Ulsan (Korea, Republic of)

2010-04-15

To evaluate the safety and the technical feasibility of the use of an endobronchial occlusion stent and to get preliminary data for the development of the optimal material required for endobronchial occlusions. A commercialized, self-expandable tracheobronchial stent was modified; one half had a polyurethane cover with an occluded end and the other half was uncovered with a flaring configuration. The occluded end was placed such that it would face the distal lung. Under fluoroscopic guidance, seven stents were placed at the lower lobar bronchus in 6 mini-pigs. The bronchial obstruction was examined immediately after stent placement. Chest radiographs were taken at days 1, 7, 14, and 28 after stent placement and the removed airways from two, two, one, and one mini-pigs sacrificed on corresponding days were examined for the maintenance of bronchial obstruction. Stents were successfully placed and induced the immediate bronchial obstruction in all mini-pigs. Five of seven airways with occlusion stents maintained an obstruction until the mini-pigs were sacrificed. Proximal stent migration occurred in two mini-pigs (29%), and pulmonary consolidations were observed distal to four of the stents (57%). The placement of an endobronchial occlusion stent and the obstruction of targeted bronchi seem to be feasible, but an add-on check valve should be considered to prevent stent migration and obstructive pneumonia
Self-Expandable Metal Stent for Closure of a Large Leak after Total Gastrectomy

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G. Curcio

2010-08-01

Full Text Available In recent years, self-expandable metallic stents (SEMSs have emerged as a promising treatment alternative for the bridging and sealing of esophageal perforations and extensive anastomotic leaks after esophageal resection or total gastrectomy. A 56-year-old woman underwent a total gastrectomy with Roux-en-Y end-to-side esophagojejunostomy for a gastric signet ring cell carcinoma. Ten days later, esophagogastroduodenoscopy showed a 2 cm fistula in the distal end of the Roux limb of the anastomosis. This was confirmed by gastrografin esophagography. The patient was started on total parenteral nutrition. Having deemed clipping treatment for this fistula unfeasible, we decided to insert a partially silicone-coated SEMS (Evolution Controlled Release Esophageal Stent System, Cook Medical, Winston-Salem, N.C., USA. The stent was removed after ten days. Gastrografin esophagography showed no further contrast extravasation, and esophagogastroduodenoscopy showed closure of the fistula. No clinical complications were observed, and the patient was able to start normal per os nutrition. In conclusion, the treatment of symptomatic leaks in patients who have undergone esophagojejunostomy is challenging, and leakage from the jejunal stump can be a potentially serious complication. In the treatment of leakage after total gastrectomy, plastic stents (which are either too light or exercise too little radial force and totally covered metallic stents may not adhere sufficiently to the esophagojeujunal walls and, as a result, migrate beyond the anastomosis. The promising results of this report suggest that early stenting, using a partially silicone-coated SEMS, is a feasible alternative to surgical treatment in this category of patients.
Carotid Angioplasty and Stenting

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Carotid angioplasty and stenting Overview Carotid angioplasty (kuh-ROT-id AN-jee-o-plas-tee) and stenting ... to better see and examine the blood vessels. Food and medications You'll receive instructions on what ...
Supera self-expanding stents for endovascular treatment of femoropopliteal disease: a review of the clinical evidence

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Bishu K

2015-07-01

Full Text Available Kalkidan Bishu,1,2 Ehrin J Armstrong1,21Division of Cardiology, University of Colorado, Aurora, 2Denver VA Medical Center, Denver, CO, USAAbstract: Femoropopliteal lesions account for a significant proportion of endovascular interventions for peripheral artery disease in patients with disabling claudication or chronic limb ischemia. The femoropopliteal artery crosses two joint structures (hip and knee joints and courses through the muscular adductor canal in the thigh, which places the artery at increased biomechanical stress. There is a critical need for stent platforms with a reduced risk of stent fracture while maintaining patency during long-term follow-up. The Supera peripheral stent system has a braided nickel–titanium alloy stent designed to withstand the unique stressors along the course of the femoropopliteal artery. This design may be associated with improved patency in association with reduced stent fracture rates on short- and medium-term follow-up. Further studies, including randomized controlled studies, comparing the Supera interwoven nickel–titanium alloy stent system with other stent platforms and angioplasty alone are needed.Keywords: peripheral artery disease, femoropopliteal atherosclerosis, SUPERA interwoven nitinol stent, stent fracture
Self-Expandable Metallic Stent Placement in Malignant Gastric Outlet Obstruction: A Comparison Between 2 Brands of Stents.

Science.gov (United States)

Ye, Bing-Wei; Lee, Kuei-Chuan; Hsieh, Yun-Cheng; Li, Chung-Pin; Chao, Yee; Hou, Ming-Chih; Lin, Han-Chieh

2015-07-01

Malignant gastric outlet obstruction is a late complication of intraabdominal malignancy. Self-expandable metallic stent placement has been a safe palliative treatment to relieve obstructive symptoms. We aimed to assess the efficacy and safety of metallic stents in our patients and analyzed the clinical outcome of different brands. Seventy-one patients with inoperable gastric outlet obstruction receiving WallFlex enteral stents (WallFlex group) or Bonastents (Bonastent group) since April 2010 were analyzed retrospectively. The overall technical and clinical success rates of stent placement were 100% and 93%, respectively. The baseline characteristics and clinical outcomes including procedure-related complications, restenosis, and reintervention rates were comparable between the 2 groups. However, the Bonastent group had a higher rate of stent fracture than the WallFlex group (13.3% vs 0%, P = 0.03). The mean duration of overall stent patency was 132.7 days. The mean duration of survival was 181.9 days. Resumption of regular diet or low residual diet at day 7 after stent insertion predicted stent patency (hazard ratio [HR]: 0.28, P = 0.01). Cancer with gastric origin (HR: 0.25, P = 0.045) and poststent chemotherapy (HR: 0.38, P = 0.006) predicted lower mortality; however, peritoneal carcinomatosis (HR: 3.09, P = 0.04) correlated with higher mortality. Metallic stent placement is a safe and effective method for relieving gastric outlet obstruction. Except higher rate of stent fracture in the Bonastent group, there is no significant difference in clinical outcomes between the Bonastent group and the WallFlex group.
Comparison of retrievable stents and permanent stents for Budd-Chiari syndrome due to obstructive inferior vena cava.

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Bi, Yonghua; Chen, Hongmei; Ding, Penxu; Ren, Jianzhuang; Han, Xinwei

2018-05-30

To compare long-term outcomes of retrievable stents and permanent stents for BCS due to long-segment obstructive IVC. Between July 2000 and August 2016, 42 patients with BCS due to long-segment obstructive IVC were treated with retrievable stents (RS) and 41 patients were treated with permanent stents (PS). The retrievable stents was removed eventually after thrombus disappeared. Patients were subsequently followed-up by color Doppler sonography or CT scanning. All retrievable stent placements were successfully, and 37 retrievable stents were retrieved 8 to 29 days later. Forty-two stents were implanted in PS Group. One failure retrieval of retrievable stents occurred, and two failures of cannulations were found in PS Group. Two deaths may procedure-related and died from acute pulmonary thromboembolism perioperatively. One patient developed acute cerebral infarction and recovered after treatment. In PS Group, minor complications were found in 3 patients. The length of IVC lesion segment, length and thickness of IVC thrombus decreased significantly, and diameter of retrocaval IVC and diaphragm IVC increased significantly in both groups. During follow up, 3 patients died from liver failure in RS Group and 2 patients died in PS Group. RS Group showed a significantly higher primary patency rate than PS Group. Cumulative 1-, 3-, and 5-year secondary patency rates were 95.2%, 89.6%, 89.6% in RS Group, and 100%, 96.6%, 96.6% in PS Group (p= 0.7109). Retrievable stents is effective for BCS due to long-segment obstructive IVC, with a higher primary patency rate. This article is protected by copyright. All rights reserved.
Clinical and angiographic outcomes after stent-assisted coiling of cerebral aneurysms with Enterprise and Neuroform stents: a comparative analysis of the literature.

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King, Brent; Vaziri, Sasha; Singla, Amit; Fargen, Kyle M; Mocco, J

2015-12-01

The most widely used intracranial stents for stent-assisted coiling are Neuroform (NEU) and Enterprise stents (ENT). This study compares published outcomes between the ENT and NEU coil-assist systems and comments on the published safety and efficacy of stent-assisted coiling in general. A literature search was performed through PubMed for all published series of ENT or NEU stent-assisted coiling of cerebral aneurysms from 2004 to 2014. All studies including 10 or more published cases of stent-assisted coiling with ENT or NEU were included. 47 studies met the inclusion criteria, containing 4238 aneurysms in 4039 patients. 2111 aneurysms were treated with NEU and 2127 were treated with ENT. Mean follow-up was 14.1 months. Overall, thromboembolic events occurred in 6.4% of aneurysms, intracranial hemorrhage (ICH) in 2.6%, permanent morbidity in 3.9%, and mortality in 2.3%. Initial and final 100% angiographic occlusion was seen in 53% and 69% of patients, respectively. Deployment failures (pstent-assisted coiling devices to date, containing over 4200 aneurysms in more than 4000 patients. Comparative analyses demonstrate that both devices are reported to be safe and effective with comparable permanent morbidity. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Comparison of visibility for four self-expanding nitinol bare stents in vitro

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Wiesinger, Benjamin; Stutz, Alexander; Schmehl, Joerg; Groezinger, Gerd; Claussen, Claus Detlef; Wiskirchen, Jakub

2012-01-01

Background Sufficient radiopacity of stents is a prerequisite for safe interventions and minimization of the radiation dose for the patient and the interventionist. Modern nitinol stents are considered less radiopaque compared to formerly used stents. Purpose To evaluate the objective detection rate (ODR) and the subjective radiopacity score (SRS) of four self-expanding nitinol stents with their markers on a phantom human pelvis. Material and Methods We evaluated the ODR (as a percentage of correctly identified stents) and the SRS (on a scale from 0 = not visible to 4 = excellent visibility) for four self-expanding nitinol stents (SinusSuperflex, SMART, Luminexx, Zilver) with 8 mm diameter and 40 mm length. Stents were placed on a phantom human pelvis and images of the stents were taken in four different positions (right and left lumbosacral joint and near the right and left limbus acetabuli) using the following modes: spotfilm, pulsed fluoroscopy (4, 7.5, 15, and 30 pulses/min) and at three different digital magnification modes. Dose area products (DAPs) were assessed. Results ODR and SRS, respectively, were significantly increased for the SMART stent compared to all other tested stents (P < 0.05): SMART 93.53% and 2.43, SinusSuperflex 90.81% and 2.21, Luminexx 90.39% and 2.20, and Zilver 89.28% and 2.21. ODR was significantly reduced in position 3 where the bone overlap was more pronounced for all stents (detection rates 77.14-79.56%). An increase in magnification significantly improved the ODR and SRS for all stents (70.33-99.25% and 1.07-3.28, respectively, P < 0.05). Increased pulsing frequency did not improve the ODR of the various stents but did increase the DAP. Conclusion The SMART stent had the best overall performance. In the presence of bone overlap, all self-expanding nitinol stents had poor results. Increased pulsing frequency did not improve ODR or SRS but did increase the DAP. Use of digital magnification modes had no effect on DAP increasing ODR
Pulmonary Arterial Stent Implantation in an Adult with Williams Syndrome

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Reesink, Herre J.; Henneman, Onno D. F.; Delden, Otto M. van; Biervliet, Jules D.; Kloek, Jaap J.; Reekers, Jim A.; Bresser, Paul

2007-01-01

We report a 38-year-old patient who presented with pulmonary hypertension and right ventricular dysfunction due to pulmonary artery stenoses as a manifestation of Williams syndrome, mimicking chronic thromboembolic pulmonary hypertension. The patient was treated with balloon angioplasty and stent implantation. Short-term follow-up showed a good clinical result with excellent patency of the stents but early restenosis of the segments in which only balloon angioplasty was performed. These stenoses were subsequently also treated successfully by stent implantation. Stent patency was observed 3 years after the first procedure
Comparison of the Absorbable Polymer Sirolimus-Eluting Stent (MiStent) to the Durable Polymer Everolimus-Eluting Stent (Xience) (from the DESSOLVE I/II and ISAR-TEST-4 Studies).

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Lansky, Alexandra J; Kastrati, Adnan; Edelman, Elazer R; Parise, Helen; Ng, Vivian G; Ormiston, John; Wijns, William; Byrne, Robert A

2016-02-15

We compared the outcomes of a novel, thin-strut, cobalt-chromium, absorbable, polymer sirolimus-eluting stent (APSES; MiStent) to the durable polymer cobalt-chromium everolimus-eluting stent (EES; Xience). A propensity-matched analysis was performed comparing data from the DES With Sirolimus and a Bioabsorbable Polymer for the Treatment of Patients With De Novo Lesions in the Native Coronary Arteries (DESSOLVE) I and II studies, evaluating the APSES to the EES arm of the Intracoronary Stenting and Angiographic Results: Test Efficacy of 3 Limus-Eluting Stents-4 study. Target lesion failure (TLF) and its components were evaluated at 12 months and annually to 3 years; 805 patients (APSES = 153; EES = 652) were included with propensity matching in 204 patients (APSES = 102; EES = 102). APSES compared with EES had lower TLF at 1 year (3.0% vs 8.0%, p = 0.12) driven by a difference in target lesion revascularization (TLR; 1% vs 6%, p = 0.05), with no difference in target vessel myocardial infarction (p = 0.56) or stent thrombosis (p = 0.31). At 3 years, TLF (5.0% vs 12.5%, p = 0.07) and TLR (2.0% vs 8.4%, p = 0.04) remained lower with APSES. By landmark analysis, there was no significant difference in TLF between 1 and 3 years (p = 0.36). In conclusion, in a propensity-matched analysis, the APSES demonstrated reduced clinically indicated TLR rates at 1 and 3 years compared with the durable polymer EES, with minimal accrual of events between 1 and 3 years. Copyright © 2016 Elsevier Inc. All rights reserved.
Influence of stent design and use of protection devices on outcome of carotid artery stenting: a pooled analysis of individual patient data.

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Wodarg, Fritz; Turner, Elisabeth L; Dobson, Joanna; Ringleb, Peter A; Mali, Willem P; Fraedrich, Gustav; Chatellier, Gilles; Bequemin, Jean-Pierre; Brown, Martin M; Algra, Ale; Mas, Jean-Louis; Jansen, Olav; Bonati, Leo H

2018-04-19

Carotid artery stenting is an alternative to endarterectomy for the treatment of symptomatic carotid stenosis but was associated with a higher risk of procedural stroke or death in randomized controlled trials (RCTs). Technical aspects of treatment may partly explain these results. The purpose of this analysis was to investigate the influence of technical aspects such as stent design or the use of protection devices, as well as clinical variables, on procedural risk. We pooled data of 1557 individual patients receiving stent treatment in three large RCTs comparing stenting versus endarterectomy for symptomatic carotid stenosis. The primary outcome event was any procedural stroke or death occurring within 30 days after stenting. Procedural stroke or death occurred significantly more often with the use of open-cell stents (61/595 patients, 10.3%) than with closed-cell stents (58/962 patients, 6.0%; RR 1.76; 95% CI 1.23 to 2.52; P=0.002). Procedural stroke or death occurred in 76/950 patients (8.0%) treated with protection devices (predominantly distal filters) and in 43/607 (7.1%) treated without protection devices (RR 1.10; 95% CI 0.71 to 1.70; P=0.67). Clinical variables predicting the primary outcome event were age, severity of the qualifying event, history of prior stroke, and level of disability at baseline. The effect of stent design remained similar after adjustment for these variables. In symptomatic carotid stenosis, the use of stents with a closed-cell design is independently associated with a lower risk of procedural stroke or death compared with open-cell stents. Filter-type protection devices do not appear to reduce procedural risk. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Wing-shaped plastic stents vs. self-expandable metal stents for palliative drainage of malignant distal biliary obstruction: a randomized multicenter study.

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Schmidt, Arthur; Riecken, Bettina; Rische, Susanne; Klinger, Christoph; Jakobs, Ralf; Bechtler, Matthias; Kähler, Georg; Dormann, Arno; Caca, Karel

2015-05-01

Previous studies have shown superior patency rates for self-expandable metal stents (SEMS) compared with plastic stents in patients with malignant biliary obstruction. The aim of this study was to compare stent patency, patient survival, and complication rates between a newly designed, wing-shaped, plastic stent and SEMSs in patients with unresectable, malignant, distal, biliary obstruction. A randomized, multicenter trial was conducted at four tertiary care centers in Germany. A total of 37 patients underwent randomization between March 2010 and January 2013. Patients underwent endoscopic retrograde cholangiography with insertion of either a wing-shaped, plastic stent without lumen or an SEMS. Stent failure occurred in 10/16 patients (62.5 %) in the winged-stent group vs. 4/18 patients (22.2 %) in the SEMS group (P = 0.034). The median time to stent failure was 51 days (range 2 - 92 days) for the winged stent and 80 days (range 28 - 266 days) for the SEMS (P = 0.002). Early stent failure (stent failure was significantly higher in the winged-stent group compared with the SEMS group. A high incidence of early stent failure within 8 weeks was observed in the winged-stent group. Thus, the winged, plastic stent without central lumen may not be appropriate for mid or long term drainage of malignant biliary obstruction. Study registration ClinicalTrials.gov (NCT01063634). © Georg Thieme Verlag KG Stuttgart · New York.
Coronary Stents in Diabetic Patients: State of the Knowledge.

Science.gov (United States)

Codner, Pablo; Gurm, Hitinder Singh; Motivala, Apurva

2017-04-01

This review article aims to summarize the findings of the most relevant research that compared the use of paclitaxel vs. "limus" based drug eluting stent (DES) in diabetic patients and to define the current state of knowledge with new stent technologies in this patient population. Since drug eluting stents (DES) were introduced, it has been of great interest to establish whether paclitaxel or sirolimus eluting stents have the same safety and efficacy features for patients with coronary artery disease. The answer to this question is particularly relevant for diabetic patients. Several randomized trials, registry-based studies, and meta-analyses have assessed the performance of these different DES in diabetic patients. The most recently published data favors limus over paclitaxel DES in diabetic patients, but most of these studies compared first vs. second generation DES with the inherent caveats of comparing different platforms, alloys, and drug delivery vehicles. In this literature review, we found that there is robust evidence favoring the use of DES over bare metal stents in diabetic patients with coronary artery disease. We also found that the current state of knowledge is that the everolimus eluting stents have better safety and efficacy than paclitaxel eluting stents in diabetic patients and hence should be the preferred choice. New revascularization strategies including bio-absorbable scaffolds, polymer free stents, and bio-degradable polymers are being studied in diabetic patients with encouraging results.
Stent angioplasty for the treatment of symptomatic stenosis of middle cerebral artery

International Nuclear Information System (INIS)

Lu Huisheng; Niu Huiming; Chao Yuanxiang; Li Xiaoning; Wu Dingfeng; Zhang Chenhong; Yang Jie; Zhang Liang

2010-01-01

Objective: To investigate the safety and feasibility of endovascular stent angioplasty in treating symptomatic stenosis of middle cerebral artery. Methods: Endovascular angioplasty with coronary stents was performed in 27 patients with symptomatic stenosis of middle cerebral artery. The clinical results were reviewed and analyzed. Results: Of the total 27 patients, successful placement of the coronary stents was achieved in 24. Angiography immediately after the procedure showed that the stenotic degree of the diseased artery was markedly decreased from preoperative (80 ± 19)% to postoperative (8 ±4)%, the improvement was very obvious. Percutaneous transcatheter angioplasty had to be employed in two cases because of the failure of stent placement. A mean follow-up period of 18 months was carried out. During the following up period no transient cerebral ischemia attack occurred in 25 patients and no newly-developed cerebral infarction in region fed by the responsible vessels occurred either.Re-irrigation cerebral hemorrhage was seen in one patient, which occurred three hours after the placement of the stent. In one case the placed stent fell off and immigrated into the siphon of internal carotid artery, and the displaced stent was took out later with a catching apparatus. In another case re-stenosis occurred six months after the stenting. Conclusion: Percutaneous endovascular stent angioplasty is a safe and effective treatment for symptomatic stenosis of middle cerebral artery, although its long-term results need to be further evaluated. (authors)
Biomimicry, vascular restenosis and coronary stents.

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Schwartz, R S; van der Giessen, W J; Holmes, D R

1998-01-01

Biomimicry is in its earliest stages and is being considered in the realm of tissue engineering. If arterial implants are to limit neointimal thickening, purely passive structures cannot succeed. Bioactivity must be present, either by pharmacologic intervention or by fabricating a 'living stent' that contains active cellular material. As tissue engineering evolves, useful solutions will emerge from applying this knowledge directly to vascular biologic problems resulting from angioplasty, stenting, and vascular prosthesis research.
Clinical Outcome After DK Crush Versus Culotte Stenting of Distal Left Main Bifurcation Lesions: The 3-Year Follow-Up Results of the DKCRUSH-III Study.

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Chen, Shao-Liang; Xu, Bo; Han, Ya-Ling; Sheiban, Imad; Zhang, Jun-Jie; Ye, Fei; Kwan, Tak W; Paiboon, Chitprapai; Zhou, Yu-Jie; Lv, Shu-Zheng; Dangas, George D; Xu, Ya-Wei; Wen, Shang-Yu; Hong, Lang; Zhang, Rui-Yan; Wang, Hai-Chang; Jiang, Tie-Ming; Wang, Yan; Sansoto, Teguh; Chen, Fang; Yuan, Zu-Yi; Li, Wei-Min; Leon, Martin B

2015-08-24

The present study aimed to investigate the difference in major adverse cardiac events (MACE) at 3 years after double-kissing (DK) crush versus culotte stenting for unprotected left main distal bifurcation lesions (LMDBLs). The multicenter and randomized DKCRUSH-III (Comparison of double kissing crush versus culotte stenting for unprotected distal left main bifurcation lesions: results from a multicenter, randomized, prospective study) showed that DK crush stenting was associated with fewer MACE at 1-year follow-up in patients with LMDBLs compared with culotte stenting. Here, we report the 3-year clinical outcome of the DKCRUSH-III study. A total of 419 patients with LMDBLs who were randomly assigned to either the DK crush or culotte group in the DKCRUSH-III study were followed for 3 year. The primary endpoint was the occurrence of a MACE at 3 years. Stent thrombosis (ST) was the safety endpoint. Patients were classified by simple and complex LMDBLs according to the DEFINITION (Definition and Impact of Complex Bifurcation Lesions on Clinical Outcomes After Percutaneous Coronary Intervention Using Drug-Eluting Stents) study criteria. At 3 years, MACE occurred in 49 patients the culotte group and in 17 patients in the DK crush group (cumulative event rates of 23.7% and 8.2%, respectively; p DK crush group (p = 0.007). Complex LMDBLs were associated with a higher rate of MACE (35.3%) at 3 years compared with a rate of 8.1% in patients with simple LMDBLs (p DK] Crush Versus Culotte Stenting for the Treatment of Unprotected Distal Left Main Bifurcation Lesions: DKCRUSH-III, a Multicenter Randomized Study Comparing Double-Stent Techniques; ChiCTR-TRC-11001877). Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
The underdilation of nitinol stents at TIPS implantation: Solution or illusion?

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Mollaiyan, Ashkan [University Hospital, Department of Radiology, Hugstetterstrasse 55, 79106 Freiburg (Germany); Bettinger, Dominik [University Hospital, Department of Gastroenterology, Hugstetterstrasse 55, 79106 Freiburg (Germany); Berta-Ottenstein-Programme, Faculty of Medicine, University of Freiburg (Germany); Rössle, Martin, E-mail: Martin-Roessle@t-online.de [University Hospital, Department of Gastroenterology, Hugstetterstrasse 55, 79106 Freiburg (Germany); Praxiszentrum für Gastroenterologie, Bertoldstrasse 48, 79098 Freiburg (Germany)

2017-04-15

Purpose: This study investigates the behaviour of self-expanding nitinol stents at the time of TIPS-implantation and thereafter. Methods: Hundred consecutive patients with cirrhosis receiving a TIPS revision were included. The smallest stent diameter was measured radiologically immediately after implantation and before shunt revision. Accuracy of the measurement was assessed by comparing the nominal stent diameter with the largest stent diameter measured at the time of revision. Results: Pearson correlation between largest measured and nominal diameters was excellent (r = 0.952, p < 0.001) showing that measurements are accurate. At TIPS implantation all stents were markedly underdilated reaching only 76–92% of their nominal diameter. Smallest measured diameters were similar (8 mm) irrespective of the nominal diameter (8, 9, 10 mm) of the stent. In addition, smallest diameters of 10 mm stents were similar irrespective whether 8, 9 or 10 mm balloons were used. During a mean follow-up of 12.7 ± 17.8 months (median 3 months, range 1–81) stents expanded by 0.5–1.6 mm dependent on the nominal stent size (8, 9, 10 mm) and the grade of primary underdilation. No significant difference was found between Viatorr and bare stents. Conclusions: At TIPS-implantation, the compliance of the surrounding tissue predominantly determines the stent diameter. The nominal size of the stent or the dilatation balloon has little influence. Accurate adjustment of a desired pressure gradient is, therefore, not possible. During follow-up, stents expand towards their nominal diameter questioning the usefulness of underdilation.
The underdilation of nitinol stents at TIPS implantation: Solution or illusion?

International Nuclear Information System (INIS)

Mollaiyan, Ashkan; Bettinger, Dominik; Rössle, Martin

2017-01-01

Purpose: This study investigates the behaviour of self-expanding nitinol stents at the time of TIPS-implantation and thereafter. Methods: Hundred consecutive patients with cirrhosis receiving a TIPS revision were included. The smallest stent diameter was measured radiologically immediately after implantation and before shunt revision. Accuracy of the measurement was assessed by comparing the nominal stent diameter with the largest stent diameter measured at the time of revision. Results: Pearson correlation between largest measured and nominal diameters was excellent (r = 0.952, p < 0.001) showing that measurements are accurate. At TIPS implantation all stents were markedly underdilated reaching only 76–92% of their nominal diameter. Smallest measured diameters were similar (8 mm) irrespective of the nominal diameter (8, 9, 10 mm) of the stent. In addition, smallest diameters of 10 mm stents were similar irrespective whether 8, 9 or 10 mm balloons were used. During a mean follow-up of 12.7 ± 17.8 months (median 3 months, range 1–81) stents expanded by 0.5–1.6 mm dependent on the nominal stent size (8, 9, 10 mm) and the grade of primary underdilation. No significant difference was found between Viatorr and bare stents. Conclusions: At TIPS-implantation, the compliance of the surrounding tissue predominantly determines the stent diameter. The nominal size of the stent or the dilatation balloon has little influence. Accurate adjustment of a desired pressure gradient is, therefore, not possible. During follow-up, stents expand towards their nominal diameter questioning the usefulness of underdilation.
Comparison of devices used for stent-assisted coiling of intracranial aneurysms.

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Benjamin Izar

Full Text Available INTRODUCTION: Two self-expandable stents, the Neuroform and the Enterprise stent, are widely used for stent-assisted coiling (SAC of complex shaped intracranial aneurysms. However, comparative knowledge about technical feasibility, peri- and post-procedural morbidity and mortality, packing densities as well as follow-up data is limited. MATERIAL AND METHODS: We conducted a retrospective study to investigate differences in aneurysms stented with the Enterprise or Neuroform stents. Angiographic follow-up (mean 19.42 months was available in 72.6% (61/84 of aneurysms treated with stent-assisted coiling. We further sought to compare stent-assisted coiling to a matched patient population with aneurysms treated by conventional coil embolization. RESULTS: The stenting success rate of the Enterprise was higher compared to the Neuroform stent (46/48 and 42/51, respectively. In 5 of 9 cases in which the Neuroform stent was not navigable to the landing zone, we successfully deployed an Enterprise stent instead. Eventually, 42 aneurysms were coiled after stenting in each group. We observed no significant differences in peri-procedural complication rate, post-procedural hospital stay, packing density, recurrence rate or number of in-stent stenosis. Strikingly, 36.1% of followed aneurysms in the SAC group showed progressive occlusion on angiographic follow-up imaging. The packing density was significantly higher in aneurysms treated by SAC as compared to conventionally coiled aneurysms, while recanalization rate was significantly lower in the SAC group. CONCLUSION: The procedural success rate is higher using the Enterprise, but otherwise both stents exhibited similar characteristics. Lower recurrence frequency and complication rates comparable to conventional coil embolization emphasize the importance of stent-assisted coiling in the treatment of complex aneurysms. Progressive occlusion on angiographic follow-up was a distinct and frequent observation in the
Development and application of stent-based image guided navigation system for oral and maxillofacial surgery

International Nuclear Information System (INIS)

Lee, Woo Jin; Kim, Dae Seung; Yi, Won Jin; Lee, Sam Sun; Choi, Soon Chul; Heo, Min Suk; Huh, Kyung Hoe; Kim, Myung Jin; Lee, Jee Ho

2009-01-01

The purpose of this study was to develop a stent-based image guided surgery system and to apply it to oral and maxillofacial surgeries for anatomically complex sites. We devised a patient-specific stent for patient-to-image registration and navigation. Three dimensional positions of the reference probe and the tool probe were tracked by an optical camera system and the relative position of the handpiece drill tip to the reference probe was monitored continuously on the monitor of a PC. Using 8 landmarks for measuring accuracy, the spatial discrepancy between CT image coordinate and physical coordinate was calculated for testing the normality. The accuracy over 8 anatomical landmarks showed an overall mean of 0.56 ± 0.16 mm. The developed system was applied to a surgery for a vertical alveolar bone augmentation in right mandibular posterior area and possible interior alveolar nerve injury case of an impacted third molar. The developed system provided continuous monitoring of invisible anatomical structures during operation and 3D information for operation sites. The clinical challenge showed sufficient accuracy and availability of anatomically complex operation sites. The developed system showed sufficient accuracy and availability in oral and maxillofacial surgeries for anatomically complex sites.
Predictors of the patency of self-expandable metallic stents in malignant gastroduodenal obstruction.

Science.gov (United States)

Kim, Seung Han; Chun, Hoon Jai; Yoo, In Kyung; Lee, Jae Min; Nam, Seung Joo; Choi, Hyuk Soon; Kim, Eun Sun; Keum, Bora; Seo, Yeon Seok; Jeen, Yoon Tae; Lee, Hong Sik; Um, Soon Ho; Kim, Chang Duck

2015-08-14

To investigate the predictive factors of self-expandable metallic stent patency after stent placement in patients with inoperable malignant gastroduodenal obstruction. A total of 116 patients underwent stent placements for inoperable malignant gastroduodenal obstruction at a tertiary academic center. Clinical success was defined as acceptable decompression of the obstructive lesion within the malignant gastroduodenal neoplasm. We evaluated patient comorbidities and clinical statuses using the World Health Organization's scoring system and categorized patient responses to chemotherapy using the Response Evaluation Criteria in Solid Tumors criteria. We analyzed the relationships between possible predictive factors and stent patency. Self-expandable metallic stent placement was technically successful in all patients (100%), and the clinical success rate was 84.2%. In a multivariate Cox proportional hazards model, carcinoembryonic antigen (CEA) levels were correlated with a reduction in stent patency [P = 0.006; adjusted hazard ratio (aHR) = 2.92, 95%CI: 1.36-6.25]. Palliative chemotherapy was statistically associated with an increase in stent patency (P = 0.009; aHR = 0.27, 95%CI: 0.10-0.72). CEA levels can easily be measured at the time of stent placement and may help clinicians to predict stent patency and determine the appropriate stent procedure.
Stenting-plasty with brachial puncture in the treatment of subclavian steal syndrome

International Nuclear Information System (INIS)

Chen Quan; Jing Zaiping; Zhao Zhiqing; Feng Xiang; Lu Qingsheng; Mei Zhijun

2007-01-01

Objective: To study the clinical effect of stenting-plasty with retrograde brachial puncture for subclavian steal syndrome patients. Methods: To analyze the clinical results of stenting-plasty with retrograde brachial puncture in 15 patients with subclavian steal syndrome. Results: MRA or DSA showed the subclavian arteries with different degrees of stenosis (80%-100%) in all patients. Stenting-plasty with retrograde brachia] puncture was used in all patients. After placement of wall or polmaz stent, the pulse recovered and the syndrome disappeared. Postoperative angiography showed patency of the artery and stent. The patients were followed up for 3-30 months without recurrence of symptoms. Conclusions: Stenting-plasty with retrograde brachial puncture is a rather proper method to treat subclavian steal syndrome with more coincidence to the vascular anatomy, decrease the maneuver trouble and increase the successful rate. (authors)
Combined Arterial Infusion and Stent Implantation Compared with Metal Stent Alone in Treatment of Malignant Gastroduodenal Obstruction

International Nuclear Information System (INIS)

Wang Zhongmin; Chen Kemin; Gong Ju; Zheng Yunfeng; Wang Tianxiang

2009-01-01

.38 to 1.48 (p < 0.01). There were no short-term complications. Late complications including hematemesis (n = 3), migration (n = 12), and stent occlusion due to tumor overgrowth (n = 5) were evenly distributed between the groups. In the DIT group chemotherapy-induced neutropenia and transient renal dysfunction were detected in six patients, which improved after symptomatic management. Mean survival time after the procedure was 5.9 and 11.1 months for MSI and DIT, respectively (P < 0.001). In conclusion, both MSI and DIT offer effective palliation for malignant gastroduodenal obstruction, but DIT appears to offer superior survival over MSI alone. Ideally, a prospective randomized trial comparing these two techniques should be carried out to validate this result.
Use of flow-diverting stents as salvage treatment following failed stent-assisted embolization of intracranial aneurysms.

Science.gov (United States)

Heiferman, Daniel M; Billingsley, Joshua T; Kasliwal, Manish K; Johnson, Andrew K; Keigher, Kiffon M; Frudit, Michel E; Moftakhar, Roham; Lopes, Demetrius K

2016-07-01

Flow-diverting stents, including the Pipeline embolization device (PED) and Silk, have been beneficial in the treatment of aneurysms previously unable to be approached via endovascular techniques. Recurrent aneurysms for which stent-assisted embolization has failed are a therapeutic challenge, given the existing intraluminal construct with continued blood flow into the aneurysm. We report our experience using flow-diverting stents in the repair of 25 aneurysms for which stent-assisted embolization had failed. Nineteen (76%) of these aneurysms at the 12-month follow-up showed improved Raymond class occlusion, with 38% being completely occluded, and all aneurysms demonstrated decreased filling. One patient developed a moderate permanent neurologic deficit. Appropriate stent sizing, proximal and distal construct coverage, and preventing flow diverter deployment between the previously deployed stent struts are important considerations to ensure wall apposition and prevention of endoleak. Flow diverters are shown to be a reasonable option for treating previously stented recurrent cerebral aneurysms. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Experimental study of different nickel-titanium memory tracheal stents in dogs

International Nuclear Information System (INIS)

Lang Xu; He Nengshu; Fan Hailun

2009-01-01

Objective: Since membrane -covered metal tracheal stent was applied successfully to treat the airway stenosis, it has been widely used and obtained satisfactory result during the past years. The purpose of our study was provide theoretical rational for treatment with membrane-covered tracheal stent by using animal experiment. Methods: The nickel- titanium memory stents of 22 mm in diameter and 6 cm in length were deployed in 18 dogs. The dogs were grouped into full- length membrane-covered group (n=6), partial-length membrane-covered group (membrane was covered for 4 cm in the medial part of the stent, n=6), and naked stent group (n=6). After the stent placement dysphagia or dysphonia was monitored daily. Twenty-four weeks later, the dogs were executed. Speiments were taken from the cephalic, medial, and caudal trachea under the stent. HE stain and proliferating cell nuclear antigen (PCNA) were evaluated. Results: After the stent placement, no dyspnea, dysphagia or dysphonia but cough was present in each dog. There was no significant difference in symptom between the three groups. Inflammation reaction, metaplasia from low columnar epithelium to spuamous epithelium, and mild granulation tissue hyperplasia in the underlying mucosa were present in each group. However, fibrosis and tracheal straitness were present only in the non-membrane-covered area, but not in the membrane-covered area. More PCNA expression was observed in the non-membrane -covered area than in the membrane-covered area. Conclusion: Both membrane-covered and non-membrane-covered stents can cause similar symptoms. However, the membrane -covered tracheal stent has good biological compatibility and would not induce tracheal straitness. The non-membrane -covered tracheal stent could induce a severe pathologic reaction and tracheal straitness. (authors)
Endovascular treatment of experimentally induced aneurysms in rabbits using stents: a feasibility study

International Nuclear Information System (INIS)

Hans, F.J.; Thiex, R.; Gilsbach, J.M.; Krings, T.; Moeller-Hartmann, W.; Dreeskamp, H.; Stein, K.P.; Meetz, A.; Thron, A.; Pfeffer, J.; Scherer, K.; Brunn, A.

2003-01-01

Although Guglielmi detachable coil (GDC) systems have been generally accepted for treatment of intracranial aneurysms, primary stenting of aneurysms using porous stents or implantation of coils after stent placement remains experimental. Testing of these new methods requires an animal model which imitates human aneurysms in size, configuration and neck morphology. We assessed in detail the technical requirements of and steps for transfemoral stent treatment of experimentally induced aneurysms at the top of the brachiocephalic trunk in rabbits. We created aneurysms in ten rabbits by distal ligation and intraluminal digestion of the right common carotid artery with elastase. We treated five animals with porous stents alone, and five with stents plus coiling via the meshes of the stent, which permitted dense packing of coils. No complications related to the procedures occurred. In all animals, even in those treated solely with porous stents, total occlusion of the aneurysm was achieved. Our animal model can be suitable for testing the biocompatibility and occlusion rate of new methods and devices for the treatment of experimental aneurysms. (orig.)
Covered Metallic Stents With an Anti-Migration Design vs. Uncovered Stents for the Palliation of Malignant Gastric Outlet Obstruction: A Multicenter, Randomized Trial

Science.gov (United States)

Lee, Hyuk; Min, Byung-Hoon; Lee, Jeong Hoon; Shin, Cheol Min; Kim, Younjoo; Chung, Hyunsoo; Lee, Sang Hyub

2015-01-01

OBJECTIVES: Previous studies reported comparable stent patency between covered self-expandable metallic stents (SEMS) and uncovered SEMS (UCS) for palliation of malignant gastric outlet obstruction (GOO). The aim of this study was to evaluate the efficacy and safety of the newly developed WAVE-covered SEMS (WCS), which has an anti-migration design, compared with UCS in gastric cancer patients with symptomatic GOO. METHODS: A total of 102 inoperable gastric cancer patients with symptomatic GOO were prospectively enrolled from five referral centers and randomized to undergo UCS or WCS placement. Stent patency and recurrence of obstructive symptoms were assessed at 8 weeks and 16 weeks after stent placement. RESULTS: At the 8-week follow-up, both stent patency rates (72.5% vs. 62.7%) and re-intervention rates (19.6% vs. 19.6%) were comparable between the WCS and the UCS groups. Both stent stenosis (2.4% vs. 8.1%) and migration rates (9.5% vs. 5.4%) were comparable between WCS and UCS groups. At the 16-week follow-up, however, the WCS group had a significantly higher stent patency rate than the UCS group (68.6% vs. 41.2%). Re-intervention rates in the WCS and UCS groups were 23.5% and 39.2%, respectively. Compared with the UCS group, the WCS group had a significantly lower stent restenosis rate (7.1% vs. 37.8%) and a comparable migration rate (9.5% vs. 5.4%). Overall stent patency was significantly longer in the WCS group than in the UCS group. No stent-associated significant adverse events occurred in either the WCS or UCS groups. In the multivariate analysis, WCS placement and chemotherapy were identified as independent predictors of 16-week stent patency. CONCLUSIONS: WCS group showed comparable migration rate and significantly more durable long-term stent patency compared with UCS group for the palliation of GOO in patients with inoperable gastric cancer. PMID:26372507
Functional Nanoarchitectures For Enhanced Drug Eluting Stents

Science.gov (United States)

Saleh, Yomna E.; Gepreel, Mohamed A.; Allam, Nageh K.

2017-01-01

Different strategies have been investigated to allow for optimum duration and conditions for endothelium healing through the enhancement of coronary stents. In this study, a nanoarchitectured system is proposed as a surface modification for drug eluting stents. Highly oriented nanotubes were vertically grown on the surface of a new Ni-free biocompatible Ti-based alloy, as a potential material for self-expandable stents. The fabricated nanotubes were self-grown from the potential stent substrate, which are also proposed to enhance endothelial proliferation while acting as drug reservoir to hinder Vascular Smooth Muscle Cells (VSMC) proliferation. Two morphologies were synthesized to investigate the effect of structure homogeneity on the intended application. The material was characterized by field-emission scanning electron microscope (FESEM), X-ray diffraction (XRD), Raman spectroscopy, energy dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). Nanoindentation technique was used to study the mechanical properties of the fabricated material. Cytotoxicity and proliferation studies were performed and compared for the two fabricated nanoarchitectures, versus smooth untextured samples, using in-vitro cultured endothelial cells. Finally, the drug loading capacity was experimentally studied and further supported by computational modeling of the release profile.
Stent Thrombosis With Drug-Eluting Stents and Bioresorbable Scaffolds: Evidence From a Network Meta-Analysis of 147 Trials.

Science.gov (United States)

Kang, Si-Hyuck; Chae, In-Ho; Park, Jin-Joo; Lee, Hak Seung; Kang, Do-Yoon; Hwang, Seung-Sik; Youn, Tae-Jin; Kim, Hyo-Soo

2016-06-27

This study sought to perform a systematic review and network meta-analysis to compare the relative safety and efficacy of contemporary DES and BVS. To improve outcomes of patients undergoing percutaneous coronary revascularization, there have been advances in the design of drug-eluting stents (DES), including the development of drug-eluting bioresorbable vascular scaffolds (BVS). Prospective, randomized, controlled trials comparing bare-metal stents (BMS), paclitaxel-eluting stents (PES), sirolimus-eluting stents (SES), Endeavor zotarolimus-eluting stents (E-ZES), cobalt-chromium (CoCr) everolimus-eluting stents (EES), platinum-chromium (PtCr)-EES, biodegradable polymer (BP)-EES, Resolute zotarolimus-eluting stents (R-ZES), BP biolimus-eluting stents (BP-BES), hybrid sirolimus-eluting stents (H [Orsiro]-SES), polymer-free sirolimus- and probucol-eluting stents, or BVS were searched in online databases. The primary endpoint was definite or probable stent thrombosis at 1 year. A total of 147 trials including 126,526 patients were analyzed in this study. All contemporary DES were superior to BMS and PES in terms of definite or probable stent thrombosis at 1 year. CoCr-EES, PtCr-EES, and H-SES were associated with significantly lower risk than BVS. CoCr-EES and H-SES were superior to SES and BP-BES. The risk of myocardial infarction was significantly lower with H-SES than with BVS. There were no significant differences regarding all-cause or cardiac mortality. Contemporary devices including BVS showed comparably low risks of repeat revascularization. Contemporary DES, including biocompatible DP-DES, BP-DES, and polymer-free DES, showed a low risk of definite or probable stent thrombosis at 1 year. BVS had an increased risk of device thrombosis compared with CoCr-EES, PtCr-EES, and H-SES. Data from extended follow-up are warranted to confirm the long-term safety of contemporary coronary devices. Copyright © 2016 American College of Cardiology Foundation. Published by
Low-profile stent system for treatment of atherosclerotic renal artery stenosis : The GREAT trial

NARCIS (Netherlands)

Sapoval, Marc; Zahringer, Markus; Pattynama, Peter; Rabbia, Claudio; Vignali, Claudio; Maleux, Geert; Boyer, Louis; Szczerbo-Trojanowska, Malgorzata; Jaschke, Werner; Hafsahl, Geir; Downes, Mark; Beregi, Jean Paul; Veeger, Nic; Talen, Aly

PURPOSE: The Palmaz Genesis Peripheral Stainless Steel Balloon Expandable Stent in Renal Artery Treatment (GREAT) Trial was designed to assess the safety and performance of a low-profile stent for the treatment of obstructive renal artery disease by looking at 6-month renal artery patency uniformly
Palliation of dysphagia in patients with malignant esophageal strictures. Comparison of results of radiotherapy, chemotherapy and esophageal stent treatment

Energy Technology Data Exchange (ETDEWEB)

Cwikiel, M. [Dept. of Oncology, Univ. Hospital, Lund (Sweden); Cwikiel, W. [Diagnostic Radiology, Univ. Hospital, Lund (Sweden); Albertsson, M. [Dept. of Oncology, Univ. Hospital, Lund (Sweden)

1996-06-01

Dysphagia is the earliest and the most common symptom of malignant disease in the esophagus. The palliative effects on dysphagia of radiotherapy (RT) and chemotherapy (CT) were evaluated retrospectively and compared with the effect of the self-expanding stent, evaluated in the prospective study. After completion of treatment, 78 (56%) of 140 patients treated with RT; 31 (49%) of 63 patients treated with CT; and 53 (81%) of 66 patients treated with stent insertion were free from dysphagia. Stent treatment has a good and prompt effect on dysphagia and can be recommended for palliation of patients with malignant esophageal strictures. (orig.).

Biodegradable airway stents in infants - Potential life-threatening pitfalls.

Science.gov (United States)

Sztanó, B; Kiss, G; Márai, K; Rácz, G; Szegesdi, I; Rácz, K; Katona, G; Rovó, L

2016-12-01

The solution of severe tracheobronchial obstructions in early childhood means a great challenge. Biodegradable stents were intended to be a minimally invasive temporary solution which may decrease the number of interventions and limit the possible complications of stenting procedures. However, our first experiences have brought out a new, - especially in childhood - potentially life-threatening complication of this concept. Five SX-ELLA biodegradable polydioxanone stents was applied in three patients because of severe tracheobronchial obstruction: congenital tracheomalacia (7 day-old), acquired tracheomalacia (10 month-old), and congenital trachea-bronchomalacia (10 month-old). The breathing of all children improved right after the procedure. We observed degradation of the stent from the 5th postoperative week which resulted in large intraluminar fragments causing significant airway obstruction: one patient died of severe pneumonia, the other baby required urgent bronchoscopy to remove the obstructing 'foreign body' from the trachea. In the third case repeated stent placements successfully maintained the tracheal lumen. Polydioxanone stents may offer an alternative to metallic or silastic stents for collapse or external compression of the trachea in children; however, large decaying fragments mean a potential risk especially in the small size pediatric airway. The fragmentation of the stent, which generally starts in the 4-6 postoperative weeks, may create large sharp pieces. These may be anchored to the mucosa and covered by crust leading to obstruction. As repeated interventions are required, we do not consider the application of biodegradable stents unambiguously advantageous. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Timing of silicone stent removal in patients with post-tuberculosis bronchial stenosis

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Jung Seop Eom

2013-01-01

Full Text Available Context: In patients with post-tuberculosis bronchial stenosis (PTBS, the severity of bronchial stenosis affects the restenosis rate after the silicone stent is removed. In PTBS patients with incomplete bronchial obstruction, who had a favorable prognosis, the timing of stent removal to ensure airway patency is not clear. Aims: We evaluated the time for silicone stent removal in patients with incomplete PTBS. Settings and Design: A retrospective study examined PTBS patients who underwent stenting and removal of a silicone stent. Methods: Incomplete bronchial stenosis was defined as PTBS other than total bronchial obstruction, which had a luminal opening at the stenotic segment on bronchoscopic intervention. The duration of stenting was defined as the interval from stent insertion to removal. The study included 44 PTBS patients and the patients were grouped at intervals of 6 months according to the duration of stenting. Results: Patients stented for more than 12 months had a significantly lower restenosis rate than those stented for less than 12 months (4% vs. 35%, P = 0.009. Multiple logistic regression revealed an association between stenting for more than 12 months and a low restenosis rate (odds ratio 12.095; 95% confidence interval 1.097-133.377. Moreover, no restenosis was observed in PTBS patients when the stent was placed more than 14 months previously. Conclusions: In patients with incomplete PTBS, stent placement for longer than 12 months reduced restenosis after stent removal.
Investigation of adverse events associated with an off-label use of arterial stents and CE-marked iliac vein stents in the iliac vein: insights into developing a better iliac vein stent.

Science.gov (United States)

Shida, Takuya; Umezu, Mitsuo; Iwasaki, Kiyotaka

2018-06-01

We analyzed the adverse events associated with an off-label use of arterial stents and CE-marked iliac vein stents for the treatment of iliac venous thromboembolism and investigated their relationships with the anatomical features of the iliac vein, to gain insights into the development of a better iliac vein stent. Reports of adverse events following the use of stents in the iliac vein were retrieved from the Manufacturer and User Facility Device Experience (MAUDE) database that contain suspected device-associated complications reported to the Food and Drug Administration. Data from 2006 to 2016 were investigated. The literature analysis was also conducted using PubMed, Cochrane Library, EMBASE, and Web of Science focusing on English articles published up to 4 October 2016. The analysis of 88 adverse events from the MAUDE database and 182 articles from the literature revealed that a higher number of adverse events had been reported following the use of arterial stents in the iliac vein compared to CE-marked iliac vein stents. While stent migration and shortening were reported only for the arterial stents, stent fracture and compression occurred regardless of the stent type, even though a vein does not pulsate. A study of the anatomical features of the iliac vein implies that bending, compression, and kink loads are applied to the iliac vein stents in vivo. For designing, developing, and pre-clinical testing of stents intended for use in the iliac vein, the above mechanical load environments induced by the anatomical features should be considered.
Use of guiding sheaths in peroral fluoroscopic gastroduodenal stent placement

International Nuclear Information System (INIS)

Bae, Jae-Ik; Shin, Ji Hoon; Song, Ho-Young; Yoon, Chang Jin; Nam, Deok Ho; Choi, Won-Chan; Lim, Jin-Oh

2005-01-01

Our purpose was to assess the safety and usefulness of guiding sheaths in peroral fluoroscopic gastroduodenal stent placement. Two types of guiding sheath were made from straight polytetrafluoroethylene tubes. Type A was 80 cm in length, 4 mm in outer diameter and 3 mm in inner diameter. Type B was 70 cm in length, 6 mm in outer diameter and 5 mm in inner diameter. The type A sheath was used in 18 patients in whom a catheter-guide wire combination failed to pass through a stricture. The type B sheath was used in 22 patients in whom a stent delivery system failed to pass through the stricture due to loop formation within the gastric lumen. The overall success rate for guiding a catheter-guide wire through a stricture after using the type A sheath was 89%. The overall success rate for passing a stent delivery system through a stricture after using the type B sheath was 100%. All procedures were tolerated by the patients without any significant complications. The guiding sheaths were safe and useful in peroral fluoroscopic gastroduodenal stent placement. (orig.)
Clinical significance of balloon dilatation angiography during cerebral venous sinus stenosis stenting

Directory of Open Access Journals (Sweden)

Xiang-yu CAO

2016-12-01

Full Text Available Objective To explore the clinical significance of balloon dilatation angiography during cerebral venous sinus stenosis stenting to predict the reflux of perforator veins after operation. Methods A total of 93 patients (including 51 with cerebral venous sinus stenosis and intracranial hypertension and 42 with intractable pulsatile tinnitus caused by cerebral venous sinus stenosis who were treated by stent implantation were analyzed retrospectively. Among those patients, the diameter of transverse and sigmoid sinuses of 63 cases were measured based on angiography, and stent was selected according to the measurement result. The other 30 cases were given angiography on ipsilateral carotid artery or vertebral artery when the balloon was dilated in the venous sinus to confirm the reflux of perforator veins. If the venous reflux decreased in the angiography, stent with diameter 1-2 mm less than that of venous sinus could be selected. Results The success rate of stenting was 100% (93/93. In 63 cases, 45 cases were planted 9 mm × 40 mm stents, 15 were planted 8 mm × 40 mm stents, 3 were planted 7 mm × 40 mm stents. The average diameter of stents was (8.67 ± 0.68 mm. There were 11 cases (17.46% with slow perforator venous reflux after operation. In the other 30 cases, 3 cases were planted 8 mm × 40 mm stents, 11 were planted 7 mm × 40 mm stents, and 16 were planted 6 mm × 40 mm stents. The average diameter of stents was (7.57 ± 0.67 mm. There was only one case (3.33% with slow perforator venous reflux after operation. The difference of stent diameter between 2 groups was statistically significant (t = 15.632, P = 0.001. The occurrence rate of perforator vein occlusion after operation between 2 groups was significantly different (adjusted χ 2 = 60.065, P = 0.001. Conclusions Perforator vein occlusion after cerebral venous sinus stenting is common complication. Balloon dilatation angiography could predict the possibility of perforator vein
Experimental 16-row CT evaluation of in-stent restenosis using new stationary and moving cardiac stent phantoms: experimental examination

International Nuclear Information System (INIS)

Yamamura, J.; Adam, G.; Begemann, P.G.; Stevendaal, U. van; Grass, M.; Koester, R.

2006-01-01

Purpose: The aim of this study was to evaluate in-stent restenosis using a newly developed stationary and moving cardiac stent phantom with three built-in artificial stenoses and a 16-row MDCT. Materials and Methods: A newly developed coronary stent phantom with three artificial stenoses - low (approx. 30%), medium (approx. 50%) and high (approx. 70%) - was attached to a moving heart phantom and used to evaluate the ability of 16-row MDCT to visualize in-stent restenosis. High resolution scans (16 x 0.75 mm, 250 mm FOV) were made to identify the baseline for image quality. The non-moving phantom was scanned (16 x 0.75 mm, routine cardiac scan protocol) first without and then with implementation of an ECG signal at various simulated heart rates (HR 40 to 120 bpm) and pitches (0.15 to 0.3). The moving cardiac phantom was scanned at the same simulated heart rates but at a pitch of 0.15. Images were reconstructed at every 10% of the RR interval using a multi-cycle real cone-beam reconstruction algorithm. Multi-planar reformations (MPR) were made for the image evaluation. The image quality was assessed using a three-point scale, and stent patency and stenoses detection were evaluated using a four-point scale. To evaluate the image quality and to grade the stent stenoses, the median values were calculated while considering the reconstruction interval. Results: The image quality for the static phantom was adequate in 97% of the measurements. In this phantom, every stenosis was detected independent of the pitch and heart rate used. The dynamic stent phantom yielded the best results at 0%, 40%, and 50% of the RR interval at a pitch of 0.15. The low stenosis was visible at a simulated heart rate of up to 80 bpm. Patency can be detected at heart rates greater than 80 bpm. (orig.)
Comparison of Self-Expanding Polyethylene Terephthalate and Metallic Stents Implanted in Porcine Iliac Arteries

International Nuclear Information System (INIS)

Wilczek, Krzysztof; Scheerder, Ivan de; Wang Kai; Verbeken, Eric; Piessens, Jan

1996-01-01

Purpose: Comparison of the biocompatibility of self-expanding polyethylene terephthalate (PET) stents with self-expanding metallic stents (Wallstents). Methods: Diameter- and length-matched PET stents and Wallstents were symmetrically implanted in the paired iliac arteries of 13 crossbred domestic swine. Stent deployment was studied angiographically and with intravascular ultrasound immediately after stent implantation. The angiographic stented lumen diameter was measured using quantitative vessel analysis before, immediately after stenting, and at 6-week follow-up. Cross-section histopathology and area morphometry were performed. Results: Immediately poststenting, intravascular ultrasound revealed proximal dislocation of 5 of the 13 PET stents, whereas all metal stents were firmly embedded at the implantation site. At 6-week follow-up, three of the remaining PET stents were totally or subtotally occluded by organized thrombus, whereas all metal stents were patent. Compared with immediately poststenting, the angiographic lumen diameter within the five remaining PET stents was reduced by 30%, and that of the metallic stents was virtually unaltered (p < 0.02). This observation was confirmed by postmortem morphometry, wherein the PET-stented vessel segments a diameter stenosis of 40% was measured vs only 9% in the metallic stents (p < 0.0001). Conclusion: PET-stent deployment is difficult to control due to the lack of radiopacity of this stent. PET stents seem to be more thrombogenic and lead to significantly more neointimal proliferation than metallic stents
Primary endpoint results of the OMEGA Study: One-year clinical outcomes after implantation of a novel platinum chromium bare metal stent

Energy Technology Data Exchange (ETDEWEB)

Wang, John C., E-mail: john.wang@medstar.net [MedStar Union Memorial Hospital, Baltimore MD (United States); Carrié, Didier, E-mail: carrie.didier@chu-toulouse.fr [Centre Hôpital Universitaire Rangueil, Toulouse (France); Masotti, Monica, E-mail: MASOTTI@clinic.ub.es [Hospital Clinic, University of Barcelona (Spain); Erglis, Andrejs, E-mail: a.a.erglis@stradini.lv [Pauls Stradins Clinical University Hospital, University of Latvia, Riga (Latvia); Mego, David, E-mail: David.Mego@arheart.com [Arkansas Heart Hospital, Little Rock, AR (United States); Watkins, Matthew W., E-mail: Matthew.Watkins@vtmednet.org [University of Vermont Medical Center, Burlington VT (United States); Underwood, Paul, E-mail: Paul.underwood@bsci.com [Boston Scientific, Marlborough MA USA (United States); Allocco, Dominic J., E-mail: Dominic.allocco@bsci.com [Boston Scientific, Marlborough MA USA (United States); Hamm, Christian W., E-mail: C.Hamm@kerckhoff-klinik.de [Kerckhoff Heart and Thoraxcenter, Bad Nauheim (Germany)

2015-03-15

Background/purpose: Bare metal stents (BMS) have similar rates of death and myocardial infarction (MI) compared to drug-eluting stents (DES). DES lower repeat revascularization rates compared to BMS, but may have higher rates of late stent thrombosis (ST) potentially due to impaired endothelialization requiring longer dual anti-platelet therapy (DAPT). OMEGA evaluated a novel BMS designed to have improved deliverability and radiopacity, in comparison to currently available platforms. Methods/materials: OMEGA was a prospective, multicenter, single-arm study enrolling 328 patients at 37 sites (US and Europe). Patients received the OMEGA stent (bare platinum chromium element stent) for the treatment of de novo native coronary artery lesions (≤ 28 mm long; diameter ≥ 2.25 mm to ≤ 4.50 mm). The primary endpoint was 9-month target lesion failure (TLF: cardiac death, target vessel-related MI, target lesion revascularization [TLR]) compared to a prespecified performance goal (PG) based on prior generation BMS. All major cardiac events were independently adjudicated. DAPT was required for a minimum of 1 month post procedure. Results: In the OMEGA study, the mean age was 65; 17% had diabetes mellitus. The primary endpoint was met; 9 month TLF rate was 11.5%, and the upper 1-sided 95% confidence bound of 14.79% was less than the prespecified PG of 21.2% (p < 0.0001). One-year event rates were low including a TLF rate of 12.8% and an ST rate of 0.6% at 12 months. Conclusions: One-year outcomes of OMEGA show low rates of TLF, revascularization and ST. This supports safety and efficacy of the OMEGA BMS for the treatment of coronary artery disease. - Highlights: • The OMEGA study evaluated a novel platinum chromium bare metal stent. • OMEGA enrolled 328 patients at 37 sites (US and Europe). • The primary endpoint of 9 month target lesion failure was 11.5%. • One-year event rates were low including an ST rate of 0.6% at 12 months.
Primary endpoint results of the OMEGA Study: One-year clinical outcomes after implantation of a novel platinum chromium bare metal stent

International Nuclear Information System (INIS)

Wang, John C.; Carrié, Didier; Masotti, Monica; Erglis, Andrejs; Mego, David; Watkins, Matthew W.; Underwood, Paul; Allocco, Dominic J.; Hamm, Christian W.

2015-01-01

Background/purpose: Bare metal stents (BMS) have similar rates of death and myocardial infarction (MI) compared to drug-eluting stents (DES). DES lower repeat revascularization rates compared to BMS, but may have higher rates of late stent thrombosis (ST) potentially due to impaired endothelialization requiring longer dual anti-platelet therapy (DAPT). OMEGA evaluated a novel BMS designed to have improved deliverability and radiopacity, in comparison to currently available platforms. Methods/materials: OMEGA was a prospective, multicenter, single-arm study enrolling 328 patients at 37 sites (US and Europe). Patients received the OMEGA stent (bare platinum chromium element stent) for the treatment of de novo native coronary artery lesions (≤ 28 mm long; diameter ≥ 2.25 mm to ≤ 4.50 mm). The primary endpoint was 9-month target lesion failure (TLF: cardiac death, target vessel-related MI, target lesion revascularization [TLR]) compared to a prespecified performance goal (PG) based on prior generation BMS. All major cardiac events were independently adjudicated. DAPT was required for a minimum of 1 month post procedure. Results: In the OMEGA study, the mean age was 65; 17% had diabetes mellitus. The primary endpoint was met; 9 month TLF rate was 11.5%, and the upper 1-sided 95% confidence bound of 14.79% was less than the prespecified PG of 21.2% (p < 0.0001). One-year event rates were low including a TLF rate of 12.8% and an ST rate of 0.6% at 12 months. Conclusions: One-year outcomes of OMEGA show low rates of TLF, revascularization and ST. This supports safety and efficacy of the OMEGA BMS for the treatment of coronary artery disease. - Highlights: • The OMEGA study evaluated a novel platinum chromium bare metal stent. • OMEGA enrolled 328 patients at 37 sites (US and Europe). • The primary endpoint of 9 month target lesion failure was 11.5%. • One-year event rates were low including an ST rate of 0.6% at 12 months
Biodegradable stents for the treatment of refractory or recurrent benign esophageal stenosis.

Science.gov (United States)

Imaz-Iglesia, Iñaki; García-Pérez, Sonia; Nachtnebel, Anna; Martín-Águeda, Belén; Sánchez-Piedra, Carlos; Karadayi, Bilgehan; Demirbaş, Ali Rıza

2016-06-01

Esophageal stents are used for the treatment of refractory and recurrent dyphagias. In 2007, esophageal biodegradable stents (EBS) were authorised as an alternative to existing metal and plastic stents in Europe. The advantages claimed for EBS are fewer complications concerning tissue ingrowth, stent migration and stent removal. We performed a systematic review to evaluate the efficacy and safety of EBS compared to fully-covered self-expanding metal stents, self-expanding plastic stents, and esophageal dilation for the treatment of refractory or recurrent benign esophageal stenosis. Three comparative studies (one randomized controlled trial and two cohort studies) were assessed. The studies used different inclusion criteria, had a very small (sample) size and the quality of the evidence was very low. Expert commentary: The current evidence is insufficient to determine the relative efficacy or safety of esophageal biodegradable stents. The results of this systematic review should be updated once new evidence is available.
[Developments in percutaneous coronary intervention and coronary stents].

Science.gov (United States)

Simsek, C; Daemen, J; Zijlstra, F

2014-01-01

In The Netherlands, more than 30.000 patients undergo a percutaneous coronary intervention every year, during which a coronary stent implantation will be performed in 90% of the cases. It is estimated that more than 5 million coronary stent implantations will be performed worldwide this year. While these numbers are impressive, however, coronary stents still have as a limitation the possibility of stent thrombosis. This has been and is an important stimulus for the development of both coronary stents, from a bare metal stent via a drug eluting stent to the present-day development of bio-absorbable stents, and anti-platelet drugs,from acenocoumarol to thieropyridines. The possibility of shortening the period of use of this powerful medication by developing new kinds of non-thrombogenic stents would, for example, make it possible to achieve significant reductions in subsequent bleeding during (dental) procedures.
Endoscopic Dilatation versus Oesophageal Stent in Benign Oesophageal Stricture

Directory of Open Access Journals (Sweden)

Hadyanto Caputra

2016-09-01

Full Text Available Aim: Oesophageal stricture is one of the causes of dysphagia. It is a condition in which the lumen of oesophagus is narrowed by fibrotic tissue in the oesophageal wall. It is usually caused by inflammation or any other cause that leads to necrotizing of tissue. It is mainly differentiated into benign or malignant. The aim of this article is to answer the clinical question on the effectiveness of oesophageal stenting compared to endoscopic dilatation in patient with benign oesophageal stricture due to ingestion of corrosive substances, who had undergone several endoscopic dilatations. Method: We conducted search of relevant articles using PubMed search engine to answer the clinical question. Keywords being used during the search process were: ("oesophageal stricture"[All Fields] OR "oesophageal stenosis"[All Fields] AND (("dilatation"[All Fields] AND ("stents"[MeSH Terms] OR "stents"[All Fields] OR "stent"[All Fields]. Results were further converged by adding specific filters, which were full text articles and clinical trial. Results: The chosen article was further appraised in order to identify its validity and eligibility to answer the clinical question. We chose to use CONSORT (statement to improve the quality of reporting of RCTs to facilitate the critical appraisal and interpretation of RCTs. Conclusion: Stenting was associated with greater dysphagia, co-medication and adverse events. No randomized controlled trials which compared biodegradable stents with other stents or with balloon dilatation was identified. Lack of adequately robust evidence for effectiveness and cost-effectiveness formed the rationale of this trial.
Safety and efficacy of limus-eluting stents and balloon angioplasty for sirolimus-eluting in-stent restenosis

Energy Technology Data Exchange (ETDEWEB)

Ota, Hideaki [Division of Interventional Cardiology, MedStar Washington Hospital Center, Washington, DC 20010 (United States); Mahmoudi, Michael [University of Surrey, Guildford Road, Surrey, GU2-7XH (United Kingdom); Kitabata, Hironori; Torguson, Rebecca; Chen, Fang; Satler, Lowell F.; Suddath, William O.; Pichard, Augusto D. [Division of Interventional Cardiology, MedStar Washington Hospital Center, Washington, DC 20010 (United States); Waksman, Ron, E-mail: ron.waksman@medstar.net [Division of Interventional Cardiology, MedStar Washington Hospital Center, Washington, DC 20010 (United States)

2015-03-15

Objectives: The aim of this study was to compare the safety and efficacy of everolimus-eluting stent (EES), sirolimus-eluting stent (SES), and plain old balloon angioplasty (POBA) for the treatment of SES in-stent restenosis (S-ISR). Background: The optimal treatment for drug-eluting in-stent restenosis remains controversial. Methods: The study cohort comprised 310 consecutive patients (444 lesions) who presented with S-ISR to our institution and underwent treatment with EES (43 patients), SES (102), or POBA (165). The analyzed clinical parameters were the 1-year rates of death, Q-wave myocardial infarction (MI), target lesion revascularization (TLR), target vessel revascularization (TVR), definite stent thrombosis (ST) and major adverse cardiac event (MACE) defined as the composite of death, MI, or TLR at 1-year. Results: The three groups were well matched for the conventional risk factors for coronary artery disease except for smoking. The 1-year analyzed clinical parameters were similar in the three groups: MACE (EES = 14%, SES = 18%, POBA = 20%; p = 0.65), death (EES = 2.3%, SES = 6.2%, POBA = 6.1%; p = 0.61), MI (EES = 4.8%, SES = 2.1%, POBA = 2.5%; p = 0.69), TLR (EES = 11.9%, SES = 12.1%, POBA = 24%; p = 0.78), and TVR (EES = 11.9%, SES = 24.8%, POBA = 22.2%; p = 0.23). There were no cases of definite ST. MACE-free rate was significantly lower in patients with recurrent in-stent restenosis (log-rank p = 0.006). Presentation with acute MI, number of treated lesions and a previous history of MI were found to be independent predictors of MACE. Conclusions: In patients presenting with S-ISR, treatment with implantation of an EES, SES, or POBA is associated with similar clinical outcomes. Patients presenting with recurrent ISR may have a poorer clinical outcome.
Balloon dilatation and balloon-expandable stents for PTA of proximal venous stenoses in haemodialysis patients. Dilatation und ballonexpandierbare Stents zur Therapie zentralvenoeser Stenosen bei Dialysepatienten

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Landwehr, P; Lackner, K [Wuerzburg Univ. (Germany, F.R.). Inst. fuer Roentgendiagnostik; Goetz, R [Wuerzburg Univ. (Germany, F.R.). Abt. fuer Nephrologie

1990-09-01

On 10 dialysis patients we performed 12 balloon dilatations, 2 catheter lyses, 6 stent implants (Palmaz stent) and one atherectomy of central venous stenoses or occlusions (v. subclavia, v. brachiocephalica) at the shunt arm of the patient. The primary success rate was, in balloon PTA and lysis, 12/14 interventions, and in stent placement and atherectomy 7/7. The angiographical and clinical primary result after stent implantation was significantly better than after conventional dilatation. After 66% of the balloon dilatations recidivation occurred within the first year; this can be treated by means of repeated PTA. Whether long-term exclusion of recurrence can be achieved by stent implantation, must be established by means of follow-up studies that are at present in progress. (orig.).
Polymeric Biodegradable Stent Insertion in the Esophagus

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Kai Yang

2016-04-01

Full Text Available Esophageal stent insertion has been used as a well-accepted and effective alternative to manage and improve the quality of life for patients diagnosed with esophageal diseases and disorders. Current stents are either permanent or temporary and are fabricated from either metal or plastic. The partially covered self-expanding metal stent (SEMS has a firm anchoring effect and prevent stent migration, however, the hyperplastic tissue reaction cause stent restenosis and make it difficult to remove. A fully covered SEMS and self-expanding plastic stent (SEPS reduced reactive hyperplasia but has a high migration rate. The main advantage that polymeric biodegradable stents (BDSs have over metal or plastic stents is that removal is not require and reduce the need for repeated stent insertion. But the slightly lower radial force of BDS may be its main shortcoming and a post-implant problem. Thus, strengthening support of BDS is a content of the research in the future. BDSs are often temporarily effective in esophageal stricture to relieve dysphagia. In the future, it can be expect that biodegradable drug-eluting stents (DES will be available to treat benign esophageal stricture, perforations or leaks with additional use as palliative modalities for treating malignant esophageal stricture, as the bridge to surgery or to maintain luminal patency during neoadjuvant chemoradiation.
Use of retrievable self-expanding stent in treating childhood benign oesophageal stricture

International Nuclear Information System (INIS)

Yu Juming; Fan Guoping; Zhong Weixing; Zhu Ming

2007-01-01

Objective: To evaluate the methods and effect of retrievable self-expanding esophageal stent in treating benign esophageal stenosis of children. Methods: The covered retrievable expandable nitinol stents were placed in 10 children with corrosive esophageal stenosis and post-anastomotic stenosis, age ranged from 2 to 12 years, the dysphagia scores were 3, Barium esophagography was taken before the use of retrievable stent. Results: The stents were placed safely in all patients without complications and were successfully removed after all. After the stent placement, all patients could take solid food without dysphagia. During 6 to 12 months follow-up after the stent removal, all children could eat satisfactorily with the dysphagia score as 0. Conclusion: The use of covered retrievable expandable stent is effective and safe in treating childhood benign esophageal stenosis. (authors)
Endovascular therapy of carotid stenosis with self-expandable stent

International Nuclear Information System (INIS)

Liu Jianmin; Huang Qinghai; Hong Bo; Xu Yi; Zhao Wenyuan; Zhang Yongwei; Zhang Long; Zhou Xiaoping

2002-01-01

Objective: To summarize the experience of endovascular treatment of carotid stenosis with expandable stents. Methods: Fifty-two patients with carotid stenosis who experienced repeated transient ischemic attacks or cerebral infarction were admitted to our hospital. The stenosis was pre-expanded with undetachable balloon, and self-expandable stents were implanted across the stenosis. A balloon catheter was used to further expand stents in 29 patients. Results: The stent was accurately implanted, and total disappearance of stenosis was obtained in 34 patients, the degree of stenosis reduced more than 90% in 16 patients, and more than 70% in 2 patients. The patients recovered well and no complications related to the procedure occurred. None experienced TIA or infarction postoperatively in 52 cases and follow-up imaging in 19 patients (6 - 12 months) demonstrated no restenosis. Conclusion: Endovascular stenting may be a safe and valid choice for the treatment of extracranial carotid stenosis
Incidence of bacterial colonisation after indwelling of double-J ureteral stent

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Hasan Riza Aydin

2016-01-01

Full Text Available Objective: To determine the bacterial colonisation after double-J stent use and the risk factors for bacteriuria linked to the stent. Materials and Methods: A total of 102 patients (61 men and 41 women, mean age 47.5 ± 14.16 were examined. The stents were removed under aseptic conditions, and a urine culture was obtained before the removal of the stents. After the stents were removed, the upper, central and lower sections were separated, and washing water was sent through the stent. Results: Bacterial colonisation was found in 29.4% (30 of 102 of the stents. The most frequently observed microorganisms were determined as staphylococcus, coagulase negative (8 of 30 and E. coli (5 of 30. The washing fluid used to clean the interior of the catheter produced pathogens in 8 patients (7.8%, and these pathogens were observed to be the same microorganisms that colonised the outside of the stent. There was no statistical difference between the patients with colonisation and those without in terms of age, gender, duration of stenting and reason for stent insertion. Conclusions: Though stent colonisation does not always entail symptomatic urinary tract infections, as shown in our study, the pathogens in the urine culture are the same as those colonising the stent, confirming the reality that colonisation is the main factor in these events. Additionally, according to our study, significant colonisation may be found in the first 3 weeks, contrary to the literature, causing us to consider that urinary tract infections may develop even in the early period.
[Complications and the management of fully covered retrievable metal stent placement in benign tracheal stenosis].

Science.gov (United States)

Wang, Zheng-yu; Wang, Yong-li; Chen, Guang-li; Liang, Xi-hong; Wang, Zhen-chang; Ma, Jian-zhong; Wu, Guang-zhong; Zhang, Xiao-ping

2012-11-01

To study complications and the management of the use of covered retrievable expandable metallic stents in the treatment of benign tracheal stenosis. Fully covered retrievable metal stents were placed in 21 patients with benign tracheal stenosis. Stent-related complications and the management were reviewed and analysed. Twenty-eight fully covered retrievable metallic stents were successfully placed fluoroscopically in 21 patients. Stents were removed 4 - 12 months [mean (5.5 ± 2.2) mouths] after placement in all patients. Stent-related complications included granulation tissue (n = 18), stent migration (n = 4), stent expectoration (n = 2), halitosis (n = 8), mucous retention (n = 21) and mucus plugging (n = 1). Granulation tissue was removed with a carbon dioxide laser in 2 patients. Stents were replaced for 2 times and 3 times respectively in 2 patients after stent migration and stent expectoration. An additional stent was placed in 2 patients after stent migration. Symptom of halitosis was relieved after prolonged course of systemic antibiotics treatment in 8 patients. Symptom of mucous retention was relieved with nebulized saline and N-acetylcysteine saline inhalation. Mucous plug was expelled after severe coughing after suctioning using an aspirator in one patient. There were statistically significant differences in stricture diameter, rank of tachypnea and pulmonary function (FEV(1)) in all 21 patients before stent insertion and after stents removal. No patient has experienced recurrence during the follow-up period of 1 - 36 months [mean (23.2 ± 8.0) months]. Fully covered retrievable metallic stent may be a safe and effective in benign tracheal stenosis. Stent-related complications may be effectively managed.
Circumferential and fusiform intracranial aneurysms: reconstructive endovascular treatment with self-expandable stents

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Lubicz, Boris [Erasme University Hospital, Department of Neuroradiology, Brussels (Belgium); Hopital Erasme, Service de Radiologie (EA 2691), Brussels (Belgium); Collignon, Laurent; Baleriaux, Danielle [Erasme University Hospital, Department of Neuroradiology, Brussels (Belgium); Lefranc, Florence; Bruneau, Michael; Brotchi, Jacques; Witte, Olivier de [Erasme University Hospital, Department of Neurosurgery, Brussels (Belgium)

2008-06-15

We report our experience with endovascular treatment (EVT) of circumferential and fusiform intracranial aneurysms by a reconstructive approach with self-expandable stents. A retrospective review of our prospectively maintained database identified all circumferential and fusiform aneurysms treated by a reconstructive endovascular approach over a 3-year period. Clinical charts, procedural data, and angiographic results were reviewed. From April 2004 to May 2007, 13 patients were identified, of whom 12 were asymptomatic and 1 presented with a subarachnoid hemorrhage. Two patients with an aneurysm {<=}2 mm were treated by stent-within-stent placement without coiling (group 1). In 11 patients with a larger aneurysm, stenting with subsequent coiling was performed (group 2). In this latter approach, a balloon was temporarily inflated within the stent to ensure safe coil delivery. All patients showed an excellent clinical outcome. Asymptomatic procedural complications occurred in three patients, two with cervical internal carotid artery dissection and one with retroperitoneal hematoma. In patients of group 1, the aneurysm had completely disappeared at 6 months. In patients of group 2, aneurysm occlusion was complete in three and incomplete in eight. Follow-up angiography in 12 patients showed four with further thrombosis, six with stable results, and two with minor recanalization. Circumferential and fusiform intracranial aneurysms may be treated by a reconstructive endovascular approach with self-expandable stents. In small aneurysms, a stent-within-stent technique is effective, whereas stenting and subsequent coiling is indicated in larger aneurysms. This therapeutic protocol is associated with good clinical and anatomical results. (orig.)

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