Biodegradable Metals for Cardiovascular Stent Application: Interests and New Opportunities

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Maryam Moravej

2011-06-01

Full Text Available During the last decade, biodegradable metallic stents have been developed and investigated as alternatives for the currently-used permanent cardiovascular stents. Degradable metallic materials could potentially replace corrosion-resistant metals currently used for stent application as it has been shown that the role of stenting is temporary and limited to a period of 6–12 months after implantation during which arterial remodeling and healing occur. Although corrosion is generally considered as a failure in metallurgy, the corrodibility of certain metals can be an advantage for their application as degradable implants. The candidate materials for such application should have mechanical properties ideally close to those of 316L stainless steel which is the gold standard material for stent application in order to provide mechanical support to diseased arteries. Non-toxicity of the metal itself and its degradation products is another requirement as the material is absorbed by blood and cells. Based on the mentioned requirements, iron-based and magnesium-based alloys have been the investigated candidates for biodegradable stents. This article reviews the recent developments in the design and evaluation of metallic materials for biodegradable stents. It also introduces the new metallurgical processes which could be applied for the production of metallic biodegradable stents and their effect on the properties of the produced metals.

Transient coronary aneurysm formation after Nevo™ stent implantation versus persistent coronary aneurysm after Cypher Select™ stent implantation

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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....

Factors leading to tracheobronchial self-expandable metallic stent fracture.

Science.gov (United States)

Chung, Fu-Tsai; Lin, Shu-Min; Chen, Hao-Cheng; Chou, Chun-Liang; Yu, Chih-Teng; Liu, Chien-Ying; Wang, Chun-Hua; Lin, Horng-Chyuan; Huang, Chien-Da; Kuo, Han-Pin

2008-11-01

This retrospective study was to determine factors that contribute to self-expandable metallic stent fracture in patients with tracheobronchial disease. From 2001 to 2006, 139 patients (age, 62.1 +/- 15.4 years; range, 23-87 years) with benign (n = 62) and malignant (n = 77) tracheobronchial disease received 192 Ultraflex (Boston Scientific, Natick, Mass) self-expandable metallic stents (98 in patients with benign disease and 94 in patients with malignant disease). Seventeen fractured self-expandable metallic stents were found; the incidence was 12.2% (17/139 patients) among patients with tracheobronchial disease. Tortuous airway (odds ratio, 4.06; 95% confidence interval, 1.04-18.34; P = .04) independently predicted self-expandable metallic stent fracture. Most self-expandable metallic stent fractures (64.7%, 11/17) were detected 500 to 1000 days after self-expandable metallic stent implantation. Clinical presentations for patients with fractured self-expandable metallic stents included dyspnea exacerbation (70.6%, 12/17) and cough (23.5%, 4/17). Self-expandable metallic stent fracture is not uncommon in patients with tracheobronchial disease. Tortuous airway is an independent predictor for it. Although management of the fractured self-expandable metallic stent in our study was feasible and safe, self-expandable metallic stents should be restricted to a more select population.

Drug-eluting stents and bare metal stents in patients with NSTE-ACS

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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....

Percutaneous pulmonary valve implantation preceded by routine prestenting with a bare metal stent

DEFF Research Database (Denmark)

Demkow, Marcin; Biernacka, Elzbieta Katarzyna; Spiewak, Mateusz

2011-01-01

Objectives: To evaluate the effectiveness and safety of percutaneous pulmonary valve implantation (PPVI) with routine prestenting with a bare metal stent (BMS). Background: PPVI is a relatively new method of treating patients with repaired congenital heart disease (CHD). Results of PPVI performed.......6 ± 22.7 to 38.8 ± 10.4 mm Hg on the day following implantation (P = 0.001). At 1-month and 6-month follow-ups, mean RVOT gradient was 34.0 ± 9.8 and 32.0 ± 12.2 mm Hg, respectively. In patients with significant pulmonary regurgitation, mean pulmonary regurgitation fraction decreased from 19% ± 6% to 2...

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

Many patients with malignant gastroduodenal obstruction have an unresectable primary lesion and distant metastases, which may prompt palliative management to allow the patient to eat and to improve the quality of life. Intraluminal metallic stent implantation (MSI) under fluoroscopic guidance has been reported to be an effective option for symptomatic relief in these patients, with a good safety record. An alternative, dual interventional therapy (DIT), has been used during the last decade, in which prosthesis insertion is followed by intra-arterial chemotherapy via the tumor-feeding arteries. The aim of this study was to compare success rates, complication rates, and survival time between MSI and DIT in patients who presented with gastroduodenal obstruction from advanced upper gastrointestinal tract cancer. All consecutive patients with malignant gastroduodenal obstruction seen at our center between October 2002 and August 2007 were retrospectively studied. Patients were treated palliatively by either MSI or DIT by the patient's or the next of kin's decision. Outcomes included technical and clinical success, complication rates, and survival. Of the 164 patients with malignant gastric and duodenal outlet obstructions, 80 (49%) underwent stent insertion as the primary therapy, while the remaining 84 (51%) received DIT. Clinical characteristics were similar between the two groups. In the MSI cohort initial stent implantation was successful in 73 patients (91%), two stents were used in 5 patients, and delayed additional stent insertion for stent obstruction related to tumor overgrowth was required in 3 patients during follow-up. In the DIT cohort the technical success rate was 94%, 3 patients required two stents, and stent obstruction occurred in 2 patients after initial stent placement. Early postprocedural clinical success, indicated by average dysphagia score, improved significantly in both groups: MSI group, from 4.56 to 1.51 (P < 0.01); and DIT group, from 4

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

The effects of dextromethorphan on the outcome of percutaneous coronary intervention with bare-metal stent implantation

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Wen-Cheng Liu

2018-01-01

Full Text Available Background: In the era of drug-eluting stents, although bare-metal stent (BMS remains an option for percutaneous coronary intervention (PCI, restenosis remains the Achilles' heel of BMS implantation. A recent study demonstrated several pleiotropic anti-inflammatory effects of dextromethorphan (DXM. This study aims to evaluate the effects of DXM on the outcome of PCI with BMS implantation.Methods: In this prospective, double-blind, randomized trial, we enrolled 55 patients who underwent PCI with BMS implantation from May 2006 to February 2009. The patients were divided into DXM (60 mg once daily and placebo groups. We compared mortality rates, myocardial infarction (MI, target lesion revascularization (TLR, restenosis, stent thrombosis, and plasma levels of high-sensitivity C-reactive protein (hs-CRP with repeated coronary angiography 6 months after the initial procedure.Results: During the 6-month follow-up period, no events of death, MI and stent thrombosis were reported in both groups. The TLR rate was 16.7% in patients receiving DXM compared to 24% receiving a placebo (P = 0.521. The restenosis rate was 30% in patients receiving DXM as compared to 40% receiving the placebo (P = 0.571. Although nonsignificant, the percentage of hs-CRP elevation was lower in the DXM group (20% compared to the placebo group 32%; P = 0.363.Conclusions: DXM is safe to use in patients who underwent PCI. Although DXM therapy following BMS implantation did not significantly reduce the TLR and restenosis rates, it implied a trend toward a lower TLR and restenosis and reduced inflammation in the DXM group compared to the placebo group. Nonetheless, further extensive studies are warranted to elucidate the anti-restenosis effects of DXM.

Similarities and differences in coatings for magnesium-based stents and orthopaedic implants

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Jun Ma

2014-07-01

Full Text Available Magnesium (Mg-based biodegradable materials are promising candidates for the new generation of implantable medical devices, particularly cardiovascular stents and orthopaedic implants. Mg-based cardiovascular stents represent the most innovative stent technology to date. However, these products still do not fully meet clinical requirements with regards to fast degradation rates, late restenosis, and thrombosis. Thus various surface coatings have been introduced to protect Mg-based stents from rapid corrosion and to improve biocompatibility. Similarly, different coatings have been used for orthopaedic implants, e.g., plates and pins for bone fracture fixation or as an interference screw for tendon-bone or ligament-bone insertion, to improve biocompatibility and corrosion resistance. Metal coatings, nanoporous inorganic coatings and permanent polymers have been proved to enhance corrosion resistance; however, inflammation and foreign body reactions have also been reported. By contrast, biodegradable polymers are more biocompatible in general and are favoured over permanent materials. Drugs are also loaded with biodegradable polymers to improve their performance. The key similarities and differences in coatings for Mg-based stents and orthopaedic implants are summarized.

The stenting strategy of drug-eluting stents for coronary artery disease in patients on dialysis

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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.

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)

Long-term outcome after drug-eluting versus bare-metal stent implantation in patients with ST-segment elevation myocardial infarction: 3-year follow-up of the randomized DEDICATION (Drug Elution and Distal Protection in Acute Myocardial Infarction) Trial

DEFF Research Database (Denmark)

Kaltoft, Anne; Kelbaek, Henning; Thuesen, Leif

2010-01-01

The purpose of this study was to compare long-term clinical outcomes after implantation of drug-eluting stents (DES) and bare-metal stents (BMS) in patients with ST-segment elevation myocardial infarction (STEMI).......The purpose of this study was to compare long-term clinical outcomes after implantation of drug-eluting stents (DES) and bare-metal stents (BMS) in patients with ST-segment elevation myocardial infarction (STEMI)....

Intra-stent tissue evaluation within bare metal and drug-eluting stents > 3 years since implantation in patients with mild to moderate neointimal proliferation using optical coherence tomography and virtual histology intravascular ultrasound.

Science.gov (United States)

Kitabata, Hironori; Loh, Joshua P; Pendyala, Lakshmana K; Omar, Alfazir; Ota, Hideaki; Minha, Sa'ar; Magalhaes, Marco A; Torguson, Rebecca; Chen, Fang; Satler, Lowell F; Pichard, Augusto D; Waksman, Ron

2014-04-01

We aimed to compare neointimal tissue characteristics between bare-metal stents (BMS) and drug-eluting stents (DES) at long-term follow-up using optical coherence tomography (OCT) and virtual histology intravascular ultrasound (VH-IVUS). Neoatherosclerosis in neointima has been reported in BMS and in DES. Thirty patients with 36 stented lesions [BMS (n=17) or DES (n=19)] >3years after implantation were prospectively enrolled. OCT and VH-IVUS were performed and analyzed independently. Stents with ≥70% diameter stenosis were excluded. The median duration from implantation was 126.0months in the BMS group and 60.0months in the DES group (p 3years to stents had evidence of intimal disruption. The percentage volume of necrotic core (16.1% [9.7, 20.3] vs. 9.7% [7.0, 16.5], p=0.062) and dense calcium (9.5% [3.8, 13.6] vs. 2.7% [0.4, 4.9], p=0.080) in neointima tended to be greater in BMS-treated lesions. Intra-stent VH-TCFA (BMS vs. DES 45.5% vs. 18.2%, p=0.361) did not differ significantly. At long-term follow-up beyond 3 years after implantation, the intra-stent neointimal tissue characteristics appeared similar for both BMS and DES. Copyright © 2014 Elsevier Inc. All rights reserved.

Metallic stent implantation in patients with iliac artery occlusion: long-term patency rate and factors related to recurrence

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Chung, Seok Kyun; Kim, Jae Kyu; Yoon, Woong; Kim, Jeong; Park, Jin Gyoon; Kang, Heoung Keun; Choi, Soo JinNa [Chonnam National University Hospital School of Medicine, Gwangju (Korea, Republic of)

2003-09-01

To determine the long-term patency rate in 68 patients with iliac artery occlusion who underwent metallic stent implantation, and to analyze the factors related to recurrence. Sixty-eight patients with occlusive disease of the iliac artery underwent implantation of a self-expandable metallic stent. The clinical symptoms were intermittent claudication (n=48), resting pain (n=11), and gangrene (n=9). Stent patency was determined by follow-up angiography and color Doppler imaging, and the cumulative patency rate using the Kaplan-Meier method. Cox's proportional hazard model was used to analyse recurrence-related factors involving clinical symptoms (Fontaine stage), risk factors, and anatomical factors such as lesion location, length, and the development of collaterals. The duration of follow-up varied from 1 day to 73 months (mean, 23.8 months). Arterial occlusion recurred in 16 of 68 patients (23.5%), and the cumulative patency rate was as follows: 95.4% at one month, 93.2% at six months, 80.1% at one year, 73.2% at two years, 68.9% at three years, and 62% at five years. According to a statistical analysis of risk factors, the recurrence (p=0.04) than in those without it, but in patients who smoked, hypertension, DM, and previous cerebrovascular disease were not statistically significant. With regard to anatomical factors, the recurrent rate for lesions involving the external iliac artery was 6.5 times higher (p=0.02) than for those involving the common iliac artery. Variations in the fontaine stage were not statistically significant indicators of recurrence. The recurrence rate after implantation of an iliac artery stent is higher in patients with heart disease than in those without it, and higher for occlusive lesions involving the external iliac artery than for those of the common iliac artery.

Metallic stent implantation in patients with iliac artery occlusion: long-term patency rate and factors related to recurrence

International Nuclear Information System (INIS)

Chung, Seok Kyun; Kim, Jae Kyu; Yoon, Woong; Kim, Jeong; Park, Jin Gyoon; Kang, Heoung Keun; Choi, Soo JinNa

2003-01-01

To determine the long-term patency rate in 68 patients with iliac artery occlusion who underwent metallic stent implantation, and to analyze the factors related to recurrence. Sixty-eight patients with occlusive disease of the iliac artery underwent implantation of a self-expandable metallic stent. The clinical symptoms were intermittent claudication (n=48), resting pain (n=11), and gangrene (n=9). Stent patency was determined by follow-up angiography and color Doppler imaging, and the cumulative patency rate using the Kaplan-Meier method. Cox's proportional hazard model was used to analyse recurrence-related factors involving clinical symptoms (Fontaine stage), risk factors, and anatomical factors such as lesion location, length, and the development of collaterals. The duration of follow-up varied from 1 day to 73 months (mean, 23.8 months). Arterial occlusion recurred in 16 of 68 patients (23.5%), and the cumulative patency rate was as follows: 95.4% at one month, 93.2% at six months, 80.1% at one year, 73.2% at two years, 68.9% at three years, and 62% at five years. According to a statistical analysis of risk factors, the recurrence (p=0.04) than in those without it, but in patients who smoked, hypertension, DM, and previous cerebrovascular disease were not statistically significant. With regard to anatomical factors, the recurrent rate for lesions involving the external iliac artery was 6.5 times higher (p=0.02) than for those involving the common iliac artery. Variations in the fontaine stage were not statistically significant indicators of recurrence. The recurrence rate after implantation of an iliac artery stent is higher in patients with heart disease than in those without it, and higher for occlusive lesions involving the external iliac artery than for those of the common iliac artery

Sex differences in the outcomes of stent implantation in mini-swine model.

Science.gov (United States)

Kunio, Mie; Wong, Gee; Markham, Peter M; Edelman, Elazer R

2018-01-01

Sex-related differences have been noted in cardiovascular anatomy, pathophysiology, and treatment responses, yet we continued to drive evaluation of vascular device development in animal models without consideration of animal sex. We aimed to understand sex-related differences in the vascular responses to stent implantation by analyzing the pooled data of endovascular interventions in 164 Yucatan mini-swine (87 female, 77 male). Bare metal stents (BMS) or drug-eluting stents (DES) were implanted in 212 coronary arteries (63 single BMS implantation, 68 single DES implantation, 33 overlapped BMS implantation, and 48 overlapped DES implantation). Histomorphological parameters were evaluated from vascular specimens at 3-365 days after stent implantation and evaluated values were compared between female and male groups. While neointima formation at all times after implantation was invariant to sex, statistically significant differences between female and male groups were observed in injury, inflammation, adventitial fibrosis, and neointimal fibrin deposition. These differences were observed independently, i.e., for different procedure types and at different follow-up timings. Only subtle temporal sex-related differences were observed in extent and timing of resolution of inflammation and fibrin clearance. These subtle sex-related differences may be increasingly important as interventional devices meld novel materials that erode and innovations in drug delivery. Erodible materials may act differently if inflammation has a different temporal sequence with sex, and drug distribution after balloon or stent delivery might be different if the fibrin clearance speaks to different modes of pharmacokinetics in male and female swine.

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

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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.

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.

Scintigraphic examinations after stent implantation in central airways

International Nuclear Information System (INIS)

Richter, W.S.; Kettner, B.I.; Munz, D.L.

1998-01-01

Endotracheal and endobronchial stent implantation has been developed as an effective treatment of benign and malignant airway stenosis and of tracheo- or bronchoesophageal fistulas. The selection of the stent type depends on the kind and site of disease. Chest X-ray and bronchoscopy are the procedures of choice for monitoring of stent position, structure, and function. However, with scintigraphic methods the effects of stent implantation on pulmonary ventilation and perfusion can be assessed non-invasively. The validation of the effect of a stent implantation on mucociliary and tussive clearance remains to be elucidated. (orig.) [de

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...

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

stents at 2-year follow-up. In randomised studies completed to date, CoCr-EES has the lowest rate of stent thrombosis within 2 years of implantation. The finding that CoCr-EES also reduced stent thrombosis compared with bare-metal stents, if confirmed in future randomised trials, represents a paradigm shift. The Cardiovascular Research Foundation. Copyright © 2012 Elsevier Ltd. All rights reserved.

Metallic stent implantation in the treatment of malignant tracheal stenosis under general anaesthesia

International Nuclear Information System (INIS)

Bai Xuming; Jin Yong; Xie Hong; Cheng Long; Gu Xingshi; Chang Liuhui

2012-01-01

Objective: To evaluate the safety and feasibility of the tracheal stent implantation for treatment of malignant tracheal stenosis under general anaesthesia. Methods: Eighteen patients with malignant tracheal stenosis underwent preoperative 64-slice spiral CT scan and airway reconstruction. The stenotic sites were located in main tracheal trunk (5 patients), in right main bronchus (1 patient), in trachea and left main bronchus (4 patients), in trachea and right main bronchus (3 patients), in main tracheal trunk and bilateral main bronchus (5 patients). The degree of stenosis was rated 51% to 70% in 7 cases, 71% to 90% in 11 cases. All patients, 17 patients of ASA grade Ⅳ and 1 patient of grade Ⅲ, presented with severe dyspnea. Under general anaesthesia, implantation of metallic stent was performed through the sputum aspiration hole of the connecting tubing with DSA guidance. The NBP, ECG, RR, SaO 2 of the patients were recorded and compared with t test during the entire procedure. At the end of the procedure, relief of dyspnea, complications related to anesthesia and operation were recorded. Results: The success rate of stent placement was 18/18, and dyspnea was significantly relived in all patients. Slightly bloody sputum occurred in 7 cases. The stent was obstructed by sputum in 1 case,and the patient was treated with medication. There were no severe complications. The operative course were rated 11 to 9 in 17 cases, and 6 to 8 in 1 case. All 18 patients were cooperative during the procedure. Sixteen patients rated the procedure as very comfortable and 2 rated the procedure as comfortable. Respiratory rate (RR) and heart rate (HR) decreased in all patients after the operation [(37.1 ± 2.8)/min and (106.5 ± 14.2) bpm before the operation respectively, (18.6 ± 1.4)/min and (73.2 ± 7.6) bpm after the operation respectively], t=17.81 and 3.80, P<0.01. Pulse oxygen saturation (SaO 2 ) during the operation [(91.2 ± 1.8)%]increased [(76.3 ± 8.6 )% before the

The use of expandable metallic airway stents for tracheobronchial obstruction in children.

Science.gov (United States)

Filler, R M; Forte, V; Fraga, J C; Matute, J

1995-07-01

Expandable metallic angioplasty stents (Palmaz stent) have been implanted in the trachea and/or bronchi of seven children. Three children had severe tracheal stenosis after tracheoplasty for congenital tracheal stenosis repair, and four had tracheomalacia or bronchomalacia with or without vascular compression. The mean age at stenting was 9.7 months (range, 2 to 15 months). Balloon expandable stents were inserted into the trachea or bronchus through a 3.5-mm bronchoscope under fluoroscopic control. Initially a single tracheal stent was used for all patients except for one with obstruction in the trachea and both bronchi, in whom three stents were implanted. Three children had recurrent airway obstruction 1 month later; one was cured with a second stent; one child died 1 year later; and the other is being treated for heart disease. The others have no serious respiratory problems. The stents in all have been in place for 1 to 25 (mean, 11) months. No immediate complications were noted. Early and late bronchoscopy showed incomplete epithelialization of the stent and patches of granulation tissue on it. Two stents were removed bronchoscopically, one at the completion of treatment for tracheomalacia and the other at the time of recurrent airway obstruction. This preliminary experience indicates that expandable metallic stents have a useful role in the treatment of selected lower airway obstructions.

Metallic Zinc Exhibits Optimal Biocompatibility for Bioabsorbable Endovascular Stents

Science.gov (United States)

Bowen, Patrick K.; Guillory, Roger J.; Shearier, Emily R.; Seitz, Jan-Marten; Drelich, Jaroslaw; Bocks, Martin; Zhao, Feng; Goldman, Jeremy

2015-01-01

Although corrosion resistant bare metal stents are considered generally effective, their permanent presence in a diseased artery is an increasingly recognized limitation due to the potential for long-term complications. We previously reported that metallic zinc exhibited an ideal biocorrosion rate within murine aortas, thus raising the possibility of zinc as a candidate base material for endovascular stenting applications. This study was undertaken to further assess the arterial biocompatibility of metallic zinc. Metallic zinc wires were punctured and advanced into the rat abdominal aorta lumen for up to 6.5 months. This study demonstrated that metallic zinc did not provoke responses that often contribute to restenosis. Low cell densities and neointimal tissue thickness, along with tissue regeneration within the corroding implant, point to optimal biocompatibility of corroding zinc. Furthermore, the lack of progression in neointimal tissue thickness over 6.5 months or the presence of smooth muscle cells near the zinc implant suggest that the products of zinc corrosion may suppress the activities of inflammatory and smooth muscle cells. PMID:26249616

Cutaneous and systemic hypersensitivity reactions to metallic implants.

Science.gov (United States)

Basko-Plluska, Juliana L; Thyssen, Jacob P; Schalock, Peter C

2011-01-01

Cutaneous reactions to metal implants, orthopedic or otherwise, are well documented in the literature. The first case of a dermatitis reaction over a stainless steel fracture plate was described in 1966. Most skin reactions are eczematous and allergic in nature, although urticarial, bullous, and vasculitic eruptions may occur. Also, more complex immune reactions may develop around the implants, resulting in pain, inflammation, and loosening. Nickel, cobalt, and chromium are the three most common metals that elicit both cutaneous and extracutaneous allergic reactions from chronic internal exposure. However, other metal ions as well as bone cement components can cause such hypersensitivity reactions. To complicate things, patients may also develop delayed-type hypersensitivity reactions to metals (ie, in-stent restenosis, prosthesis loosening, inflammation, pain, or allergic contact dermatitis) following the insertion of intravascular stents, dental implants, cardiac pacemakers, or implanted gynecologic devices. Despite repeated attempts by researchers and clinicians to further understand this difficult area of medicine, the association between metal sensitivity and cutaneous allergic reactions remains to be fully understood. This review provides an update of the current knowledge in this field and should be valuable to health care providers who manage patients with conditions related to this field.

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...

Distribution of nickel after modified nitinol stent implantation in animals

Science.gov (United States)

Chepeleva, E.; Sergeevichev, D.; Lotkov, A.; Kashin, O.; Korobeynikov, A.; Kozyr, K.; Baystrukov, V.; Zubarev, D.; Kretov, E.; Pokushalov, E.

2017-09-01

Intravascular stenting of arteries in atherosclerotic lesions is one of the most frequently performed procedures in cardiovascular surgery today. Most stents are made of various stainless-steel alloys and other metals (such as nitinol). Nitinol is a biocompatible, superplastic and corrosion resistant material with an important feature of shape memory. However, the composition of this alloy includes nickel, which shows toxicity to the kidneys, liver, lungs, heart and other organs when it accumulates in the organism. In this research we investigated the nickel content in serum, urine and hair of the laboratory animals after implantation of nitinol stents treated with plasma ionic surface modification by silicon.

Safety and efficacy of everolimus-eluting stents for bare-metal in-stent restenosis

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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.

The technique study and primary clinical application of inverted Y-shaped self-expandable metal airway stent

International Nuclear Information System (INIS)

Han Xinwei; Wu Gang; Ma Ji; Yang Ruimin; Guan Sheng; Ma Nan; Wang Yanli

2007-01-01

Objective: To investigate the feasibility and primary therapeutic effect of inverted Y-shaped self-expandable metal stent for complex airway stenosis. Methods: On the standpoint of the peculiar anatomic structure and the pathological changes of complex airway stenosis, we designed the inverted Y-shaped self-expandable metal stent. Under the fluoroscopic guidance, 7 stents were implanted in 7 cases of airway complex stenosis. Results: The inverted Y-shaped self-expandable metal stents were placed seccussfully, with instantaneous relief of dyspnea and improvement of living quality. Conclusion: The placement of inverted Y-shaped self-expandable metal stent is feasible and safe for treating airway complex stenosis. (authors)

A Critical Review on Metallic Glasses as Structural Materials for Cardiovascular Stent Applications.

Science.gov (United States)

Jafary-Zadeh, Mehdi; Praveen Kumar, Gideon; Branicio, Paulo Sergio; Seifi, Mohsen; Lewandowski, John J; Cui, Fangsen

2018-02-27

Functional and mechanical properties of novel biomaterials must be carefully evaluated to guarantee long-term biocompatibility and structural integrity of implantable medical devices. Owing to the combination of metallic bonding and amorphous structure, metallic glasses (MGs) exhibit extraordinary properties superior to conventional crystalline metallic alloys, placing them at the frontier of biomaterials research. MGs have potential to improve corrosion resistance, biocompatibility, strength, and longevity of biomedical implants, and hence are promising materials for cardiovascular stent applications. Nevertheless, while functional properties and biocompatibility of MGs have been widely investigated and validated, a solid understanding of their mechanical performance during different stages in stent applications is still scarce. In this review, we provide a brief, yet comprehensive account on the general aspects of MGs regarding their formation, processing, structure, mechanical, and chemical properties. More specifically, we focus on the additive manufacturing (AM) of MGs, their outstanding high strength and resilience, and their fatigue properties. The interconnection between processing, structure and mechanical behaviour of MGs is highlighted. We further review the main categories of cardiovascular stents, the required mechanical properties of each category, and the conventional materials have been using to address these requirements. Then, we bridge between the mechanical requirements of stents, structural properties of MGs, and the corresponding stent design caveats. In particular, we discuss our recent findings on the feasibility of using MGs in self-expandable stents where our results show that a metallic glass based aortic stent can be crimped without mechanical failure. We further justify the safe deployment of this stent in human descending aorta. It is our intent with this review to inspire biodevice developers toward the realization of MG-based stents.

A Critical Review on Metallic Glasses as Structural Materials for Cardiovascular Stent Applications

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Mehdi Jafary-Zadeh

2018-02-01

Full Text Available Functional and mechanical properties of novel biomaterials must be carefully evaluated to guarantee long-term biocompatibility and structural integrity of implantable medical devices. Owing to the combination of metallic bonding and amorphous structure, metallic glasses (MGs exhibit extraordinary properties superior to conventional crystalline metallic alloys, placing them at the frontier of biomaterials research. MGs have potential to improve corrosion resistance, biocompatibility, strength, and longevity of biomedical implants, and hence are promising materials for cardiovascular stent applications. Nevertheless, while functional properties and biocompatibility of MGs have been widely investigated and validated, a solid understanding of their mechanical performance during different stages in stent applications is still scarce. In this review, we provide a brief, yet comprehensive account on the general aspects of MGs regarding their formation, processing, structure, mechanical, and chemical properties. More specifically, we focus on the additive manufacturing (AM of MGs, their outstanding high strength and resilience, and their fatigue properties. The interconnection between processing, structure and mechanical behaviour of MGs is highlighted. We further review the main categories of cardiovascular stents, the required mechanical properties of each category, and the conventional materials have been using to address these requirements. Then, we bridge between the mechanical requirements of stents, structural properties of MGs, and the corresponding stent design caveats. In particular, we discuss our recent findings on the feasibility of using MGs in self-expandable stents where our results show that a metallic glass based aortic stent can be crimped without mechanical failure. We further justify the safe deployment of this stent in human descending aorta. It is our intent with this review to inspire biodevice developers toward the realization

A Critical Review on Metallic Glasses as Structural Materials for Cardiovascular Stent Applications

Science.gov (United States)

Jafary-Zadeh, Mehdi; Praveen Kumar, Gideon

2018-01-01

Functional and mechanical properties of novel biomaterials must be carefully evaluated to guarantee long-term biocompatibility and structural integrity of implantable medical devices. Owing to the combination of metallic bonding and amorphous structure, metallic glasses (MGs) exhibit extraordinary properties superior to conventional crystalline metallic alloys, placing them at the frontier of biomaterials research. MGs have potential to improve corrosion resistance, biocompatibility, strength, and longevity of biomedical implants, and hence are promising materials for cardiovascular stent applications. Nevertheless, while functional properties and biocompatibility of MGs have been widely investigated and validated, a solid understanding of their mechanical performance during different stages in stent applications is still scarce. In this review, we provide a brief, yet comprehensive account on the general aspects of MGs regarding their formation, processing, structure, mechanical, and chemical properties. More specifically, we focus on the additive manufacturing (AM) of MGs, their outstanding high strength and resilience, and their fatigue properties. The interconnection between processing, structure and mechanical behaviour of MGs is highlighted. We further review the main categories of cardiovascular stents, the required mechanical properties of each category, and the conventional materials have been using to address these requirements. Then, we bridge between the mechanical requirements of stents, structural properties of MGs, and the corresponding stent design caveats. In particular, we discuss our recent findings on the feasibility of using MGs in self-expandable stents where our results show that a metallic glass based aortic stent can be crimped without mechanical failure. We further justify the safe deployment of this stent in human descending aorta. It is our intent with this review to inspire biodevice developers toward the realization of MG-based stents

Clinical application of self-expandable metallic stents in the treatment of malignant tracheal stenosis under general anesthesia

International Nuclear Information System (INIS)

Wang Weitao; Shi Haibin; Yang Zhengqiang; Liu Sheng; Zhou Chungao; Zhao Linbo; Xia Jinguo; Li Linsun

2009-01-01

Objective: To evaluate the safety and efficacy of self-expandable metallic stent placement for the treatment of malignant tracheal stenosis under general anesthesia and fluoroscopic guidance. Methods: Under general anesthesia the placement of self-expandable metallic stent was performed in 10 patients with malignant tracheal stenosis, the procedure was completed under fluoroscopic guidance in all patients. Results: Successful tracheal stenting was achieved in all 10 patients. In one patient, a Y-shaped stent was used as the tracheal carina was involved in the airway stenosis. The symptoms of dyspnea and asthma were markedly improved immediately after the implantation of stent in all patients. Conclusion: Tracheal implantation of self-expandable metallic stent under general anesthesia and fluoroscopic guidance is a safe and effective treatment for malignant tracheal stenosis, it can promptly relieve various symptoms caused by malignant tracheal stenosis and obviously improve patient's living quality, therefore,t his technique is of great value in clinical practice. (authors)

Self-made metal stent in treatment of nasolacrimal duct obstruction

International Nuclear Information System (INIS)

Du Wei; Pang Ruilin; Luo Gang; Gu Jingchuan; Gong Yongxiang

2003-01-01

Objective: To evaluate application of self-made metal stent in treatment of nasolacrimal duct obstruction. Methods: In total 15 cases, self-made metal stents made of stainless steel wire were implanted in 18 obstructed nasolacrimal ducts. The lacrimal passages were rinsed and re-canalized followed by antegrade inserting the guide wire from upper dacryon. A dilator was inserted over the guide wire, and then a stent was released from a sheath into the impaired section of nasolacrimal duct. Dacryocystography was performed before and after the interventional procedure. Results: Dacryocystography showed patent nasolacrimal duct after treatment. Epiphora disappeared completely in 11 cases (13 ducts), improved in 4 cases (5 ducts). These cases had been followed up for 61-219 days (167 days in average). Relapse was found in 2 cases (2 ducts) in three months. Those 2 stents were removed by surgical procedure and found occluded by granulation. Conclusion: Interventional placement of the self-made metal stent is a simple, safe, low-cost and effective treatment of the nasolacrimal duct obstruction

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

Percutaneous treatment of superior vena cava syndrome using metallic stents

International Nuclear Information System (INIS)

De Gregorio Ariza, Miguel Angel; Gimeno, Maria Jose; Alfonso, Eduardo; Mainar, Antonio; Medrano, Joaquin; Lopez-Marin, Paloma; Gamboa, Pablo; Tobio, Ricardo; Herrera, Marcos

2003-01-01

The purpose of this study was to evaluate the results of treatment of superior vena cava syndrome (SVCS) in patients with benign and malignant disease using expandable metallic stent. From January 1995 to April 2000, 87 expandable stents were implanted in 82 patients (59 men, 23 women; mean age 57.8 years, age range 39-79 years) for the treatment of SVCS. The SVCS was defined as symptomatic bilateral obstruction of venous drainage from head, neck and upper extremities. In 68 patients SVCS was due to malignant neoplasia, and in 14 cases it was due to benign aetiology. All patients were treated with expandable stent. We implanted 81 Wallstent prostheses and 6 Palmaz stents. Adjuvant thrombolysis was applied in 12 patients who required fibrinolysis. After recanalization, the stent was implanted in all cases in SVC (infra- or supra-azygos vein). All patients were treated with heparin of low molecular weight (HBPM) during 6 months. Patency was analyzed according to clinical symptoms and Doppler US or venograms exploration. Technical success was observed in all cases. Clinical success was reached in 78 of 82 patients (95.1%) (absence of symptoms in 2 or 3 days). Four patients suffered immediate thrombosis which required fibrinolitic treatment with a new prosthesis placement in 1 case. The follow-up for the malignant process was of 7.1 months (range 1-39 months) and in benign cases was 31.2 months (range 11-61 months). Sixty-two (91.1%) patients with malignancy died without SVCS symptomatology. All the patients with benign pathology are alive. Clinical primary patency in malignant cases was 87% with assisted patency of 96.2%. Endovascular therapy using metallic stent and thrombolysis is a successful method to treat SVCS due to benign or malignant aetiology. (orig.)

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.

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.

AMS INSIGHT--absorbable metal stent implantation for treatment of below-the-knee critical limb ischemia: 6-month analysis.

Science.gov (United States)

Bosiers, Marc; Peeters, Patrick; D'Archambeau, Olivier; Hendriks, Jeroen; Pilger, Ernst; Düber, Christoph; Zeller, Thomas; Gussmann, Andreas; Lohle, Paul N M; Minar, Erich; Scheinert, Dierk; Hausegger, Klaus; Schulte, Karl-Ludwig; Verbist, Jürgen; Deloose, Koen; Lammer, J

2009-05-01

Endoluminal treatment of infrapopliteal artery lesions is a matter of controversy. Bioabsorbable stents are discussed as a means to combine mechanical prevention of vessel recoil with the advantages of long-term perspectives. The possibility of not having a permanent metallic implant could permit the occurrence of positive remodeling with lumen enlargement to compensate for the development of new lesions. The present study was designed to investigate the safety of absorbable metal stents (AMSs) in the infrapopliteal arteries based on 1- and 6-month clinical follow-up and efficacy based on 6-month angiographic patency. One hundred seventeen patients with 149 lesions with chronic limb ischemia (CLI) were randomized to implantation of an AMS (60 patients, 74 lesions) or stand-alone percutaneous transluminal angioplasty (PTA; 57 patients, 75 lesions). Seven PTA-group patients "crossed over" to AMS stenting. The study population consisted of patients with symptomatic CLI (Rutherford categories 4 and 5) and de novo stenotic (>50%) or occlusive atherosclerotic disease of the infrapopliteal arteries who presented with a reference diameter of between 3.0 and 3.5 mm and a lesion length of <15 mm. The primary safety endpoint was defined as absence of major amputation and/or death within 30 days after index intervention and the primary efficacy endpoint was the 6-month angiographic patency rate as confirmed by core-lab quantitative vessel analysis. The 30-day complication rate was 5.3% (3/57) and 5.0% (3/60) in patients randomized for PTA alone and PTA followed by AMS implantation, respectively. On an intention-to-treat basis, the 6-month angiographic patency rate for lesions treated with AMS (31.8%) was significantly lower (p = 0.013) than the rate for those treated with PTA (58.0%). Although the present study indicates that the AMS technology can be safely applied, it did not demonstrate efficacy in long-term patency over standard PTA in the infrapopliteal vessels.

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.

In-vitro study on the accuracy of a simple-design CT-guided stent for dental implants

International Nuclear Information System (INIS)

Huh, Young June; Choi, Bo Ram; Huh, Kyung Hoe; Yi, Won Jin; Heo, Min Suk; Lee, Sam Sun; Choi, Soon Chul

2012-01-01

An individual surgical stent fabricated from computed tomography (CT) data, called a CT-guided stent, would be useful for accurate installation of implants. The purpose of the present study was to introduce a newly developed CT-guided stent with a simple design and evaluate the accuracy of the stent placement. A resin template was fabricated from a hog mandible and a specially designed plastic plate, with 4 metal balls inserted in it for radiographic recognition, was attached to the occlusal surface of the template. With the surgical stent applied, CT images were taken, and virtual implants were placed using software. The spatial positions of the virtually positioned implants were acquired and implant guiding holes were drilled into the surgical stent using a specially designed 5-axis drilling machine. The surgical stent was placed on the mandible and CT images were taken again. The discrepancy between the central axis of the drilled holes on the second CT images and the virtually installed implants on the first CT images was evaluated. The deviation of the entry point and angulation of the central axis in the reference plane were 0.47±0.27 mm, 0.57±0.23 mm, and 0.64±0.16 degree, 0.57±0.15 degree, respectively. However, for the two different angulations in each group, the 20 degree angulation showed a greater error in the deviation of the entry point than did the 10 degree angulation. The CT-guided template proposed in this study was highly accurate. It could replace existing implant guide systems to reduce costs and effort.

The treatment of complex airway diseases with inverted Y-shaped self-expandable metal stent

International Nuclear Information System (INIS)

Li Jianming; Jia Guangzhi

2011-01-01

Objective: To investigate the application and therapeutic effects of inverted Y-shaped self-expandable metal airway stent in treating complex airway diseases (stenosis or fistula). Methods: According to the distinctive anatomic structure and the pathological changes of complex airway stenosis or fistula, the inverted y-shaped self-expandable metal airway stent was designed. Under fluoroscopic monitoring, a total of 12 inverted Y-shaped self-expandable metal stents were implanted in 12 patients with complex airway diseases. Results: Stent placement in the trachea-bronchial tree was technically successful in all patients. After the operation, the symptom of dyspnea was immediately relieved and the bucking following food intake disappeared. The general physical condition and living quality were much improved in all patients. Conclusion: The use of inverted Y-shaped self-expandable metal airway stent for the management of complex airway stenosis involving the tracheal carina was a simple and safe procedure and it has satisfactory short-term clinical results. (authors)

Cutaneous and systemic hypersensitivity reactions to metallic implants

DEFF Research Database (Denmark)

Basko-Plluska, Juliana L; Thyssen, Jacob P; Schalock, Peter C

2011-01-01

) following the insertion of intravascular stents, dental implants, cardiac pacemakers, or implanted gynecologic devices. Despite repeated attempts by researchers and clinicians to further understand this difficult area of medicine, the association between metal sensitivity and cutaneous allergic reactions......Cutaneous reactions to metal implants, orthopedic or otherwise, are well documented in the literature. The first case of a dermatitis reaction over a stainless steel fracture plate was described in 1966. Most skin reactions are eczematous and allergic in nature, although urticarial, bullous......, and vasculitic eruptions may occur. Also, more complex immune reactions may develop around the implants, resulting in pain, inflammation, and loosening. Nickel, cobalt, and chromium are the three most common metals that elicit both cutaneous and extracutaneous allergic reactions from chronic internal exposure...

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.

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.

Experimental research of covered stent implanted in canine hepatic artery

International Nuclear Information System (INIS)

Zhou Bing; Liu Linxiang; Li Minghua; Wang Yongli; Cheng Yongde

2007-01-01

Objective: To evaluate the feasibility of success rate of implantation, post-procedure stenosis rate, apposition ability and endothelialization level, etc. for implantation with balloon-expandable covered stent in canine hepatic artery. Methods: 8 adult canines were implanted with balloon-expendable stents covered by expandable poly Teflon ester membrane (e-PTFEM). Follow-up DSA was performed immediately, 2, 4 and 12 wk after the procedure. The canines were sacrificed for histopathologic examination and statistical analysis with correlation of implantation manenvor and angiographic manifestations. Results: 8 cases were all implanted with the covered stents in proper hepatic artery/right hepatic artery successfully; showing good apposition ability and non-opacification of the separated branches. 2 cases showed intraluminal obvious stenosis( > 50%)of the stent at 2 weeks follow-up, so did 3 cases at 12 weeks follow-up, and the total stenosis rate was 37.5% and 5 cases manifested full endothelialization (3 different locations of the sample all manifested full endothelialization), 3 cased manifested partial endothelialization (at least 1 location of the sample didn't show full endothelialization), and the two terminal parts were easier to get endothelialization than the central part. Before and after the stent implantation, hepatic function of all cases didn't demonstrate any obvious changes. Conclusions: Balloon-expandable covered stent can be implanted in canine hepatic artery. successfully, with good apposition ability, full endothelialization, and no influence on hepatic function. (authors)

Intravascular local gene transfer mediated by protein-coated metallic stent.

Science.gov (United States)

Yuan, J; Gao, R; Shi, R; Song, L; Tang, J; Li, Y; Tang, C; Meng, L; Yuan, W; Chen, Z

2001-10-01

To assess the feasibility, efficiency and selectivity of adenovirus-mediated gene transfer to local arterial wall by protein-coated metallic stent. A replication-defective recombinant adenovirus carrying the Lac Z reporter gene for nuclear-specific beta-galactosidase (Ad-beta gal) was used in this study. The coating for metallic stent was made by immersing it in a gelatin solution containing crosslinker. The coated stents were mounted on a 4.0 or 3.0 mm percutaneous transluminal coronary angioplasty (PTCA) balloon and submersed into a high-titer Ad-beta gal viral stock (2 x 10(10) pfu/ml) for 3 min, and then implanted into the carotid arteries in 4 mini-swines and into the left anterior descending branch of the coronary artery in 2 mini-swines via 8F large lumen guiding catheters. The animals were sacrificed 7 (n = 4), 14 (n = 1) and 21 (n = 1) days after implantation, respectively. The beta-galactosidase expression was assessed by X-gal staining. The results showed that the expression of transgene was detected in all animal. In 1 of carotid artery with an intact intima, the beta-gal expression was limited to endothelial cells. In vessels with denuded endothelium, gene expression was found in the sub-intima, media and adventitia. The transfection efficiency of medial smooth muscle cells was 38.6%. In 2 animals sacrificed 7 days after transfection, a microscopic examination of X-gal-stained samples did not show evidence of transfection in remote organs and arterial segments adjacent to the treated arterial site. Adenovirus-mediated arterial gene transfer to endothelial, smooth muscle cells and adventitia by protein-coated metallic stent is feasible. The transfection efficiency is higher. The coated stent may act as a good carrier of adenovirus-mediated gene transfer and have a potential to prevent restenosis following PTCA.

Immediate outcomes of eptifibatide therapy during intracoronary stent implantation.

Science.gov (United States)

Shariati, Hooman; Sanei, Hamid; Pourmoghadas, Ali; Salehizadeh, Leila; Amirpour, Afshin

2016-01-01

The objective of the present study was to assess the major immediate outcomes of eptifibatide therapy during intracoronary stent implantation. In an interventional study, patients undergoing percutaneous coronary intervention (PCI) were randomized into either the eptifibatide ( n = 100) or the control ( n = 107) group. In each group, demographic and clinical characteristics such as cardiac death, stent thrombosis (ST), myocardial infarction (MI), rates of target lesion and vessel revascularization, cerebral vascular accident (CVA), and emergency coronary artery bypass grafting (CABG) were recorded. The overall rates of major adverse events such as mortality, Stent thrombosis (ST), Myocardial Infarction (MI), target lesion revascularization (TLR), target vessel revascularization (TVR), CVA, and emergency CABG within 24 h after stent implantation were low and comparable between the two groups; P > 0.05 considered significant for all comparisons. There were no statistical differences between the clinical outcomes of groups administered with single-dose intracoronary eptifibatide and control groups among patients undergoing PCI during stent implantation.

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.

[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

Magnetic resonance evaluation of luminal patency after polylactide stent implantation: an experimental study in a rabbit aorta model

International Nuclear Information System (INIS)

Hietala, Eeva-Maija; Salminen, Ulla-Stina; Harjula, Ari L.J.; Maasilta, Paula; Staahls, Anders; Vaelimaa, Tero; Kivisaari, Leena

2003-01-01

Intravascular metallic stents cause magnetic field distortions, disturbing luminal detection. Our aim was to evaluate the effect of polylactic acid (PLA) stents on magnetic resonance angiography (MRA). Biodegradable double spiral helical PLA stents (n=12) or stainless steel (SS) (n=6) stents were implanted into the infrarenal aortas of New Zealand White rabbits. All SS- and 6 PLA-stented animals as well as 6 non-operated control rabbits were imaged with gadolinium-enhanced MRA (1.5 T), and infrarenal aortic diameters (proximal, distal, and narrowest), together with the stent artifact, were measured. Six of the PLA-stented rabbits were followed up, and MRA was assessed at 2, 6, 9, and 12 months after the stent implantation. Image artifacts caused by the SS stents were visualized in all cases. The PLA stents caused no magnetic field distortion, allowing imaging of the underlying vessel including the vessel lumen. In the follow-up group of 6 rabbits with a PLA stent, 5 of 6 were patent at the end of the follow-up of 12 months. These stents allowed luminal detection at all time points, with no significant differences in aortic measurements emerging during the whole follow-up period. When immediately postoperatively scanned SS and PLA rabbits were compared with controls, no differences were observable in proximal diameters. Instead, the percentage of distal luminal loss was greater in the PLA-stented rabbits, as compared with SS stents (p<0.01). The PLA stenting in small vessels allows evaluation of luminal patency with MRA both immediately after implantation and during follow-up. (orig.)

Scintigraphic examinations after stent implantation in central airways; Szintigraphische Untersuchungen bei Stents in den zentralen Atemwegen

Energy Technology Data Exchange (ETDEWEB)

Richter, W.S.; Kettner, B.I.; Munz, D.L. [Klinik und Poliklinik fuer Nuklearmedizin, Universitaetsklinikum Charite, Medizinische Fakulteat der Humboldt-Univ. zu Berlin (Germany)

1998-03-01

Endotracheal and endobronchial stent implantation has been developed as an effective treatment of benign and malignant airway stenosis and of tracheo- or bronchoesophageal fistulas. The selection of the stent type depends on the kind and site of disease. Chest X-ray and bronchoscopy are the procedures of choice for monitoring of stent position, structure, and function. However, with scintigraphic methods the effects of stent implantation on pulmonary ventilation and perfusion can be assessed non-invasively. The validation of the effect of a stent implantation on mucociliary and tussive clearance remains to be elucidated. (orig.) [Deutsch] Die endotracheale und -bronchiale Stentimplantation wurde in den letzten Jahren als effektive Massnahme bei benignen und malignen Stenosen der Atemwege, drohendem Atemwegsverschluss und bei tracheo- bzw. bronchooesophagealen Fisteln eingefuehrt. Der gewaehlte Stenttyp richtet sich nach dem Implantationsort und den krankheitsbedingten Veraenderungen. Zum Monitoring von Lage, Struktur und Funktion eines Stents dienen Thoraxroentgenaufnahmen und die Bronchoskopie. Nuklearmedizinische Verfahren koennen nicht-invasiv den Effekt der Stenteinlage auf Lungenventilation und -perfusion belegen. Die Validierung des Effekts einer Stentimplantation auf die mukoziliaere und tussive Clearance steht noch aus. (orig.)

The underdilation of nitinol stents at TIPS implantation: Solution or illusion?

Energy Technology Data Exchange (ETDEWEB)

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.

Risk factors for in-stent restenosis of vertebral artery origin after stent implantation: a Meta-analysis

Directory of Open Access Journals (Sweden)

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

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...

Self-expandable medical memorial metallic stent with 125I seeds for the treatment of esophageal carcinoma: a retrospective analysis

International Nuclear Information System (INIS)

Zhang Shuo; Lu Bin

2011-01-01

Objective: To discuss the curative effect and safety of the implantation of self-expandable medical memorial metallic stent with 125 I seeds for the treatment of advanced esophageal carcinomas. Methods: Implantation of self-expandable medical memorial metallic stent with 125 I seeds was performed in 32 patients with advanced esophageal canner. The clinical data were retrospectively analyzed. The technical success rate, the operation time, the immediate and mid-term effectiveness, the survival time, the complications, the body weight, the blood picture, the immune indexes, the average hospitalization days and hospitalization expenses were analyzed. Results: The average operation time was (18±5) minutes. Successful stent implantation was achieved in all 32 patients (100%). No 125 I seeds fell off during the procedure. The remission rate of dysphagia was 100%. Esophageal restenosis occurred in four patients, and displacement of the stent was seed in one patient. One month after the treatment, 90% of patients had a Karnofsky performance score over 60. The mean survival time was (8.7±6.6) months. The average hospitalization time was (7.8±3.7) days and the mean hospitalization cost was (12±3) thousand Chinese Yuan. Conclusion: For the treatment of esophageal carcinomas, the implantation of self-expandable medical memorial metallic stent with 125 I seeds is safe, effective and simple. This treatment can markedly improve the symptom of dysphagia and significantly prolong the patient's survival time. (authors)

Pulmonary Arterial Stent Implantation in an Adult with Williams Syndrome

International Nuclear Information System (INIS)

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

Preservation of keratinized mucosa around implants using a prefabricated implant-retained stent: a case-control study

OpenAIRE

Kim, Chang-Soon; Duong, Hieu Pham; Park, Jung-Chul; Shin, Hyun-Seung

2016-01-01

Purpose The aim of this study was to clinically assess the impact of a prefabricated implant-retained stent clipped over healing abutments on the preservation of keratinized mucosa around implants after implant surgery, and to compare it with horizontal external mattress sutures. Methods A total of 50 patients were enrolled in this study. In the test group, a prefabricated implant-retained stent was clipped on the healing abutment after implant surgery to replace the keratinized tissue bucco-...

Endoscopic management of complications of self-expandable metal stents for treatment of malignant esophageal stenosis and tracheoesophageal fistulas.

Science.gov (United States)

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

2017-08-01

Self-expandable metal stent (SEMS) implantation may rapidly improve the symptoms of malignant esophageal stenosis and tracheoesophageal fistulas (TEF). However, dysphagia often returns subsequently and repeated endoscopic intervention may be necessary. The aims of the study were to identify the risk factors of complications, and the frequency and efficacy of repeated endoscopic interventions; and to provide technical recommendations on appropriate stent selection. We analyzed retrospectively the clinical data of 212 patients with locally advanced esophageal cancer who underwent SEMS implantation. A total of 238 SEMS implantations were performed with 99.06% technical success and 1.26% procedure-related deaths in the enrolled 212 cases. Complications occurred in 84 patients (39.62%) and in 55 cases (25.94%) repeated endoscopic procedures were required. Early reintervention 24-48 h after the stent implantations was necessary due to stent migration (12 cases), arrhythmia (2 cases), intolerable retrosternal pain (1 case) and dyspnea (1 case). An average of 1.98 repeated gastroscopies (range 1-6; median 2), 13.58 weeks (range 1.5-48; median 11) after the stent implantation were performed during the follow-up period: 37 stent repositions, 23 restent implantations, 15 endoscopic esophageal dilations and 7 stent removals. In 48 cases (87.3%) oral feeding of patients was made possible by endoscopic interventions. In a quarter of SEMS implantations, complications occur that can be successfully managed by endoscopic interventions. Our experiences have shown that individualized stent choice may substantially reduce the complications rate and make repeated endoscopic interventions easier.

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.)

Basic Knowledge about Metal Stent Development

Directory of Open Access Journals (Sweden)

Seok Jeong

2016-03-01

Full Text Available Biliary self-expandable metal stents (SEMS, a group of non-vascular stents, have been used in the palliative management of biliary obstruction around the world. However, there are still unmet needs in the clinical application of biliary SEMS. Comprehensive understanding of the SEMS is required to resolve the drawbacks and difficulties of metal stent development. The basic structure of SEMS, including the materials and knitting methods of metal wires, covering materials, and radiopaque markers, are discussed in this review. What we know about the physical and mechanical properties of the SEMS is very important. With an understanding of the basic knowledge of metal stents, hurdles such as stent occlusion, migration, and kinking can be overcome to develop more ideal SEMS.

Use of Self-Expanding Metallic Ureteral Stents in the Secondary Treatment of Ureteral Stenosis Following Kidney Transplantation.

Science.gov (United States)

Xu, Guibin; Li, Xun; He, Yongzhong; Zhao, Haibo; Yang, Weiqing; Xie, Qingling

2015-10-01

To evaluate the safety and efficacy of self-expanding metal stents in the treatment of ureteral stenosis following kidney transplantation. Seven patients who developed benign stenosis after kidney transplantation were treated by a self-expanding metallic stent implantation from June 2007 to March 2014. All patients had undergone at least one open surgical procedure and one endourologic procedure for treatment of the stenosis. The extent of stenosis varied from 1.2 to 3.7 cm. Ultrasonography, urography, diuretic renography, and urine culture were performed every 3 months after stent insertion. Ureteroscopic examination was performed when needed. Stent placement was technically effective in all cases. The mean operative time was 37 minutes (range, 26-59 minutes). Lower urinary-tract symptoms and the ipsilateral flank pain were common early-stage complications and were greatly relieved after an average of 3 months. The mean follow-up duration was 38 months (range, 13-86 months), and no stent migration or fragmentation was observed. Urothelial hyperplasia occurred in only one patient and was effectively managed with a Double-J stent. Five patients had normal stable renal function; the remaining two had impaired renal function, including one patient with a preoperative renal failure who required dialysis at the end of the follow-up period (36 months). As an alternative to open surgery, implantation of a self-expanding metal stent is a safe and effective treatment for ureteral stenosis in patients who have undergone kidney transplantation.

Meta-analysis comparing efficacy and safety of first generation drug-eluting stents to bare-metal stents in patients with diabetes mellitus undergoing primary percutaneous coronary intervention

DEFF Research Database (Denmark)

De Luca, Giuseppe; Dirksen, Maurits T; Spaulding, Christian

2013-01-01

revascularization (hazard ratio 0.42, 95% confidence interval 0.29 to 0.59, p 1 year) with DES. In conclusion, this meta-analysis, based on individual patients' data from 11 randomized trials, showed that among patients with diabetes with STEMIs who undergo primary percutaneous coronary intervention, sirolimus...... with high rates of target vessel revascularization after bare-metal stent (BMS) implantation but also higher rates of ST after DES implantation. Therefore, the aim of this study was to perform a meta-analysis of individual patients' data to evaluate the long-term safety and effectiveness of DES compared......Several concerns have emerged regarding the higher risk for stent thrombosis (ST) after drug-eluting stent (DES) implantation, especially in the setting of ST-segment elevation myocardial infarction (STEMI). Few data have been reported so far in patients with diabetes mellitus, which is associated...

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

Directory of Open Access Journals (Sweden)

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.

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.

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.

Preservation of keratinized mucosa around implants using a prefabricated implant-retained stent: a case-control study

Science.gov (United States)

2016-01-01

Purpose The aim of this study was to clinically assess the impact of a prefabricated implant-retained stent clipped over healing abutments on the preservation of keratinized mucosa around implants after implant surgery, and to compare it with horizontal external mattress sutures. Methods A total of 50 patients were enrolled in this study. In the test group, a prefabricated implant-retained stent was clipped on the healing abutment after implant surgery to replace the keratinized tissue bucco-apically. In the control group, horizontal external mattress sutures were applied instead of using a stent. After the surgical procedure, the width of the buccal keratinized mucosa was measured at the mesial, middle, and distal aspects of the healing abutment. The change in the width of the buccal keratinized mucosa was assessed at 1 and 3 months. Results Healing was uneventful in both groups. The difference of width between baseline and 1 month was −0.26±0.85 mm in the test group, without any statistical significance (P=0.137). Meanwhile, the corresponding difference in the control group was −0.74±0.73 mm and it showed statistical significance (Pprefabricated implant-retained stent was shown to be effective in the preservation of the keratinized mucosa around implants and it was simple and straightforward in comparison to the horizontal external mattress suture technique. PMID:27800215

[The thermoformable spiral metallic stents in the treatment of localized ureteral stenosis: an alternative to JJ stent? Prospective multicenter study].

Science.gov (United States)

Bonniol, R; Meria, P; Safsaf, A; Albouy, B; Sibert, L

2011-06-01

Evaluation of the effectiveness and tolerance of thermoformable metallic spiral stents Memokath(®) 051 (Bard, Pnn Medical) in the treatment of localized ureteral stenosis in non-operable patients who have JJ ureteral stents. Prospective, descriptive and multicenter study of patients with ureteral strictures treated with metallic ureteral stents Memokath(®) 051. Assessment criteria (recurrent stenotic, permeability, tolerance) were measured by clinical, biological and radiological examination at 1 month, and then every 3 months. Fifteen stents (average length: 9.15 cm, range 6-15 cm) were implanted in 14 patients (mean age: 55 years, range: 38-72 years) with secondary suspended ureteral stenosis during 2 years in two centers. The median follow-up was 11 months (range 6 to 24 months). Technical difficulty was observed with two patients. Stents are still up in four patients. The stenosis recurred in four patients with spontaneous progression of stenosis but without endoprosthetics tissue invasion. Two and three migration were observed with spontaneous expulsions. Two lower urinary infections and one high occurred, resolved on antibiotic therapy, no inlay or hematuria, no pain (mean VAS score=3/10) or urinary disorders of the lower unit have been identified. Stents Memokath(®) 051 are well tolered and seem to position themselves as an interesting alternative to JJ ureteral stent in some frails patients. The refinement of contraindication should help to improve the stent's efficacity and to reduce the risk of migration and expulsion. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Cutaneous and systemic hypersensitivity reactions to metallic implants

DEFF Research Database (Denmark)

Basko-Plluska, Juliana L; Thyssen, Jacob P; Schalock, Peter C

2011-01-01

Cutaneous reactions to metal implants, orthopedic or otherwise, are well documented in the literature. The first case of a dermatitis reaction over a stainless steel fracture plate was described in 1966. Most skin reactions are eczematous and allergic in nature, although urticarial, bullous....... However, other metal ions as well as bone cement components can cause such hypersensitivity reactions. To complicate things, patients may also develop delayed-type hypersensitivity reactions to metals (ie, in-stent restenosis, prosthesis loosening, inflammation, pain, or allergic contact dermatitis...

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.

Treatment of 9 cases of pulmonary atelectasis caused by endobronchial tuberculosis with intraluminal stent implantation

International Nuclear Information System (INIS)

Ji Hongjiang; Li Qiang; Liu Zhongling; Bai Chong; Yao Xiaopeng; Zhao Lijun; Xu Hao; Dong Yuchao; Huang Haidong; Wang Qin

2007-01-01

Objective: To evaluate the effect and safety of intraluminal stent implantation in the treatment of complete airway obstruction with unilateral pulmonary atelectasis caused by endobronchial tuberculosis (EBTB). Methods: 9 cases of pulmonary atelectasis caused by EBTB were treated with high- frequency electricity/microwave, balloon dilation and endobronchial stent implantation. At the time of 1 week and 4-6 months after stenting ,the diameters of stenotic segment were measured. Results: All 9 cases with atelectasis of EBTB showed complete re-expansion within 3 days after the stent implantation. The mean diameter of the stenotic segments of 9 EBTB patients increased to 9.17 ± 1.24 mm at 7th day after stent implantation; 3 of 9 EBTB patients occured mild restenosis after implantation of tracheobronchial stents. However, combination therapy of cryotherapy and balloon dilation can effectively prevent the aggravation of restenosis. Conclusion: Comparing with traditional surgical treatment, the intraluminal stent implantation for atelectasis caused by EBTB is a new, effective, safe and microtraumatic method with reliable preservation of pulmonary function. (authors)

Clopidogrel discontinuation within the first year after coronary drug-eluting stent implantation

DEFF Research Database (Denmark)

Thim, Troels; Johansen, Martin Berg; Chisholm, Gro Egholm

2014-01-01

BACKGROUND: The impact of adherence to the recommended duration of dual antiplatelet therapy after first generation drug-eluting stent implantation is difficult to assess in real-world settings and limited data are available. METHODS: We followed 4,154 patients treated with coronary drug-eluting ......BACKGROUND: The impact of adherence to the recommended duration of dual antiplatelet therapy after first generation drug-eluting stent implantation is difficult to assess in real-world settings and limited data are available. METHODS: We followed 4,154 patients treated with coronary drug......-eluting stents in Western Denmark for 1 year and obtained data on redeemed clopidogrel prescriptions and major adverse cardiovascular events (MACE, i.e., cardiac death, myocardial infarction, or stent thrombosis) from medical databases. RESULTS: Discontinuation of clopidogrel within the first 3 months after...... stent implantation was associated with a significantly increased rate of MACE at 1-year follow-up (hazard ratio (HR) 2.06; 95% confidence interval (CI): 1.08-3.93). Discontinuation 3-6 months (HR 1.29; 95% CI: 0.70-2.41) and 6-12 months (HR 1.29; 95% CI: 0.54-3.07) after stent implantation were...

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.

Hemodynamic alterations after stent implantation in 15 cases of intracranial aneurysm.

Science.gov (United States)

Wang, Chao; Tian, Zhongbin; Liu, Jian; Jing, Linkai; Paliwal, Nikhil; Wang, Shengzhang; Zhang, Ying; Xiang, Jianping; Siddiqui, Adnan H; Meng, Hui; Yang, Xinjian

2016-04-01

Stent-assisted coiling technology has been widely used in the treatment of intracranial aneurysms. In the current study, we investigated the intra-aneurysmal hemodynamic alterations after stent implantation and their association with the aneurysm location. We first retrospectively studied 15 aneurysm cases [8 internal carotid artery-ophthalmic artery (ICA-OphA) aneurysms and 7 posterior communicating artery (PcoA) aneurysms] treated with Enterprise stents and coils. Then, based on the patient-specific geometries before and after stenting, we built virtual stenting computational fluid dynamics (CFD) simulation models. Before and after the stent deployment, the average wall shear stress (WSS) on the aneurysmal sac at systolic peak changed from 7.04 Pa (4.14 Pa, 15.77 Pa) to 6.04 Pa (3.86 Pa, 11.13 Pa), P = 0.001; the spatially averaged flow velocity in the perpendicular plane of the aneurysm dropped from 0.5 m/s (0.28 m/s, 0.7 m/s) to 0.33 m/s (0.25 m/s, 0.49 m/s), P = 0.001, respectively. Post stent implantation, the WSS in ICA-OphA aneurysms and PcoA aneurysms decreased by 14.4 % (P = 0.012) and 16.6 % (P = 0.018), respectively, and the flow velocity also reduced by 10.3 % (P = 0.029) and 10.5 % (P = 0.013), respectively. Changes in the WSS, flow velocity, and pressure were not significantly different between ICA-OphA and PcoA aneurysms (P > 0.05). Stent implantation did not significantly change the peak systolic pressure in either aneurysm type. After the stent implantation, both the intra-aneurysmal flow velocity and WSS decreased independently of aneurysm type (ICA-OphA and PcoA). Little change was observed in peak systolic pressure.

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.).

Clinical and angiographic outcomes after intracoronary bare-metal stenting.

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I-Chang Hsieh

Full Text Available BACKGROUND: Data from a large patient population regarding very long-term outcomes after BMS implantation are inadequate. This study aimed to evaluate the very long-term (8-17 years clinical and long-term (3-5 years angiographic outcomes after intracoronary bare-metal stenting (BMS. METHODS AND RESULTS: From the Cardiovascular Atherosclerosis and Percutaneous TrAnsluminal INterventions (CAPTAIN registry, a total of 2391 patients with 2966 lesions treated with 3190 BMSs between November 1995 and May 2004 were evaluated. In total, 1898 patients with 2364 lesions, and 699 patients with 861 lesions underwent 6-month and 3- to 5- year angiographic follow-up, respectively. During a mean follow-up period of 149 ± 51 months, 18.6% of the patients died (including 10.8% due to cardiac death, 6.1% developed reinfarction, 16.2% had target lesion revascularization (including 81% of the patients within the first year, 14.5% underwent new lesion stenting (including 72% of the patients after 3 years, 2.4% underwent coronary bypass surgery, and 1.6% had definite stent thrombosis. The overall cardiovascular event-free survival rate was 58.5%. The 6-month angiographic study indicated a 20% restenosis rate. The minimal luminal diameter increased from 0.65 ± 0.44 mm to 3.02 ± 0.46 mm immediately after stenting, decreased to 2.06 ± 0.77 mm at the 6-month follow-up, and increased to 2.27 ± 0.68 mm at the 3- to 5-year follow-up. CONCLUSIONS: This study provides clinical and angiographic results from a large population of patients who underwent BMS implantations after a long-term follow-up period (149 ± 51 months. The progression of coronary atherosclerosis developed over time, and presented with new lesion required stent implantation. The follow-up angiographic findings reconfirmed the late and sustained improvement in luminal diameter between 6 months and 3-5 years.

Improved two-year outcomes after drug-eluting versus bare-metal stent implantation in women and men with large coronary arteries

DEFF Research Database (Denmark)

Hansen, K W; Kaiser, C; Hvelplund, A

2013-01-01

To investigate the importance of vessel size on outcome differences by comparing the effects of drug-eluting stents (DES) versus bare-metal stents (BMS) in women and men with large coronary vessels.......To investigate the importance of vessel size on outcome differences by comparing the effects of drug-eluting stents (DES) versus bare-metal stents (BMS) in women and men with large coronary vessels....

Incidence and Potential Mechanism(s) of Post-Procedural Rise of Cardiac Biomarker in Patients With Coronary Artery Narrowing After Implantation of an Everolimus-Eluting Bioresorbable Vascular Scaffold or Everolimus-Eluting Metallic Stent

DEFF Research Database (Denmark)

Ishibashi, Yuki; Muramatsu, Takashi; Nakatani, Shimpei

2015-01-01

OBJECTIVES: This study sought to evaluate the mechanism of post-procedural cardiac biomarker (CB) rise following device implantation. BACKGROUND: A fully bioresorbable Absorb scaffold, compared with everolimus-eluting metallic stents (EES), might be associated with a higher incidence...

Esophageal carcinoma treatment with self-expanding covered stent implanted in esophagus

International Nuclear Information System (INIS)

Liu Mingguo; Ji Yan; He Nengwei

2006-01-01

Objective: To investigate the clinical significance of the treatment to esophageal cancer by self- expanding covered stent implanted into esophagus. Methods: Under fluoroscopic guidance and with guidance wire , 20 self-expanding covered stents were implanted into stenotic part of esophagus to recanalize the esophagus, then follow up to observe the clinical symptom improved. Results: Technical success was obtained 20 cases without any complication. Clinical symptom were improved in shot time. Conclusions: self-expanding covered stent is implanted in stenotic part of esophageal carcinoma to treat esophageal stenosis and enable to improved clinical symptom in shot time, if combined with transcatheter arterial infusion and embolization, Radiotherapy, Chinese medical treatment, it enable to lengthen life time remarkably. (authors)

Flexible endoscopy for pediatric tracheobronchial metallic stent placement, maintenance and long-term outcomes

Science.gov (United States)

2018-01-01

Objectives To assess the placement, surveillance management and long-term outcomes of the tracheobronchial (TB) balloon expandable metallic stent (BEMS) managed by therapeutic flexible endoscopy (TFE). Methods This is a retrospective review and analysis of all computerized medical records and related flexible endoscopy videos of pediatric patients who received TB BEMS during 20 years period, from January 1997 to December 2016. TFE techniques with forceps debridement, balloon dilatation and laser ablation were used to implant stents, perform regular surveillance, maintain their functions, and expand the diameters of BEMS. Short-length (30cm-36cm) endoscopes of OD 3.2mm to 5.0mm coupled with the noninvasive ventilation, without ventilation bag, mask or airway tube, supported the whole procedures. Results 146 BEMS were implanted in 87 consecutive children, including 84 tracheal, 15 carinal and 47 bronchial stents. At the time of placement, the mean age was 35.6 ± 54.6 month-old (range 0.3–228) and the mean body weight was 13.9 ± 10.6 kg (range 2.2–60). Surveillance period was 9.4 ± 6.7 years (range, 0.3–18.0). Satisfactory clinical improvements were noted immediately in all but two patients. Seventy-two (82.8%) patients were still alive with stable respiratory status, except two patients necessitating TFE management every two months. Fifty-one stents, including 35 tracheal and 16 bronchial ones, were successfully retrieved mainly with rigid endoscopy. Implanted stents could be significantly (stent diameters were positively correlated to the implanted duration. Altogether, 33 stents expired (15 patients), 51 were retrieved (40 patients), and 62 remained and functioning well (38 patients), with their mean duration of 7.4 ± 9.5, 34.9 ± 36.3 and 82.3 ± 62.5 months, respectively. Conclusion In pediatric patients, TFE with short-length scopes coupled with this NIV support has provided a safe, feasible and effective modality in placing and subsequently managing

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.

Science.gov (United States)

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.

Hypersensitivity reactions to metallic implants-diagnostic algorithm and suggested patch test series for clinical use

DEFF Research Database (Denmark)

Schalock, Peter C; Menné, Torkil; Johansen, Jeanne D

2011-01-01

algorithm to guide the selection of screening allergen series for patch testing is provided. At a minimum, an extended baseline screening series and metal screening is necessary. Static and dynamic orthopaedic implants, intravascular stent devices, implanted defibrillators and dental and gynaecological......Cutaneous and systemic hypersensitivity reactions to implanted metals are challenging to evaluate and treat. Although they are uncommon, they do exist, and require appropriate and complete evaluation. This review summarizes the evidence regarding evaluation tools, especially patch and lymphocyte...... transformation tests, for hypersensitivity reactions to implanted metal devices. Patch test evaluation is the gold standard for metal hypersensitivity, although the results may be subjective. Regarding pre-implant testing, those patients with a reported history of metal dermatitis should be evaluated by patch...

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.

Post-biliary sphincterotomy bleeding despite covered metallic stent deployment

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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.

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.

All-cause mortality after drug-eluting stent implantation in African-Americans.

Science.gov (United States)

Poludasu, Shyam; Cavusoglu, Erdal; Khan, Waqas; Marmur, Jonathan D

2008-12-01

Recent studies have questioned the safety of drug-eluting stents because of a higher incidence of late stent thrombosis, raising the possibility that drug-eluting stents may be associated with an increased mortality. The effect of drug-eluting stents on mortality in African-Americans is unknown. We evaluated 628 African-American patients (354 patients treated with drug-eluting stents and 274 patients treated with bare metal stents) between January 2003 and August 2005, using data from our bolus-only platelet glycoprotein IIb/IIIa inhibitor database. The primary end point was all-cause mortality obtained using social security death index. After a mean follow-up of 3+/-0.9 years, the mortality rate in the bare metal stents group was 12.8% compared with 7.1% in the drug-eluting stents group [adjusted P value=0.19; hazard ratio (HR) for bare metal stents group compared with drug-eluting stents group for death=1.4; 95% confidence interval (CI): 0.8-2.4]. In a subgroup analysis, patients presenting with acute coronary syndrome had a higher mortality when treated with bare metal stents compared with drug-eluting stents (17.1 vs. 6.3%, P=0.022; HR=2.2; 95% CI: 1.1-4.4). Patients with chronic kidney disease (all patients with creatinine >1.5 mg/dl) also had a higher mortality with bare metal stents compared with drug-eluting stents (36.7 vs. 20.4%, P=0.044; HR=2.3; 95% CI: 1.02-5.2). Drug-eluting stents seem to be safe in African-Americans and may improve survival in certain subgroups such as patients with acute coronary syndromes and chronic kidney disease.

Application of High Entropy Alloys in Stent Implants

Science.gov (United States)

Alagarsamy, Karthik

High entropy alloys (HEAs) are alloys with five or more principal elements. Due to these distinct concept of alloying, the HEA exhibits unique and superior properties. The outstanding properties of HEA includes higher strength/hardness, superior wear resistance, high temperature stability, higher fatigue life, good corrosion and oxidation resistance. Such characteristics of HEA has been significant interest leading to researches on these emerging field. Even though many works are done to understand the characteristic of these HEAs, very few works are made on how the HEAs can be applied for commercial uses. This work discusses the application of High entropy alloys in biomedical applications. The coronary heart disease, the leading cause of death in the United States kills more than 350,000 persons/year and it costs $108.9 billion for the nation each year in spite of significant advancements in medical care and public awareness. A cardiovascular disease affects heart or blood vessels (arteries, veins and capillaries) or both by blocking the blood flow. As a surgical interventions, stent implants are deployed to cure or ameliorate the disease. However, the high failure rate of stents has lead researchers to give special attention towards analyzing stent structure, materials and characteristics. Many works related to alternate material and/or design are carried out in recent time. This paper discusses the feasibility of CoCrFeNiMn and Al0.1CoCrFeNi HEAs in stent implant application. This work is based on the speculation that CoCrFeNiMn and Al0.1CoCrFeNi HEAs are biocompatible material. These HEAs are characterized to determine the microstructure and mechanical properties. Computational modeling and analysis were carried out on stent implant by applying CoCrFeNiMn and Al0.1CoCrFeNi HEAs as material to understand the structural behavior.

Functional Self-Expandable Metal Stents in Biliary Obstruction

Science.gov (United States)

Kwon, Chang-Il; Ko, Kwang Hyun; Hahm, Ki Baik

2013-01-01

Biliary stents are widely used not only for palliative treatment of malignant biliary obstruction but also for benign biliary diseases. Each plastic stent or self-expandable metal stent (SEMS) has its own advantages, and a proper stent should be selected carefully for individual condition. To compensate and overcome several drawbacks of SEMS, functional self-expandable metal stent (FSEMS) has been developed with much progress so far. This article looks into the outcomes and defects of each stent type for benign biliary stricture and describes newly introduced FSEMSs according to their functional categories. PMID:24143314

Expandable metallic stents for tracheobronchial stenoses in esophageal cancer.

Science.gov (United States)

Takamori, S; Fujita, H; Hayashi, A; Tayama, K; Mitsuoka, M; Ohtsuka, S; Shirouzu, K

1996-09-01

Tracheobronchial stenosis in patients with esophageal cancer can be life threatening. Few reports have discussed use of expandable metallic stents for central airway stenoses in patients with esophageal cancer. Twelve patients with esophageal cancer underwent placement of expandable metallic stents for respiratory distress caused by tracheobronchial stricture. Single or double metallic stents were placed in the stenotic airways under fluoroscopic guidance. Improvement in respiratory symptoms and clinical outcome were assessed. Most stenoses were located in the trachea or the left main bronchus. From one to four expandable metallic stents were placed in each stricture site, with immediate relief of respiratory symptoms in 8 patients. One patient with tracheomalacia in alive 3 years after stent placement and another is alive 6 months after stent insertion. The other 10 patients lived from 10 to 70 days (mean; survival, 35 days) after stent placement. Death was due to progression of disease. Although metallic stents are useful for relieving respiratory distress in patients with advanced esophageal cancer, additional therapies should be considered.

Elective implantation of covered stents for coarctation and recoarctation in adolescents and adults.

Science.gov (United States)

Alcibar, Juan; Blanco, Roberto; Fernandez, Luis; Arriola, Josune; Garcia, Koldobika; Peña, Natividad; Inguanzo, Ramón; Voces, Roberto; Castellanos, Enrique; Montes, Pedro M

2013-06-01

Stent implantation is an effective therapy for aortic coarctation and recoarctation. However, in adolescents and adults, aortic wall rupture and dissection can occur, as well as aneurysms during follow-up. In order to reduce these complications, we electively implant covered stents. Since 2005, we have performed the procedure using femoral access in 17 patients (2 adolescents and 15 adults), 16 electively and 1 as a rescue procedure. We used the Mullins technique in all cases, implanting a NuMED(®) covered stent. Good stent apposition was achieved in all 17 procedures; 8 patients required a distal flare. Gradient was reduced from 40 (16) mmHg to 2 (2) mmHg (P<.001) and lumen diameter increased from 4 (2) mm to 19 (3) mm (P<.001). Two exceptional cases are discussed: one patient with aortic wall rupture who underwent a rescue procedure using a stent within a covered stent and another patient with total obstruction and intercostal aneurysm in whom the outcome was fatal at 48 h postprocedure (autopsy is shown). Four-year clinical follow-up included Doppler echocardiography; an additional imaging technique was required in 13 patients. All patients recovered well and there were no complications. Covered stents are effective in treating coarctation and recoarctation in adolescents and adults, are the treatment of choice in patients with complex anatomy, and must be available in the operating room as a rescue device when implanting a conventional stent. Copyright © 2012 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

Randomized comparison between intracoronary β-radiation brachytherapy and implantation of paclitaxel-eluting stents for the treatment of diffuse in-stent restenosis

International Nuclear Information System (INIS)

Schukro, Christoph; Syeda, Bonni; Kirisits, Christian; Schmid, Rainer; Pichler, Philipp; Pokrajac, Boris; Lang, Irene; Poetter, Richard; Glogar, Dietmar

2007-01-01

Background and purpose: Intracoronary brachytherapy was the primary therapeutic option for the treatment of in-stent restenosis (ISR) during the last years. Especially for the treatment of diffuse ISR (lesions >10 mm), β-source brachytherapy was significantly superior to singular balloon angioplasty. Despite lacking clinical database, the implantation of drug eluting stents recently became a common procedure for the treatment of ISR. This randomized trial aimed to compare the efficacy of β-brachytherapy with β-radioisotopes 90 Sr/ 90 Y and paclitaxel-eluting stent implantation for the treatment of diffuse ISR. Material and methods: Thirty-seven patients with diffuse ISR were randomly assigned to β-brachytherapy after balloon angioplasty (Beta-Cath TM in 17 patients) or paclitaxel-eluting stent implantation (Taxus-Express2 TM in 20 patients). Six-month clinical follow-up was obtained for all patients, while angiographic follow-up was available for 30 patients. Results: Binary ISR (restenosis >50%) within target segment was observed in three patients treated with Beta-Cath TM , of which one needed target segment revascularisation for recurrent ISR, whereas no significant restenosis occurred in the patients treated with Taxus-Express2 TM (P = 0.037). No further major adverse cardiac (target segment revascularisation, myocardial infarction, death) was found in either group (P = NS). Stent implantation was the more time-saving (31 ± 11 min versus 60 ± 23 min, P TM arm, we found no difference in clinical outcome after implantation of paclitaxel-eluting stents for the treatment of diffuse ISR when compared to β-brachytherapy

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)

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.

The use of polymer gel dosimetry to measure dose distribution around metallic implants

International Nuclear Information System (INIS)

Nagahata, Tomomasa; Yamaguchi, Hajime; Monzen, Hajime; Nishimura, Yasumasa

2014-01-01

A semi-solid polymer dosimetry system using agar was developed to measure the dose distribution close to metallic implants. Dosimetry of heterogeneous fields where electron density markedly varies is often problematic. This prompted us to develop a polymer gel dosimetry technique using agar to measure the dose distribution near substance boundaries. Varying the concentration of an oxygen scavenger (tetra-hydroxymethyl phosphonium chloride) showed the absorbed dose and transverse relaxation rate of the magnetic resonance signal to be linear between 3 and 12 Gy. Although a change in the dosimeter due to oxidization was observed in room air after 24 hours, no such effects were observed in the first 4 hours. The dose distribution around the metal implants was measured using agar dosimetry. The metals tested were a lead rod, a titanium hip joint, and a metallic stent. A maximum 30% dose increase was observed near the lead rod, but only a 3% increase in the absorbed dose was noted near the surface of the titanium hip joint and metallic stent. Semi-solid polymer dosimetry using agar thus appears to be a useful method for dosimetry around metallic substances. (author)

[The use of polymer gel dosimetry to measure dose distribution around metallic implants].

Science.gov (United States)

Nagahata, Tomomasa; Yamaguchi, Hajime; Monzen, Hajime; Nishimura, Yasumasa

2014-10-01

A semi-solid polymer dosimetry system using agar was developed to measure the dose distribution close to metallic implants. Dosimetry of heterogeneous fields where electron density markedly varies is often problematic. This prompted us to develop a polymer gel dosimetry technique using agar to measure the dose distribution near substance boundaries. Varying the concentration of an oxygen scavenger (tetra-hydroxymethyl phosphonium chloride) showed the absorbed dose and transverse relaxation rate of the magnetic resonance signal to be linear between 3 and 12 Gy. Although a change in the dosimeter due to oxidization was observed in room air after 24 hours, no such effects were observed in the first 4 hours. The dose distribution around the metal implants was measured using agar dosimetry. The metals tested were a lead rod, a titanium hip joint, and a metallic stent. A maximum 30% dose increase was observed near the lead rod, but only a 3% increase in the absorbed dose was noted near the surface of the titanium hip joint and metallic stent. Semi-solid polymer dosimetry using agar thus appears to be a useful method for dosimetry around metallic substances.

Computational Fluid Dynamics: Hemodynamic Changes in Abdominal Aortic Aneurysm After Stent-Graft Implantation

International Nuclear Information System (INIS)

Frauenfelder, Thomas; Lotfey, Mourad; Boehm, Thomas; Wildermuth, Simon

2006-01-01

The aim of this study was to demonstrate quantitatively and qualitatively the hemodynamic changes in abdominal aortic aneurysms (AAA) after stent-graft placement based on multidetector CT angiography (MDCT-A) datasets using the possibilities of computational fluid dynamics (CFD). Eleven patients with AAA and one patient with left-side common iliac aneurysm undergoing MDCT-A before and after stent-graft implantation were included. Based on the CT datasets, three-dimensional grid-based models of AAA were built. The minimal size of tetrahedrons was determined for grid-independence simulation. The CFD program was validated by comparing the calculated flow with an experimentally generated flow in an identical, anatomically correct silicon model of an AAA. Based on the results, pulsatile flow was simulated. A laminar, incompressible flow-based inlet condition, zero traction-force outlet boundary, and a no-slip wall boundary condition was applied. The measured flow volume and visualized flow pattern, wall pressure, and wall shear stress before and after stent-graft implantation were compared. The experimentally and numerically generated streamlines are highly congruent. After stenting, the simulation shows a reduction of wall pressure and wall shear stress and a more equal flow through both external iliac arteries after stenting. The postimplantation flow pattern is characterized by a reduction of turbulences. New areas of high pressure and shear stress appear at the stent bifurcation and docking area. CFD is a versatile and noninvasive tool to demonstrate changes of flow rate and flow pattern caused by stent-graft implantation. The desired effect and possible complications of a stent-graft implantation can be visualized. CFD is a highly promising technique and improves our understanding of the local structural and fluid dynamic conditions for abdominal aortic stent placement

Metal stents insertion in the treatment of the patients with benign oesophageal strictures

International Nuclear Information System (INIS)

Valek, V.; Benda, K.; Hrobar, P.; Mrazova, J.; Prasek, J.; Vomela, J.; Muenzova, H.; Hep, A.; Stefl, M.

1996-01-01

Between October 1993 and June 1995 the authors inserted in the Department of Radiology in University Hospital Bohunice in 16 of their patients with benign stenosis of the oesophagus an expandable metals stent. the aetiology of the stenosis was long-term reflux oesophagitis (6x), postoperative benign stenosis in anastomosis (3x), corrosive structure (2x), epidermolysis bulosa oesophagi (2x) and post-radiation structure (1x). In two patients the aetiology of the stenosis was unknown. All the patients suffered at the the of the stent insertion from marked dysphagia (stage 3 and/or 4). The indication for oesophageal stent implantation was always carefully considered by an interdisciplinary indication committee. Before the stent insertion all the stenoses have been repeatedly unsuccessfully dilated with balloon dilatation catheter. In total, 25 stents were used. In seven patients were inserted more as one stent. The intervention itself was preceded by a double contrast X-ray examination of oesophagus, oesophagoscopy with biopsy to verify the stricture aetiology, computed tomography and endosonography. No complications associated with the intervention have been encountered and stent insertions have always been well tolerated. (authors). 1 tab., 3 figs., 9 refs

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...

IVUS Findings in Late and Very Late Stent Thrombosis. A Comparison Between Bare-metal and Drug-eluting Stents.

Science.gov (United States)

Fuentes, Lara; Gómez-Lara, Josep; Salvatella, Neus; Gonzalo, Nieves; Hernández-Hernández, Felipe; Fernández-Nofrerias, Eduard; Sánchez-Recalde, Ángel; Alfonso, Fernando; Romaguera, Rafael; Ferreiro, José Luis; Roura, Gerard; Teruel, Luis; Gracida, Montserrat; Marcano, Ana Lucrecia; Gómez-Hospital, Joan-Antoni; Cequier, Ángel

2018-05-01

Stent thrombosis (ST) is a life-threatening complication after stent implantation. Intravascular ultrasound is able to discern most causes of ST. The aim of this study was to compare intravascular ultrasound findings between bare-metal stents (BMS) and drug-eluting stents (DES) in patients with late (31 days to 1 year) or very late ST (> 1 year). Of 250 consecutive patients with late or very late ST in 7 Spanish institutions, 114 patients (45.5% BMS and 54.5% DES) were imaged with intravascular ultrasound. Off-line intravascular ultrasound analysis was performed to assess malapposition, underexpansion, and neoatherosclerosis. The median time from stent implantation to ST was 4.0 years with BMS and 3.4 years with DES (P = .04). Isolated malapposition was similarly observed in both groups (36.5% vs 46.8%; P = .18) but was numerically lower with BMS (26.6% vs 48.0%; P = .07) in patients with very late ST. Isolated underexpansion was similarly observed in both groups (13.5% vs 11.3%; P = .47). Isolated neoatherosclerosis occurred only in patients with very late ST and was more prevalent with BMS (22.9%) than with DES (6.0%); P = .02. At 2.9 years' follow-up, there were 0% and 6.9% cardiac deaths, respectively (P = .06) and recurrent ST occurred in 4.0% and 5.2% of patients, respectively (P = .60). Malapposition was the most common finding in patients with late and very late ST and is more prevalent with DES in very late ST. In contrast, neoatherosclerosis was exclusively observed in patients with very late ST and mainly with BMS. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

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)

Metallic Stents for Tracheobronchial Pathology Treatment

International Nuclear Information System (INIS)

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.

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.

Metallic Stents for Tracheobronchial Pathology Treatment

Energy Technology Data Exchange (ETDEWEB)

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.

[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 endonasal dacryocystorhinostomy combined with stent implantation as treatment for acute dacryocystitis

Directory of Open Access Journals (Sweden)

Si-Si Pu

2017-02-01

Full Text Available AIM: To discuss the feasibility and clinical efficacy of endoscopic endonasal dacryocystorhinostomy(EN-DCRcombined with stent implantation for treatment of acute dacryocystitis. METHODS: A total of 31 patients(32 eyespresenting with acute dacryocystitis were treated with EN-DCR combined with stent implantation under antibiotic cover from April 2014 to December 2015. These patients were followed up for 3 to 12mo. RESULTS: The medial canthal edema and erythema was gradually reducing within 48h in all patients. The hospitalization time took 2 to 8d(average 3.8±1.6d. Patients underwent removal of stent about 3mo after surgery. Thirty-one eyes showed no symptoms such as lacrimation or pus discharging, and irrigation of lacrimal duct was unobstructed. Irrigation of lacrimal duct was passable in 1 of 32 patients who has a relative narrow ostial. Results in this series, 31 cases were cured,1case improved, the total cure rate was 97%. CONCLUSION: There is no evidence shown that EN-DCR combined with stent implantation can increase the risk of spreading infection through tissue planes, causing septicemia, and exacerbating inflammation. Instead, it has advantages like gradual reduction in inflammatory symptoms, economic benefits of reduced patient stay, maintenance of the orbicularis muscle lacrimal pump and absence of external scar. It is indicated that EN-DCR combined with stent implantation is a safe and feasible surgical procedure for patients with acute dacryocystitis.

Comparison of outcome in 1809 patients treated with drug-eluting stents or bare-metal stents in a real-world setting

Directory of Open Access Journals (Sweden)

Vogt A

2011-11-01

Full Text Available Alexander Vogt1, Anke Schoelmerich1, Franziska Pollner1, Manuela Schlitt1, Uwe Raaz1, Lars Maegdefessel2, Iris Reindl1, Michael Buerke1, Karl Werdan1, Axel Schlitt11Department of Medicine III, Martin Luther-University, Halle, Germany; 2Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA, USAPurpose: The aim of this study was to determine the long-term safety of drug-eluting stent (DES versus bare metal stent (BMS implantation in a “real-world” setting.Patients and methods: A total of 1809 patients who were treated with implantation of either BMS or DES were assessed. Kaplan-Meier and multivariate Cox regression analyses concerning primary endpoint of cardiac mortality were performed.Results: A total of 609 patients received DES. Mean age was 66.2 ± 11.3 years, 69.4% were male, and 1517 (83.8% were treated for acute coronary syndrome (unstable angina 510 [28.2%], non-ST-elevation myocardial infarction [NSTEMI] 506 [28.0%], and ST-elevation myocardial infarction [STEMI] 501 [27.7%]. Mean follow-up was 34 ± 15 months. During follow-up, 268 patients died of cardiac causes (DES 42 [7.3%]; BMS 226 [19.6%]; P < 0.001. Univariate Kaplan-Meier analysis showed an advantage of DES over BMS concerning the primary endpoint (P < 0.001. When adjusting for classic risk factors and additional factors that affect the progression of coronary heart disease (CHD, DES was not found to be superior to BMS (hazard ratio 0.996, 95% confidence interval 0.455–2.182, P = 0.993. Severely impaired renal function was an independent predictor for cardiac mortality after stent implantation.Conclusion: Treatment with DES is safe in the long term, also in patients presenting with STEMI. However, in multivariate analyses it is not superior to BMS treatment.Keywords: coronary stent, outcome, renal insufficiency, myocardial infarction, STEMI

Bioabsorbable polymer-coated sirolimus-eluting stent implantation preserves coronary vasomotion: A DESSOLVE II trial sub-study.

Science.gov (United States)

Rusinaru, Dan; Vrolix, Mathias; Verheye, Stefan; Chowdhary, Saqib; Schoors, Danny; Di Mario, Carlo; Desmet, Walter; Donohoe, Dennis J; Ormiston, John A; Knape, Charlene; Bezerra, Hiram; Lansky, Alexandra; Wijns, William

2015-12-01

We studied coronary vasomotion in patients treated with the Mistent(®) absorbable polymer sirolimus-eluting stent (APSES) and in patients implanted with the Endeavor(®) zotarolimus-eluting stent (ZES). First generation (1st-gen) drug-eluting stents (DES) induce persistent vasomotor dysfunction in the treated coronary artery. It is unknown whether and to what extent the implantation of an absorbable polymer DES impairs coronary vasomotion. This sub-study of the DESSOLVE II trial included 19 APSES Mistent(®) and 10 ZES Endeavor(®) patients. Incremental atrial pacing and quantitative coronary angiography were used to assess vasomotion proximal and distal to the stent and in a reference segment at 9 months after implantation. Percent changes in vessel diameter with pacing versus baseline were calculated and compared. Vasomotor response of the APSES group was also compared with changes observed in a historical group of 17 patients implanted with a 1st-gen sirolimus-eluting stent (SES). Normal vasomotion (vasodilatation) was preserved and of comparable magnitude in the APSES and in the ZES group both proximally (P = 0.34) and distally (P = 0.38) to the stent. This finding was not observed in the 1st-gen SES group showing marked pacing-induced vasoconstriction at both stent edges (P absorbable polymer sirolimus-eluting stent is associated with preserved coronary vasomotion, comparable to that observed after implantation of the Endeavor(®) ZES, and distinct from 1st-gen SES which induce coronary vasomotor dysfunction. © 2015 Wiley Periodicals, Inc.

Customized Hinged Covered Metallic Stents for the Treatment of Benign Main Bronchial Stenosis.

Science.gov (United States)

Han, Xinwei; Al-Tariq, Quazi; Zhao, Yanle; Li, Lei; Cheng, Zhe; Wang, Huaqi; Liu, Chao; Jiao, Dechao; Wu, Gang

2017-08-01

To address the limitations of silicone stents, we designed a hinged self-expandable covered metallic stent. The aim of this study was to evaluate the safety and efficacy of the customized stents in clinical applications. This was a retrospective analysis. Under conscious sedation and local anesthesia, the stents were implanted or removed by interventional radiologists, with fluoroscopic guidance. Of 24 patients with benign main bronchial stenosis, stents were successfully placed in 21 (87.5%). The low-pressure balloon before dilation failed in 1 case (4.17%) of left main bronchial cicatricial stenosis. In 2 other cases (8.33%), stent placement was abandoned. Stents were successfully removed between 29 and 103 days after the procedure. After stent removal, the follow-up lasted for at least 12 months. Restenosis occurred only in 1 case (4.55%) owing to bronchial collapse 3 days after stent removal. Dyspnea occurred in another case (4.55%) at 2 months after retrieval; recurrence was confirmed using bronchoscopy, leading to a left pneumonectomy. The described procedure is safe and easy to be performed and avoids the use of intubation, bronchoscopy, and general anesthesia. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Therapeutic evaluation of retrievable esophageal covered stent in treating achalasia

International Nuclear Information System (INIS)

Li Yuwei; Zhang Fuqiang; Yuan Liang; Li Yunhui; Luo Bin; Yu Li; Sun Dingqiang

2010-01-01

Objective: To evaluate the clinical effect of retrievable esophageal covered metal internal stent in treating patients with achalasia. Methods: Under DSA guidance, peroral 'Z-type' double horn covered metal internal stent implantation was performed in 16 patients with achalasia. Esophagography was carried out about 28 days after the procedure and the stent was retrieved. Results: Of 16 cases, the stent fell off into the stomach two weeks after the operation in one. And the stent was successfully replaced after it was taken out. The placed stent was successfully retrieved in all cases 28 days after the treatment. No serious complications occurred. All the patients were followed up for 3 months to 3 years. During the follow-up period restenosis of the esophagus developed in two cases (at one and 1.5 years respectively), and the restenosis degree was relived after balloon dilation. Clinically, no esophageal symptoms, such as dysphagia, occurred in all patients. Conclusion: As a simple and safe technique, the retrievable esophageal covered metal internal stent implantation is very effective with fewer complications for the treatment of achalasia. Moreover, the technique carries lower restenosis occurrence. (authors)

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.

Clinical Application of Fully Covered Self-Expandable Metal Stents in the Treatment of Bronchial Fistula.

Science.gov (United States)

Cao, Ming; Zhu, Qiang; Wang, Wei; Zhang, Tian Xiao; Jiang, Min Zhong; Zang, Qi

2016-09-01

Background The study was designed to access the feasibility, safety, and efficacy of fully covered self-expandable metal stents in the treatment of bronchial fistula. Methods Clinical data of nine patients (seven males and two females) who were treated with placement of tracheobronchial or bronchial fully covered self-expandable metal stents from August 2005 to November 2011 were analyzed retrospectively. Among these patients, seven were diagnosed with bronchopleural fistula, one with tracheopleural fistula, and one with left main bronchoesophageal fistula. Eight had accompanying thoracic empyema. The fistula orifices ranged from 3.5 mm to 25 mm in diameter. All patients received topical anesthesia. L-shaped stents were placed in six patients and I-shaped stents in three under fluoroscopic guidance. After stent placement, patients with empyema were treated with pleural lavage. Results Stent placement in the tracheobronchial tree was successful in all patients, without procedure-related complications. The operating time was 5 to 16 minutes. A small amount of bubble overflowed from the intrathoracic drainage tube of only one patient. In the other patients, the bubble in the intrathoracic drainage tube disappeared immediately or angiography showed no overflow of contrast agent from the fistula orifice. The effective rate of fistula orifice closure after stent placement was 100%, with 88.9% rated as excellent. One patient coughed the stent out 5 days after placement and hence a new stent was placed. Among the patients with empyema, one died of septicemia arising from empyema on day 8 and another died of brain metastases of lung cancer 6 months after stent insertion with persistent empyema. In the other six patients, empyema resolved after 2 to 5 months (cure rate 75%). Seven patients were followed up for 3 to 36 months. During follow-up, one stent was removed 8 months after implantation due to difficult expectoration, without recurrent empyema. The remaining

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

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.

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...

Metal artifact reduction for flat panel detector intravenous CT angiography in patients with intracranial metallic implants after endovascular and surgical treatment.

Science.gov (United States)

Pjontek, Rastislav; Önenköprülü, Belgin; Scholz, Bernhard; Kyriakou, Yiannis; Schubert, Gerrit A; Nikoubashman, Omid; Othman, Ahmed; Wiesmann, Martin; Brockmann, Marc A

2016-08-01

Flat panel detector CT angiography with intravenous contrast agent injection (IV CTA) allows high-resolution imaging of cerebrovascular structures. Artifacts caused by metallic implants like platinum coils or clips lead to degradation of image quality and are a significant problem. To evaluate the influence of a prototype metal artifact reduction (MAR) algorithm on image quality in patients with intracranial metallic implants. Flat panel detector CT after intravenous application of 80 mL contrast agent was performed with an angiography system (Artis zee; Siemens, Forchheim, Germany) using a 20 s rotation protocol (200° rotation angle, 20 s acquisition time, 496 projections). The data before and after MAR of 26 patients with a total of 34 implants (coils, clips, stents) were independently evaluated by two blinded neuroradiologists. MAR improved the assessability of the brain parenchyma and small vessels (diameter metallic implants and at a distance of 6 cm (p<0.001 each, Wilcoxon test). Furthermore, MAR significantly improved the assessability of parent vessel patency and potential aneurysm remnants (p<0.005 each, McNemar test). MAR, however, did not improve assessability of stented vessels. When an intravenous contrast protocol is used, MAR significantly ameliorates the assessability of brain parenchyma, vessels, and treated aneurysms in patients with intracranial coils or clips. 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/

Reversible defects on myocardial perfusion imaging early after coronary stent implantation: a predictor of late restenosis

International Nuclear Information System (INIS)

Kim, D. E.; Park, S. A.; Kim, C. K.; Chang, J. A.; Jeong, J. W.; Oh, S. G.; Lee, C.

2007-01-01

It appears logical that myocardial perfusion should be fixed and not reversible, in the territory supplied by a dilated coronary artery. However, several studies have demonstrated reversible perfusion in the territory supplied by a coronary artery with an optimally implanted stent. The main objective of this study was to evaluate the incidence of reversible defects detected by M-SPECT early after optimal PTCA with stent implantation. Its second objective was to determine the predictive value of detecting reversible defects after stent implantation for late restenosis. Sixty-six patients that underwent M-SPECT within 24 hours of successful PTCA with stent implantation were included. All patients were followed up clinically and angiographically. The incidence of reversible perfusion defects on M-SPECT and the rate of late restenosis in target coronary arteries were evaluated retrospectively. Reversible perfusion defects on M-SPECT were observed in 26% of the patients and in 36% of lesions following successful PTCA with stent implantation. The incidence of late restenosis was significantly higher in patients and lesions with reversible perfusion defects (47% vs. 18%). According to binary logistic regression analysis, the presence of a reversible perfusion defects was the only independent predictor of late restenosis. This study shows that the predictive value of reversible perfusion defects on M-SPECT early after stent implantation with respect to the incidence of late restenosis was 47% in patients with a reversible defect, and 18% in those without it

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.

Radiologic placement of metallic esophageal stents: preliminary experience

International Nuclear Information System (INIS)

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)

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).

A higher volume of fibrotic tissue on virtual histology prior to coronary stent implantation predisposes to more pronounced neointima proliferation.

Science.gov (United States)

Haine, Steven; Wouters, Kristien; Miljoen, Hielko; Vandendriessche, Tom; Claeys, Marc; Bosmans, Johan; Vrints, Christiaan

2018-04-01

Since neointima smooth muscle cells (SMC) mainly originate from the vessel wall, we investigated whether atherosclerotic plaque composition influences subsequent in-stent neointima proliferation and restenosis. We performed intravascular ultrasound (IVUS) with virtual histology in 98 patients prior to elective bare-metal stent (BMS) implantation in de novo coronary artery lesions. Virtual histology variables pre-percutaneous coronary intervention (PCI) were related to in-stent neointima proliferation six months after implantation assessed as late luminal loss of 0.88 mm (interquartile range (IQR) 0.37-1.23 mm) on angiography and as maximal percentage area stenosis of 42% (IQR 33-59%) and percentage volume intima hyperplasia of 27% (IQR 20-36%) on IVUS. A ridge-trace based multiple linear regression model was constructed to account for multicollinearity of the virtual histology variables and was corrected for implanted stent length (18 mm, IQR 15-23 mm), stent diameter (3.0 mm, IQR 2.75-3.5 mm) and lesion volume (146 mm³, IQR 80-201 mm³) prior to PCI. Fibrous tissue volume prior to PCI (49 mm³, IQR 30-77 mm³) was significantly and independently related to late luminal loss (p = .038), maximal percentage area stenosis (p = .041) and percentage volume intima hyperplasia (p = .004). Neither absolute nor relative amounts of fibrofatty, calcified or necrotic core tissue appeared related to any of the restenosis parameters. Subgroup analysis after exclusion of acute coronary syndrome (ACS) patients yielded similar results. Lesions with more voluminous fibrotic tissue pre-PCI show more pronounced in-stent neointima proliferation, even after correction for lesion plaque volume.

Coated metal stents installation for the treatment of malignant tumors complicated with colonic and rectal fistula

International Nuclear Information System (INIS)

Mao Aiwu; Fang Shiming; Liu Shiyi; Lin Qing; Jiang Haosheng; Jia Yiping; Gao Zhongdu

2007-01-01

Objective: To probe the clinical features of malignant colonic and rectal tumors together with coated metal stent placement. Methods: 24 cases of colonic fistula with late stage malignant tumors including 16 cases of intestinal cancer(66.7%), 2 cases of gastric and cervical cancers respectively(8.3%); 1 case of bladder, 1 case of prostate, 1 case of ovary and 1 case of gallbladder cancer(4.2%). The cause for the fistulas were direct invasion (37.5% )and radiotherapy (62.5%). The KPS was 30-60, and the median value was 40. CT were done preoperatively and followed by radiography of canulation contrast medium enema to ensure the location of the orifice of the fistula, the route of intestinal canal or complicated with obstruction and the condition with nearby tissues. Stents were finally implanted specifically according to the different situations of intestines. The sites of implanted stents and the occlusion of fistula should be strictly scrutinized; and then with careful follow up of patients complications and general condition. The procedure was carried out practically in 23 cases. Results: The successful rate of technique reached 96%(22/23), the failed one was due to the curve over sharpness of intestinal lock and resulting in non-expansion of the stent. The clinical successful rate was 91.3%. The two failed cased included the one with improper coherence to the intestinal wall leading to the stent migration and the other with a mild leakage after stent placement. The follow-up duration were 28-365 days, average 109 days, and the median value was 92 days. The average surviving period of 3 months and 6 months were 51% and 11% respectively. Conclusion: Intestinal fistula is the common complication after intestinal tumor operation and radiotherapy with poor prognosis. Metal covered stents provide a therapy of choice to improve the life quality and prolong the life span. (authors)

Ferromagnetic Bare Metal Stent for Endothelial Cell Capture and Retention.

Science.gov (United States)

Uthamaraj, Susheil; Tefft, Brandon J; Hlinomaz, Ota; Sandhu, Gurpreet S; Dragomir-Daescu, Dan

2015-09-18

Rapid endothelialization of cardiovascular stents is needed to reduce stent thrombosis and to avoid anti-platelet therapy which can reduce bleeding risk. The feasibility of using magnetic forces to capture and retain endothelial outgrowth cells (EOC) labeled with super paramagnetic iron oxide nanoparticles (SPION) has been shown previously. But this technique requires the development of a mechanically functional stent from a magnetic and biocompatible material followed by in-vitro and in-vivo testing to prove rapid endothelialization. We developed a weakly ferromagnetic stent from 2205 duplex stainless steel using computer aided design (CAD) and its design was further refined using finite element analysis (FEA). The final design of the stent exhibited a principal strain below the fracture limit of the material during mechanical crimping and expansion. One hundred stents were manufactured and a subset of them was used for mechanical testing, retained magnetic field measurements, in-vitro cell capture studies, and in-vivo implantation studies. Ten stents were tested for deployment to verify if they sustained crimping and expansion cycle without failure. Another 10 stents were magnetized using a strong neodymium magnet and their retained magnetic field was measured. The stents showed that the retained magnetism was sufficient to capture SPION-labeled EOC in our in-vitro studies. SPION-labeled EOC capture and retention was verified in large animal models by implanting 1 magnetized stent and 1 non-magnetized control stent in each of 4 pigs. The stented arteries were explanted after 7 days and analyzed histologically. The weakly magnetic stents developed in this study were capable of attracting and retaining SPION-labeled endothelial cells which can promote rapid healing.

Intravascular ultrasound assessment of minimumlumen area and intimal hyperplasia in in-stent restenosis after drug-eluting or bare-metal stent implantation. The Nordic Intravascular Ultrasound Study (NIVUS)

DEFF Research Database (Denmark)

Jensen, Lisette Okkels; Vikman, Saila; Antonsen, Lisbeth

2017-01-01

presenting with a DES or bare-metal stent (BMS) in-stent restenosis. Methods: The ``Nordic Intravascular Ultrasound Study (NIVUS)'' study was conducted in Nordic and Baltic countries as a prospective multicenter registry. Two hundred nine patients (DES n = 121 and BMS n = 88) with instent restenosis were...

The therapeutic effects and experience of tracheal stent implantation in managing severe tracheal stenosis

International Nuclear Information System (INIS)

Lv Weifu; Zhang Xingming; Zhang Xuebing; Wang Weiyu; Hou Changlong

2006-01-01

Objective: To evaluate the therapeutic effects and experience of the tracheal stent implantation for the management of severe tracheal stenosis. Materials: Thirteen patients with severe tracheal stenosis of various causes underwent high kilovoltage radiography and computed tomography for evaluating the site, form and extent of the stenosis including 10 at the trachea, 1 at the right main bronchus and 2 at left main bronchus. The C2 catheter assisted with ultra-slipping guide wire was inserted into the trachea under fluoroscopy and then a replaced high shoring guide wire was pushed through the stenotic segment and retained the stent. Results: All stents were implanted successfully with successful rate 100% together with dyspnoeic improvements. The mean survival time was 6.2 months for patients with malignant neoplasm. One patient with benign tracheal stenosis has been followed-up for 5 years without restenosis. Conclusions: The tracheal stent implantation is an effective means for severe tracheal stenosis. (authors)

An assessment on modified AZ80 alloys for prospect biodegradable CV stent applications

NARCIS (Netherlands)

Erinc, M.; Sillekens, W.H.

2009-01-01

In medicine, stents are inserted into an artery to prevent local constrictions to blood flow. Commonly used stents are permanent metal stents, yet developments in this area are more and more heading towards biodegradable stents. Implants made of materials that can dissolve in the patient's body by

Metallic stent for the treatment of iliac arterial stenosis

Energy Technology Data Exchange (ETDEWEB)

Park, Jae Hyung; Chung, Jin Wook; Han, Joon Koo; Suh, Chul Soo; Yoo, Jae Wook; Han, Man Chung [Seoul National University College of Medicine, Seoul (Korea, Republic of); Song, Chi Sung [Seoul City Boramae Hospital, Seoul (Korea, Republic of)

1993-07-15

In order to study the clinical efficacy of the metallic stent of the treatment of iliac arterial stenosis, the clinical and arteriographic findings of the 8 patients were retrospectively reviewed. All 8 patients were males with an age of 51 to 79. The Fontaine class for the functional status of lower extremities was II in 4 patients, III in 3 patents and IV in 1 patient. Self expandable Gianturco stent was inserted of in 7 iliac arteries and balloon expandable Palmaz stent was inserted in 2 iliac arteries in the 8 patients. The indications for the metallic stent application were localized dissection with significant residual stenosis in 6 sites, recoiling due to calcification in one case and eccentricity of the stenosislesionin 2 sites. The deployment of the metallic stent was successful in all the cases to maintain the patency of iliac arteries with residual stenosis less than 30%. The Fontaine class was improved to 1 in 6 patients, IIa in 1 patient and IIb in another one. During the follow up period of 3 to 14 month, none except one developed recurrence of the symptom. On the basis of our experience, we believe that metallic stent is safe and effective for the treatment of iliac arterial stenosis. However, we think that it is a complementary measure to the percutaneous transluminal angioplasty. The comparative study between different types of metallic stent and the long term effect should be investigated further.

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.

Late Migration of Two Covered Biliary Stents Through a Spontaneous Bilioenteric Fistula in a Patient with Malignant Biliary Obstruction

International Nuclear Information System (INIS)

Krokidis, Miltiadis E.; Hatzidakis, Adam A.; Manousaki, Eirini G.; Gourtsoyiannis, Nicholas C.

2008-01-01

We report a case of simultaneous late migration of two ePTFE-FEP covered biliary endoprostheses (Viabil, W.L. Gore, Flagstaff, AZ, USA) that were percutaneously implanted for the treatment of malignant obstructive jaundice. The first Viabil covered stent was placed successfully without any evidence of dislocation or other complication during follow-up. Occlusion of the stent occurred 4 months later and was treated with the placement of a second stent of the same type. Thirteen months later the patient became symptomatic. Percutaneous transhepatic cholangiography (PTC) revealed the presence of a choledocho-duodenal fistula and the disappearance of the two endoprostheses previously implanted. A third metallic stent was then percutaneously positioned through the bilioenteric fistula. The computed tomography scan that followed for the detection of the metallic bodies did not reveal the dislocated metallic stents. Stent migration is a well-known complication of uncovered metallic stents, though Viabil stent migration is assumed to be most unlikely to happen due to the stent's anchoring barbs. Furthermore, the stent had already been tightly fixed by tumor over- and ingrowth, as recognized in previous imaging. This is a very unusual case, describing the disappearance of two metallic foreign bodies encapsulated by tumor

In-stent neoatherosclerosis and tissue characteristics of restenotic lesions following implantation of second generation drug-eluting stents in unrestricted coronary lesions: Optical frequency domain imaging study.

Science.gov (United States)

Sabbah, Mahmoud; Kadota, Kazushige; El-Eraky, Azza; Kamal, Hanan M; Abdellah, Ahmed-Tageldien; El Hawary, Ahmed

2017-06-01

Differences in stent platform, polymer coatings, and antirestenotic drugs among the current in use second-generation drug-eluting stents (G2-DESs) may induce significant variations in neointimal response and vascular healing, which may impact the prevalence of neoatherosclerosis (NA) and morphological appearance of the restenotic tissue. Utilizing Optical frequency domain imaging, two independent reviewers, retrospectively compared the prevalence of neoatherosclerosis (NA), and the morphological differences, and tissue characteristics of 50 G2-DESs in-stent restenosis (ISR) lesions (35 everolimus-eluting stent [22 cobalt-chromium (CoCr), 13 platinum-chromium (PtCr)], and 15 biolimus-eluting stent [BES]) implanted liberally in unrestricted coronary lesions. More than half of the stents were implanted in type C lesions, while 40% of the stents were implanted primarily in lesions with recanalized chronic total occlusion. NA, defined as a neointima formation with the presence of lipids or calcification, was observed in fewer than half (24/50) of all ISR lesions with no significant in-between group differences (41%, 69%, and 40% in CoCr, PtCr, and BES respectively, P = 0.22), nor were there any significant differences in the morphological appearance or tissue characteristics between all G2-DESs subtypes. Acknowledging some limitations, our results may suggest that the prevalence of NA and the morphological appearance of restenotic lesions might not differ when G2-DESs are implanted in unrestricted, rather complex, coronary lesions. © 2017, Wiley Periodicals, Inc.

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

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.

Covered duodenal self-expandable metal stents prolong biliary stent patency in double stenting: The largest series of bilioduodenal obstruction.

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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 application of Y-shaped self-expandable covered metal stents in the thoracostomach-airway fistula: a single center, 11 years experience].

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Fang, Yi; Li, Tengfei; Han, Xinwei; Wu, Gang; Ren, Jianzhuang; Ren, Kewei; Lu, Huibin; Zhang, Quanhui; Li, Zongming

2015-08-01

To investigate the clinical feasibility and efficacy of Y-shaped self-expandable covered metal stents (Y-stents) in the management of thoracostomach-airway fistula. Retrospective analysis was performed for 108 patients treated for thoracostomach-airway fistula with Y-shaped self-expandable coated metal stents between April 2003 and October 2014. Y-stents were designed based on the dimensions of trachea and bronchus and sites of the fistula and then were inserted under DSA monitoring. There were 65 cases with single big Y-stent placement, 26 cases with single small Y-stent placement, 23 cases with double Y-stents placement, and 1 case with 3 Y-stents placement. Stent implantation was successfully accomplished with single manipulation in all patients. Complete occlusion of the fistula was obtained in 104 patients after the primary manipulation, and 4 patients required a secondary manipulation where a double Y-stents was inserted because of failure of primary manipulate. Ninety-two patients completed the follow-up , while 16 were lost. Fifty-nine patients died while 33 were alive with marked improvement in their quality of life. The placement of Y-stents can effectively occlude the thoracostomach-airway fistula in patients who had had the esophageal tumors resected. The technique is not only feasible but reliable to improve the quality of life of the patients.

An experimental study on expandable endovascular metallic stents in dogs

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Song, Ho Young; Kim, Hak Nam [Chonbuk National University College of Medicine, Chonju (Korea, Republic of)

1990-12-15

We constructed an expandable endovascular metallic stent in the same way as Giamturco did. Experiments were made to test the ability of these stents to be used in the vessels. A total of 20 stents were passed through a 8.5 French teflon sheath into the normal abdominal aorta. IVC, and iliac artery of four adult dogs for 4 weeks to 12 weeks; 8 stents (10 mm in diameter fully expanded and 20 mm in length) in the abnormal aorta, 7 stents (12 mm/20 mm) in the IVC, and 5 stents (8 mm/20 mm) in the iliac artery. All but two stents showed no migration, and one complete occlusion occurred in right iliac artery of a dog. Histologically, stents wires were covered by neo-intimal proliferation. The side branches of the main vessels remained patent, even stent wires across their orifices. These metallic stents may be used as an endovascular graft material in the nonsurgical treatment of several forms of vascular disease.

Hematopoietic stem cell capture and directional differentiation into vascular endothelial cells for metal stent-coated chitosan/hyaluronic acid loading CD133 antibody.

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Zhang, Shixuan; Zhang, Fan; Feng, Bo; Fan, Qingyu; Yang, Feng; Shang, Debin; Sui, Jinghan; Zhao, Hong

2015-03-01

A series of metal stents coated with chitosan/hyaluronic acid (CS/HA) loading antibodies by electrostatic self-assembled method were prepared, and the types of cells captured by antibodies and their differentiation in vascular endothelial cells (ECs) evaluated by molecular biology and scanning electron microscope. The results showed that CD133 stent can selectively capture hematopoietic stem cells (HSC),which directionally differentiate into vascular ECs in peripheral blood by (CS/HA) induction, and simultaneously inhibit migration and proliferation of immune cells and vascular smooth muscle cells (MCs). CD34 stent can capture HSC, hematopoietic progenitor cells that differentiate into vascular ECs and immune cells, promoting smooth MCs growth, leading to thrombosis, inflammation, and rejection. CD133 stent can be implanted into miniature pig heart coronary and can repair vascular damage by capturing own HSC, thus contributing to the rapid natural vascular repair, avoiding inflammation and rejection, thrombosis and restenosis. These studies demonstrated that CD133 stent of HSC capture will be an ideal coated metal stent providing a new therapeutic approach for cardiovascular and cerebrovascular disease.

Esophageal stent implantation for the treatment of esophageal strictures: its current situation and research progress

International Nuclear Information System (INIS)

Zhu Haidong; Guo Jinhe; Teng Gaojun

2011-01-01

Esophageal stent implantation has been the most common therapy for the treatment of malignant and benign esophageal stenosis. At present, this technique is widely used in treating advanced esophageal cancerous stricture, refractory esophageal benign stricture and all kinds of esophageal fistulae or perforation. This paper aims to make a comprehensive review of the current situation and research progress of the esophageal stent implantation in clinical practice. (authors)

An agent-based model of the response to angioplasty and bare-metal stent deployment in an atherosclerotic blood vessel.

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Antonia E Curtin

Full Text Available PURPOSE: While animal models are widely used to investigate the development of restenosis in blood vessels following an intervention, computational models offer another means for investigating this phenomenon. A computational model of the response of a treated vessel would allow investigators to assess the effects of altering certain vessel- and stent-related variables. The authors aimed to develop a novel computational model of restenosis development following an angioplasty and bare-metal stent implantation in an atherosclerotic vessel using agent-based modeling techniques. The presented model is intended to demonstrate the body's response to the intervention and to explore how different vessel geometries or stent arrangements may affect restenosis development. METHODS: The model was created on a two-dimensional grid space. It utilizes the post-procedural vessel lumen diameter and stent information as its input parameters. The simulation starting point of the model is an atherosclerotic vessel after an angioplasty and stent implantation procedure. The model subsequently generates the final lumen diameter, percent change in lumen cross-sectional area, time to lumen diameter stabilization, and local concentrations of inflammatory cytokines upon simulation completion. Simulation results were directly compared with the results from serial imaging studies and cytokine levels studies in atherosclerotic patients from the relevant literature. RESULTS: The final lumen diameter results were all within one standard deviation of the mean lumen diameters reported in the comparison studies. The overlapping-stent simulations yielded results that matched published trends. The cytokine levels remained within the range of physiological levels throughout the simulations. CONCLUSION: We developed a novel computational model that successfully simulated the development of restenosis in a blood vessel following an angioplasty and bare-metal stent deployment based on

[Technical feasibility of the implantation of a monorail stent system into the renal arteries without pre-dilatation].

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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.

[In hospital and mid-term outcome of patients with NIR stent implantation: multicenter ESPORT-NIR registry].

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Iñiguez, A; García, E; Seabra, R; Bordes, P; Bethencourt, A; Rigla, J

2001-05-01

Despite improvements in the results and techniques of catheter-based revascularization, few studies have evaluated the clinical results of the application of new stent designs. We describe the in-hospital and mid-term outcome of patients undergoing a stent NIR implantation. At least 1 Stent NIR was implanted in 1.004 patients (1.136 lesions) recruited from 50 centers in an international, multicenter, prospective, registry (Spain and Portugal NIR stent registry). Inclusion criteria were objective coronary ischemia related to a severe de novo lesion or first restenosis in native vessels with a reference diameter >= 2.75 mm. The primary end-point was the incidence of major adverse cardiac events within the first 7 months of follow-up. The mean age of the patients was 60 years and 82% were male. Angioplasty was indicated due to unstable angina in 61% of the cases. Stent implantation was successfully achieved in 99.6%. Clinical success (angiographic success without in-hospital major events) was achieved in 98.6% of patients. The rate of angiographic restenosis (> 50% stenosis narrowing) was 16% (CI 95%; 11.7-21.2). The accumulated major cardiac adverse event rate at seven months of follow-up was 8.7%: death (0.9%), acute myocardial infarction (1.2%) and target lesion revascularization (6.6%). In the wide setting of the population included in the ESPORT-NIR registry, stent NIR implantation was a highly effective therapy with a good mid-term clinical and angiographic outcome.

A review on biodegradable materials for cardiovascular stent application

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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.

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

[Successful correction with stent-graft of coronary artery rupture after angioplasty].

Science.gov (United States)

Demin, V V

2003-01-01

Rupture and perforation of coronary arteries complicate in average 0.5% of radiosurgical coronary interventions and often are accompanied by serious consequences and high mortality. According to-type of coronary perforation different methods of correction are used, ranging from conservative measures to urgent cardiosurgical interventions. Coronary stent-grafts with 'sandwich' type of construction ore composed from two metal stents and PTFE layer between them. Development of such stents enabled effective radioguided endovascular repair of coronary ruptures. The paper presents the first Russian experience of stout-graft implantation for coronary artery rupture occurred during direct stenting of proximal anterior descending artery and balloon angioplasty in distal segment. The rupture occurred probably because of wall fragility between affected segment and muscular bridge. Stent-graft JoStent 16 mm in length connected with 3-mm balloon was implanted with subsequent complete restitution of blood flow, resolution of pain syndrome and ECG normalization. Echocardiography in operative theatre and one day after surgery showed no intrapericardial fluid. Stent-graft devices for urgent implantation in cases of coronary rupture must be included into obligatory equipment of radiosurgical facilities.

Complication after self expandable metallic stent for esophageal cancer

International Nuclear Information System (INIS)

Nagahama, Takeshi; Maruyama, Michio; Kato, Kiyomi; Shinoura, Hiroshi; Hasegawa, Kumi; Takashima, Itaru; Ebuchi, Masakazu

2003-01-01

Major complications after placement of esophageal stent and airway stent were reviewed and evaluated. Four patients, including two patients with perforations and two patients with fistula formation, developed major complications after placement of a self expandable metallic stent. Two patients underwent additional radiation to improve stricture after stent placement. In one patient, stent placement was selected to improve esophageal stricture that occurred after radical radiation therapy. In one patient, migration of stent into the lesion caused a perforation. It can be concluded that additional radiation after stent placement increases the risk of complication. Stent migration also can lead to the risk of perforation. (author)

Self-Expandable Metallic Stent Placement in Malignant Gastric Outlet Obstruction: A Comparison Between 2 Brands of Stents.

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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.

Biodegradable Metals for Cardiovascular Stents: from Clinical Concerns to Recent Zn-Alloys.

Science.gov (United States)

Bowen, Patrick K; Shearier, Emily R; Zhao, Shan; Guillory, Roger J; Zhao, Feng; Goldman, Jeremy; Drelich, Jaroslaw W

2016-05-01

Metallic stents are used to promote revascularization and maintain patency of plaqued or damaged arteries following balloon angioplasty. To mitigate the long-term side effects associated with corrosion-resistant stents (i.e., chronic inflammation and late stage thrombosis), a new generation of so-called "bioabsorbable" stents is currently being developed. The bioabsorbable coronary stents will corrode and be absorbed by the artery after completing their task as vascular scaffolding. Research spanning the last two decades has focused on biodegradable polymeric, iron-based, and magnesium-based stent materials. The inherent mechanical and surface properties of metals make them more attractive stent material candidates than their polymeric counterparts. A third class of metallic bioabsorbable materials that are based on zinc has been introduced in the last few years. This new zinc-based class of materials demonstrates the potential for an absorbable metallic stent with the mechanical and biodegradation characteristics required for optimal stent performance. This review compares bioabsorbable materials and summarizes progress towards bioabsorbable stents. It emphasizes the current understanding of physiological and biological benefits of zinc and its biocompatibility. Finally, the review provides an outlook on challenges in designing zinc-based stents of optimal mechanical properties and biodegradation rate. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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.

Treatment of esophagopleural fistulas using covered retrievable expandable metallic stents.

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Kim, Tae-Hyung; Shin, Ji Hoon; Kim, Kyung Rae; Park, Jung-Hoon; Kim, Jin Hyoung; Song, Ho-Young

2014-04-01

To evaluate the clinical efficacy of placement of covered retrievable expandable metallic stents for esophagopleural fistulas (EPFs). During the period 1997-2013, nine patients with EPF were treated using covered retrievable expandable metallic stents. The underlying causes of EPF were esophageal carcinoma (n = 6), lung cancer (n = 2), and postoperative empyema for Boerhaave syndrome (n = 1). Technical success was achieved in eight patients (88.9%). In one patient, incomplete EPF closure was due to incomplete stent expansion. Clinical success, defined as complete EPF closure within 7 days, was achieved in five patients (55.6%). Overall fistula persistence (n = 1) or reopening (n = 4) occurred in five patients (55.6%) 0-15 days after stent placement. The causes of reopening were due to the gap between the stent and the esophagus (n = 3) or stent migration (n = 1). For fistula persistence or reopening, additional interventional management, such as gastrostomy, stent removal, or stent reinsertion, was performed. Stent migration occurred as a complication in one patient with EPF from a benign cause secondary to postoperative empyema. In the eight patients who died during the follow-up period, the mean and median survival times were 78.8 days and 46 days, respectively. Placement of a covered expandable metallic esophageal stent for the palliative treatment of EPF is technically feasible, although the rate of clinical success was poor secondary to fistula persistence or reopening. Fistula reopening was caused by the gap between the stent and the esophagus or by stent migration, and additional interventional treatment was useful to ensure enteral nutritional support. Copyright © 2014 SIR. Published by Elsevier Inc. All rights reserved.

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.)

Sealing of Airway Fistulas for Metallic Covered Z-type Stents

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Hongwu WANG

2011-08-01

Full Text Available Background and objective Treating airway fistulas, including esophagorespiratory fistulas (ERFs, bronchopleural fistulas (BPFs, and tracheomediastinal fistulas (TMFs, is difficult. The aim of this study is to evaluate the safety and clinical efficacy of metallic covered Z-type stents (CZTS for the treatment of airway fistulas through bronchoscopy or fluroscopy. Methods Thirty-eight patients with fistulas between the esophagus, mediastina, and airways (32 ERFs, 5 BPFs, and 1 TMF were retrospectively reviewed after treatment with covered metallic esophageal and airway stents. The fistulas were caused by esophageal (n=26, bronchogenic (n=11, and thyroid (n=1 carcinomas. Results Forty-six fistulas were found in 38 patients. The fistula size ranged from 0.5 cm to 7.0 cm. Forty airway covered metal stents (24 Y-type, 8 L-type, and 8 I-type and 24 esophageal metal stents were placed. Complete responses to the sealing effects of fistulas were noted in 4.3% of all the fistulas, 60.9% showed complete clinical responses, 23.9% showed partial responses, and 10.9% showed no response. An effectivity rate of 89.1% was observed, and the median survival duration of all patients was 5 months. Conclusion The use of CZTS appears to be safe and feasible for the palliative treatment of ERFs, BPFs, and TMFs. Airway stent placement is recommended for patients with ERF. In the event that airway stents fail, esophageal stents should be given. Airway bifurcation stents were observed to be especially suitable for the sealing of fistulas near the trachea carina.

Shrinking the Supply Chain for Implantable Coronary Stent Devices.

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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.

Satisfactory arterial repair 1 year after ultrathin strut biodegradable polymer sirolimus-eluting stent implantation: an angioscopic observation.

Science.gov (United States)

Ishihara, Takayuki; Awata, Masaki; Iida, Osamu; Fujita, Masashi; Masuda, Masaharu; Okamoto, Shin; Nanto, Kiyonori; Kanda, Takashi; Tsujimura, Takuya; Uematsu, Masaaki; Mano, Toshiaki

2018-01-15

The ultrathin strut biodegradable polymer sirolimus-eluting stent (Orsiro, O-SES) exhibits satisfactory clinical outcomes. However, no report to date has documented the intravascular status of artery repair after O-SES implantation. We examined 5 O-SES placed in 4 patients (age 65 ± 12 years, male 75%) presenting with stable angina pectoris due to de novo lesions in native coronary arteries. Coronary angioscopy was performed immediately after percutaneous coronary intervention and 1 year later. Angioscopic images were analyzed to determine the following: (1) dominant grade of neointimal coverage (NIC) over the stent; (2) maximum yellow plaque grade; and (3) existence of thrombus. Yellow plaque grade was evaluated both immediately after stent implantation and at the time of follow-up observation. The other parameters were evaluated at the time of follow-up examination. NIC was graded as: grade 0, stent struts exposed; grade 1, struts bulging into the lumen, although covered; grade 2, struts embedded in the neointima, but translucent; grade 3, struts fully embedded and invisible. Yellow plaque severity was graded as: grade 0, white; grade 1, light yellow; grade 2, yellow; and grade 3, intensive yellow. Angioscopic findings at 1 year demonstrated the following: dominant NIC grade 1, grade 2, and grade 3 in 1, 2, and 2 stents, respectively; all stents were covered to some extent; focal thrombus adhesion was observed in only 1 stent. Yellow plaque grade did not change from immediately after stent implantation to follow-up. O-SES demonstrated satisfactory arterial repair 1 year after implantation.

Self-Expandable Metallic Stent Placement in Malignant Gastric Outlet Obstruction

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Ye, Bing-Wei; Lee, Kuei-Chuan; Hsieh, Yun-Cheng; Li, Chung-Pin; Chao, Yee; Hou, Ming-Chih; Lin, Han-Chieh

2015-01-01

Abstract 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. PMID:26200641

Effect of biolimus-eluting stents with biodegradable polymer vs bare-metal stents on cardiovascular events among patients with acute myocardial infarction

DEFF Research Database (Denmark)

Räber, Lorenz; Kelbæk, Henning; Ostojic, Miodrag

2012-01-01

The efficacy and safety of drug-eluting stents compared with bare-metal stents remains controversial in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI).......The efficacy and safety of drug-eluting stents compared with bare-metal stents remains controversial in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI)....

Everolimus-induced Pneumonitis after Drug-eluting Stent Implantation: A Case Report

Energy Technology Data Exchange (ETDEWEB)

Sakamoto, Susumu, E-mail: susumu1029@gmail.com; Kikuchi, Naoshi; Ichikawa, Atsuo; Sano, Go; Satoh, Keita; Sugino, Keishi; Isobe, Kazutoshi; Takai, Yujiro [Toho University School of Medicine, Department of Respiratory Medicine (Japan); Shibuya, Kazutoshi [Toho University School of Medicine, Department of Pathology (Japan); Homma, Sakae [Toho University School of Medicine, Department of Respiratory Medicine (Japan)

2013-08-01

Despite the wide use of everolimus as an antineoplastic coating agent for coronary stents to reduce the rate of restenosis, little is known about the health hazards of everolimus-eluting stents (EES). We describe a case of pneumonitis that developed 2 months after EES implantation for angina. Lung pathology demonstrated an organizing pneumonia pattern that responded to corticosteroid therapy. Although the efficacy of EES for ischemic heart disease is well established, EES carries a risk of pneumonitis.

Feasibility of using bulk metallic glass for self-expandable stent applications.

Science.gov (United States)

Praveen Kumar, Gideon; Jafary-Zadeh, Mehdi; Tavakoli, Rouhollah; Cui, Fangsen

2017-10-01

Self-expandable stents are widely used to restore blood flow in a diseased artery segment by keeping the artery open after angioplasty. Despite the prevalent use of conventional crystalline metallic alloys, for example, nitinol, to construct self-expandable stents, new biomaterials such as bulk metallic glasses (BMGs) are being actively pursued to improve stent performance. Here, we conducted a series of analyses including finite element analysis and molecular dynamics simulations to investigate the feasibility of using a prototypical Zr-based BMG for self-expandable stent applications. We model stent crimping of several designs for different percutaneous applications. Our results indicate that BMG-based stents with diamond-shaped crowns suffer from severe localization of plastic deformation and abrupt failure during crimping. As a possible solution, we further illustrate that such abrupt failure could be avoided in BMG-based stents without diamond shape crowns. This work would open a new horizon for a quest toward exploiting superior mechanical and functional properties of metallic glasses to design future stents. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1874-1882, 2017. © 2016 Wiley Periodicals, Inc.

Hepatocellular Carcinoma Complicated by Gastroduodenal Obstruction: Palliative Treatment with Metallic Stent Placement

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Lee, Ye Jin; Kim, Jin Hyoung, E-mail: m1fenew@daum.net; Song, Ho-Young; Park, Jung-Hoon; Na, Han Kyu; Kim, Pyeong Hwa; Fan, Yong [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Asan Medical Center (Korea, Republic of)

2012-10-15

Purpose: To evaluate the clinical effectiveness of self-expandable metallic stents in seven patients with malignant gastroduodenal obstruction caused by inoperable hepatocellular carcinoma (HCC). Methods: Seven patients with gastroduodenal obstruction caused by advanced HCC underwent metallic stent placement from 2003 to 2010. These patients had total dysphagia (n = 5) or were able to eat only liquids (n = 2) before stent placement. Patients had Eastern Cooperative Oncology Group performance scores of 2 or 3, and Child-Pugh classification B or C. Results: Stent placement was technically successful in all seven patients (100%) and clinically successful in six (86%). Five patients could eat a soft diet, and one patient tolerated regular diet after stent placement. Stent-related obstructive jaundice occurred in one patient. One patient had hematemesis 11 days after stent placement. Overall mean survival was 51 days (range, 10-119 days). Stent patency was preserved in six patients with clinical success until death. Conclusion: Placement of a covered self-expandable metallic stent may offer good palliation in patients with gastroduodenal obstruction due to advanced HCC.

Hepatocellular Carcinoma Complicated by Gastroduodenal Obstruction: Palliative Treatment with Metallic Stent Placement

International Nuclear Information System (INIS)

Lee, Ye Jin; Kim, Jin Hyoung; Song, Ho-Young; Park, Jung-Hoon; Na, Han Kyu; Kim, Pyeong Hwa; Fan, Yong

2012-01-01

Purpose: To evaluate the clinical effectiveness of self-expandable metallic stents in seven patients with malignant gastroduodenal obstruction caused by inoperable hepatocellular carcinoma (HCC). Methods: Seven patients with gastroduodenal obstruction caused by advanced HCC underwent metallic stent placement from 2003 to 2010. These patients had total dysphagia (n = 5) or were able to eat only liquids (n = 2) before stent placement. Patients had Eastern Cooperative Oncology Group performance scores of 2 or 3, and Child-Pugh classification B or C. Results: Stent placement was technically successful in all seven patients (100%) and clinically successful in six (86%). Five patients could eat a soft diet, and one patient tolerated regular diet after stent placement. Stent-related obstructive jaundice occurred in one patient. One patient had hematemesis 11 days after stent placement. Overall mean survival was 51 days (range, 10–119 days). Stent patency was preserved in six patients with clinical success until death. Conclusion: Placement of a covered self-expandable metallic stent may offer good palliation in patients with gastroduodenal obstruction due to advanced HCC.

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.

Clinical Outcomes of Self-Expandable Metal Stents for Malignant Rectal Obstruction.

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Lee, Hyun Jung; Hong, Sung Pil; Cheon, Jae Hee; Kim, Tae Il; Kim, Won Ho; Park, Soo Jung

2018-01-01

Self-expandable metal stents are widely used to treat malignant colorectal obstruction. However, data on clinical outcomes of stent placement for rectal obstruction specifically are lacking. We aimed to investigate the clinical outcomes of self-expandable metal stents in malignant rectal obstruction in comparison with those in left colonic obstruction and to identify factors associated with clinical failure and complication. This was a retrospective study. The study was conducted at a tertiary care center. Between January 2005 and December 2013, medical charts of patients who underwent stent placement for malignant rectal or left colonic obstruction were reviewed retrospectively. Study intervention included self-expandable metal stent placement. Technical success, clinical success, and complications were measured. Technical success rates for the 2 study groups (rectum vs left colon, 93.5% vs 93.1%; p = 0.86) did not differ significantly; however, the clinical success rate was lower in patients with rectal obstruction (85.4% vs 92.1%; p = 0.02). In addition, the complication rate was higher in patients with rectal obstruction (37.4% vs 25.1%; p = 0.01). Patients with rectal obstruction showed higher rates of obstruction because of extracolonic malignancy (33.8% vs 15.8%; p stent use for palliation (78.6% vs 56.3%; p stent usage to be independent risk factors for clinical failure. Factors predictive of complications in the palliative group were total obstruction, obstruction because of extracolonic malignancy, and covered stent usage. This was a retrospective, single-center study. The efficacy and safety of stent placement for malignant rectal obstruction were comparable with those for left colonic obstruction. However, obstruction attributed to extracolonic malignancy, use of covered stents, and total obstruction negatively impacted clinical outcomes of self-expandable metal stent placement and must be considered by endoscopists. See Video Abstract at http

Effects of cobalt-chromium everolimus eluting stents or bare metal stent on fatal and non-fatal cardiovascular events

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Valgimigli, Marco; Sabaté, Manel; Kaiser, Christoph

2014-01-01

eluting stents with bare metal stents were selected. The principal investigators whose trials met the inclusion criteria provided data for individual patients. PRIMARY OUTCOMES: The primary outcome was cardiac mortality. Secondary endpoints were myocardial infarction, definite stent thrombosis, definite...... a significant reduction of cardiac mortality (hazard ratio 0.67, 95% confidence interval 0.49 to 0.91; P=0.01), myocardial infarction (0.71, 0.55 to 0.92; P=0.01), definite stent thrombosis (0.41, 0.22 to 0.76; P=0.005), definite or probable stent thrombosis (0.48, 0.31 to 0.73; P... coronary syndrome v stable coronary artery disease), diabetes mellitus, female sex, use of glycoprotein IIb/IIIa inhibitors, and up to one year v longer duration treatment with dual antiplatelets. CONCLUSIONS: This meta-analysis offers evidence that compared with bare metal stents the use of cobalt...

Coronary artery stent mimicking intracardiac thrombus on cardiac magnetic resonance imaging due to signal loss

DEFF Research Database (Denmark)

Qayyum, Abbas Ali; Vejlstrup, Niels Grove; Ahtarovski, Kiril Aleksov

2012-01-01

Since the introduction of percutaneous coronary intervention for coronary artery disease, thousands of patients have been treated with the implantation of coronary stents. Moreover, several of the patients with coronary stent undergo cardiac magnetic resonance (CMR) imaging every year. This case...... report is of a 77-year-old man who was previously treated with the implantation of a coronary stent in the left circumflex artery. He underwent CMR imaging, which revealed a process 14×21 mm in the left atrium. Cardiac contrast computed tomography did not demonstrate any cardiac pathology. While...... the signal loss on MRI associated with implanted metallic devices is known, we report a case where an implanted coronary stent in the left circumflex artery led to an intracardiac signal loss mimicking intracardiac thrombus/tumor....

Susceptibility of metallic magnesium implants to bacterial biofilm infections.

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Rahim, Muhammad Imran; Rohde, Manfred; Rais, Bushra; Seitz, Jan-Marten; Mueller, Peter P

2016-06-01

Magnesium alloys have promising mechanical and biological properties as biodegradable medical implant materials for temporary applications during bone healing or as vascular stents. Whereas conventional implants are prone to colonization by treatment resistant microbial biofilms in which bacteria are embedded in a protective matrix, magnesium alloys have been reported to act antibacterial in vitro. To permit a basic assessment of antibacterial properties of implant materials in vivo an economic but robust animal model was established. Subcutaneous magnesium implants were inoculated with bacteria in a mouse model. Contrary to the expectations, bacterial activity was enhanced and prolonged in the presence of magnesium implants. Systemic antibiotic treatments were remarkably ineffective, which is a typical property of bacterial biofilms. Biofilm formation was further supported by electron microscopic analyses that revealed highly dense bacterial populations and evidence for the presence of extracellular matrix material. Bacterial agglomerates could be detected not only on the implant surface but also at a limited distance in the peri-implant tissue. Therefore, precautions may be necessary to minimize risks of metallic magnesium-containing implants in prospective clinical applications. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1489-1499, 2016. © 2016 Wiley Periodicals, Inc.

MRI assessment of thoracic stent grafts after emergency implantation in multi trauma patients: a feasibility study

Energy Technology Data Exchange (ETDEWEB)

Rasche, Volker [University Hospital Ulm, Department of Internal Medicine II, Ulm (Germany); University Hospital Ulm, University of Ulm, Department of Internal Medicine II, Ulm (Germany); Oberhuber, Alexander; Orend, Karl-Heinz [University Hospital Ulm, Department of Vascular and Thoracic Surgery, Ulm (Germany); Trumpp, Stephan [University Hospital Ulm, Department of Internal Medicine II, Ulm (Germany); University Hospital Ulm, Department of Vascular and Thoracic Surgery, Ulm (Germany); Bornstedt, Axel; Merkle, Nico; Rottbauer, Wolfgang [University Hospital Ulm, Department of Internal Medicine II, Ulm (Germany); Hoffmann, Martin [University Hospital Ulm, Department of Diagnostic and Interventional Radiology, Ulm (Germany)

2011-07-15

To evaluate the feasibility of MRI for static and dynamic assessment of the deployment of thoracic aortic stent grafts after emergency implantation in trauma patients. Twenty patients initially presenting with a rupture of the thoracic aorta were enrolled in this study. All patients underwent thoracic endovascular aortic repair (TEVAR). The deployment of the implanted stent graft was assessed by CTA and MRI, comprising the assessment of the aortic arch with and without contrast agent, and the assessment of the motion of the stent graft over the cardiac cycle. The stent graft geometry and motion over the cardiac cycle were assessable by MRI in all patients. Flow-mediated signal variations in areas of flow acceleration could be well visualised. No statistically significant differences in stent-graft diameters were observed between CT and MRI measurements. MRI appears to be a valuable tool for the assessment of thoracic stent grafts. It shows similar performance in the accurate assessment of stent-graft dimensions to the current gold standard CTA. Its capability of providing additional functional information and the lack of ionising radiation and nephrotoxic contrast agents may make MRI a valuable tool for monitoring patients after TEVAR. (orig.)

An unusual case of aortic rupture after deployment of a bare stent in the treatment of aortic dissection in a patient with giant-cell arteritis.

Science.gov (United States)

Rynio, Pawel; Kazimierczak, Arkadiusz; Gutowski, Piotr; Cnotliwy, Miloslaw

2017-06-01

Giant-cell arteritis is associated with a higher risk of aortic aneurysm and aortic dissection formation. We present a women with aortic dissection type B treated with a stent graft and bare-metal stent implantation. After the stent deployment we noticed aortic rupture, which was successfully treated with implantation of an additional stent graft. This report highlights the difficulty of endovascular therapy in patients with giant-cell arteritis. We have to bear in mind that chronic inflammation of the aorta leads to a more fragile aortic wall than normal. We recommend the use of a stent graft over a bare-metal stent and gentle use of a balloon catheter.

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.

Midterm to long-term safety and efficacy of self-expandable nitinol stent implantation for coarctation of aorta in adults.

Science.gov (United States)

Haji Zeinali, Ali Mohammad; Sadeghian, Mohammad; Qureshi, Shakeel A; Ghazi, Payam

2017-09-01

Endovascular treatment of coarctation of aorta (CoA) by self-expandable Nitinol stents is one of the recognized treatment methods and may be an alternative to surgery or balloon-expandable stent implantation for CoA but there is little information about midterm to long term results of self-expandable stents. Sixty-two patients with CoA (40 men), with a mean age of 30.7 ± 11 years, (range 17-63 years) underwent stent implantation with Optimed self-expandable Nitinol stents between 2005 and 2014. Successful outcome was defined as peak systolic pressure gradient ≤20 mmHg after stent implantation. The patients were followed-up clinically and by echocardiography and in patients, in whom there was suspicion of recoarctation, CT angiography or recatheterization was performed. 65 stents were successfully implanted in all 62 patients. Peak systolic pressure gradient decreased from mean 62.4 ± 18 mmHg (range 35-100 mmHg) to mean 2.8 ± 5 mmHg (range 0-15 mmHg; P Stent displacement occurred in 3 patients during the procedure. These were managed successfully by an overlapping second stent. None of the patients had major complications such as aortic dissection, rupture, or vascular access problems. In follow up, only three patients had recoarctation, and two of these were managed successfully by balloon redilation or further stenting 16 and 18 months after the first procedure and one patient refused reintervention. There were two deaths, unrelated to the procedure, 12 and 78 months after the initial intervention. Follow-up of a mean of 45.5 ± 17 months (range 12-105 months) demonstrated no evidence of aneurysm formation or stent fracture. Self-expandable nitinol stents for the treatment of native and recurrent CoA is safe and has good efficacy with acceptable midterm to long-term outcome. © 2017 Wiley Periodicals, Inc.

A Comparison of Stent Implant versus Medical Treatment for Severe Symptomatic Intracranial Stenosis: A Controlled Clinical Trial

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Rezao Mohammadian

2012-11-01

Full Text Available Background: Atherosclerotic stenosis of the major intracranial arteries is the most common cause of ischemic stroke. There are limited treatments for severe intracranial stenosis, and stent placement versus medical treatment remains controversial. The aim of this study was to compare functional outcomes of these two modalities in patients with severe symptomatic intracranial stenosis. Methods: At a single center, between 2008 and 2011, patients with angiographically demonstrated severe (70–90% symptomatic intracranial atherosclerosis were divided into two groups: group A, which received only medical treatment, and group B, which underwent endovascular stent implant treatment. The severity and location of the stenosis was determined by digital subtraction angiography and the Warfarin-Aspirin Symptomatic Intracranial Disease (WASID trial criteria in all patients. The exclusion criteria were: specific causes other than atherosclerosis, such as artery dissection, fibromuscular dysplasia, vasculitis, radiation and intracranial hemorrhage, focal neurological deficit that did not correlate to internal carotid artery or middle cerebral artery stenosis. All procedures were done under light anesthesia. Technical success was defined as the reduction of stenosis to Results: Overall, 63 patients (29 in group A and 34 in group B were evaluated and followed for a mean period of 15.22 months (range 6–25. The technical success rate was 97% in a total of 34 stents in 34 patients. There was no difference between the early (within 30 days adverse event rates of the two groups. The median follow-up duration for the stent implant patients was 15 months (range 6–25, and for the medically treated cohort it was 14 months (range 8–25. The re-stenosis rate was 5.8% and the total number of late (>30 days adverse events, including stroke, myocardial infarction and death, was 1 (2.9% and 6 (20.7% in the stent implant and medical groups, respectively (p = 0.042. The

Advantages and disadvantages of biodegradable platforms in drug eluting stents.

Science.gov (United States)

Rodriguez-Granillo, Agustina; Rubilar, Bibiana; Rodriguez-Granillo, Gaston; Rodriguez, Alfredo E

2011-03-26

Coronary angioplasty with drug-eluting stent (DES) implantation is currently the most common stent procedure worldwide. Since the introduction of DES, coronary restenosis as well as the incidence of target vessel and target lesion revascularization have been significantly reduced. However, the incidence of very late stent thrombosis beyond the first year after stent deployment has more commonly been linked to DES than to bare-metal stent (BMS) implantation. Several factors have been associated with very late stent thrombosis after DES implantation, such as delayed healing, inflammation, stent mal-apposition and endothelial dysfunction. Some of these adverse events were associated with the presence of durable polymers, which were essential to allow the elution of the immunosuppressive drug in the first DES designs. The introduction of erodable polymers in DES technology has provided the potential to complete the degradation of the polymer simultaneously or immediately after the release of the immunosuppressive drug, after which a BMS remains in place. Several DES designs with biodegradable (BIO) polymers have been introduced in preclinical and clinical studies, including randomized trials. In this review, we analyze the clinical results from 6 observational and randomized studies with BIO polymers and discuss advantages and disadvantages of this new technology.

Esophagojejunal anastomotic leak managed with self expandable metallic stent

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Arvind Madurandagam Annapillai

2013-01-01

Full Text Available Esophagealjejunal anastomotic leak after gastrectomy is a serious surgical emergency with high mortality. This report describes a 57-year-old male with esophagojejunal anastomotic leak following total gastrectomy for gastric cancer and was managed successfully with self-expandable metallic stent. To our knowledge this is the first such report from India. This case report highlights the need of interdisciplinary coordination in managing this difficult clinical situation. Endotherapy with self-expandable metallic stent (SEM provided twin benefits of improving respiratory embarrassment and the joy of eating. Therapy of such difficult cases must be individualized; however, and SEM stent usage is a viable option

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 © 2011 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

Implante de Stent guiado por ultrassom intracoronariano melhora desfechos: meta-análise de ensaios randomizados

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Graciele Sbruzzi

2012-01-01

Full Text Available FUNDAMENTO: Ultrassom Intracoronariano (USIC tem sido usado como um método auxiliar a fim de otimizar o implante de stents. No entanto, o impacto desse método em alguns resultados é controverso. OBJETIVO: Analisar sistematicamente o impacto dos stents coronarianos guiados por USIC, em comparação com os stents guiados angiograficamente, sobre os resultados clínicos e angiográficos. MÉTODOS: Foi realizada uma busca em bases de dados (MEDLINE, Cochrane CENTRAL, EMBASE e referências de estudos publicados entre 1982 e 2010. Foram incluídos Ensaios Clínicos Randomizados (ECR que compararam o implante de stents coronarianos guiados por angiografia e USIC versus implante de stents coronarianos guiados apenas por angiografia (ANGIO. O seguimento mínimo foi de seis meses e os resultados avaliados foram eventos cardíacos adversos importantes (MACE, Revascularização da Lesão-alvo (RLA e reestenose angiográfica. Dois revisores extraíram os dados de forma independente. Razão de risco sumário e intervalos de confiança de 95% (CI foram calculados com modelos com efeitos aleatórios. A abordagem GRADE foi utilizada para determinar a qualidade geral de evidências para cada resultado. RESULTADOS: Dos 3.631 artigos identificados, oito ECR avaliando um total de 2.341 pacientes foram incluídos. Houve uma redução de 27% na reestenose angiográfica (95% IC: 3% -46% e uma redução de 38% em RLA (95% IC: 17% -53% em favor de USIC versus ANGIO. No entanto, os MACE não foram reduzidos por USIC (RR: 0,79; 95%CI: 0,61-1,03. Os dados MACE representam apenas 47% do tamanho ótimo de informações necessárias para detectar com segurança um efeito de tratamento plausível. CONCLUSÕES: Observamos que o implante de stent coronariano guiado por USIC oferece reduções significativas em RLA e reestenose angiográfica em comparação com implante de stent guiado por angiografia, porém não reduz casos de MACE.

Effect of Post-Dilatation Following Primary PCI With Everolimus-Eluting Bioresorbable Scaffold Versus Everolimus-Eluting Metallic Stent Implantation

DEFF Research Database (Denmark)

Yamaji, Kyohei; Brugaletta, Salvatore; Sabaté, Manel

2017-01-01

OBJECTIVES: This study sought to investigate the effect of post-dilatation on angiographic and intracoronary imaging parameters in the setting of primary percutaneous coronary intervention comparing the everolimus-eluting bioresorbable scaffold (BRS) with the everolimus-eluting metallic stent (EE...

A simplified in vivo approach for evaluating the bioabsorbable behavior of candidate stent materials.

Science.gov (United States)

Pierson, Daniel; Edick, Jacob; Tauscher, Aaron; Pokorney, Ellen; Bowen, Patrick; Gelbaugh, Jesse; Stinson, Jon; Getty, Heather; Lee, Chee Huei; Drelich, Jaroslaw; Goldman, Jeremy

2012-01-01

Metal stents are commonly used to revascularize occluded arteries. A bioabsorbable metal stent that harmlessly erodes away over time may minimize the normal chronic risks associated with permanent implants. However, there is no simple, low-cost method of introducing candidate materials into the arterial environment. Here, we developed a novel experimental model where a biomaterial wire is implanted into a rat artery lumen (simulating bioabsorbable stent blood contact) or artery wall (simulating bioabsorbable stent matrix contact). We use this model to clarify the corrosion mechanism of iron (≥99.5 wt %), which is a candidate bioabsorbable stent material due to its biocompatibility and mechanical strength. We found that iron wire encapsulation within the arterial wall extracellular matrix resulted in substantial biocorrosion by 22 days, with a voluminous corrosion product retained within the vessel wall at 9 months. In contrast, the blood-contacting luminal implant experienced minimal biocorrosion at 9 months. The importance of arterial blood versus arterial wall contact for regulating biocorrosion was confirmed with magnesium wires. We found that magnesium was highly corroded when placed in the arterial wall but was not corroded when exposed to blood in the arterial lumen for 3 weeks. The results demonstrate the capability of the vascular implantation model to conduct rapid in vivo assessments of vascular biomaterial corrosion behavior and to predict long-term biocorrosion behavior from material analyses. The results also highlight the critical role of the arterial environment (blood vs. matrix contact) in directing the corrosion behavior of biodegradable metals. Copyright © 2011 Wiley Periodicals, Inc.

Implantation of a new enteral stent in obstructive colorectal cancer using interventional radiology in patients over 70 years of age.

Science.gov (United States)

Miłek, Tomasz; Ciostek, Piotr

2015-07-01

Colorectal cancer is the second leading cause of death due to cancer in Poland. The traditional approach to treat patients included a surgical procedure. Irrespective of the surgical method being used, surgical treatment of malignant colorectal obstruction is associated with prolonged hospitalisation, and the postoperative mortality rate is approximately 5-11%. Due to these problems, more interest has been shown in less invasive methods. Prosthesis implantation is a leading endoscopic method used currently in palliative or preoperative treatment. To compare the results of implantation of traditional stents with the results of implantation of an own stent using minimally invasive methods. Left-sided colon obstruction due to cancer was an indication for transplantation. All patients were aged over 70 years and had serious concomitant diseases. The control group included 50 patients with colorectal cancer who received traditional stents in the period 2009-2011. Our stent covers only the internal length of a tumour. It is not equipped with anti-migration flares. To minimize the risk of migration it has a system of hooks that are responsible for permanent anchorage of the stent within the tumour mass. Implantation technical and clinical success defined as effective decompression of intestinal obstruction was 100% in both groups. There were 2 cases of stent migration in the control group. It is possible to achieve a secure surgical anastomosis after intestinal decompression. Stent implantation is fast and safe thanks to the positioning system that was used. The use of labelled hooks is a secure anti-migration solution.

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

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

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...

Drug-eluting stents versus bare-metal stents for acute coronary syndrome

DEFF Research Database (Denmark)

Feinberg, Joshua; Nielsen, Emil Eik; Greenhalgh, Janette

2017-01-01

-EXPANDED, and BIOSIS from their inception to January 2017. We also searched two clinical trials registers, the European Medicines Agency and the US Food and Drug Administration databases, and pharmaceutical company websites. In addition, we searched the reference lists of review articles and relevant trials. SELECTION...... CRITERIA: Randomised clinical trials assessing the effects of drug-eluting stents versus bare-metal stents for acute coronary syndrome. We included trials irrespective of publication type, status, date, or language. DATA COLLECTION AND ANALYSIS: We followed our published protocol and the methodological...

Biodegradable biliary stent implantation in the treatment of benign bilioplastic-refractory biliary strictures: preliminary experience.

Science.gov (United States)

Mauri, Giovanni; Michelozzi, Caterina; Melchiorre, Fabio; Poretti, Dario; Tramarin, Marco; Pedicini, Vittorio; Solbiati, Luigi; Cornalba, Gianpaolo; Sconfienza, Luca Maria

2013-12-01

To evaluate feasibility, safety, and outcome of patients treated with biodegradable biliary stents for benign biliary stenosis refractory to other treatments. Between March 2011 and September 2012, ten patients (seven men, three women; age 59 ± 7 years) with recurrent cholangitis due to postsurgical biliary stricture, previous multiple unsuccessful (two to five) bilioplasties, and unsuitability for surgical/endoscopic repair underwent percutaneous implantation of a biodegradable biliary stent. Patients were followed-up clinically and with ultrasound at 1, 3 and 6 months, and then at 6-month intervals. Stent implantation was always feasible. No immediate major or minor complications occurred. In all patients, 48-h cholangiographic control demonstrated optimal stent positioning and stenosis resolution. In a median follow-up time of 16.5 months (25th-75th percentiles = 11-20.25 months) no further invasive treatment was needed. Three patients experienced transient episodes of cholangitis. Neither re-stenosis nor dilatation of the biliary tree was documented during follow-up. No stent was visible at the 6-month follow-up. Percutaneous placement of biodegradable biliary stents represents a new option in treating benign biliary stenoses refractory to treatment with bilioplasty. This technique seems to be feasible, effective and free from major complications. Further investigations are warranted to confirm our preliminary results.

Stents Eluting 6-Mercaptopurine Reduce Neointima Formation and Inflammation while Enhancing Strut Coverage in Rabbits.

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Matthijs S Ruiter

Full Text Available The introduction of drug-eluting stents (DES has dramatically reduced restenosis rates compared with bare metal stents, but in-stent thrombosis remains a safety concern, necessitating prolonged dual anti-platelet therapy. The drug 6-Mercaptopurine (6-MP has been shown to have beneficial effects in a cell-specific fashion on smooth muscle cells (SMC, endothelial cells and macrophages. We generated and analyzed a novel bioresorbable polymer coated DES, releasing 6-MP into the vessel wall, to reduce restenosis by inhibiting SMC proliferation and decreasing inflammation, without negatively affecting endothelialization of the stent surface.Stents spray-coated with a bioresorbable polymer containing 0, 30 or 300 μg 6-MP were implanted in the iliac arteries of 17 male New Zealand White rabbits. Animals were euthanized for stent harvest 1 week after implantation for evaluation of cellular stent coverage and after 4 weeks for morphometric analyses of the lesions.Four weeks after implantation, the high dose of 6-MP attenuated restenosis with 16% compared to controls. Reduced neointima formation could at least partly be explained by an almost 2-fold induction of the cell cycle inhibiting kinase p27Kip1. Additionally, inflammation score, the quantification of RAM11-positive cells in the vessel wall, was significantly reduced in the high dose group with 23% compared to the control group. Evaluation with scanning electron microscopy showed 6-MP did not inhibit strut coverage 1 week after implantation.We demonstrate that novel stents coated with a bioresorbable polymer coating eluting 6-MP inhibit restenosis and attenuate inflammation, while stimulating endothelial coverage. The 6-MP-eluting stents demonstrate that inhibition of restenosis without leaving uncovered metal is feasible, bringing stents without risk of late thrombosis one step closer to the patient.

Relation of body mass index to risk of stent thrombosis after percutaneous coronary intervention

DEFF Research Database (Denmark)

Schmiegelow, Michelle; Torp-Pedersen, Christian; Gislason, Gunnar H

2012-01-01

Stent thrombosis is a devastating complication after percutaneous coronary intervention (PCI), but the influence of obesity on risk of stent thrombosis is unclear, and it is unknown if this relation is dependent on stent type. The objective of this study was to examine the relation between body...... mass index (BMI) and stent thrombosis after PCI with bare-metal stent (BMS) or drug-eluting stent (DES). We followed 5,515 patients who underwent PCI with implantation of ≥1 BMS or DES at a high-volume tertiary invasive cardiology center from 2000 through 2006. Only patients with a single type of stent...... (BMS or DES) implanted at the index PCI were included. Median follow-up period was 26 months (interquartile range 12 to 44) and definite stent thrombosis occurred in 78 patients. Hazard ratio of definite stent thrombosis adjusted for number of stents at the index PCI was 0.92 (95% confidence interval...

Metallic stent in the treatment of ureteral obstruction: Experience of single institute

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Chien-Chang Li

2011-10-01

Conclusion: Patients with ureteral obstructions can be treated sufficiently with the Resonance® metallic stent. Patients who had gynecological malignancies and received radiotherapy had a higher failure rate after Resonance® metallic stent insertion.

Outcomes of Prosthetic Hemodialysis Grafts after Deployment of Bare Metal versus Covered Stents at the Venous Anastomosis

Energy Technology Data Exchange (ETDEWEB)

Kim, Charles Y., E-mail: charles.kim@duke.edu; Tandberg, Daniel J.; Rosenberg, Michael D.; Miller, Michael J.; Suhocki, Paul V.; Smith, Tony P. [Duke University Medical Center, Division of Vascular and Interventional Radiology (United States)

2012-08-15

Purpose: To compare postintervention patency rates after deployment of bare metal versus covered stents across the venous anastomosis of prosthetic arteriovenous (AV) grafts. Methods: Review of our procedural database over a 6 year period revealed 377 procedures involving stent deployment in an AV access circuit. After applying strict inclusion criteria, our study group consisted of 61 stent deployments in 58 patients (median age 58 years, 25 men, 33 women) across the venous anastomosis of an upper extremity AV graft circuit that had never been previously stented. Both patent and thrombosed AV access circuits were retrospectively analyzed. Within the bare metal stent group, 20 of 32 AV grafts were thrombosed at initial presentation compared to 18 of 29 AV grafts in the covered stent group. Results: Thirty-two bare metal stents and 29 covered stents were deployed across the venous anastomosis. The 3, 6, and 12 months primary access patency rates for bare metal stents were not significantly different than for covered stents: 50, 41, and 22 % compared to 59, 52, and 29 %, respectively (p = 0.21). The secondary patency rates were also not significantly different: 78, 78, and 68 % for bare metal stents compared to 76, 69, and 61 % for covered stents, respectively (p = 0.85). However, covered stents demonstrated a higher primary stent patency rate than bare metal stents: 100, 85, and 70 % compared to 75, 67, and 49 % at 3, 6, and 12 months (p < 0.01). Conclusion: The primary and secondary access patency rates after deployment of bare metal versus covered stents at the venous anastomosis were not significantly different. However, bare metal stents developed in-stent stenoses significantly sooner.

Outcomes of Prosthetic Hemodialysis Grafts after Deployment of Bare Metal versus Covered Stents at the Venous Anastomosis

International Nuclear Information System (INIS)

Kim, Charles Y.; Tandberg, Daniel J.; Rosenberg, Michael D.; Miller, Michael J.; Suhocki, Paul V.; Smith, Tony P.

2012-01-01

Purpose: To compare postintervention patency rates after deployment of bare metal versus covered stents across the venous anastomosis of prosthetic arteriovenous (AV) grafts. Methods: Review of our procedural database over a 6 year period revealed 377 procedures involving stent deployment in an AV access circuit. After applying strict inclusion criteria, our study group consisted of 61 stent deployments in 58 patients (median age 58 years, 25 men, 33 women) across the venous anastomosis of an upper extremity AV graft circuit that had never been previously stented. Both patent and thrombosed AV access circuits were retrospectively analyzed. Within the bare metal stent group, 20 of 32 AV grafts were thrombosed at initial presentation compared to 18 of 29 AV grafts in the covered stent group. Results: Thirty-two bare metal stents and 29 covered stents were deployed across the venous anastomosis. The 3, 6, and 12 months primary access patency rates for bare metal stents were not significantly different than for covered stents: 50, 41, and 22 % compared to 59, 52, and 29 %, respectively (p = 0.21). The secondary patency rates were also not significantly different: 78, 78, and 68 % for bare metal stents compared to 76, 69, and 61 % for covered stents, respectively (p = 0.85). However, covered stents demonstrated a higher primary stent patency rate than bare metal stents: 100, 85, and 70 % compared to 75, 67, and 49 % at 3, 6, and 12 months (p < 0.01). Conclusion: The primary and secondary access patency rates after deployment of bare metal versus covered stents at the venous anastomosis were not significantly different. However, bare metal stents developed in-stent stenoses significantly sooner.

Current state of the absorbable metallic (magnesium) stent.

Science.gov (United States)

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.

Palliation of malignant gastric obstruction : fluoroscopic guided covered metallic stent placement

International Nuclear Information System (INIS)

Lee, Jeong Min; Han, Young Min; Kim, Chong Soo; Lee, Sang Yong; Choi, Ki Chul; Lee, Soo Tak; Han, Hyun Young

2000-01-01

To demonstrate the feasibility and clinical efficacy of self-expanding, covered metallic stent placement for the palliative treatment of malignant gastric obstruction. Under fluoroscopic guidance, the placement of self-expanding, covered stents was attempted in 23 patients (age range, 31-78 years) with inoperable or recurrent gastric malignancies. All 23 suffered dysphagia and/or vomiting after the ingestion of soft foods, or swallowing difficulty. Three different types of self-expanding, covered metallic stents were used and in all patients, these were placed perorally using over the guide wire technique. Success was defined both technically and clinically. Stent placement was technically successful in 19 patients (82.6%) but because the guidewire failed to successfully negotiate the sites at which there was obstruction, was unsuccessful in four (17.4%). Stent placement was well tolerated in all patients except one, in whom an acutely angled efferent loop from remnant stomach was present. In this case, stent placement required a strong metallic guidewire. After placement, 17 of the 19 patients (89.5%) were able to ingest solid and/or soft foods without dysphagia and showed a markedly decreased incidence of vomiting. Two others showed some improvement in the frequency of vomiting but were able to ingest only a liquid diet. In one patient, the stent migrated two days after the procedure. During the follow-up period of 2-7 months (mean, 74 days), there were no clinically significant complications. For the short-term palliative treatment of patients with gastric inlet or outlet obstruction, the placement of self-expanding metallic stents has proven relatively easy and safe, as well as reasonably effective. (author)

Self-Expanding Metal Stenting for Palliation of Patients with Malignant Colonic Obstruction

DEFF Research Database (Denmark)

Meisner, Søren; González-Huix, Ferran; Vandervoort, Jo G

2012-01-01

Background. Self-expanding metal stents can alleviate malignant colonic obstruction in incurable patients and avoid palliative stoma surgery. Objective. Evaluate stent effectiveness and safety on palliation of patients with malignant colorectal strictures. Design. Two prospective, one Spanish....... Interventions(s). Self-expanding metal stent placement. Main Outcome Measures. Procedural success, clinical success, and safety. Results. Procedural success was 98.4% (251). Clinical success rates were 87.8% at 30 days, 89.7% at 3 months, 92.8% at 6 months, and 96% at 12 months. Overall perforation rate was 5...... for patients with malignant colonic obstruction should be self-expanding metal stent placement due to high rates of technical success and efficacy in symptom palliation and few complications....

Stent-in-Stent Technique for the Treatment of Proximal Bronchial Restenosis after Insertion of Metallic Stents: A Report of Two Cases

Directory of Open Access Journals (Sweden)

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.

Technological Advances in Stent Therapies: a Year in Review.

Science.gov (United States)

Raffoul, Jad; Nasir, Ammar; Klein, Andrew J P

2018-04-07

Stent technology has rapidly evolved since the first stainless steel bare metal stents with substantial developments in scaffolding, polymer, drug choice, drug delivery, and elution mechanisms. Most recently, there has been the evolution of bioabsorbable vascular scaffolds, potentially eliminating the need for long-term foreign object retention. These rapid developments have led to an ever-expanding selection of new stents, making the choice of which to use in which patient challenging. Operators must balance potential short- and long-term clinical ramifications, namely stent thrombosis, in-stent restenosis, target lesion revascularization, and target lesion failure. In this review, we hope to provide insight for interventional cardiologists on the details of stent technology and how this impacts outcomes, stent selection, and duration of dual-antiplatelet therapy duration post drug-eluting stent implantation.

Expandable esophageal metallic stents coating with silicone rubber: An experimental study in rabbits

Energy Technology Data Exchange (ETDEWEB)

Song, Ho Young; Han, Young Min; Son, Myung Hee; Kim, Jong Soo; Choi, Ki Chul; Kuh, Ja Hong; Chae, Soo Wan [Chonbuk National University Medical School, Chonju (Korea, Republic of); Kim, Hak Nam [Chungju Lee Rha Hospital, Chungju (Korea, Republic of)

1990-10-15

To determine the effect of the expandable esophageal metallic stents on the esophagus, we constructed an expandable metallic stent. It was stainless steel wire formed in a zig-zag pattern in fully expanded diameter. Twenty stents were introduced in the normal esophagus through a 8.5 French-teflon sheath in 10 rabbits for 1 week to 12 weeks. Three out of the 20 stents migrated slightly. At 1 week after the placement of the stent, the mucosa partly revealed pressure necrosis and some regeneration, the muscle layer below the stent wires found compressed and thinned. At 8 weeks, the mucosa showed complete regeneration, and the stent wires were found covered by fibrous tissue.

Renal Transplant Ureteral Stenosis: Treatment by Self-Expanding Metallic Stent

International Nuclear Information System (INIS)

Cantasdemir, Murat; Kantarci, Fatih; Numan, Furuzan; Mihmanli, Ismail; Kalender, Betul

2003-01-01

We report the use of a metallic stent in a transplant ureteral stenosis. A 28-year-old man with chronic renal failure due to chronic pyelonephritis, who received a living-donor renal transplant, presented with transplant ureteral stenosis. The stenosis was unresponsive to balloon dilation and was treated by antegrade placement of a self-expanding Memotherm stent. The stentedureter stayed patent for 3 years. It may be reasonable to treat post-transplant ureteral stenosis resistant to balloon dilation with self-expanding metallic stents. However, long-term follow-up is required to evaluate the efficacy of this treatment

Effects of cobalt-chromium everolimus eluting stents or bare metal stent on fatal and non-fatal cardiovascular events: patient level meta-analysis.

Science.gov (United States)

Valgimigli, Marco; Sabaté, Manel; Kaiser, Christoph; Brugaletta, Salvatore; de la Torre Hernandez, Jose Maria; Galatius, Soeren; Cequier, Angel; Eberli, Franz; de Belder, Adam; Serruys, Patrick W; Ferrante, Giuseppe

2014-11-04

To examine the safety and effectiveness of cobalt-chromium everolimus eluting stents compared with bare metal stents. Individual patient data meta-analysis of randomised controlled trials. Cox proportional regression models stratified by trial, containing random effects, were used to assess the impact of stent type on outcomes. Hazard ratios with 95% confidence interval for outcomes were reported. Medline, Embase, the Cochrane Central Register of Controlled Trials. Randomised controlled trials that compared cobalt-chromium everolimus eluting stents with bare metal stents were selected. The principal investigators whose trials met the inclusion criteria provided data for individual patients. The primary outcome was cardiac mortality. Secondary endpoints were myocardial infarction, definite stent thrombosis, definite or probable stent thrombosis, target vessel revascularisation, and all cause death. The search yielded five randomised controlled trials, comprising 4896 participants. Compared with patients receiving bare metal stents, participants receiving cobalt-chromium everolimus eluting stents had a significant reduction of cardiac mortality (hazard ratio 0.67, 95% confidence interval 0.49 to 0.91; P=0.01), myocardial infarction (0.71, 0.55 to 0.92; P=0.01), definite stent thrombosis (0.41, 0.22 to 0.76; P=0.005), definite or probable stent thrombosis (0.48, 0.31 to 0.73; Pstents the use of cobalt-chromium everolimus eluting stents improves global cardiovascular outcomes including cardiac survival, myocardial infarction, and overall stent thrombosis. © Valgimigli et al 2014.

Metallic ureteral stents in malignant ureteral obstruction: short-term results and radiological features predicting stent failure in patients with non-urological malignancies.

Science.gov (United States)

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.

Type D personality predicts death or myocardial infarction after bare metal stent or sirolimus-eluting stent implantation

DEFF Research Database (Denmark)

Pedersen, Susanne S.; Lemos, Pedro A; van Vooren, Priya R

2004-01-01

We investigated the effect of Type D personality on the occurrence of adverse events at nine months in patients with ischemic heart disease (IHD) after percutaneous coronary intervention (PCI) with sirolimus-eluting stents (SESs) or bare stents. Type D patients experience increased negative...

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

Interventional MRA: concepts for active visualization of catheters and stents

International Nuclear Information System (INIS)

Quick, H.H.; Ladd, M.E.

2003-01-01

A precondition to safe guidance of vascular guidewires and catheters during the course of magnetic resonance (MR)-guided vascular intervention is a high-contrast visualization of the instruments. The integration of miniature radiofrequency (RF) coils and coaxial cables into guidewires and catheters enables the reception of RF signal from the lumen of blood vessels, and thus the active visualization of the instruments. Moreover, metallic vascular implants (stents) can be modified to act as intravascular RF antennas that inductively couple their RF signal to a conventional surface RF coil. Such stent resonators show signal amplification inside the lumen of the stent and thus can be visualized with high contrast in MR images. Furthermore, once such a device has been implanted, the method offers the potential for non-invasive long-term follow-up of the stent patency. (orig.) [de

The Impact of Post-Procedural Asymmetry, Expansion, and Eccentricity of Bioresorbable Everolimus-Eluting Scaffold and Metallic Everolimus-Eluting Stent on Clinical Outcomes in the ABSORB II Trial.

Science.gov (United States)

Suwannasom, Pannipa; Sotomi, Yohei; Ishibashi, Yuki; Cavalcante, Rafael; Albuquerque, Felipe N; Macaya, Carlos; Ormiston, John A; Hill, Jonathan; Lang, Irene M; Egred, Mohaned; Fajadet, Jean; Lesiak, Maciej; Tijssen, Jan G; Wykrzykowska, Joanna J; de Winter, Robbert J; Chevalier, Bernard; Serruys, Patrick W; Onuma, Yoshinobu

2016-06-27

The study sought to investigate the relationship between post-procedural asymmetry, expansion, and eccentricity indices of metallic everolimus-eluting stent (EES) and bioresorbable vascular scaffold (BVS) and their respective impact on clinical events at 1-year follow-up. Mechanical properties of a fully BVS are inherently different from those of permanent metallic stent. The ABSORB II (A bioresorbable everolimus-eluting scaffold versus a metallic everolimus-eluting stent for ischaemic heart disease caused by de-novo native coronary artery lesions) trial compared the BVS and metallic EES in the treatment of a de novo coronary artery stenosis. Protocol-mandated intravascular ultrasound imaging was performed pre- and post-procedure in 470 patients (162 metallic EES and 308 BVS). Asymmetry index (AI) was calculated per lesion as: (1 - minimum scaffold/stent diameter/maximum scaffold/stent diameter). Expansion index and optimal scaffold/stent expansion followed the definition of the MUSIC (Multicenter Ultrasound Stenting in Coronaries) study. Eccentricity index (EI) was calculated as the ratio of minimum and maximum scaffold/stent diameter per cross section. The incidence of device-oriented composite endpoint (DoCE) was collected. Post-procedure, the metallic EES group was more symmetric and concentric than the BVS group. Only 8.0% of the BVS arm and 20.0% of the metallic EES arm achieved optimal scaffold/stent expansion (p 0.30 is an independent predictor of DoCE (hazard ratio: 3.43; 95% confidence interval: 1.08 to 10.92; p = 0.037). BVS implantation is more frequently associated with post-procedural asymmetric and eccentric morphology compared to metallic EES. Post-procedural devices asymmetry were independently associated with DoCE following percutaneous coronary intervention. However, this approach should be viewed as hypothesis generating due to low event rates. (ABSORB II Randomized Controlled Trial [ABSORB II]; NCT01425281). Copyright © 2016 American

Metallic stent placement in hemodialysis graft patients after insufficient balloon dilation

International Nuclear Information System (INIS)

Liang, Huei-Lung; Pan, Huay-Ben; Lin, Yih-Huie; Chen, Chiung-Yu; Lai, Pin-Hong; Yang, Chien-Fang; Chung, Hsiao-Min; Wu, Tung-Ho; Chou, Kang-Ju

2006-01-01

We wanted to report our experience of metallic stent placement after insufficient balloon dilation in graft hemodialysis patients. Twenty-three patients (13 loop grafts in the forearm and 10 straight grafts in the upper arm) underwent metallic stent placement due to insufficient flow after urokinase thrombolysis and balloon dilation. The indications for metallic stent deployment included 1) recoil and/or kinked venous stenosis in 21 patents (venous anastomosis: 17 patients, peripheral outflow vein: four patients); and 2) major vascular rupture in two patients. Metallic stents 8-10mm in diameter and 40-80 mm in length were used. Of them, eight stents were deployed across the elbow crease. Access patency was determined by clinical follow-up and the overall rates were calculated by Kaplan-Meier survival analysis. No procedure-related complications (stent fracture or central migration) were encountered except for a delayed Wallstent shortening/migration at the venous anastomosis, which resulted in early access failure. The overall primary and secondary patency rates (±standard error) of all the vascular accesses in our 23 patients at 3, 6, 12 and 24 months were 69%±9 and 88%±6,41% ±10 and 88%±6, 30%±10 and 77%±10, and 12%±8 and 61%±13, respectively. For the forearm and upper-arm grafts, the primary and secondary patency rates were 51%±16 and 86%±13 vs 45%±15 and 73%±13 at 6 months, and 25%±15 and 71%±17 vs 23%±17 and 73%±13 at 12 months (ρ = .436 and .224), respectively. Metallic stent placement is a safe and effective means for treating peripheral venous lesions in dialysis graft patients after insufficient balloon dilation. No statistically difference in the patency rates between the forearm and upper-arm patient groups was seen

Anastomotic leak after oesophagectomy and stent implantation: a systematic review

Directory of Open Access Journals (Sweden)

A.N. Kanatas

2011-12-01

Full Text Available Anastomotic leaks following oesophageal cancer resection have a high mortality. Stents have an established position in the palliation of dysphagia due to malignancy and in treating malignant perforation or fistula. They are increasingly used for benign conditions such as spontaneous oesophageal perforation with encouraging results. In this systematic review we examine the available evidence and attempt to define the role of stents in the management of oesophageal anastomotic leaks after resection for cancer. It is evident from the review that plastic- and metal-covered stents are an effective strategy for the treatment of anastomotic leaks. Vigilance is required as complications such as stent migration and incomplete sealing are not uncommon. Further clinical studies with greater methodological rigor in terms of sample size and study design may confirm that stents have an important contribution to make in the management of oesophageal anastomotic leak.

Osseoconductive and Corrosion-Inhibiting Plasma-Sprayed Calcium Phosphate Coatings for Metallic Medical Implants

Directory of Open Access Journals (Sweden)

Robert B. Heimann

2017-11-01

Full Text Available During the last several decades, research into bioceramic coatings for medical implants has emerged as a hot topic among materials scientists and clinical practitioners alike. In particular, today, calcium phosphate-based bioceramic materials are ubiquitously used in clinical applications to coat the stems of metallic endoprosthetic hips as well as the surfaces of dental root implants. Such implants frequently consist of titanium alloys, CoCrMo alloy, or austenitic surgical stainless steels, and aim at replacing lost body parts or restoring functions to diseased or damaged tissues of the human body. In addition, besides such inherently corrosion-resistant metals, increasingly, biodegradable metals such as magnesium alloys are being researched for osseosynthetic devices and coronary stents both of which are intended to remain in the human body for only a short time. Biocompatible coatings provide not only vital biological functions by supporting osseoconductivity but may serve also to protect the metallic parts of implants from corrosion in the aggressive metabolic environment. Moreover, the essential properties of hydroxylapatite-based bioceramic coatings including their in vitro alteration in contact with simulated body fluids will be addressed in this current review paper. In addition, a paradigmatic shift is suggested towards the development of transition metal-substituted calcium hexa-orthophosphates with the NaSiCON (Na superionic conductor structure to be used for implant coatings with superior degradation resistance in the corrosive body environment and with pronounced ionic conductivity that might be utilized in novel devices for electrical bone growth stimulation.

[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.

Fatal dissection of the descending aorta after implantation of a stent in a 19-year-old female with Turner's syndrome.

NARCIS (Netherlands)

Fejzic, Z.; Oort, A.M. van

2005-01-01

We report a fatal dissection of the descending aorta as a complication after a two-staged implantation of a stent to relieve aortic coarctation in a young female with Turner's syndrome. Implantation of the stent, with dilation up to 70 percent, and half a year later re-dilation to 100 percent, was

Transcatheter aortic value implantation with self-expandable nitinol valved stent: an experimental study in sheep

International Nuclear Information System (INIS)

Jiang Haibin; Huang Xinmiao; Bai Yuan

2011-01-01

Objective: to determine the feasibility and safety of transcatheter aortic valve implantation with domestic self-expandable nitinol valved stent in experimental sheep. Methods: A fresh pig pericardium was cross-linked with a 0.6% glutaraldehyde solution for 36 hours and then sutured on a nitinol self-expandable stent. Ten healthy sheep of (46.00±2.60) kg body weight were chosen for the study. Under general anesthesia, the device was delivered through catheter into the native aortic valve of the sheep via the femoral artery or abdominal aorta. The animals were followed up for three months. Results: Six devices were successfully delivered at the desired position in six sheep with no occurrence of complications. Angiographic and hemodynamic studies confirmed that the stents were fixed at correct position with competent valve function immediately and 90 days after the procedure. Technical failure or fatal complications occurred in the remaining four sheep. Conclusion: Implantation of a domestic nitinol self-expandable stent at the aortic valve position through a transcatheter approach is feasible in experimental sheep. (authors)

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.

Fluoroscopically guided placement of self-expandable metallic stents and stent-grafts in the treatment of acute malignant colorectal obstruction.

Science.gov (United States)

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.

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.

Endoscopic trimming of metallic stents with the use of argon plasma

NARCIS (Netherlands)

Christiaens, Paul; Decock, Sofie; Buchel, Otto; Bulté, Katrien; Moons, Veerle; D'Haens, Geert; van Olmen, Gust

2008-01-01

The endoscopic placement of metallic stents for palliation of malignant obstruction of the GI or biliary tract is an established practice and as such is often applied. Use of these stents, however, has its problems. Stent migration may cause obstruction of the bowel lumen. Migration of a biliary

cancerous esophagotracheal fistula: treatment of placement with covered self-expanding metallic stent

International Nuclear Information System (INIS)

Han Xinwei; Li Tianxiao; Wang Ruilin; Fan Qingxia

1997-01-01

Purpose: To treat the esophagotracheal fistula that was the main cause of death in patients with esophageal carcinoma, the placement of the stent was studied. Materials and methods: Under the fluoroscopic guidance, 28 stents (5 stents made in USA and 23 in China) were successfully implanted in all the 28 patients with esophagotracheal fistula. Results: The aphagia of the patients was greatly improved and a normal diet could be swallowed at once after the placement of the stents. The 27 cases of inhalation pneumonia that caused by the fistula was recovered. Conclusion: The result indicated that the treatment with the placement of the covered self-expanding stent is simple, safe, and effective for most patients with aphagia and pneumonia due to esophagotracheal fistula

[Fine mesh metal endoprostheses for treatment of extensive cervical and intrathoracic tracheomalacia].

Science.gov (United States)

Wilmes, E; Berger, H; Dienemann, H; Jolk, A

1994-01-01

The treatment of tracheal stenoses caused by tracheomalacia is mainly carried out by means of sleeve resection, tracheopexy with ring support or other tracheoplastic operative procedures. If patients cannot be treated by surgical operative strategies, conventional stents are usually used to dilate the trachea. The use of a self-expanding elastic metal prosthesis in 5 patients with tracheal airway obstruction caused by tracheomalacia proved to be a true alternative in the therapy of tracheobronchial stenoses. We report on the long term use of 5 patients with tracheal stenoses treated by implantation of elastic metal wallstents. The implantation of the stents resulted in immediate improvement in respiratory function in all 5 patients. None of the patients experienced complications secondary to the stent placement. The stents were well tolerated (long-time follow-up 26 months). The implantation of self-expanding metal stents type "wallstent" seems to offer alternative possibilities for the treatment of tracheomalacia.

A Zr-based bulk metallic glass for future stent applications: Materials properties, finite element modeling, and in vitro human vascular cell response.

Science.gov (United States)

Huang, Lu; Pu, Chao; Fisher, Richard K; Mountain, Deidra J H; Gao, Yanfei; Liaw, Peter K; Zhang, Wei; He, Wei

2015-10-01

Despite the prevalent use of crystalline alloys in current vascular stent technology, new biomaterials are being actively sought after to improve stent performance. In this study, we demonstrated the potential of a Zr-Al-Fe-Cu bulk metallic glass (BMG) to serve as a candidate stent material. The mechanical properties of the Zr-based BMG, determined under both static and cyclic loadings, were characterized by high strength, which would allow for the design of thinner stent struts to improve stent biocompatibility. Finite element analysis further complemented the experimental results and revealed that a stent made of the Zr-based BMG was more compliant with the beats of a blood vessel, compared with medical 316L stainless steel. The Zr-based BMG was found to be corrosion resistant in a simulated body environment, owing to the presence of a highly stable ZrO2-rich surface passive film. Application-specific biocompatibility studies were conducted using human aortic endothelial cells and smooth muscle cells. The Zr-Al-Fe-Cu BMG was found to support stronger adhesion and faster coverage of endothelial cells and slower growth of smooth muscle cells than 316L stainless steel. These results suggest that the Zr-based BMG could promote re-endothelialization and potentially lower the risk of restenosis, which are critical to improve vascular stent implantation integration. In general, findings in this study raised the curtain for the potential application of BMGs as future candidates for stent applications. Vascular stents are medical devices typically used to restore the lumen of narrowed or clogged blood vessel. Despite the clinical success of metallic materials in stent-assisted angioplasty, post-surgery complications persist due to the mechanical failures, corrosion, and in-stent restenosis of current stents. To overcome these hurdles, strategies including new designs and surface functionalization have been exercised. In addition, the development of new materials with

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

Long-term outcome of self expandable metal stents for biliary obstruction in chronic pancreatitis.

Science.gov (United States)

Waldthaler, Alexander; Schütte, Kerstin; Weigt, Jochen; Kropf, Siegfried; Malfertheiner, Peter; Kahl, Stefan

2013-01-10

Insertion of a self-expandable metal stent is still controversial for treatment of benign common bile duct stenosis but can be a valuable alternative to surgical treatment. Aim of our study was to analyze the efficacy of covered and uncovered self-expandable metal stent in patients with chronic pancreatitis and common bile duct stenosis. Twenty patients with common bile duct stenosis due to alcoholic chronic pancreatitis were retrospective analyzed. All patients had advanced chronic pancreatitis, presenting with calcifications in pancreatic head. Uncovered self-expandable metal stent (uSEMS) were used in 11 patients (3 females, 8 males) while in 9 patients (3 females, 6 males) partially covered self-expandable metal stent (cSEMS) were inserted. All patients treated with self-expandable metal stent had contraindications for surgery. Overall mean follow up time was 155 weeks: 206 (52-412) weeks in uSEMS, and 93 (25-233) weeks in cSEMS, respectively. Stent patency was in mean 118 weeks: 159 (44-412) weeks in uSEMS and 67 (25-150) weeks in cSEMS (P=0.019). In the uSEMS group, reintervention was necessary in 5 patients (45%) due to stent obstruction, whereas in the cSEMS group 4 patients (44%) needed reintervention (2 obstructions, 2 migration). Stent migration is an early complication, compared to obstruction (P<0.05), and in cSEMS obstruction occurred significantly earlier compared to uSEMS (P<0.05). Patency of uSEMS was significantly longer compared to partially cSEMS. Available self-expandable metal stent, unfortunately, do not meet the demands on successful treatment of benign common bile duct stenosis.

Intracoronary stent implantation: new approach using a monorail system and new large-lumen 7F catheters from the brachial route.

Science.gov (United States)

Jenny, D B; Robert, G P; Fajadet, J C; Cassagneau, B G; Marco, J

1992-04-01

In this brief report we describe a case of successful multivessel PTCA with intracoronary stent implantation using a new large-lumen 7F catheter from the left brachial approach. The application of this technique should be considered for intravascular stent implantation when anticoagulation ideally should not be interrupted or in anatomical situations limiting femoral vascular access.

Absorbable magnesium-based stent: physiological factors to consider for in vitro degradation assessments.

Science.gov (United States)

Wang, Juan; Smith, Christopher E; Sankar, Jagannathan; Yun, Yeoheung; Huang, Nan

2015-03-01

Absorbable metals have been widely tested in various in vitro settings using cells to evaluate their possible suitability as an implant material. However, there exists a gap between in vivo and in vitro test results for absorbable materials. A lot of traditional in vitro assessments for permanent materials are no longer applicable to absorbable metallic implants. A key step is to identify and test the relevant microenvironment and parameters in test systems, which should be adapted according to the specific application. New test methods are necessary to reduce the difference between in vivo and in vitro test results and provide more accurate information to better understand absorbable metallic implants. In this investigative review, we strive to summarize the latest test methods for characterizing absorbable magnesium-based stent for bioabsorption/biodegradation behavior in the mimicking vascular environments. Also, this article comprehensively discusses the direction of test standardization for absorbable stents to paint a more accurate picture of the in vivo condition around implants to determine the most important parameters and their dynamic interactions.

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

Drug-eluting stent implantation for the percutaneous treatment of vertebro-basilar arterial stenosis

International Nuclear Information System (INIS)

Ma Rujun; Liu Jianmin; Huang Haiqing; Hong Bo; Xu Yi; Zhao Wenyuan; Zhao Rui; Chen Jun

2006-01-01

Objective: To evaluate the early results and mid-term outcomes following angioplasty of vertebro-basilar arterial stenosis with drug-eluting stents. Methods: All of the patients presented with recurrent TIA or ceretral infarction with >50% stenoses in vertebro-basilar arteries, and having failure in maximal medical therapy. All of the lesions were treated with primary stenting under local or general anesthesia and followed by continual anticoagulant therapy of clopidogrel and aspirin together with clinical follow-up and vascular imagings. Results: Of 28 stenoses (27 patients), 27 lesions were successfully treated with implantation of 24 Cypher stents, 2 Taxus stents and one Firebird stent. The mean stenotic severity reduced from (74 ± 6.7)% to (8.7 ± 4.4)%. Two patients had inchemic events relating to penetration vascular obstruction. During 2-14 months follow-up, the patients were clinically asymptomatic with no recurrent TIA/stoke. Angiographic follow-up was obtained in 14 patients at a mean of 7.2 months. Proximal restenosis (<50%) occurred in one patient (3.3%), and corrected with restenting, while others were free of intra-stent restenoses. Conclusion: Using DES in cerebrovascular stenosis is safe and effective with lowing the risk of intra-stent restenosis in comparison with bare stent. Further study for long term efficiency is still in need. (authors)

Temporary metal internal stent dilation for colorectal obstruction and effect on operation methods

International Nuclear Information System (INIS)

Chen Niwei; Cheng Yingsheng; Fan Youben; Jin Huimin; Xu Huimin

2005-01-01

Objective: To explore the methods and clinical value of temporary internal metal stent through endoscopy under X ray control for treating patients with malignant colorectal obstruction. Methods: 27 patients with malignant colorectal obstruction were treated by temporary metallic internal stent placement via endoscopy under the X ray guidance. Results: 27 patients with colorectal obstruction symptoms were all got rid of the trouble within 48 hours after the stent placement. Selective stage I colorectal cancer resection and anastomosis were performed after bowel preparation. Conclusions: Metallic internal stent placement can loosen the colorectal obstructive symptoms with higher successful rate via endoscopy under X ray control and furthermore for promotion of stage I colorectal cancer resection and anastomosis. (authors)

The SYNERGY biodegradable polymer everolimus eluting coronary stent: Porcine vascular compatibility and polymer safety study.

Science.gov (United States)

Wilson, Gregory J; Marks, Angela; Berg, Kimberly J; Eppihimer, Michael; Sushkova, Natalia; Hawley, Steve P; Robertson, Kimberly A; Knapp, David; Pennington, Douglas E; Chen, Yen-Lane; Foss, Aaron; Huibregtse, Barbara; Dawkins, Keith D

2015-11-15

SYNERGY is a novel platinum chromium alloy stent that delivers abluminal everolimus from an ultrathin poly-lactide-co-glycide (PLGA) biodegradable polymer. This study evaluated the in vivo degradation of the polymer coating, everolimus release time course, and vascular compatibility of the SYNERGY stent. SYNERGY stents were implanted in arteries of domestic swine. Devices were explanted at predetermined time points (up to 120 days) and the extent of PLGA coating or everolimus remaining on the stents was quantified. Everolimus levels in the arterial tissue were also evaluated. A pathological analysis on coronary arteries of single and overlapping stents was performed at time points between 5 and 270 days. PLGA bioabsorption began immediately after implantation, and drug release was essentially complete by 90 days; PLGA absorption was substantially complete by 120 days (>90% of polymer was absorbed) leaving a bare metal SYNERGY stent. Vascular response was similar among SYNERGY and control stents (bare metal, polymer-only, and 3× polymer-only). Mild increases in para-strut fibrin were seen for SYNERGY at an early time point with no significant differences in all other morphological and morphometric parameters through 270 days or endothelial function (eNOS immunostaining) at 90 or 180 days. Inflammation was predominantly minimal to mild for all device types. In a swine model, everolimus was released by 90 days and PLGA bioabsorption was complete shortly thereafter. The SYNERGY stent and its biodegradable polymer, even at a 3× safety margin, demonstrated vascular compatibility similar to bare metal stent controls. © 2015 Wiley Periodicals, Inc.

Self-expandable metal stents for relieving malignant colorectal obstruction: short-term safety and efficacy within 30 days of stent procedure in 447 patients

DEFF Research Database (Denmark)

Meisner, Søren; González-Huix, Ferran; Vandervoort, Jo G

2011-01-01

The self-expandable metal stent (SEMS) can alleviate malignant colonic obstruction and avoid emergency decompressive surgery.......The self-expandable metal stent (SEMS) can alleviate malignant colonic obstruction and avoid emergency decompressive surgery....

Covered versus uncovered self-expandable metal stents for malignant biliary strictures: A meta-analysis and systematic review.

Science.gov (United States)

Moole, Harsha; Bechtold, Matthew L; Cashman, Micheal; Volmar, Fritz H; Dhillon, Sonu; Forcione, David; Taneja, Deepak; Puli, Srinivas R

2016-09-01

Self-expandable metal stents (SEMS) are used for palliating inoperable malignant biliary strictures. It is unclear if covered metal stents are superior to uncovered metal stents in these patients. We compared clinical outcomes in patients with covered and uncovered stents. Studies using covered and uncovered metallic stents for palliation in patients with malignant biliary stricture were reviewed. Articles were searched in MEDLINE, PubMed, and Ovid journals. Fixed and random effects models were used to calculate the pooled proportions. Initial search identified 1436 reference articles, of which 132 were selected and reviewed. Thirteen studies (n = 2239) for covered and uncovered metallic stents which met the inclusion criteria were included in this analysis. Odds ratio for stent occlusion rates in covered vs. uncovered stents was 0.79 (95 % CI = 0.65 to 0.96). Survival benefit in patients with covered vs. uncovered stents showed the odds ratio to be 1.29 (95 % CI = 0.95 to 1.74). Pooled odds ratio for migration of covered vs. uncovered stents was 9.9 (95 % CI = 4.5 to 22.3). Covered stents seemed to have significantly lesser occlusion rates, increased odds of migration, and increased odds of pancreatitis compared to uncovered stents. There was no statistically significant difference in the survival benefit, overall adverse event rate, and patency period of covered vs. uncovered metal stents in patients with malignant biliary strictures.

Physical property and MR imaging of self-expandable metallic stents

Energy Technology Data Exchange (ETDEWEB)

Roh, Hong Gee; Kang, Sung Gwon; Cho, Young Kook; Kim, Hyung Jin; Lim, Myung Kwan; Cho, Soon Gu; Yoh, Kyu Tong; Suh, Chang Hae [Inha Univ., College of Medicine, Seoul (Korea, Republic of)

1998-09-01

In order to furnish basic information prior to their use, the physical properties of various self-expandable metallic stents and their MR characteristics were evaluated. Four commercially available self-expandable metallic stents-Gianturco-the Rosch, Hanaro, Memotherm, and Wallstent-were used in this study. For evaluation of the physical properties of each, hoop strengths and changes in radii according to the degrees of longitudinal flexion were compared. Stent characteristics seen on MR images were evaluated by measuring magnetic torque and by comparing images obtained in the vascular phantom using SE T1TI, FSE T2WI, and FMPSPGR sequences. These images were analyzed with special emphasis on artifact size and the apparant shepe of the stent. Hoop strength was greatest in the Gianturco-Rosch stent, followed by the Memotherm, Hanaro, and Wallstent. When flexed in the longitudinal axis, the radius of the Hanaro and Memotherm stent decreased slightly as a larger flexion angle was applied. When this was 90 deg, however, the connection of the Gianturco-Rosch stent collapsed. In contrast, the radius of the Wallstent became larger as a larger flexion angle was applied. At the portal of the MR imaging unit, neither the Memotherm nor Wallstent showed deflection; except for a thin hyperintense rim at both ends, their images were excellent, and the lumina of these stents were also clearly seen. In contrast, the Gianturco-Rosch and Hanaro stent demonstrated large deflexion and showed a severe black-hole artifact. As a result, visualization of the stents themselves and their lumina was impossible. The Gianturco-Rosch stent showed greatrer hoop strength than the others. The Wallstent showed good longitudinal flexibility and was thought to be effective in tortuous vessels. For follow-up after placement, especially when the nonferromagnetic Memotherm and Wallstent are used, MR imaging appears to be safe and useful.=20.

Treatment of cuff-related tracheal stenosis with a fully covered retrievable expandable metallic stent

International Nuclear Information System (INIS)

Chen, G.; Wang, Z.; Liang, X.; Wang, Y.; Wang, Y.; Wang, Z.; Xian, J.

2013-01-01

Aim: To investigate the clinical effectiveness, complications, and optimal duration of use of covered retrievable expandable metallic stents in the management of cuff-related tracheal stenosis. Materials and methods: Twenty-one patients with cuff-related tracheal stenosis, Meyer–Cotton grade II (29%) and III (71%), who underwent fluoroscopically guided placement of covered retrievable expandable metallic stents were studied. Sixty-four-section computed tomography (CT) and bronchovideoscopy were performed prior to stent insertion, 1 month after stent insertion, in the case of stent-related complications, and after stent removal. Clinical manifestations, Hugh–Jones classification, and forced expiratory volume in 1 s (FEV1) were used to evaluate respiratory function before and after stent insertion and removal. The diameter of the stricture and FEV1 changes before insertion and after removal were analysed using the paired samples t-test. A p-value of ≤0.05 was considered statistically significant. Results: Twenty-one patients had 27 covered retrievable expandable metallic stents placed. Stents were electively removed from 20 patients. The median duration of stent placement was 5 months (range 4–12 months). One stent was not removed due to mucopolysaccharidosis type II (MPS II or Hunter syndrome) with tracheomalacia. After stent removal, airway dimensions increased and airway occlusion was symptomatically relieved in all patients. CT and bronchovideoscopy showed patent lumens with increased dimensions. Stent-related complications occurred in 19 (91%) patients, including granulation tissue formation (n = 18, 86%), stent migration and stent expectoration (n = 2, 10%), mucus plugging (n = 1, 5%), and halitosis (n = 6, 29%). Some patients experienced multiple complications, which were all managed effectively while the stent was still in place. There was a statistically significant difference in the diameter of the stricture and FEV1 between the time of stent

Treatment of cuff-related tracheal stenosis with a fully covered retrievable expandable metallic stent.

Science.gov (United States)

Chen, G; Wang, Z; Liang, X; Wang, Y; Wang, Y; Wang, Z; Xian, J

2013-04-01

To investigate the clinical effectiveness, complications, and optimal duration of use of covered retrievable expandable metallic stents in the management of cuff-related tracheal stenosis. Twenty-one patients with cuff-related tracheal stenosis, Meyer-Cotton grade II (29%) and III (71%), who underwent fluoroscopically guided placement of covered retrievable expandable metallic stents were studied. Sixty-four-section computed tomography (CT) and bronchovideoscopy were performed prior to stent insertion, 1 month after stent insertion, in the case of stent-related complications, and after stent removal. Clinical manifestations, Hugh-Jones classification, and forced expiratory volume in 1 s (FEV1) were used to evaluate respiratory function before and after stent insertion and removal. The diameter of the stricture and FEV1 changes before insertion and after removal were analysed using the paired samples t-test. A p-value of ≤0.05 was considered statistically significant. Twenty-one patients had 27 covered retrievable expandable metallic stents placed. Stents were electively removed from 20 patients. The median duration of stent placement was 5 months (range 4-12 months). One stent was not removed due to mucopolysaccharidosis type II (MPS II or Hunter syndrome) with tracheomalacia. After stent removal, airway dimensions increased and airway occlusion was symptomatically relieved in all patients. CT and bronchovideoscopy showed patent lumens with increased dimensions. Stent-related complications occurred in 19 (91%) patients, including granulation tissue formation (n = 18, 86%), stent migration and stent expectoration (n = 2, 10%), mucus plugging (n = 1, 5%), and halitosis (n = 6, 29%). Some patients experienced multiple complications, which were all managed effectively while the stent was still in place. There was a statistically significant difference in the diameter of the stricture and FEV1 between the time of stent insertion and removal. An improvement in

Serial intravascular ultrasound analysis of peri-stent remodeling and proximal and distal edge effects after sirolimus-eluting or paclitaxel-eluting stent implantation in patients with diabetes mellitus

DEFF Research Database (Denmark)

Jensen, Lisette Okkels; Maeng, Michael; Mintz, Gary S

2009-01-01

Patients with diabetes have an increased risk of in-stent restenosis after coronary stent implantation. Serial intravascular ultrasound was used to study chronic arterial responses and edge effects after implantation of Cypher (Cordis, Johnson & Johnson, Miami Lakes, Florida) or Taxus (Boston......-up. The increase in peri-stent external elastic membrane (EEM) volume was more pronounced in the Taxus group (292.4 +/- 132.6 to 309.5 +/- 146.8 mm(3)) than in the Cypher group (274.4 +/- 137.2 to 275.4 +/- 140.1 mm(3); p = 0.005). Peri-stent plaque volume increased in the Taxus group (152.5 +/- 73.7 to 166.......1 +/- 85.1 mm(3)), but was unchanged in the Cypher group (153.5 +/- 75.5 to 151.5 +/- 75.8 mm(3); p = 0.002). In proximal and distal reference segments, mean lumen area decreased within the entire 5-mm edge segment (proximal and distal) because of plaque progression (distal, 5.5 +/- 3.6 to 5.8 +/- 3.7 mm(2...

Biliary drainage of the common bile duct with an enteral metal stent

NARCIS (Netherlands)

dek, Irene M.; van den Elzen, Bram D. J.; Fockens, Paul; Rauws, Erik A. J.

2009-01-01

In this case report we present an elderly patient who was referred to our hospital with recurrent episodes of cholangitis that persisted after placement of five metal stents for a distal common bile duct (CBD) stenosis. All metal stents were endoscopically removed from the CBD by forceps after

Effective treatment of benign biliary strictures with a removable, fully covered, self-expandable metal stent: A prospective, multicenter European study

Science.gov (United States)

Schmidt, Arthur; Pickartz, Tilman; Lerch, Markus M; Fanelli, Fabrizio; Fiocca, Fausto; Lucatelli, Pierleone; Cereatti, Fabrizio; Hoffmeister, Albrecht; van Steenbergen, Werner; Kraft, Matthias; Meier, Benjamin

2016-01-01

Background Temporary placement of removable, fully covered, self-expandable metal stents (fcSEMS) for treatment of benign biliary strictures (BBS) has been reported to be effective. However, the optimal extraction time point remains unclear and stent migration has been a major concern. Objective The objective of this study was to evaluate the efficacy and safety of this treatment modality using an fcSEMS with a special antimigration design and prolonged stent indwell time. Methods We performed a prospective, single-arm study at six tertiary care centers in Europe. Patients with BBS underwent endoscopic or percutaneous implantation of an fcSEMS (GORE® VIABIL® Biliary Endoprosthesis, W.L. Gore & Associates, Flagstaff, AZ, USA). The devices were scheduled to be removed nine months later, and patients were to return for follow-up for an additional 15 months. Results Forty-three patients were enrolled in the study. Stricture etiology was chronic pancreatitis in the majority of patients (57.5%). All fcSEMS were placed successfully, either endoscopically (76.7%) or percutaneously (23.3%). Stent migration was observed in two patients (5.2%). Primary patency of the SEMS prior to removal was 73.0%. All attempted stent removals were successful. At removal, stricture was resolved or significantly improved without need for further therapy in 78.9% of patients. Stricture recurrence during a follow-up of two years post-implant was observed in two patients. Conclusions Temporary placement of the fcSEMS is a feasible, safe and effective treatment for BBS. The design of the device used in this study accounts for very low migration rates and facilitates easy stent retrieval, even after it has been in place for up to 11 months. PMID:28507752

Effective treatment of benign biliary strictures with a removable, fully covered, self-expandable metal stent: A prospective, multicenter European study.

Science.gov (United States)

Schmidt, Arthur; Pickartz, Tilman; Lerch, Markus M; Fanelli, Fabrizio; Fiocca, Fausto; Lucatelli, Pierleone; Cereatti, Fabrizio; Hoffmeister, Albrecht; van Steenbergen, Werner; Kraft, Matthias; Meier, Benjamin; Caca, Karel

2017-04-01

Temporary placement of removable, fully covered, self-expandable metal stents (fcSEMS) for treatment of benign biliary strictures (BBS) has been reported to be effective. However, the optimal extraction time point remains unclear and stent migration has been a major concern. The objective of this study was to evaluate the efficacy and safety of this treatment modality using an fcSEMS with a special antimigration design and prolonged stent indwell time. We performed a prospective, single-arm study at six tertiary care centers in Europe. Patients with BBS underwent endoscopic or percutaneous implantation of an fcSEMS (GORE® VIABIL® Biliary Endoprosthesis, W.L. Gore & Associates, Flagstaff, AZ, USA). The devices were scheduled to be removed nine months later, and patients were to return for follow-up for an additional 15 months. Forty-three patients were enrolled in the study. Stricture etiology was chronic pancreatitis in the majority of patients (57.5%). All fcSEMS were placed successfully, either endoscopically (76.7%) or percutaneously (23.3%). Stent migration was observed in two patients (5.2%). Primary patency of the SEMS prior to removal was 73.0%. All attempted stent removals were successful. At removal, stricture was resolved or significantly improved without need for further therapy in 78.9% of patients. Stricture recurrence during a follow-up of two years post-implant was observed in two patients. Temporary placement of the fcSEMS is a feasible, safe and effective treatment for BBS. The design of the device used in this study accounts for very low migration rates and facilitates easy stent retrieval, even after it has been in place for up to 11 months.

Análise morfométrica da carótida de suínos submetidos a angioplastia com ou sem implante de stent de cromo-cobalto Morphometric analysis of swine carotid artery angioplasty with or without cobalt-chromium stent implantation

Directory of Open Access Journals (Sweden)

João Luiz de Lara Elesbão

2010-06-01

Full Text Available Contexto: A hiperplasia intimal é a reação tardia mais comum decorrente da angioplastia. O uso de stents de cromo-cobalto é bem estudado na circulação coronariana, porém não há muitos estudos que abordem o uso desses stents nas circulações carotídea e periférica. Objetivo: Analisar mediante morfometria a reação intimal presente na artéria carótida de suínos submetidos a angioplastia isoladamente e a angioplastia seguida de implante de stent de cromo-cobalto. Materiais e métodos: Em oito suínos, foi realizada angioplastia da artéria carótida comum direita e angioplastia seguida de implante de um stent de cromo-cobalto na artéria carótida comum esquerda. Após 4 semanas, os animais foram submetidos a eutanásia para a retirada de amostras de tecido arterial e preparo de lâminas histológicas. As imagens das lâminas foram digitalizadas e analisadas por programa de morfometria digital. A análise estatística foi realizada através da média e desvio padrão das áreas em cada grupo, utilizando-se o Teste t de Student. O valor de p Background: Intimal hyperplasia is the most common delayed response to angioplasty. The use of cobalt-chromium stents is well studied in the coronary circulation; however, there are few studies on their use in the carotid and peripheral circulation. Objective: To analyze the intimal reaction in a swine carotid artery undergoing simple angioplasty and angioplasty followed by implantation of cobalt-chromium stent. Materials and methods: We carried out angioplasty in the right common carotid artery and angioplasty with cobalt-chromium stent in the left common carotid artery in eight swine. Four weeks later, all animals were sacrificed for arterial tissue sampling and preparation of histological slides. Slide images were scanned and analyzed using a digital morphometry program. Statistical analysis was performed by mean values and standard deviations of the areas in each group, using the Student's t

The use of balloon-expandable metallic stents in the treatment of pediatric tracheomalacia and bronchomalacia.

Science.gov (United States)

Furman, R H; Backer, C L; Dunham, M E; Donaldson, J; Mavroudis, C; Holinger, L D

1999-02-01

To evaluate the use of balloon-expandable metallic stents in the treatment of children with tracheomalacia and bronchomalacia in whom conventional therapy has failed. Retrospective case series. Tertiary pediatric otolaryngology and cardiothoracic surgery referral center. Six patients were identified as having undergone bronchoscopic placement of metallic balloon-expandable stents between 1994 and 1997. The age at stent placement, prior surgical interventions, and indications for and sites of stent placement were noted. Also, the complications related to stent placement and the current airway status of the patients were reviewed. Twelve balloon-expandable metallic angioplasty stents (Palmaz; Johnson & Johnson Interventional Systems Co, Warren, NJ) were placed bronchoscopically in 6 patients. Six stents were placed in the lower trachea, and 6 were placed in the main bronchi. The stents were balloon expanded under fluoroscopic guidance. Discontinuation of mechanical ventilation. The age at stent placement ranged from 1.5 to 38 months (mean age at placement, 10 months). The indications for stent placement were (1) tracheomalacia or bronchomalacia, (2) pericardial patch or slide tracheoplasty failure, and (3) bronchomalacia caused by tetralogy of Fallot and large pulmonary arteries. The primary complication of stent placement was postoperative granulation tissue formation. One patient required the removal of 2 tracheal stents because of granulation tissue formation. There were 2 deaths in the series, 1 possibly related to stent placement. Four of the 6 patients were weaned from mechanical ventilation, and 3 experienced prolonged relief of airway obstruction. Metallic balloon-expandable stents are effective in relieving lower tracheomalacia and bronchomalacia in select patients. Only patients in whom conventional therapy has failed should be considered for stent placement.

Surface modification of coronary artery stent by Ti-O/Ti-N complex film coating prepared with plasma immersion ion implantation and deposition

International Nuclear Information System (INIS)

Huang, N.; Leng, Y.X.; Yang, P.

2006-01-01

This paper reported the work of surface coating of Ti-O/Ti-N complex films on coronary stents by means of the plasma immersion ion implantation/deposition process. The deformation behavior of the Ti-O/Ti-N coated stainless steel stents was investigated. In vivo investigation of the anticoagulation behavior of Ti-O coated coronary stents was also performed. The results of mechanical characterization of the Ti-O/Ti-N coated stents show that the film has strong binding strength, and to some extent the ability to withstand plastic deformation. The biological response behavior of the coated stent surface was significantly different from the uncoated. The results of implantation of stents into rabbit ventral aorta show no thrombus formation on the surfaces of the Ti-O coated stents, although serious coagulation had occurred on the surfaces of unmodified stents over a period of 4 weeks under conditions with no anticoagulant

Safety and efficacy of self-expandable metal stents for obstructive proximal and distal large bowel cancer.

Science.gov (United States)

Mitra, V; Hu, M; Majumdar, D; Krishnan, V; Chaudhury, B; Hancock, J; Dwarakanath, D

2017-03-01

Self-expandable metal stents are often used to treat obstructive large bowel cancers. This study assessed the safety and efficacy of colonic stent insertion carried out in a district general hospital. Methods A retrospective review was carried out between 1 January 2007 and 28 February 2014 to identify patients who underwent stent insertion for malignant colorectal obstruction. Results Seventy-five patients (median age 75.2 years, 70.6% male) with primary colorectal cancer underwent stent insertion - 53 underwent semi-elective self-expanded metal stent insertion (for subacute bowel obstruction) and 22 had emergency stent inserted (for acute bowel obstruction). The majority (88%) had self-expanded metal stents inserted for palliation. Technical and clinical success rates were 98.7% and 91.2%, respectively. One patient had stent-related perforation; there was no procedure-related mortality. Conclusion This study shows that self-expanded metal stent insertion in malignant colorectal obstruction is safe and effective and can be successfully delivered in a district general hospital with high technical and clinical success rates.

Effectiveness of percutaneous metal stent placement in cholangiocarcinoma patients with midterm follow-up: Single center experience

International Nuclear Information System (INIS)

Kose, Fatih; Oguzkurt, Levent; Besen, Ayberk; Sumbul, Taner; Sezer, Ahmet; Karadeniz, Cemile; Disel, Umut; Mertsoylu, Huseyin; Ozyilkan, Ozgur

2012-01-01

Purpose: Patients with advanced cholangiocarcinoma present with high rate of local complications. The primary aim of this study is to report clinical course of advanced cholangiocarcinoma patients those who were presented with biliary obstruction and treated with percutaneous biliary stenting. Material and methods: Patients with unresectable locally advanced or metastatic cholangiocarcinoma followed by our center for a period of 4 years were analyzed. For statistical analysis demographic and clinical characteristics of patients, primary biliary drainage method, metal stent occlusion rate, time to stent occlusion, and overall survival rates were recorded. Results: A total of 34 eligible patients were analyzed. 27 patients had metal stent placement. These 27 patients formed the basis of this study. Median overall survival (OS) was 6.0 months. After metal stent deployment bilurubin levels were normalized within a mean of 10 days. During the follow-up period, 13 patients were experienced metal stent occlusion. Median TtSO was 10 weeks. Cytotoxic chemotherapy was administered to 14 (52%) patients. Patients without stent dysfunction had significantly higher rate of chemotherapy exposure rate (p = 0.021). Statistical analysis, however, failed to exhibit significant effect of stent dysfunction on OS. Conclusion: In advanced cholangiocarcinoma, relief of bile duct obstruction is an important part of the initial patient management. This study therefore described the clinical value of percutaneous metal stent in cholangiocarcinoma patients and raises the question about patency of metal stent in cholangiocarcinoma whether we can expect success similar to the success achieved in pancreas carcinoma.

Effectiveness of percutaneous metal stent placement in cholangiocarcinoma patients with midterm follow-up: Single center experience

Energy Technology Data Exchange (ETDEWEB)

Kose, Fatih, E-mail: fatihkose@gmail.com [Baskent University Faculty of Medicine, Department of Medical Oncology, Adana (Turkey); Oguzkurt, Levent [Department of Interventional Radiology, Adana (Turkey); Besen, Ayberk; Sumbul, Taner; Sezer, Ahmet; Karadeniz, Cemile; Disel, Umut; Mertsoylu, Huseyin; Ozyilkan, Ozgur [Baskent University Faculty of Medicine, Department of Medical Oncology, Adana (Turkey)

2012-08-15

Purpose: Patients with advanced cholangiocarcinoma present with high rate of local complications. The primary aim of this study is to report clinical course of advanced cholangiocarcinoma patients those who were presented with biliary obstruction and treated with percutaneous biliary stenting. Material and methods: Patients with unresectable locally advanced or metastatic cholangiocarcinoma followed by our center for a period of 4 years were analyzed. For statistical analysis demographic and clinical characteristics of patients, primary biliary drainage method, metal stent occlusion rate, time to stent occlusion, and overall survival rates were recorded. Results: A total of 34 eligible patients were analyzed. 27 patients had metal stent placement. These 27 patients formed the basis of this study. Median overall survival (OS) was 6.0 months. After metal stent deployment bilurubin levels were normalized within a mean of 10 days. During the follow-up period, 13 patients were experienced metal stent occlusion. Median TtSO was 10 weeks. Cytotoxic chemotherapy was administered to 14 (52%) patients. Patients without stent dysfunction had significantly higher rate of chemotherapy exposure rate (p = 0.021). Statistical analysis, however, failed to exhibit significant effect of stent dysfunction on OS. Conclusion: In advanced cholangiocarcinoma, relief of bile duct obstruction is an important part of the initial patient management. This study therefore described the clinical value of percutaneous metal stent in cholangiocarcinoma patients and raises the question about patency of metal stent in cholangiocarcinoma whether we can expect success similar to the success achieved in pancreas carcinoma.

Self-expendable metallic stents for palliative treatment of malignant esophagogastric strictures: experiences in 103 patients

Energy Technology Data Exchange (ETDEWEB)

Kim, Sun Ah; Do, Young Soo; Lee, Byung Hee; Oh, Hoon Il; Kim, Soo Ah; Kim, Ki Soo; Chin, Soo Yil [Korea Cancer Center Hospital, Seoul (Korea, Republic of)

1995-10-15

To evaluate the effects and complication of self-expandable metallic stent for the treatment of malignant esophagogastric strictures. From September 1991 to March 1995, 110 stents were placed under fluoroscopic guidance in 103 patients. Of the 103 patients, there were 73 patients with esophageal cancer, 14 patients with gastric cancer, 12 patients with recurrence after surgery, three patients with esophageal compression by metastatic mediastinal lymphadenopathy, and one patient with esophageal invasion by lung cancer. Seventeen patients had esophagorespiratory fistulas. Under fluoroscopic guidance, 113 self-expandable metallic stents (99 Song stents, 14 Strecker stents) were placed in 103 patients. After stent placement, 68 (66%) of the patients could ingest solid food, 26 (25.2%) could ingest soft food whereas three (2.9%) were not able to have food. Esophagorespiratory fistulas were occluded immediately after stent insertion. All stents were placed without any technical failures or procedural morbidity or mortality. Complications included restenosis in 13, gastroesophageal reflux in 11, stent tube migration in eight, massive bleeding in four, delayed esophageal perforation in one, stent obstruction by food impaction in one patient. Self-expandable metallic stent seems to be relatively safe and effective procedure in the palliative treatment of malignant esophagogastric stricture.

Stent valve implantation in conventional redo aortic valve surgery to prevent patient-prosthesis mismatch.

Science.gov (United States)

Ferrari, Enrico; Franciosi, Giorgio; Clivio, Sara; Faletra, Francesco; Moccetti, Marco; Moccetti, Tiziano; Pedrazzini, Giovanni; Demertzis, Stefanos

2017-03-01

The goal was to show the technical details, feasibility and clinical results of balloon-expandable stent valve implantation in the aortic position during conventional redo open-heart surgery in selected obese patients with a small aortic prosthesis and severe patient-prosthesis mismatch. Two symptomatic overweight patients (body mass index of 31 and 38), each with a small aortic prosthesis (a 4-year-old, 21-mm Hancock II biological valve and a 29-year-old, 23-mm Duromedic mechanical valve), increased transvalvular gradients (59/31 and 74/44 mmHg) and a reduced indexed effective orifice area (0.50 and 0.43 cm 2 /m 2 ) underwent implantation of two 26-mm balloon-expandable Sapien 3 valves during standard on-pump redo valve surgery. Using full re-sternotomy, cardiopulmonary bypass and cardioplegic arrest, the two balloon-expandable stent valves were implanted under direct view using a standard aortotomy, after prosthesis removal and without annulus enlargement. Aortic cross-clamp times were 162 and 126 min; cardiopulmonary bypass times were 178 and 180 min; total surgical times were 360 and 318 min. At discharge, echocardiograms showed transvalvular peak and mean gradients of 13/9 and 23/13 mmHg and indexed effective orifice areas of 0.64 and 1.08 cm 2 /m 2 . The 3-month echocardiographic follow-up showed transvalvular peak and mean gradients of 18/9 and 19/11 mmHg and indexed effective orifice areas of 0.78 cm 2 /m 2 and 0.84 cm 2 /m 2 , with improved symptoms (New York Heart Association class 1). Implantation of a balloon-expandable stent valve during redo aortic valve surgery is feasible in selected cases and prevents patient-prosthesis mismatch in obese patients without need for aortic annulus enlargement. Moreover, in the case of stent valve degeneration, this approach permits additional valve-in-valve procedures with large stent valves and prevents re-redo surgery. © The Author 2016. Published by Oxford University Press on behalf of the

Estudio comparativo en pacientes con implante de stent liberador de droga y stent convencional. Resultados clínicos e indicaciones

Directory of Open Access Journals (Sweden)

Mariano Albertal

2006-01-01

Full Text Available Antecedentes Estudios aleatorizados demostraron la superioridad del uso de stents liberadores de droga (SL sobre el stent convencional (SC. La información en nuestro medio sobre el implante de SL es escasa. Objetivo Comparar los resultados clínicos obtenidos en pacientes sometidos a implante de SL versus SC en un centro terciario de la Argentina. Material y métodos Se incluyeron todos los pacientes sometidos a angioplastia electiva desde abril de 2003 hasta junio de 2005 y se dividieron en dos grupos: los pacientes sometidos a implante de uno o más SL (grupo SL, n = 373 y los sometidos solamente a implante de SC (grupo SC, n = 857. Resultados Las características basales fueron similares entre los dos grupos. En el grupo SL se observó un porcentaje mayor de lesiones en la arteria descendente anterior (50,6 versus 40,6%; p 0,001, gracias a una reducción de la tasa de cirugía coronaria (1,4% versus 5,8%; p = 0,045. Conclusión El uso de SL en un centro terciario de la Argentina demostró que es seguro y, en comparación con el implante de sólo SC, dio por resultado una tasa menor de reintervención, primariamente por haber reducido la tasa de cirugía de revascularización miocárdica

New expandable metallic stents: An experimental study in vessels of dogs

International Nuclear Information System (INIS)

Song, Ho Young; Lee, Jung Min; Chung, Jin Young; Chung, Gyung Ho; Kim, Bog Yi; Kuh, Ja Houng

1992-01-01

Three-types of expandable metallic stents were constructed to evaluate the differences between the stents: one, formed in a cylindrical zigzag pattern wth stainless steel wire (Gianturco stent), another, made by coating the Gianturco stent with silicone rubber (Silicone stent), the third, made by coating the Gianturco stent with 24 carat gold (Gold stent) for tissue acceptance. A total of 69 stents (each 23 stents of Gianturco, Silicone, and Gold stents) of 8-12 mm in diameter and 20 mm long were placed into normal abdominal aorta, inferior vena cava and lilac artery of nine adults dogs for 2 weeks to 11 months. It was more difficult to introduce Silicone stent into an introducing sheath than Gianturco or Gold stent due to the thickness of silicone rubber. Four Gianturco stents and three Silicone stents showed migration but Gold stent did not. Luminal narrowing or occlusion was noted in 3 Silicone stents. In 2 Gianturco stents, and in 1 Gold stent. Neointimal proliferation over the stent wires was more rapid and even in Gold stent than Silicone or Gianturco stent. Although further study is needed, Gold stent seems to be better than Gianturco or Silicone stent as an endovascular graft material

New expandable metallic stents: An experimental study in vessels of dogs

Energy Technology Data Exchange (ETDEWEB)

Song, Ho Young; Lee, Jung Min; Chung, Jin Young; Chung, Gyung Ho; Kim, Bog Yi; Kuh, Ja Houng [Chunbuk National University Medical School, Chunju (Korea, Republic of)

1992-07-15

Three-types of expandable metallic stents were constructed to evaluate the differences between the stents: one, formed in a cylindrical zigzag pattern wth stainless steel wire (Gianturco stent), another, made by coating the Gianturco stent with silicone rubber (Silicone stent), the third, made by coating the Gianturco stent with 24 carat gold (Gold stent) for tissue acceptance. A total of 69 stents (each 23 stents of Gianturco, Silicone, and Gold stents) of 8-12 mm in diameter and 20 mm long were placed into normal abdominal aorta, inferior vena cava and lilac artery of nine adults dogs for 2 weeks to 11 months. It was more difficult to introduce Silicone stent into an introducing sheath than Gianturco or Gold stent due to the thickness of silicone rubber. Four Gianturco stents and three Silicone stents showed migration but Gold stent did not. Luminal narrowing or occlusion was noted in 3 Silicone stents. In 2 Gianturco stents, and in 1 Gold stent. Neointimal proliferation over the stent wires was more rapid and even in Gold stent than Silicone or Gianturco stent. Although further study is needed, Gold stent seems to be better than Gianturco or Silicone stent as an endovascular graft material.

Drug-eluting versus bare-metal stents in large coronary arteries

DEFF Research Database (Denmark)

Kaiser, Christoph; Galatius, Soeren; Erne, Paul

2010-01-01

Recent data have suggested that patients with coronary disease in large arteries are at increased risk for late cardiac events after percutaneous intervention with first-generation drug-eluting stents, as compared with bare-metal stents. We sought to confirm this observation and to assess whether...

Tracheal stenosis after treatment with metallic stent: a situation worse than the initial problem

International Nuclear Information System (INIS)

Barreto, Jaime; Mejia, Bibiana; Nino, Federico; Garavito, Carlos

2008-01-01

Stens are a tubular device for use in trachea, carina or main bronchus to provide a support and maintain the permeability of these structures. There are two groups: Metallic and Silicone stent. Either metallic and silicone stents has a special properties. Metallic stent are very attractive option due to relative easy in their placement. The accumulated experience in this therapy has allowed to recognize several complications to take into consideration mainly in patients with tracheal benign stenosis. FDA has recommended don't use metallic stents, covered and not covered in benign diseases. We report a case of a tracheal stenosis secondary to prolonged ortho tracheal intubation that required extensive interventions to control symptoms of central airway obstruction, between April and July of 2005.

[Management of malignant and benign airway stenosis by stent implantation].

Science.gov (United States)

Gyulai, Márton; Slavei, Krisztina; Pénzes, István; Strausz, János

2006-11-12

In the last few decades the different bronchoscopic procedures have gained an important role in the treatment of airway stenosis, and the number of implanted airway stents has also greatly increased. Between 1998 and 2004 the authors implanted altogether 108 airway prosthesis in 90 patients at the Institute of Pulmonology of Pest County. 58% of the patients were males, 42% females, the average age was 57.5 years, the average follow-up time was 7 months. On the basis of different etiology the patients were separated into two main groups. In 57% the airway stenosis was caused by malignant illnesses, in these cases stents can be used only with palliative purpose. However, in case of benign lesions they can offer a long-term solution and require an adequate follow-up of the patients. The authors' main aim was to get an overall picture of the interventions they had done by processing the data, with the help of the measurable characteristics that make possible to follow the airways' permeability and its changes. Analysing the results of the respiratory function and blood gas examinations they didn't find a significant difference inspite of the subjective improvement.

Ion implantation and amorphous metals

International Nuclear Information System (INIS)

Hohmuth, K.; Rauschenbach, B.

1981-01-01

This review deals with ion implantation of metals in the high concentration range for preparing amorphous layers (>= 10 at%, implantation doses > 10 16 ions/cm 2 ). Different models are described concerning formation of amorphous phases of metals by ion implantation and experimental results are given. The study of amorphous phases has been carried out by the aid of Rutherford backscattering combined with the channeling technique and using transmission electron microscopy. The structure of amorphous metals prepared by ion implantation has been discussed. It was concluded that amorphous metal-metalloid compounds can be described by a dense-random-packing structure with a great portion of metal atoms. Ion implantation has been compared with other techniques for preparing amorphous metals and the adventages have been outlined

Expandable metallic stents in the palliative treatment of malignant tracheobronchial stenosis

Energy Technology Data Exchange (ETDEWEB)

Park, Jong Woong; Jung, Gyoo Sik; Kim, Seong Min; Lee, Seung Ryong; Kim, Hyun Sook; Huh, Jin Do; Joh, Young Duk [Kosin Medical College, Pusan (Korea, Republic of)

1998-05-01

The purpose of this study is to report the outcome of using expandable metallic stent in the management of malignant tracheobronchial stenosis with dyspnea. Under fluoroscopic and bronchoscopic guidance, seven patients with malignant airway stenosis were treated with ten expandable metallic stents. The cause of stenosis was metastasis from esophageal cancer in five patients, recurrent adenoid cystic carcinoma of the trachea in one, and primary lung cancer in one. The major sites of obstruction were the trachea in four patients, the left main bronchus in one, the trachea and left main bronchus in one, and the trachea and both bronchi in one. Chest radiography (n=7), bronchoscopy (n=5), pulmonary function test (PFT)(n=3), and spirometry(n=1) were performed before and after stent placement. In all seven patients, the stent was successfully placed at the lesion sites and dyspnea began to improve immediately. After the procedure, chest radiography and bronchoscopy showed an increase in airway diameter. After the procedure, chest radiography and bronchoscopy showed an increase in airway diameter. After stent placement, forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) improved 53% and 56%, respectively. Peak flow velocity also changed from 46 L/min to 200 L/min. During median follow-up of 67 (41-1565) days, one stent migration occurred. In one patient, proximal tumor overgrowth occurred, and in one, tumor ingrowth was treated with balloon dilatation. For in the palliative treatment of malignant tracheobronchial stenosis with dyspnea, placement of expandable metal stents is safe and effective. (author). 21 refs., 1 tabs., 3 figs.

Expandable metallic stents in the palliative treatment of malignant tracheobronchial stenosis

International Nuclear Information System (INIS)

Park, Jong Woong; Jung, Gyoo Sik; Kim, Seong Min; Lee, Seung Ryong; Kim, Hyun Sook; Huh, Jin Do; Joh, Young Duk

1998-01-01

The purpose of this study is to report the outcome of using expandable metallic stent in the management of malignant tracheobronchial stenosis with dyspnea. Under fluoroscopic and bronchoscopic guidance, seven patients with malignant airway stenosis were treated with ten expandable metallic stents. The cause of stenosis was metastasis from esophageal cancer in five patients, recurrent adenoid cystic carcinoma of the trachea in one, and primary lung cancer in one. The major sites of obstruction were the trachea in four patients, the left main bronchus in one, the trachea and left main bronchus in one, and the trachea and both bronchi in one. Chest radiography (n=7), bronchoscopy (n=5), pulmonary function test (PFT)(n=3), and spirometry(n=1) were performed before and after stent placement. In all seven patients, the stent was successfully placed at the lesion sites and dyspnea began to improve immediately. After the procedure, chest radiography and bronchoscopy showed an increase in airway diameter. After the procedure, chest radiography and bronchoscopy showed an increase in airway diameter. After stent placement, forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) improved 53% and 56%, respectively. Peak flow velocity also changed from 46 L/min to 200 L/min. During median follow-up of 67 (41-1565) days, one stent migration occurred. In one patient, proximal tumor overgrowth occurred, and in one, tumor ingrowth was treated with balloon dilatation. For in the palliative treatment of malignant tracheobronchial stenosis with dyspnea, placement of expandable metal stents is safe and effective. (author). 21 refs., 1 tabs., 3 figs

Esophagojejunal Anastomosis Fistula, Distal Esophageal Stenosis, and Metalic Stent Migration after Total Gastrectomy

Directory of Open Access Journals (Sweden)

Nadim Al Hajjar

2015-01-01

Full Text Available Esophagojejunal anastomosis fistula is the main complication after a total gastrectomy. To avoid a complex procedure on friable inflamed perianastomotic tissues, a coated self-expandable stent is mounted at the site of the anastomotic leak. A complication of stenting procedure is that it might lead to distal esophageal stenosis. However, another frequently encountered complication of stenting is stent migration, which is treated nonsurgically. When the migrated stent creates life threatening complications, surgical removal is indicated. We present a case of a 67-year-old male patient who was treated at our facility for a gastric adenocarcinoma which developed, postoperatively, an esophagojejunostomy fistula, a distal esophageal stenosis, and a metallic coated self-expandable stent migration. To our knowledge, this is the first reported case of an esophagojejunostomy fistula combined with a distal esophageal stenosis as well as with a metallic coated self-expandable stent migration.

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)

Serious Complication of Percutaneous Angioplasty with Stent Implantation in so Called "Chronic Cerebrospinal Venous Insufficiency" in Multiple Sclerosis Patient

Directory of Open Access Journals (Sweden)

Ondřej Doležal

2012-01-01

Full Text Available We report female patient, age 51, with clinically definitive multiple sclerosis (CDMS since 1998, who underwent two PTA procedures with stent implantation for CCSVI in 2010. Expanded disability status scale (EDSS worsened since the procedure from 4.5 to 6. Total number of three stents was implanted (two of them in the right internal jugular vein. In six month time, in 2011, patient was referred for independent examination by computer tomography (CT phlebography for right-sided neck pain. Dislocation of stents on the right side and thrombosis of left sided stent was found. Conservative approach was used so far. Our short report is showing possible complications of PTA and stenting in jugular veins in so called CCSVI and bringing information about neurological state (EDSS worsening in a subject. Continuation of stent migration in the future is probable, possibly resulting in pulmonary embolism with fatal risk for the patient. We strongly ask for restriction of PTA procedure in so called CCSVI, which concept was not proven to be relevant to MS.

Outcomes of secondary self-expandable metal stents versus surgery after delayed initial palliative stent failure in malignant colorectal obstruction.

Science.gov (United States)

Yoon, Jin Young; Park, Soo Jung; Hong, Sung Pil; Kim, Tae Il; Kim, Won Ho; Cheon, Jae Hee

2013-01-01

When re-intervention is required due to an occluded first colorectal self-expanding metal stent for malignant colorectal obstruction, serious controversies exist regarding whether to use endoscopic re-stenting or surgery. To compare the clinical outcomes in patients who underwent stent re-insertion versus palliative surgery as a second intervention. A total of 115 patients who received either self-expandable metal stent (SEMS) insertion or palliative surgery for treatment of a second occurrence of malignant colorectal obstruction after the first SEMS placement were retrospectively studied between July 2005 and December 2009. The median overall survival (8.2 vs. 15.5 months) and progression-free survival (4.0 vs. 2.7 months) were not significantly different between the stent and surgery groups (p = 0.895 and 0.650, respectively). The median lumen patency in the stent group was 3.4 months and that in the surgery group was 7.9 months (p = 0.003). The immediate complication rate after second stent insertion was 13.9% and late complication rate was observed in 12 of 79 (15.2%) patients. There was no mortality related to the SEMS procedure. The complication and mortality rates associated with palliative surgery were 3.5% (2/57) and 12.3% (7/57), respectively. Although there is no significant difference in the overall survival between stenting and surgery, a secondary stent insertion had a lower mortality rate despite a shorter duration of temporary colorectal decompression compared to that of palliative surgery.

Th1, Th17, CXCL16 and homocysteine elevated after intracranial and cervical stent implantation.

Science.gov (United States)

Tang, Yanyan; Wei, Yunfei; Ye, Ziming; Qin, Chao

2017-08-01

The presence of Th1 and Th17 cells has been observed as major inducers in inflammation and immune responses associated stenting. However, there is rare data on the impact of Th1, Th17, CXCL16 and homocysteine after cerebral stent implantation. Here, we performed the statistical analysis to first evaluate the variation of the Th17and Th1 cells and their related cytokines, CXCL16 and homocysteine in the peripheral blood of patients with cerebral stenting. The flow cytometry was used to detect the proportion of Th1 and Th17 cells in peripheral blood mononuclear cells (PBMCs). The enzyme-linked immunosorbent assay was used to measure the serum concentrations of IFN-γ, IL-17 and CXCL16. Plasma homocysteine was examined by immunoturbidimetry. The level of Th1, CXCL16 and homocysteine showed an increase at 3 d, followed by the continuous decrease at 7 d and 3 months. The frequency of Th17 cells increased to a peak at three days, and subsequently decreased with a higher level than baseline. Our data revealed that the variation in Th1, Th17, CXCL16 and homocysteine in peripheral blood of patients with stenting may be implicated in inflammation after intracranial and cervical stent implantation. A better understanding of these factors will provide help for further drug design and clinical therapy.

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

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

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

Late lumen loss and intima hyperplasia after sirolimus-eluting and zotarolimus-eluting stent implantation in diabetic patients: the diabetes and drug-eluting stent (DiabeDES III) angiography and intravascular ultrasound trial

DEFF Research Database (Denmark)

Jensen, Lisette Okkels; Mæng, Michael; Thayssen, Per

2011-01-01

Patients with diabetes mellitus have increased risk of in-stent restenosis after coronary stent implantation due to neointimal hyperplasia (NIH). The aim of this study was to use quantitative coronary angiography (QCA) and volumetric intravascular ultrasound (IVUS) to evaluate the effects...... of the sirolimus-eluting Cypher® stent (SES) and the zotarolimus-eluting Endeavor® stent (ZES) on angiographic late lumen loss and intima hyperplasia in diabetic patients....

Expandable metal stents for tracheal obstruction: permanent or temporary? A cautionary tale.

OpenAIRE

Hind, C R; Donnelly, R J

1992-01-01

An expandable metal stent inserted via a long term tracheostomy successfully relieved life threatening respiratory obstruction due to benign tracheal stenosis. Later the patient's tracheostomy suction catheter became stuck on the stent and dislodged it. The stent was removed electively, without damaging the trachea, with a rigid biopsy forceps.

Temporary placement of metallic stent could lead to long-term benefits for benign tracheobronchial stenosis.

Science.gov (United States)

Zhou, Guo-Wu; Huang, Hai-Dong; Sun, Qin-Ying; Xiong, Ye; Li, Qiang; Dong, Yu-Chao; Zhang, Wei

2015-12-01

The permanent placement of metallic stent for benign tracheobronchial stenosis (BTS) was controversial. This study was conducted to evaluate the long-term outcomes of temporary placement of metallic stent for BTS. The BTS patients who received temporary placement of retrievable self-expanded metallic stents were included between 2008 and 2011. Pre-stenting and follow-up respiratory status was analyzed. And symptom recurrence-free survival (SRFS) was assessed. A total of 49 stents were successfully temporarily placed in 40 consecutive BTS patients whose etiologies included endobronchial tuberculosis (EBTB) (n=22), post-tracheostomy stenosis (n=10), post-intubation stenosis (n=6) and post radiotherapy stricture (n=2). All stents were removed integrally after a median 18 days' stenting period, without major complications. During the median 27 months follow-up period after stent removal, a total of 22 patients were free of recurrence. And the overall 3-year SRFS rate was 52.0%. According to the etiology, the 3-year SRFS rates were 59.1% and 42.9% in the patients with EBTB and non-EBTB, respectively. Compared with pre-stenting, the follow-up internal diameter of stricture, Hugh-Jones scale, 6-minute walk test (6MWT) and percentage of forced expiratory volume in one second (FEV1%) were significantly improved. Multivariate analysis suggested that granulation tissue growth and tracheobronchial malacia might be independent factors of poor prognosis. Temporary placement of retrievable metallic stent may be an alternative treatment for BTS patients.

The use of self expandable metallic stent in the management of malignant biliary obstruction

Energy Technology Data Exchange (ETDEWEB)

Han, Joon Koo; Choi, Byung Ihn; Chung, Jin Wook; Park, Jae Hyung; Han, Gi Seok; Han, Man Chung [Seoul National University College of Medicine, Seoul (Korea, Republic of)

1993-05-15

Self expandable metallic stent is a good alternative of percutaneous transhepatic biliary drainage because it can eliminate numerous problems caused by external drainage catheter, such as tube dislodgement, bile leakage and psychotic problems. Authors analyzed initial results of self expandable metallic stents used in the patient with malignant biliary obstruction to evaluate the efficacy of the procedure and to find the technical problems in the procedure. Self expandable metallic stents were inserted in 14 patients: three with recurrent stomach cancer: three with gallbladder cancer: seven with Klaskin tumor: one with common duct cancer. Gianturco type stent was used in 9 cases ans Wallstent was used in 2 cases. In remaining three case, both Z-stent and Wallstent were used in the same patient. The average period of follow up was 104 days (4-409 days). In 13 cases, the patency of the bile duct was restored by the stent (technical success: 92.9%). Occlusions of the stent were found in two cases, after two and 13 months, respectively. Causes of failure and stent occlusion were associated duodenal obstruction, tumor overgrowth and shortening of Wallstent. In remaining 11 patients, one patient was lost to follow up an 10 patients did not show recurrent jaundice until death or last follow up. There was no major complication related to the procedure. The insertion of self expandable metallic stent is a safe procedure and can eliminate major disadvantages of PTBD. Overstenting, overlapping and evaluation of associated GI tract obstruction is crucial for obtaining technical success and long-term patency.

The use of self expandable metallic stent in the management of malignant biliary obstruction

International Nuclear Information System (INIS)

Han, Joon Koo; Choi, Byung Ihn; Chung, Jin Wook; Park, Jae Hyung; Han, Gi Seok; Han, Man Chung

1993-01-01

Self expandable metallic stent is a good alternative of percutaneous transhepatic biliary drainage because it can eliminate numerous problems caused by external drainage catheter, such as tube dislodgement, bile leakage and psychotic problems. Authors analyzed initial results of self expandable metallic stents used in the patient with malignant biliary obstruction to evaluate the efficacy of the procedure and to find the technical problems in the procedure. Self expandable metallic stents were inserted in 14 patients: three with recurrent stomach cancer: three with gallbladder cancer: seven with Klaskin tumor: one with common duct cancer. Gianturco type stent was used in 9 cases ans Wallstent was used in 2 cases. In remaining three case, both Z-stent and Wallstent were used in the same patient. The average period of follow up was 104 days (4-409 days). In 13 cases, the patency of the bile duct was restored by the stent (technical success: 92.9%). Occlusions of the stent were found in two cases, after two and 13 months, respectively. Causes of failure and stent occlusion were associated duodenal obstruction, tumor overgrowth and shortening of Wallstent. In remaining 11 patients, one patient was lost to follow up an 10 patients did not show recurrent jaundice until death or last follow up. There was no major complication related to the procedure. The insertion of self expandable metallic stent is a safe procedure and can eliminate major disadvantages of PTBD. Overstenting, overlapping and evaluation of associated GI tract obstruction is crucial for obtaining technical success and long-term patency

Fully-covered metal stents with endoscopic suturing vs. partially-covered metal stents for benign upper gastrointestinal diseases: a comparative study

Science.gov (United States)

Ngamruengphong, Saowanee; Sharaiha, Reem; Sethi, Amrita; Siddiqui, Ali; DiMaio, Christopher J.; Gonzalez, Susana; Rogart, Jason; Jagroop, Sophia; Widmer, Jessica; Im, Jennifer; Hasan, Raza Abbas; Laique, Sobia; Gonda, Tamas; Poneros, John; Desai, Amit; Wong, Katherine; Villgran, Vipin; Brewer Gutierrez, Olaya; Bukhari, Majidah; Chen, Yen-I; Hernaez, Ruben; Hanada, Yuri; Sanaei, Omid; Agarwal, Amol; Kalloo, Anthony N.; Kumbhari, Vivek; Singh, Vikesh; Khashab, Mouen A.

2018-01-01

Background and study aims  Self-expandable metallic stents (SEMS) have been increasingly used in benign conditions (e. g. strictures, fistulas, leaks, and perforations). Fully covered SEMS (FSEMS) were introduced to avoid undesirable consequences of partially covered SEMS (PSEMS), but come with higher risk of stent migration. Endoscopic suturing (ES) for stent fixation has been shown to reduce migration of FSEMS. Our aim was to compare the outcomes of FSEMS with ES (FS/ES) versus PSEMS in patients with benign upper gastrointestinal conditions. Patients and methods  We retrospectively identified all patients who underwent stent placement for benign gastrointestinal conditions at seven US tertiary-care centers. Patients were divided into two groups: FSEMS with ES (FS/ES group) and PSEMS (PSEMS group). Clinical outcomes between the two groups were compared. Results  A total of 74 (FS/ES 46, PSEMS 28) patients were included. On multivariable analysis, there was no significant difference in rate of stent migration between FS/ES (43 %) and PSEMS (15 %) (adjusted odds ratio 0.56; 95 % CI 0.15 – 2.00). Clinical success was similar [68 % vs. 64 %; P  = 0.81]. Rate of adverse events (AEs) was higher in PSEMS group [13 (46 %) vs. 10 (21 %); P  = 0.03). Difficult stent removal was higher in the PSEMS group (n = 5;17 %) vs. 0 % in the FS/ES group; P  = 0.005. Conclusions  The proportion of stent migration of FS/ES and PSEMS are similar. Rates of other stent-related AEs were higher in the PSEMS group. PSEMS was associated with tissue ingrowth or overgrowth leading to difficult stent removal, and secondary stricture formation. Thus, FSEMS with ES for stent fixation may be the preferred modality over PSEMS for the treatment of benign upper gastrointestinal conditions. PMID:29404384

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)

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

Efficacy of Retrievable Metallic Stent with Fixation String for Benign Stricture after Upper Gastrointestinal Surgery

Science.gov (United States)

Kim, Jeong-Eun; Lee, Myungsu; Hur, Saebeom; Kim, Minuk; Lee, Sang Hwan; Cho, Soo Buem; Kim, Chan Sun; Han, Joon Koo

2016-01-01

Objective To determine the efficacy of retrievable metallic stent with fixation string for benign anastomotic stricture after upper gastrointestinal (UGI) surgery. Materials and Methods From June 2009 to May 2015, a total of 56 retrievable metallic stents with fixation string were placed under fluoroscopy guidance in 42 patients who were diagnosed with benign anastomotic stricture after UGI surgery. Clinical success was defined as achieving normal regular diet (NRD). Results The clinical success rate after the first stent placement was 57.1% (24/42). After repeated stent placement and/or balloon dilation, the clinical success rate was increased to 83.3% (35/42). Six (14.3%) patients required surgical revision to achieve NRD. One (2.4%) patient failed to achieve NRD. Stent migration occurred in 60.7% (34/56) of patients. Successful rate of removing the stent using fixation string and angiocatheter was 94.6% (53/56). Distal migration occurred in 12 stents. Of the 12 stents, 10 (83.3%) were successfully removed whereas 2 could not be removed. No complication occurred regarding distal migration. Conclusion Using retrievable metallic stent with a fixation string is a feasible option for managing early benign anastomotic stricture after UGI surgery. It can reduce complications caused by distal migration of the stent. PMID:27833405

Removal of self expandable metallic airway stent: A rare case report

Directory of Open Access Journals (Sweden)

Rakesh K Chawla

2013-01-01

Full Text Available Covered self expandable metallic airway stents (SEMS have been used for benign tracheal stenosis, post intubation tracheal stenosis, tracheal burn or trauma, tracheo-broncho-malacia, and extrinsic compression of trachea. Their placement is considered to be permanent, with open surgery the only way to remove the stent, though there are few cases reports of their removal with the bronchoscope, but the complications after their removal are very high. In our patient, one and a half years after placement of SEMS, she developed cough with dyspnoea, video bronchoscopy showed stenosis above the level of stent with granulation tissue inside the stent, stent fracture in lower part and stent migration to right main bronchus, thus she had all conceivable complications of stent placement. The stent was removed with the help of rigid bronchoscope under general anaesthesia. She was discharged the following day. The case is being reported because it was unique in having all the possible complications of stent placement, and rare as we could take out the stent in Toto. Thirdly, the stent could be removed without any complication.

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.

[Treatment of tracheobronchomalacia with expandable metallic stents].

Science.gov (United States)

Antón-Pacheco Sánchez, J; García Vázquez, A; Cuadros García, J; Cano Novillo, I; Villafruela Sanz, M; Berchi García, F J

2002-10-01

Tracheomalacia is an unfrequent disease that causes tracheal collapse during breathing. It is generally associated to esophageal atresia, but cases of primary tracheomalacia and others secondary to extrinsic compression, have also been described. Spontaneous resolution is generally the rule and only a few cases need surgical treatment. When this therapy fails or is not indicated for any reason, endoluminal tracheobronchial stents may be used. We have treated two patients with four expandable metallic stents: one had severe tracheomalacia associated to esophageal atresia and the other tracheobronchomalacia secondary to cardiomegaly. Results have been good in both cases.

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.

[Clinical application of a fully covered self-expandable metallic stent in treatment of airway fistula].

Science.gov (United States)

Zhu, Qiang; Zang, Qi; Jiang, Zhong-min; Wang, Wei; Cao, Ming

2013-06-01

To assess the feasibility, safety and efficacy of the use of a fully covered self-expandable stent for the treatment of airway fistula. From August 2005 to November 2011, 9 patients underwent treatment by the introduction of a tracheo-bronchial or bronchial fully covered self-expandable metallic stent. There were 7 males and 2 females, aged from 28-65 years with a mean of 46 years. In this group, 7 cases were diagnosed as bronchopleural fistula, 1 case as tracheopleural fistula, 1 case as broncho-esophageal fistula, 8 cases with thoracic empyema. The fistula orifices were from 3.5-25.0 mm in diameter with a mean 8.4 mm. All patients received topical anesthesia, and L-shaped stent was placed in 6 patients and I-shaped stent in 3 patients under fluoroscopic guidance. After the stent placement, the patients with empyema were treated with continual irrigation of the empyema cavity. Stent placement in the tracheo-bronchial tree was technically successful in all patients, without procedure-related complications. The operating time was from 5-16 minutes, mean time (10 ± 4) minutes. Except for 1 patient, immediate closure of the airway fistula was achieved in the other patients after the procedure, as shown by the immediate cessation of bubbling in the chest drain system or the contrast examination. In this study, 1 patient coughed the inserted stent out due to irritable cough on the 5th day and had to receive repositioning of a new stent. Among the patients who were with empyema, 1 patient died of septicemia on the 8th day and 1 patient died of brain metastases from lung cancer 6 months after the stent insertion with empyema not cured, the other 6 patients' empyema healed from 2-5 months, mean time 3.7 months. Seven patients were followed from 3 to 36 months with a median of 13.5 months. During follow-up, 1 stent was removed from a patient 8 months after the stent implantation without empyema recurred. The remaining patient presented good tolerability to the existence of

Bioabsorbable Stent Quo Vadis: A Case for Nano-Theranostics

Science.gov (United States)

Gundogan, Buket; Tan, Aaron; Farhatnia, Yasmin; Alavijeh, Mohammad S.; Cui, Zhanfeng; Seifalian, Alexander M.

2014-01-01

Percutaneous coronary intervention (PCI) is one of the most commonly performed invasive medical procedures in medicine today. Since the first coronary balloon angioplasty in 1977, interventional cardiology has seen a wide array of developments in PCI. Bare metal stents (BMS) were soon superseded by the revolutionary drug-eluting stents (DES), which aimed to address the issue of restenosis found with BMS. However, evidence began to mount against DES, with late-stent thrombosis (ST) rates being higher than that of BMS. The bioabsorbable stent may be a promising alternative, providing vessel patency and support for the necessary time required and thereafter degrade into safe non-toxic compounds which are reabsorbed by the body. This temporary presence provides no triggers for ST, which is brought about by non-endothelialized stent struts and drug polymers remaining in vivo for extended periods of time. Likewise, nano-theranostics incorporated into a bioabsorbable stent of the future may provide an incredibly valuable single platform offering both therapeutic and diagnostic capabilities. Such a stent may allow delivery of therapeutic particles to specific sites thus keeping potential toxicity to a minimum, improved ease of tracking delivery in vivo by embedding imaging agents, controlled rate of therapy release and protection of the implanted therapy. Indeed, nanocarriers may allow an increased therapeutic index as well as offer novel post-stent implantation imaging and diagnostic methods for atherosclerosis, restenosis and thrombosis. It is envisioned that a nano-theranostic stent may well form the cornerstone of future stent designs in clinical practice. PMID:24672583

Clinical Study on Using 125I Seeds Articles Combined with Biliary Stent Implantation in the Treatment of Malignant Obstructive Jaundice.

Science.gov (United States)

Wang, Tao; Liu, Sheng; Zheng, Yan-Bo; Song, Xue-Peng; Sun, Bo-Lin; Jiang, Wen-Jin; Wang, Li-Gang

2017-08-01

Aim: To study the feasibility and curative effect of 125 I seeds articles combined with biliary stent implantation in the treatment of malignant obstructive jaundice. Patients and Methods: Fifty patients with malignant obstructive jaundice were included. Twenty-four were treated by biliary stent implantation combined with intraluminal brachytherapy by 125 I seeds articles as the experimental group, while the remaining 26 were treated by biliary stent implantation only as the control group. The goal of this study was to evaluate total bilirubin, direct bilirubin and tumor markers (cancer antigen (CA)-199, CA-242 and carcinoembryonic antigen (CEA)), as well as biliary stent patency status and survival time before and after surgery. Results: Jaundice improved greatly in both groups. The decreases of CA-199 and CA-242 had statistical significance (p=0.003 and p=0.004) in the experimental group. The ratio of biliary stent patency was 83.3% (20/24) in the experimental group and 57.7% (15/26) in the control group (p=0.048). The biliary stent patency time in the experimental group was 1~15.5 (mean=9.84) months. The biliary stent patency time in the control group was 0.8~9 (mean=5.57) months, which was statistically significant (p=0.018). The median survival time was 10.2 months in the experimental group, while 5.4 months in control group (pjaundice possibly by inhibiting the proliferation of vascular endothelial cells and the growth of tumor. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Brachytherapy and percutaneous stenting in the treatment of cholangiocarcinoma: A prospective randomised study

International Nuclear Information System (INIS)

Valek, Vlastimil; Kysela, Petr; Kala, Zdenek; Kiss, Igor; Tomasek, Jiri; Petera, Jiri

2007-01-01

Purpose: To evaluate the effect of radiation therapy including intraluminal brachyterapy with iridium-192 on survival of patients with malignant biliary strictures (cholangiocarcinoma, histologically improved) treated with metallic stent in a prospective randomised study. Method and materials: In the prospective randomised study, 21 patients with cholangiocarcinoma were treated with implantation of percutaneous stents followed with intraluminal Ir-192 brachytherapy (mean dose 30 Gy) and external radiotherapy (mean dose 50 Gy) and 21 patients were treated only with stents insertion. We did not find any statistically significant differences in age and tumor localization between these two groups of patients. Results: All the patients died. In the group of patients treated with brachytherapy and with stent implantation, the mean survival time was 387.9 days. In the group of patients treated only with stent insertion the mean survival was 298 days. In effort to eliminate possible effect of external radiotherapy we treated the control group of eight patients with cholangiocarcinoma by stent insertion and brachyterapy only. Conclusion: Our results show that combined radiation therapy could extend the survival in the patients with cholangiocarcinoma obstruction

Reintervention for stent occlusion after bilateral self-expandable metallic stent placement for malignant hilar biliary obstruction.

Science.gov (United States)

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.

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.

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...

Novel biliary self-expanding metal stents: indications and applications.

Science.gov (United States)

Blero, Daniel; Huberty, Vincent; Devière, Jacques

2015-03-01

Endoscopic insertion of a self-expanding metal stent (SEMS) through a malignant common bile duct stricture is the first line of palliation for malignant jaundice. Patency of these stents remains a major concern. SEMS dysfunction can result from tumor ingrowth, overgrowth and/or clogging. Initial SEMS modifications involved covering the central part of the stent in order to reduce ingrowth and ultimately increase patency. Fully covered stents became available shortly after reports of their use in human patients. The potential removability and radial strength of SEMS have led to evaluation of their use in new indications including benign biliary strictures, post sphincterotomy bleeding and perforation. Other aspects of development include the addition of features such as anti-reflux valves, drug elution and spontaneous biodegradability. These aspects and their clinical implications are reviewed and discussed.

Long-Term Safety of Drug-Eluting and Bare-Metal Stents

DEFF Research Database (Denmark)

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...

Covered Biodegradable Stent: New Therapeutic Option for the Management of Esophageal Perforation or Anastomotic Leak

International Nuclear Information System (INIS)

Černá, Marie; Köcher, Martin; Válek, Vlastimil; Aujeský, René; Neoral, Čestmír; Andrašina, Tomáš; Pánek, Jiří; Mahathmakanthi, Shankari

2011-01-01

Purpose: This study was designed to evaluate our experience with the treatment of postoperative anastomotic leaks and benign esophageal perforations with covered biodegradable stents. Materials and Methods: From 2008 to 2010, we treated five men with either an anastomotic leak or benign esophageal perforation by implanting of covered biodegradable Ella-BD stents. The average age of the patients was 60 (range, 38–74) years. Postoperative anastomotic leaks were treated in four patients (1 after esophagectomy, 1 after resection of diverticulum, 2 after gastrectomy). In one patient, perforation occurred as a complication of the treatment of an esophageal rupture (which occurred during a balloon dilatation of benign stenosis) with a metallic stent. Results: Seven covered biodegradable stents were implanted in five patients. Primary technical success was 100%. Clinical success (leak sealing) was achieved in four of the five patients (80%). Stent migration occurred in three patients. In two of these patients, the leak had been sealed by the time of stent migration, therefore no reintervention was necessary. In one patient an additional stent had to be implanted. Conclusion: The use of biodegradable covered stents for the treatment of anastomotic leaks or esophageal perforations is technically feasible and safe. The initial results are promising; however, larger number of patients will be required to evaluate the capability of these biodegradable stents in the future. The use of biodegradable material for coverage of the stent is essential.

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

Computational hemodynamics of an implanted coronary stent based on three-dimensional cine angiography reconstruction.

Science.gov (United States)

Chen, Mounter C Y; Lu, Po-Chien; Chen, James S Y; Hwang, Ned H C

2005-01-01

Coronary stents are supportive wire meshes that keep narrow coronary arteries patent, reducing the risk of restenosis. Despite the common use of coronary stents, approximately 20-35% of them fail due to restenosis. Flow phenomena adjacent to the stent may contribute to restenosis. Three-dimensional computational fluid dynamics (CFD) and reconstruction based on biplane cine angiography were used to assess coronary geometry and volumetric blood flows. A patient-specific left anterior descending (LAD) artery was reconstructed from single-plane x-ray imaging. With corresponding electrocardiographic signals, images from the same time phase were selected from the angiograms for dynamic three-dimensional reconstruction. The resultant three-dimensional LAD artery at end-diastole was adopted for detailed analysis. Both the geometries and flow fields, based on a computational model from CAE software (ANSYS and CATIA) and full three-dimensional Navier-Stroke equations in the CFD-ACE+ software, respectively, changed dramatically after stent placement. Flow fields showed a complex three-dimensional spiral motion due to arterial tortuosity. The corresponding wall shear stresses, pressure gradient, and flow field all varied significantly after stent placement. Combined angiography and CFD techniques allow more detailed investigation of flow patterns in various segments. The implanted stent(s) may be quantitatively studied from the proposed hemodynamic modeling approach.

Medium-term follow-up after deployment of ultraflex expandable metallic stents to manage endobronchial pathology.

Science.gov (United States)

Madden, Brendan P; Park, John E S; Sheth, Abhijat

2004-12-01

Between March 1997 and March 2004 we deployed 80 Ultraflex metallic expandable stents (Boston Scientific, Waterson, MA) in 69 patients under direct vision using rigid bronchoscopy. We report our medium- to long-term experience in patients for whom these stents were deployed. To date 15 patients have been followed for more than 1 year (median 41 months, range 12 to 83 months) after stent deployment. Indications for stenting in these patients were neoplasia (5), stricture (5), airway malacia (1), iatrogenic tracheal tear (1), and compression from an aortic aneurysm (1), a right interrupted aortic arch (1), and a right brachiocephalic artery aneurysm with tracheomalacia (1). Ten tracheal stents (9 covered, 1 uncovered) and 10 bronchial stents (8 uncovered, 2 covered) were inserted, and 5 patients received two stents. Five of these patients experienced no long-term problems. Complications included troublesome halitosis (5), which was difficult to treat despite various antibiotic regimes; granulation tissue formation above and below the stent that was successfully treated with low-power Nd:YAG laser therapy (7); and metal fatigue (1). We did not encounter stent migration. We conclude that Ultraflex expandable metallic stents have an important role in the management of selected patients with diverse endobronchial pathologies and are well tolerated in the long-term. Although associated granulation tissue can be successfully treated with Nd:YAG laser, halitosis can be a difficult problem to address.

Permanent Pacemaker-Induced Superior Vena Cava Syndrome: Successful Treatment by Endovascular Stent

International Nuclear Information System (INIS)

Lanciego, Carlos; Rodriguez, Mario; Rodriguez, Adela; Carbonell, Miguel A.; Garcia, Lorenzo Garcia

2003-01-01

The use of metallic stents in the management of benign and malignant superior vena cava syndrome (SVCS) is well documented. Symptomatic stenosis or occlusion of the SVC is a rare complication of a transvenous permanent pacemaker implant. Suggested treatments have included anticoagulation therapy, thrombolysis, balloon angioplasty and surgery. More recently, endovascular stenting has evolved as an attractive alternative but the data available in the literature are limited. We describe a case in which venous stenting with a Wallstent endoprosthesis was used successfully. The patient remains symptom free and with normal pacemaker function 36 months later

Enhanced drug delivery capabilities from stents coated with absorbable polymer and crystalline drug.

Science.gov (United States)

Carlyle, Wenda C; McClain, James B; Tzafriri, Abraham R; Bailey, Lynn; Zani, Brett G; Markham, Peter M; Stanley, James R L; Edelman, Elazer R

2012-09-28

Current drug eluting stent (DES) technology is not optimized with regard to the pharmacokinetics of drug delivery. A novel, absorbable-coating sirolimus-eluting stent (AC-SES) was evaluated for its capacity to deliver drug more evenly within the intimal area rather than concentrating drug around the stent struts and for its ability to match coating erosion with drug release. The coating consisted of absorbable poly-lactide-co-glycolic acid (PLGA) and crystalline sirolimus deposited by a dry-powder electrostatic process. The AC-SES demonstrated enhanced drug stability under simulated use conditions and consistent drug delivery balanced with coating erosion in a porcine coronary implant model. The initial drug burst was eliminated and drug release was sustained after implantation. The coating was absorbed within 90 days. Following implantation into porcine coronary arteries the AC-SES coating is distributed in the surrounding intimal tissue over the course of several weeks. Computational modeling of drug delivery characteristics demonstrates how distributed coating optimizes the load of drug immediately around each stent strut and extends drug delivery between stent struts. The result was a highly efficient arterial uptake of drug with superior performance to a clinical bare metal stent (BMS). Neointimal thickness (0.17±0.07 mm vs. 0.28±0.11 mm) and area percent stenosis (22±9% vs. 35±12%) were significantly reduced (pstent implantation in an overlap configuration in porcine coronary arteries. Inflammation was significantly reduced in the AC-SES compared to the BMS at both 30 and 90 days after implantation. Biocompatible, rapidly absorbable stent coatings enable the matching of drug release with coating erosion and provide for the controlled migration of coating material into tissue to reduce vicissitudes in drug tissue levels, optimizing efficacy and reducing potential toxicity. Copyright © 2012 Elsevier B.V. All rights reserved.

Hemobilia into a metallic biliary stent due to pseudoaneurysm. A case report

International Nuclear Information System (INIS)

Morishita, Naoki; Nishida, Tsutomu; Hayashi, Yoshito

2013-01-01

A 48-year-old man with locally advanced pancreatic cancer underwent combined treatment with gemcitabine and proton radiation therapy. Because of subsequent obstruction of the common bile duct, a metallic biliary stent was placed and he received further gemcitabine chemotherapy. During chemotherapy, he developed an acute abdomen with a sudden-onset of tarry stool and jaundice. Gastroduodenoscopy revealed hemobilia from the biliary metallic stent. Contrast-enhanced abdominal computed tomography revealed the presence of a pseudoaneurysm arising from the right hepatic artery adjacent to the top of the stent. Hemostasis of the right hepatic artery pseudoaneurysm was achieved via transcatheter arterial embolization using cyanoacrylate. (author)

An approach to tracheostomy in a patient with an expandable metallic tracheal stent.

Science.gov (United States)

Madden, Brendan P; Sheth, Abhijat

2005-09-01

With increasing use of expandable metallic stents to manage patients with a variety of endobronchial pathologies, some will have a subsequent need for tracheostomy insertion. We describe a successful technique to insert a tracheostomy using rigid and fibre-optic bronchoscopy in a patient who had an 8 cm expandable metallic tracheal stent deployed previously on account of tracheomalacia.

Retrograde Colonic Stent Implantation Assisted by Percutaneous Colostomy: A Case Report

Energy Technology Data Exchange (ETDEWEB)

Lim, Hyoung Gun; Han, Hyun Young; Chun, Tong Jin [Eulji Medical Center, Seoul (Korea, Republic of)

2009-10-15

We present a patient with disseminated pancreatic cancer who presented with symptoms of acute obstruction of the sigmoid colon. It was not possible to pass the region of the obstruction with a guide wire under colonoscopy and fluoroscopy. Consequently retrograde implantation of stents was performed successfully with the assistance of a minimally-sized colostomy when compared with a previously described procedure in the literature.

Retrograde Colonic Stent Implantation Assisted by Percutaneous Colostomy: A Case Report

International Nuclear Information System (INIS)

Lim, Hyoung Gun; Han, Hyun Young; Chun, Tong Jin

2009-01-01

We present a patient with disseminated pancreatic cancer who presented with symptoms of acute obstruction of the sigmoid colon. It was not possible to pass the region of the obstruction with a guide wire under colonoscopy and fluoroscopy. Consequently retrograde implantation of stents was performed successfully with the assistance of a minimally-sized colostomy when compared with a previously described procedure in the literature

Cost-effectiveness of drug-eluting stents versus bare-metal stents in patients undergoing percutaneous coronary intervention

OpenAIRE

Baschet, Louise; Bourguignon, Sandrine; Marque, S?bastien; Durand-Zaleski, Isabelle; Teiger, Emmanuel; Wilquin, Fanny; Levesque, Karine

2016-01-01

Objective To determine the cost-effectiveness of drug-eluting stents (DES) compared with bare-metal stents (BMS) in patients requiring a percutaneous coronary intervention in France, using a recent meta-analysis including second-generation DES. Methods A cost-effectiveness analysis was performed in the French National Health Insurance setting. Effectiveness settings were taken from a meta-analysis of 117?762 patient-years with 76 randomised trials. The main effectiveness criterion was major c...

Second generation drug-eluting stents versus bare-metal stents for percutaneous coronary intervention of the proximal left anterior descending artery

DEFF Research Database (Denmark)

Mangione, Fernanda Marinho; Biering-Sørensen, Tor; Nochioka, Kotaro

2017-01-01

OBJECTIVES: To compare mid-term outcomes between patients undergoing proximal left anterior descending artery (LAD) percutaneous coronary intervention (PCI) with second generation drug-eluting stent (DES) or bare-metal stent (BMS). BACKGROUND: PCI with BMS and first-generation DES have shown to b...

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)

Expandable metallic stent: experimental and clinical experience in tracheobronchial tree

Energy Technology Data Exchange (ETDEWEB)

Song, Ho Young; Lee, Sang Young; Chung, Jin Young; Han, Young Min; Kim, Jong Soo; Choi, Ki Chul; Hong, Ki Whan; Rhee, Yang Kun [Chonbuk National University Medical School, Jeonju (Korea, Republic of)

1991-05-15

To maintain or reestablish an adequate airway in a patient with tracheobronchial narrowing coming from various causes, we constructed self-expanding metallic stents the same way Gianturco did, using them in 2 patients after an experimental study with rabbits. Twenty stents (10mm in diameter fully expanded and 20mm in length) were introduced into the trachea or bronchi of 10 Newzealand rabbits (weight, 2.5-3.0kg) through a 8.5 French Teflon sheath. No difficulties were encountered in the placement of the stents. At follow-up (4-12 weeks), no stent showed migration. Three rabbits died of pneumonia or bronchial perforation. Histologically, mucosal inflammation was noted at the sites of stent placement, and stent wires were covered by proliferated epithelium with intact cilia. During the last 4 months, 2 stents were used in 2 patients, one in a patient with endobronchial tuberculosis (3.0cm in length and 1.0cm in diameter fully expanded) and the other (3.0cm in length and 1.5cm in diameter) in a patient with a subglottic mass. In both patients the stents were successfully placed. Just after the placement of the stents dyspnea subsided in both patients, and there was no mortality or morbidity. These stents seem to be effective in the treatment of tracheobronchial stenosis, tracheomalacia, and airway collapse following tracheal reconstruction.

Expandable metallic stent: experimental and clinical experience in tracheobronchial tree

International Nuclear Information System (INIS)

Song, Ho Young; Lee, Sang Young; Chung, Jin Young; Han, Young Min; Kim, Jong Soo; Choi, Ki Chul; Hong, Ki Whan; Rhee, Yang Kun

1991-01-01

To maintain or reestablish an adequate airway in a patient with tracheobronchial narrowing coming from various causes, we constructed self-expanding metallic stents the same way Gianturco did, using them in 2 patients after an experimental study with rabbits. Twenty stents (10mm in diameter fully expanded and 20mm in length) were introduced into the trachea or bronchi of 10 Newzealand rabbits (weight, 2.5-3.0kg) through a 8.5 French Teflon sheath. No difficulties were encountered in the placement of the stents. At follow-up (4-12 weeks), no stent showed migration. Three rabbits died of pneumonia or bronchial perforation. Histologically, mucosal inflammation was noted at the sites of stent placement, and stent wires were covered by proliferated epithelium with intact cilia. During the last 4 months, 2 stents were used in 2 patients, one in a patient with endobronchial tuberculosis (3.0cm in length and 1.0cm in diameter fully expanded) and the other (3.0cm in length and 1.5cm in diameter) in a patient with a subglottic mass. In both patients the stents were successfully placed. Just after the placement of the stents dyspnea subsided in both patients, and there was no mortality or morbidity. These stents seem to be effective in the treatment of tracheobronchial stenosis, tracheomalacia, and airway collapse following tracheal reconstruction

Broken Esophageal Stent Successfully Treated by Interventional Radiology Technique

International Nuclear Information System (INIS)

Zelenak, Kamil; Mistuna, Dusan; Lucan, Jaroslav; Polacek, Hubert

2010-01-01

Esophageal stent fractures occur quite rarely. A 61-year-old male patient was previously treated for rupture of benign stenosis, occurring after dilatation, by implanting an esophageal stent. However, a year after implantation, the patient suffered from dysphagia caused by the broken esophageal stent. He was treated with the interventional radiology technique, whereby a second implantation of the esophageal stent was carried out quite successfully.

Clinical outcomes with drug-eluting and bare-metal stents in patients with ST-segment elevation myocardial infarction

DEFF Research Database (Denmark)

Palmerini, Tullio; Biondi-Zoccai, Giuseppe; Della Riva, Diego

2013-01-01

The authors investigated the relative safety and efficacy of different drug-eluting stents (DES) and bare metal stents (BMS) in patients with ST-segment elevation myocardial infarction (STEMI) using a network meta-analysis.......The authors investigated the relative safety and efficacy of different drug-eluting stents (DES) and bare metal stents (BMS) in patients with ST-segment elevation myocardial infarction (STEMI) using a network meta-analysis....

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)

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

Utility of MR cholangiography for follow-up examination after metallic stent placement in the bile duct

Energy Technology Data Exchange (ETDEWEB)

Park, Chul Hi; Yang, Dal Mo; Kim Hak Soo; Cho, Seung Whi; Kim, Hyung Sik; Jin Wook; Hwang, Hee Young [Gachon Medical College Gil Medical Center, Incheon (Korea, Republic of)

2002-09-01

To evaluate the efficacy of MR cholangiography for follow-up examination after metallic stent placement in the bile duct. Between December 1999 and June 2000, 15 patients with biliary obstruction in whom metallic biliary stents had been placed underwent MR cholangiography during follow-up examination. The causes of obstruction were hilar cholangiocarcinoma (n=6), common bile duct cancer (n=5), gall bladder cancer (n=1) and pancreatic cancer (m=3). The types of self-expandable metallic stent employed were the nitinol stent (n=2), the endocoil nitinol stent (n=3), the ultraflexed diamond stent (n=5), and the wallstent (n=5). Using MR cholangiography, we measured the diameter of that part of the biliary stent which showed high signal intensity, assigning one point if this was less than one third of the stent diameter, two points of between one third and two thirds, and three points if more than two thirds. We decided that a higher score indicated fewer artifacts. The score was 1.7-3 (mean, 2.3) points for the endocoil nitinol stent, 1.7-2.3 (mean, 2) for the nitinol stent, and 1-3 (mean, 1.7) for the ultraflex diamond stent. In most cases, two thirds of the stent diameter was observed. For the wallstent, the score was 1-1.7 (mean, 1.3) points and the inner portion of the stent was almost invisible. MR cholangiography is not useful for follow-up examination after the placement of wallstents and three other types of nitinol stent in the bile duct.

Self-expanding oesophageal metal stents for the palliation of dysphagia due to extrinsic compression

Energy Technology Data Exchange (ETDEWEB)

Gupta, N.K.; Boylan, C.E.; Razzaq, R.; England, R.E.; Mirra, L.; Martin, D.F. [Dept. of Radiology, South Manchester University Hospitals NHS Trust, Withington Hospital (United Kingdom)

1999-07-01

The role of self-expanding metallic stents is well established in the palliation of oesophageal stenosis and dysphagia due to primary oesophageal malignancy. However, their role in palliation of dysphagia due to external compressive mediastinal malignancies is not well established. The purpose of this study was to assess the efficacy of self-expanding metallic stents in the palliation of dysphagia due to extrinsic oesophageal compression by mediastinal malignancy. Between January 1995 and January 1998, 21 patients with oesophageal compression due to malignant mediastinal tumours underwent oesophageal stent placement for palliation of dysphagia. Complete data were available in 17 patients (10 men and 7 women). The mean age was 63.5 years (range 46-89 years). A total of 19 stents were placed successfully. The dysphagia grade prior to and after oesophageal stent placement was assessed and the complications documented. Of the 17 patients, 16 reported an improvement in dysphagia. The mean dysphagia score improved from 3.1 prior to treatment to 1.3 after treatment. In 1 patient the stent slipped during placement and another stent was placed satisfactorily. Early complications (within 48 h) in the form of mild to moderate retrosternal chest pain occurred in 5 patients. This was treated symptomatically. Late complications (after 48 h) in the form of bolus impaction occurred in 2 patients. This was successfully treated with oesophagoscopy and removal of bolus. In 2 patients the stent was overgrown by tumour and in one of these an additional stent was placed. In 1 patient incomplete closure of a tracheo-oesophageal fistula was observed. There was no procedure- or stent-related mortality. The mean survival time of this group was 2.1 months. Self-expanding metallic stents can be safely and effectively used in the palliation of dysphagia due to external mediastinal malignancies. (orig.)

Self-expanding oesophageal metal stents for the palliation of dysphagia due to extrinsic compression

International Nuclear Information System (INIS)

Gupta, N.K.; Boylan, C.E.; Razzaq, R.; England, R.E.; Mirra, L.; Martin, D.F.

1999-01-01

The role of self-expanding metallic stents is well established in the palliation of oesophageal stenosis and dysphagia due to primary oesophageal malignancy. However, their role in palliation of dysphagia due to external compressive mediastinal malignancies is not well established. The purpose of this study was to assess the efficacy of self-expanding metallic stents in the palliation of dysphagia due to extrinsic oesophageal compression by mediastinal malignancy. Between January 1995 and January 1998, 21 patients with oesophageal compression due to malignant mediastinal tumours underwent oesophageal stent placement for palliation of dysphagia. Complete data were available in 17 patients (10 men and 7 women). The mean age was 63.5 years (range 46-89 years). A total of 19 stents were placed successfully. The dysphagia grade prior to and after oesophageal stent placement was assessed and the complications documented. Of the 17 patients, 16 reported an improvement in dysphagia. The mean dysphagia score improved from 3.1 prior to treatment to 1.3 after treatment. In 1 patient the stent slipped during placement and another stent was placed satisfactorily. Early complications (within 48 h) in the form of mild to moderate retrosternal chest pain occurred in 5 patients. This was treated symptomatically. Late complications (after 48 h) in the form of bolus impaction occurred in 2 patients. This was successfully treated with oesophagoscopy and removal of bolus. In 2 patients the stent was overgrown by tumour and in one of these an additional stent was placed. In 1 patient incomplete closure of a tracheo-oesophageal fistula was observed. There was no procedure- or stent-related mortality. The mean survival time of this group was 2.1 months. Self-expanding metallic stents can be safely and effectively used in the palliation of dysphagia due to external mediastinal malignancies. (orig.)

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.

Science.gov (United States)

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...

Frequency of Angina Pectoris After Percutaneous Coronary Intervention and the Effect of Metallic Stent Type.

Science.gov (United States)

Gaglia, Michael A; Torguson, Rebecca; Lipinski, Michael J; Gai, Jiaxiang; Koifman, Edward; Kiramijyan, Sarkis; Negi, Smita; Rogers, Toby; Steinvil, Arie; Suddath, William O; Satler, Lowell F; Pichard, Augusto D; Waksman, Ron

2016-02-15

Although metallic coronary stents significantly reduce angina pectoris compared with optimal medical therapy, angina after percutaneous coronary intervention (PCI) remains frequent. We, therefore, sought to compare the incidence of any angina during the 1 year after PCI among the spectrum of commercially available metallic stents. Metallic stent type was classified as bare metal stent, Cypher, Taxus Express, Xience V, Promus Element, and Resolute. The primary end point was patient-reported angina within 1 year of PCI. Multivariable logistic regression was performed to assess the independent association of stent type with any angina at 1 year. Overall, 8,804 patients were queried in regard to angina symptoms; 32.3% experienced angina at some point in the first year after PCI. Major adverse cardiovascular events, a composite of all-cause mortality, target vessel revascularization, and Q-wave myocardial infarction, increased with angina severity: 6.8% for patients without angina, 10.0% for patients with class 1 or 2 angina, and 19.7% for patients with class 3 or 4 angina (p angina at 1 year after PCI. Baseline Canadian Cardiovascular Society class 3 or 4 angina, history of coronary artery bypass grafting, and history of PCI were associated with a higher likelihood of angina at 1 year; increasing age, male gender, presentation with acute coronary syndrome, and higher stented length were associated with less angina. In conclusion, metallic stent type is not associated with the occurrence of angina at up to 1 year after PCI. Copyright © 2016 Elsevier Inc. All rights reserved.

Tracheal Self-Expandable Metallic Stents: A Comparative Study of Three Different Stents in a Rabbit Model.

Science.gov (United States)

Serrano, Carolina; Lostalé, Fernando; Rodríguez-Panadero, Francisco; Blas, Ignacio de; Laborda, Alicia; de Gregorio, Miguel Angel

2016-03-01

The objective of this study was to assess tracheal reactivity after the deployment of different self-expandable metal stents (SEMS). Forty female New Zealand rabbits were divided into four groups. Three groups received three different SEMS: steel (ST), nitinol (NiTi), or nitinol drug-eluting stent (DES); the fourth group was the control group (no stent). Stents were deployed percutaneously under fluoroscopic guidance. Animals were assessed by multi-slice, computed tomography (CT) scans, and tracheas were collected for anatomical pathology (AP) study. Data from CT and AP were statistically analyzed and correlated. The DES group had the longest stenosis (20.51±14.08mm vs. 5.84±12.43 and 6.57±6.54mm in NiTi and ST, respectively, day 30; Pstent. CT was more effective in detecting wall thickening (positive correlation of 68.9%; Pstent, while DES caused significant lesions that may be related to drug dosage. This type of DES stent is therefore not recommended for the treatment of tracheobronchial stenosis. Copyright © 2015 SEPAR. Published by Elsevier Espana. All rights reserved.