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Sample records for bare metal stent

  1. Biolimus-eluting stents with biodegradable polymer versus bare-metal stents in acute myocardial infarction

    DEFF Research Database (Denmark)

    Räber, Lorenz; Kelbæk, Henning; Taniwaki, Masanori

    2014-01-01

    BACKGROUND: This study sought to determine whether the 1-year differences in major adverse cardiac event between a stent eluting biolimus from a biodegradable polymer and bare-metal stents (BMSs) in the COMFORTABLE trial (Comparison of Biolimus Eluted From an Erodible Stent Coating With Bare Meta...... to improve cardiovascular events compared with BMS beyond 1 year. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NTC00962416....

  2. Bare Metal Stenting for Endovascular Exclusion of Aortic Arch Thrombi

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    Mahnken, Andreas H., E-mail: mahnken@med.uni-marburg.de [University Hospital Giessen and Marburg, Philipps University of Marburg, Department of Diagnostic Radiology (Germany); Hoffman, Andras; Autschbach, Ruediger; Damberg, Anneke L. M., E-mail: anneke.damberg@rwth-aachen.de [University Hospital RWTH Aachen, Department of Thoracic, Cardiac and Vascular Surgery (Germany)

    2013-08-01

    BackgroundAortic thrombi in the ascending aorta or aortic arch are rare but are associated with a relevant risk of major stroke or distal embolization. Although stent grafting is commonly used as a treatment option in the descending aorta, only a few case reports discuss stenting of the aortic arch for the treatment of a thrombus. The use of bare metal stents in this setting has not yet been described.MethodsWe report two cases of ascending and aortic arch thrombus that were treated by covering the thrombus with an uncovered stent. Both procedures were performed under local anesthesia via a femoral approach. A femoral cutdown was used in one case, and a total percutaneous insertion was possible in the second case.ResultsBoth procedures were successfully performed without any periprocedural complications. Postoperative recovery was uneventful. In both cases, no late complications or recurrent embolization occurred at midterm follow-up, and control CT angiography at 1 respectively 10 months revealed no stent migration, freely perfused supra-aortic branches, and no thrombus recurrence.ConclusionTreating symptomatic thrombi in the ascending aorta or aortic arch with a bare metal stent is feasible. This technique could constitute a minimally invasive alternative to a surgical intervention or complex endovascular therapy with fenestrated or branched stent grafts.

  3. Intravascular ultrasound assessed incomplete stent apposition and stent fracture in stent thrombosis after bare metal versus drug-eluting stent treatment the Nordic Intravascular Ultrasound Study (NIVUS)

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  4. 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.

  5. 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.

  6. Stent thrombosis, myocardial infarction, and death after drug-eluting and bare-metal stent coronary interventions

    DEFF Research Database (Denmark)

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

    2007-01-01

    OBJECTIVES: The aim of the study was to examine outcomes subsequent to implantation of drug-eluting stents (DES) and bare-metal stents (BMS). BACKGROUND: Use of DES might be associated with increased risk of stent thrombosis (ST), myocardial infarction (MI), and death. METHODS: From January 2002 ...

  7. Stent malapposition, as a potential mechanism of very late stent thrombosis after bare-metal stent implantation: A case report

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

    2014-04-15

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

  8. Clinical utility of platinum chromium bare-metal stents in coronary heart disease

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    Jorge C

    2015-08-01

    Full Text Available Claudia Jorge,1 Christophe Dubois1,2 1Department of Cardiovascular Medicine, University Hospitals Leuven, 2Department of Cardiovascular Sciences, Katholieke Universiteit Leuven, Leuven, Belgium Abstract: Coronary stents represent a key development for the treatment of obstructive coronary artery disease since the introduction of percutaneous coronary intervention. While drug-eluting stents gained wide acceptance in contemporary percutaneous coronary intervention practice, further developments in bare-metal stents remain crucial for patients who are not candidates for drug-eluting stents, or to improve metallic platforms for drug elution. Initially, stent platforms used biologically inert stainless steel, restricting stent performance due to limitations in flexibility and strut thickness. Later, cobalt chromium stent alloys outperformed steel as the material of choice for stents, allowing latest generation stents to be designed with significantly thinner struts, while maintaining corrosion resistance and radial strength. Most recently, the introduction of the platinum chromium alloy refined stent architecture with thin struts, high radial strength, conformability, and improved radiopacity. This review will provide an overview of the novel platinum chromium bare-metal stent platforms available for coronary intervention. Mechanical properties, clinical utility, and device limitations will be summarized and put into perspective. Keywords: bare metal stent, coronary stent alloys, coronary artery disease

  9. Comparison of Bare metal Vs Drug eluting stents for in-stent Restenosis among Diabetics

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    Kakhaber Etsadashvili

    2011-06-01

    Full Text Available Background: Diabetes mellitus is associated with an increased risk of restenosis, stent thrombosis, and death afterpercutaneous coronary interventions. Little is known about the late outcome of patients with diabetes mellitus whoreceive drug-eluting stents (DES or bare metal stents (BMS.Methods: From January 2008 to January 2010, six patients with DES and 20 with BMS, ISR were identified at ourinstitution.Results: The median age of our diabetic cohort was 63 years, and 87 of the patients were male. For two years, ratesof repeat target-vessel revascularization were significantly lower among diabetic patients treated with DEScompared with those treated with BMS (5.8% vs. 17.0%, p=0.003.Conclusions: DES is effective among diabetic patients in substantially reducing the need for repeat TVR.

  10. The Integrity bare-metal stent made by continuous sinusoid technology.

    Science.gov (United States)

    Turco, Mark A

    2011-05-01

    The Integrity Coronary Stent System (Medtronic Vascular, CA, USA) is a low-profile, open-cell, cobalt-chromium-alloy advanced bare-metal iteration of the well-known Driver/Micro-Driver Coronary Stent System (Medtronic Vascular). The Integrity stent is made with a process called continuous sinusoid technology. This process allows stent construction via wrapping a single thin strand of wire around a mandrel in a sinusoid configuration, with laser fusion of adjacent crowns. The wire-forming process and fusion pattern provide the stent with a continuous preferential bending plane, intended to allow easier access to, and smoother tracking within, distal and tortuous vessels while radial strength is maintained. Continuous sinusoid technology represents innovation in the design of stent platforms and will provide a future stent platform for newer technology, including drug-eluting stent platforms, drug-filled stents and core wire stents.

  11. 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 safe...

  12. 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...

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

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    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.

  14. Successful treatment of coronary artery pseudoaneurysm by graft stent, which developed after the implantation of bare metal stent

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    Utku Şenol

    2013-03-01

    Full Text Available Although coronary artery pseudoaneurysm which couldoccur following percutaneous coronary interventions is arare complication, it can be mortal. As soon as the pseudoaneurysmis diagnosed, it should be treated by percutaneousintervention or surgery. Graft stent implantationis a preferred treatment for appropriate patients. In thiscase report, we presented a successful treatment of coronaryartery pseudoaneurysm by graft stent; which developedafter the implantation of bare metal stent into theleft anterior descending coronary artery. J Clin Exp Invest2013; 4 (1: 126-129Key words: Coronary artery, pseudoaneurysm, graft stent

  15. 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....

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

    DEFF Research Database (Denmark)

    Valgimigli, Marco; Sabaté, Manel; Kaiser, Christoph

    2014-01-01

    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-chromium......OBJECTIVES: To examine the safety and effectiveness of cobalt-chromium everolimus eluting stents compared with bare metal stents. DESIGN: 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. DATA SOURCES AND STUDY SELECTION: Medline, Embase, the Cochrane Central Register of Controlled Trials. Randomised controlled trials that compared cobalt-chromium everolimus...

  17. Spectral Analysis Related to Bare-Metal and Drug-Eluting Coronary Stent Implantation

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

    2014-08-15

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

  18. Spectral Analysis Related to Bare-Metal and Drug-Eluting Coronary Stent Implantation

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    Rose Mary Ferreira Lisboa da Silva

    2014-08-01

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

  19. Efficacy and safety of drug-eluting stent implantation for the treatment of in-stent restenosis occurring within bare-metal stent and drug-eluting stent*

    OpenAIRE

    Ge, Heng; Zhang, Qing; Zhou, Wei; He, Qing; Han, Zhi-hua; He, Ben

    2010-01-01

    Objective: Although drug-eluting stent (DES) implantation is the primary treatment modality for bare-metal stent (BMS) in-stent restenosis (ISR), little is known about the efficacy and safety profile of DES in the treatment of DES-ISR. The goal of this study was to compare the clinical outcomes following DES treatment for BMS-ISR and DES-ISR. Methods: Rates of major adverse cardiac events (MACE) were compared in 97 consecutive patients who underwent DES implantation for the treatment of ISR (...

  20. 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)....

  1. Very late bare-metal stent thrombosis, rare but stormy!

    LENUS (Irish Health Repository)

    Ali, Mohammed

    2011-08-01

    Recurrent in-stent thrombosis is rarely reported, with catastrophic clinical consequences of either acute coronary syndrome or death. We present a case of recurrent in-stent thrombosis with its outcome and a concise literature review.

  2. Intravascular ultrasound assessment of very late bare-metal stent thrombosis: a case report

    Institute of Scientific and Technical Information of China (English)

    Ji Hyun Lee; Kyung Min Kim; Jun Won Lee; Sung Gyun Ahn; Young Jin Youn

    2012-01-01

    Very late stent thrombosis (VLST) is increasingly being regarded as a complication of drug-eluting stents (DES),and delayed endothelization,local hypersensitivity reactions,and late stent malapposition due to excessive positive remodeling have been postulated as mechanisms.Considering that stent endothelialization seems to be completed within 4 weeks following bare-metal stent (BMS) placement and that BMS do not possess antiproliferative coating,the mechanism of VLST may differ between patients with DES and those with BMS.We report a case of VLST 9 years after BMS implantation,in which thrombus from the ruptured neointima was confirmed by intravascular ultrasound.This finding suggests that de novo plaque rupture at the neointimal layer within the stent may be one of the explanations for VLST.

  3. Lesion length impacts long term outcomes of drug-eluting stents and bare metal stents differently.

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    Shang-Hung Chang

    Full Text Available BACKGROUND: Long lesions have been associated with adverse outcomes in percutaneous coronary interventions with bare metal stents (BMS. However, the exact impact of lesion length on the short- and long-term outcomes of drug-eluting stent (DES implantations is not as clear. METHODS AND RESULTS: This study compared the impact of lesion length on angiographic and clinical outcomes of BMS and DES in a single-center prospective registry. Lesion length was divided into tertiles. The primary endpoints were angiographically defined binary in-stent restenosis (ISR rate and major adverse cardiac event (MACE. Of the 4,312 de novo lesions in 3,447 consecutive patients in the CAPTAIN registry, 2,791 lesions (of 2,246 patients received BMS, and the remaining 1,521 lesions (of 1,201 patients received DES. The mean follow-up duration was 4.5 years. The longer the lesion, the higher the ISR rate (14%, 18%, and 29%, p<0.001 and the lower the MACE-free survivals (p = 0.007 in the BMS group. However, lesion length showed no such correlation with ISR rates (4.7%, 3.3%, and 7.8%, p = 0.67 or MACE-free survivals (p = 0.19 in the DES group. CONCLUSIONS: In our single-center prospective registry, lesion length defined in tertiles has no impact on the short-term (ISR or long-term (MACE outcomes of patients implanted with DES. In contrast, longer lesion correlates with higher ISR and MACE rates in BMS group.

  4. Bare metal or drug-eluting stent implantation in last remaining vessel PCI? A serious dilemma.

    Science.gov (United States)

    Zhang, Lei; Zhu, Jianhua; Kiemeneij, Ferdinand

    2009-04-01

    This case report describes the treatment of an old male diabetic patient with last remaining vessel coronary artery disease and poor left ventricular function. In presence of an old occlusion of the left main coronary artery, a subtotal stenosis of a dominant right coronary artery required angioplasty. After ample consideration it was decided to implant a bare metal stent (BMS) instead of a drug-eluting stent (DES). The major reason was the fear for early discontinuation of clopidogrel in case a drug-eluting stent was placed. The procedure and follow-up are described followed by an overview of current literature concerning similar pathology.

  5. The Development of Coronary Artery Stents: From Bare-Metal to Bio-Resorbable Types

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    Ming-Yun Ho

    2016-07-01

    Full Text Available Coronary artery disease is the leading cause of death worldwide. Conventional balloon angioplasty is associated with high rates of complications such as coronary dissection and vessel recoil. The deployment of bare-metal stents (BMSs can overcome these problems and achieve a better patency rate than simple balloon angioplasty. It has been shown that the stent design including structure platform, size, length, and strut thickness has a major influence on the clinical results. Even though angioplasty with BMS implantation is widely used in coronary interventions, the restenosis rate due to neointimal hyperplasia remains high. Therefore, drug-eluting stents (DESs coated with anti-proliferative agents and polymers have been developed to reduce the restenosis rate and improve the clinical outcomes. Although the repeat revascularization rate of DESs is lower than that of BMSs, the long-term stent thrombosis rate is higher than for BMSs. Therefore, new and emerging generations of stents, in which, for example, thinner struts and bioresorbable polymers are used, are available for clinical use. However, there are only a limited number of clinical trials, in which these newer stents have been compared with BMSs and first- and second-generation DESs. The purpose of this review was to provide up-to-date information on the evolution of coronary artery stents from BMSs to DESs to bioresorbable stents (BRSs.

  6. Comparison of neointimal morphology of in-stent restenosis with sirolimus-eluting stents versus bare metal stents: virtual histology-intravascular ultrasound analysis.

    Science.gov (United States)

    Yamamoto, Yoshihiro; Otani, Hajime; Iwasaka, Junji; Park, Haengnam; Sakuma, Takao; Kamihata, Hiroshi; Iwasaka, Toshiji

    2011-09-01

    Sirolimus-eluting stents (SES) have reduced the incidence of restenosis and target lesion revascularization compared to bare metal stents (BMS). However, inhibition of endothelialization and neointimal formation after SES implantation may produce vulnerable plaques. The present study compared the neointimal morphology of in-stent restenosis (ISR) between SES and BMS using virtual histology-intravascular ultrasound (VH-IVUS). Thirty ISR lesions (SES n = 15, BMS n = 15) demonstrated by coronary angiography in 30 patients with stable angina pectoris were analyzed with VH-IVUS between 6 months to 3 years after stent implantation. Tissue maps were reconstructed from radiofrequency data using VH-IVUS software. ISR lesions after SES implantation consisted of a significantly increased necrotic core (NC) compared to BMS (12.9 vs. 5.6% of neointimal volume, p stent thrombosis after SES implantation.

  7. 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.

  8. Outcome of overlapping heterogenous drug-eluting stents and of overlapping drug-eluting and bare metal stents.

    Science.gov (United States)

    Burzotta, Francesco; Siviglia, Massimo; Altamura, Luca; Trani, Carlo; Leone, Antonio Maria; Romagnoli, Enrico; Mazzari, Mario Attilio; Mongiardo, Rocco; Niccoli, Giampaolo; Brancati, Marta; Biondi-Zoccai, Giuseppe; Rebuzzi, Antonio Giuseppe; Schiavoni, Giovanni; Crea, Filippo

    2007-02-01

    Overlapping homogenous drug-eluting stents (DESs) may be used instead of overlapping bare metal stents (BMSs) to treat coronary lesions longer than available stents. Yet, no data are available on patients treated with overlapping heterogenous DESs or DESs and BMSs. We prospectively assessed 9-month clinical outcome and 6-month angiographic late loss (evaluated at 5 different lesion segments) in a consecutive series of 40 patients who received overlapping homogenous DESs (sirolimus-eluting stent [SES] or paclitaxel-eluting stent [PES]), heterogenous DESs (SES + PES), or overlapping DESs and BMSs. In 8 patients (7 with angiographic follow-up) with overlapping heterogenous DESs, no angiographic or clinical adverse event was observed. Moreover, in-segment late loss was similar to that of patients who received homogenous DESs. In 8 patients (7 with angiographic follow-up) with overlapping DESs and BMSs, there was a higher incidence of major adverse events (3 repeat percutaneous coronary interventions and 1 death, 50% adverse event rate) and worse in-segment binary restenosis rate compared with patients treated with homogenous or heterogenous DESs (p = 0.02 and 0.012, respectively). Late lumen loss at the site of stent overlap showed significant differences according to type of overlapped stent (1.00 +/- 0.76 mm in DES-BMS overlap, 0.32 +/- 0.55 mm in PES-PES overlap, 0.13 +/- 0.11 in SES-PES overlap, and 0.08 +/- 0.10 mm in SES-SES overlap, p = 0.005). In conclusion, the present study suggests that overlap of DESs and BMSs should be avoided because the antirestenotic effect of DESs is skewed by contiguous BMS implantation. Overlap between SESs and PESs in this very preliminary report was associated with no specific adverse event.

  9. 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 emoti...

  10. Clinical outcome after management of unprotected left main in-stent restenosis after bare metal or drug-eluting stents

    Institute of Scientific and Technical Information of China (English)

    CHEN Shao-liang; QIAN Jun; Kwan Tak W; XU Bo; Gary Mintz; YE Fei; ZHANG Jun-jie; KAN Jing; SUN Xue-wen; ZHANG Ai-ping; CHEN Jin-guo

    2010-01-01

    Background Implantation of either bare metal stent (BMS) or drug-eluting stent (DES) has been used in every day practice for patients with unprotected left main stenosis (UPLMS). There are still a lack of data regading the subsequent results of UPLMS in-stent restenosis (ISR). The present study aimed at determing the clinical outcome of UPLMS ISR patients after implantation of either BMS or DES.Methods Patients with UPLMS ISR after stenting were included. The primary endpoint was the cumulative major adverse cardiac events (MACE), including cardiac death, myocardial infarction (Ml), and target vessel revascularization (TVR).Results UPLMS ISR rate was 14.8% (n=73, 15.7% after BMS, 14.5% for DES) after average of (3.89±2.01) years (range from 1 to 10.5 years) follow-up. Angiographic follow-up between 6-8 months was available in 85.3%. Of these,repeat percutaneous coronary intervention (PCI) was used in 62 (84.9%) patients, with medicine only in 9 (12.4%) and coronary artery bypass graft (CABG) in 2 (2.7%). Most repeat PCI patients were with unstable angina (87.0%), and had decreased left ventricular ejection fraction ((42.58±5.12)%), fewer focal/ostial left circumflex branch (LCX) lesions, in relative to medicine only group. After (31.9±23.3) months, the MACE, Ml, TVR and cardiac death were 31.5%, 1.4%, 24.1% and 8.2%, respectively. Definite and possible stent thrombosis occurred in 1 (1.4%) patient.Conclusions Medical therapy for asymptomatic isolated ostial LCX was safe. Repeat PCI for UPLMS ISR was associated with acceptable early and short-term clinical outcome. Further study was needed to elucidate the role of CABG in treating UPLMS ISR.

  11. Long-Term Outcome After Drug-Eluting Versus Bare-Metal Stent Implantation in Patients With ST-Segment Elevation Myocardial Infarction

    DEFF Research Database (Denmark)

    Holmvang, Lene; Kelbæk, Henning Skov; Kaltoft, Anne

    2013-01-01

    This study sought to compare the long-term effects of drug-eluting stent (DES) compared with bare-metal stent (BMS) implantation in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention.......This study sought to compare the long-term effects of drug-eluting stent (DES) compared with bare-metal stent (BMS) implantation in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention....

  12. Hemocompatibility Improvement of Chromium-Bearing Bare-Metal Stent Platform After Magnetoelectropolishing

    Science.gov (United States)

    Rokicki, Ryszard; Haider, Waseem; Maffi, Shivani Kaushal

    2015-01-01

    Research was undertaken to determine the influence of the increased content of chromium in the outermost passive layer of magneto-electrochemically refined Co-Cr alloy L-605 surface on its hemocompatibility. The chemistry, roughness, surface energy, and wettability of conventionally electropolished (EP) and magnetoelectropolished (MEP) samples were studied with x-ray photoelectron spectroscopy (XPS), open circuit potential, atomic force microscopy, and contact angle meter. In vitro hemocompatibility of tested material surfaces was assessed using two important indicators of vascular responses to biomaterial, namely endothelialization and platelets adhesion. The endothelialization was assessed by seeding and incubating samples with human umbilical vein endothelial cells (HUVEC) for 3 days before counting and observing them under a fluorescent microscope. The platelet (rich plasma blood) adhesion and activation test on EP and MEP L-605 alloy surfaces was assessed using a laser scanning confocal microscope. The XPS analysis of MEP samples showed significant enrichment of the passive layer with Cr and O when compared with the EP one. The amount of other elements in the passive layer did not show a significant difference between EP and MEP treatments. The adhesion of HUVEC cells shows remarkable affinity to surfaces enriched in Cr (MEP) with almost 100% confluency. In addition, the number of platelets that adhered to standard EP surfaces was higher compared to the MEP surface. The present study shows that the chromium-enriched surface of cobalt-chromium alloy L-605 by the magnetoelectropolishing process tremendously improves surface hemocompatibility with regard to stent functionality by enhanced endothelialization and lower platelet adhesion and should be taken under consideration as an alternative surface of biodegradable polymer drug-eluting stents, polymer-free drug-eluting stents as well as bare-metal stents.

  13. A prospective randomized antiplatelet trial of cilostazol versus clopidogrel in patients with bare metal stent

    Institute of Scientific and Technical Information of China (English)

    CHEN Yun-dai; LU Yan-ling; JIN Ze-ning; YUAN Fei; L(U) Shu-zheng

    2006-01-01

    Background Cilostazol is a newly developed antiplatelet drug that has been widely applied for clinical use. Its antiplatelet action appears to be mainly related to inhibition of intracellular phosphodiesterase activity. Recently,cilostazol has been used for antiplatelet therapy after coronary bare metal stent implantation for thrombosis and restenosis prevention. This prospective randomized and double blind trial was designed to investigate the safety and efficacy of cilostazol for the prevention of late restenosis and acute or subacute stent thrombosis.Methods One hundred and twenty patients who underwent elective stent were randomly assigned to treatment group with cilostazol 200 mg/d (n = 60), clopidogrel 75 mg/d and aspirin 100 mg/d or to control group with clopidogrel treatment 75 mg/d (n = 60) and aspirin 100 mg/d. Follow-up coronary angiography was performed 6-9 months later.Results Nine months major adverse cardio-cerebral event (MACCE) were lower in treatment groups (P<0.05).The quantitative coronary angiography (QCA) at 6 months follow-up showed that minimum lumen diameter(MLD) was higher in treatment group than that of control group [(2.14±0.52)mm vs (1.82 ±0.36)mm, P<0.05].Late lumen loss (LL) [(0.82 ± 0.42)mm vs (1.31 ± 0.58)mm; P<0.01 ], restenosis rate (RR) (14% vs 32%; P<0.05)and target lesion revascularizaion (TLR) rate (5% vs 17%; P<0.05) were lower in treatment group than in control group.Conclusion Cilostazol therapy is an effective regimen for prevention not only stent thrombosis but also RR and TLR through reducing MLD without the risk of increasing bleeding.

  14. 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...... with routine prestenting have never been reported. Methods: Consecutive patients who underwent PPVI for homograft dysfunction with prestenting with BMS were studied. The schedule of follow-up assessment comprised clinical evaluation, cardiovascular magnetic resonance, transthoracic echocardiography, and chest...... X-ray to screen for device integrity. Results: PPVI was performed with no serious complications in all patients (n = 10, mean age 26.8 ± 4.0 years, 60% males). In nine patients with significant pulmonary stenosis, peak right ventricular outflow tract (RVOT) gradient was reduced from a mean of 80...

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    Aims: The use of drug-eluting stents (DES) in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) is controversial and not yet endorsed in clinical guidelines. Methods and results: This was an a priori planned post hoc analysis involving 754 NSTE-ACS patients from the random...

  16. Mid-Term Follow-Up of Drug-Eluting Stenting for In-Stent Restenosis: Bare-Metal Stents versus Drug- Eluting Stents

    Directory of Open Access Journals (Sweden)

    Negar Faramarzi

    2015-10-01

    Full Text Available Background: Despite major advances in percutaneous coronary intervention (PCI, in-stent restenosis (ISR remains a therapeutic challenge. We sought to compare the mid-term clinical outcomes after treatment with repeat drug-eluting stent (DES implantation (“DES sandwich” technique with DES placement in the bare-metal stent (DES-in-BMS in a "real world" setting.Methods: We retrospectively identified and analyzed clinical and angiographic data on 194 patients previously treated with the DES who underwent repeat PCI for ISR with a DES or a BMS. ISR was defined, by visual assessment, as a luminal stenosis greater than 50% within the stent or within 5 mm of its edges. We recorded the occurrence of major adverse cardiac events (MACE, defined as cardiac death, non-fatal myocardial infarction, and the need for target vessel revascularization (TVR.Results: Of the 194 study participants, 130 were men (67.0% and the mean ± SD of age was 57.0 ± 10.4 years, ranging from37 to 80 years. In-hospital events (death and Q-wave myocardial infarction occurred at a similar frequency in both groups. Outcomes at twelve months were also similar between the groups with cumulative clinical MACE at one-year follow-up of 9.6% and 11.3% in the DES-in-BMS and the DES-in-DES groups, respectively (p value = 0.702. Although not significant, there was a trend toward a higher TVR rate in the intra-DES ISR group as compared to the intra-BMS ISR group (0.9% BMS vs. 5.2% DES; p value = 0.16.Conclusion: Our study suggests that the outcome of the patients presenting with ISR did not seem to be different between the two groups of DES-in-DES and DES-in-BMS at one-year follow-up, except for a trend toward more frequent TVR in the DES-in-DES group. Repeat DES implantation for DES restenosis could be feasible and safe with a relatively low incidence of MACE at mid-term follow-up.

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

    Science.gov (United States)

    Baschet, Louise; Bourguignon, Sandrine; Marque, Sébastien; 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 cardiac event-free survival. Effectiveness and costs were modelled over a 5-year horizon using a three-state Markov model. Incremental cost-effectiveness ratios and a cost-effectiveness acceptability curve were calculated for a range of thresholds for willingness to pay per year without major cardiac event gain. Deterministic and probabilistic sensitivity analyses were performed. Results Base case results demonstrated that DES are dominant over BMS, with an increase in event-free survival and a cost-reduction of €184, primarily due to a diminution of second revascularisations, and an absence of myocardial infarction and stent thrombosis. These results are robust for uncertainty on one-way deterministic and probabilistic sensitivity analyses. Using a cost-effectiveness threshold of €7000 per major cardiac event-free year gained, DES has a >95% probability of being cost-effective versus BMS. Conclusions Following DES price decrease, new-generation DES development and taking into account recent meta-analyses results, the DES can now be considered cost-effective regardless of selective indication in France, according to European recommendations. PMID:27621830

  18. Microvascular Coronary Flow Comparison in Acute Myocardial Infarction Angioplasty treated with a mesh covered stent (MGUARD Stent) versus Bare Metal Stent

    Energy Technology Data Exchange (ETDEWEB)

    Lindefjeld, Dante S., E-mail: dslindef@puc.cl [Hospital Clínico, Pontificia Universidad Católica de Chile (Chile); Hospital Dr. Sótero del Río, Santiago-Chile (Chile); Guarda, Eduardo [Hospital Clínico, Pontificia Universidad Católica de Chile (Chile); Méndez, Manuel [Hospital Clínico, Pontificia Universidad Católica de Chile (Chile); Hospital Dr. Sótero del Río, Santiago-Chile (Chile); Martínez, Alejandro [Hospital Clínico, Pontificia Universidad Católica de Chile (Chile); Pérez, Osvaldo [Hospital Clínico, Pontificia Universidad Católica de Chile (Chile); Hospital Dr. Sótero del Río, Santiago-Chile (Chile); Fajuri, Alejandro; Marchant, Eugenio [Hospital Clínico, Pontificia Universidad Católica de Chile (Chile); Aninat, Mauricio; Torres, Humberto [Hospital Dr. Gustavo Fricke, Viña del Mar-Chile (Chile); Dussaillant, Gastón [Hospital Clínico Universidad de Chile, Santiago-Chile (Chile)

    2013-01-15

    Background: Distal embolization of thrombus/platelet aggregates decreases myocardial reperfusion during primary percutaneous coronary intervention (PCI), and is associated with worse immediate and long-term prognosis of patients with ST-elevation myocardial infarction (STEMI). Objective: Assess the efficacy of a mesh covered stent (MGuard™ stent, MGS) in preventing distal embolization and microvascular reperfusion impairment during primary PCI, compared with a bare metal stent (BMS). Methods: Forty patients with STEMI referred for primary PCI were randomized for stenting the culprit lesion with the MGS (n = 20) or a BMS (n = 20). Blinded experts performed off-line measurements of angiographic epicardial and microvascular reperfusion criteria: TIMI flow grade, myocardial blush, corrected TIMI frame count (cTFC). Results: At baseline clinical, angiographic and procedural variables were not different between groups. Post PCI TIMI flow grade was similar in both groups. We observed better myocardial Blush grade in group MGS compared to BMS (median value 3.0 vs 2.5, 2p = 0.006) and cTFC (mean cTFC: MGS 19.65 ± 4.07 vs BMS 27.35 ± 7.15, 2p < 0.001, cTFC mean difference MGS-BMS: 7.7, CI 95%: 3.94 to 11.46). MGS stent group had a higher percentage of successful angioplasty (cTFC ≤ 23: MGS 85% vs BMS 30%, 2p < 0.001). We had two cases of acute stent thrombosis (one for each group) at 30 days follow up, but no clinical events at 6 months follow up. Conclusions: In this exploratory study, MGS significantly improved microvascular reperfusion criteria compared with a BMS in primary PCI. However its safety and impact on clinical outcomes should be verified in larger randomized clinical trials.

  19. Improved outcomes of elderly patients treated with drug-eluting versus bare metal stents in large coronary arteries

    DEFF Research Database (Denmark)

    Kurz, David J; Bernheim, Alain M; Tüller, David

    2015-01-01

    BACKGROUND: Drug-eluting stents (DES) improve outcomes in elderly patients with small coronary artery disease compared with bare-metal stents (BMS), but randomized data in elderly patients in need of large coronary stents are not available. METHODS: Planned secondary analysis of patients ≥75 years...... recruited to the "BASKET-PROVE" trial, in which 2,314 patients undergoing percutaneous coronary intervention for large (≥3.0 mm) native vessel disease were randomized 2:1 to DES (everolimus- vs sirolimus-eluting stents 1:1) versus BMS. All patients received 12 months of dual antiplatelet therapy....... The primary end point was a composite of cardiac death or nonfatal myocardial infarction at 2 years. RESULTS: Comparison of DES versus BMS among 405 patients ≥75 years showed significantly lower rates of the primary end point for DES (5.0% vs 11.6%; hazard ration (HR) 0.64 [0.44-0.91]; P = .014). Rates...

  20. Long-term benefits and risks of drug-eluting compared to bare-metal stents in patients with versus without chronic kidney disease

    DEFF Research Database (Denmark)

    Wanitschek, Maria; Pfisterer, Matthias; Hvelplund, Anders;

    2013-01-01

    AIMS: Chronic kidney disease (CKD) is associated with worse outcomes in patients with coronary artery disease (CAD). How CKD influences the benefit-risk balance of drug-eluting stents (DES) versus bare-metal stents (BMS) is less known. METHODS AND RESULTS: In the multicentre BASKET-PROVE trial, 2...

  1. Technical and clinical outcome of transjugular intrahepatic portosystemic stent shunt: Bare metal stents (BMS) versus viatorr stent-grafts (VSG)

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, Christof M., E-mail: cmsommer@gmx.com [Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, INF 110, 69120 Heidelberg (Germany); Gockner, Theresa L.; Stampfl, Ulrike; Bellemann, Nadine [Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, INF 110, 69120 Heidelberg (Germany); Sauer, Peter; Ganten, Tom [Department of Gastroenterology, University Hospital Heidelberg, Heidelberg (Germany); Weitz, Juergen [Department of General, Abdominal and Transplantation Surgery, University Hospital Heidelberg, Heidelberg (Germany); Kauczor, Hans U.; Radeleff, Boris A. [Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, INF 110, 69120 Heidelberg (Germany)

    2012-09-15

    Highlights: ► Twelve month mean number of TIPS revisions per patient was significantly lower in VSG. ► First TIPS revision was performed significantly later in the VSG. ► There was no significant difference of hepatic encephalopathy in both study groups. -- Abstract: Purpose: To compare retrospectively angiographical and clinical results in patients undergoing transjugular intrahepatic portosystemic stent-shunt (TIPS) using BMS or VSG. Materials and methods: From February 2001 to January 2010, 245 patients underwent TIPS. From those, 174 patients matched the inclusion criteria with elective procedures and institutional follow-up. Group (I) consisted of 116 patients (mean age, 57.0 ± 11.1 years) with BMS. Group (II) consisted of 58 patients with VSG (mean age, 53.5 ± 16.1 years). Angiographic and clinical controls were scheduled at 3, 6 and 12 months, followed by clinical controls every 6 months. Primary study goals included hemodynamic success, shunt patency as well as time to and number of revisions. Secondary study goals included clinical success. Results: Hemodynamic success was 92.2% in I and 91.4% in II (n.s.). Primary patency was significantly higher in II compared to I (53.8% after 440.4 ± 474.5 days versus 45.8% after 340.1 ± 413.8 days; p < 0.05). The first TIPS revision was performed significantly later in II compared to I (288.3 ± 334.7 days versus 180.1 ± 307.0 days; p < 0.05). In the first angiographic control, a portosystemic pressure gradient ≥15 mmHg was present in 73.9% in I and in 39.4% in II (p < 0.05). Clinical success was 73.7–86.2% after 466.3 ± 670.1 days in I and 85.7–90.5% after 617.5 ± 642.7 days in II (n.s.). Hepatic encephalopathy was 37.5% in I and 36.5% in II (n.s.). Conclusion: VSG increased primary shunt patency as well as decreased time to and number of TIPS revisions. There was a trend of higher clinical success in VSG without increased hepatic encephalopathy.

  2. Impending rupture of saphenous vein graft aneurysm with floating fractured bare metal stent treated by coil embolization and covered stent implantation.

    Science.gov (United States)

    Kodama, Atsuko; Kurita, Tairo; Kato, Osamu; Suzuki, Takahiko

    2016-11-01

    Aneurysmal degeneration of a saphenous vein graft (SVG) is a rare, but potentially fatal complication of coronary artery bypass graft (CABG) surgery. In this case report, a patient that had undergone prior CABG surgery and bare metal stent (BMS) implantation at the site of a stenotic SVG lesion presented at our hospital with chest pain, and an SVG aneurysm was detected at the previous BMS implantation site. In addition, the implanted BMS was fractured and floating in the SVG aneurysm. The SVG aneurysm was successfully occluded by percutaneous intervention, using a combination of distal covered stent deployment at the site of the anastomosis between the native coronary artery and the SVG and proximal coil embolization of the aneurysm.

  3. Sirolimus-eluting versus bare-metal stent implantation in patients with ostial lesions

    DEFF Research Database (Denmark)

    Jørgensen, Erik; Kelbæk, Henning; Kløvgaard, Lene;

    2010-01-01

    To investigate the efficacy of implantation of sirolimus-eluting stents (SES) in the ostium of coronary arteries.......To investigate the efficacy of implantation of sirolimus-eluting stents (SES) in the ostium of coronary arteries....

  4. Comparison of Bare Metal and Drug-Eluting Stents in Patients with Chronic Kidney Disease (From the NHLBI Dynamic Registry)

    Science.gov (United States)

    Green, Sandy M.; Selzer, Faith; Mulukutla, Suresh R.; Tadajweski, Edward J.; Green, Jamie A.; Wilensky, Robert L.; Laskey, Warren K.; Cohen, Howard A.; Rao, Sunil V.; Weisbord, Steven D.; Lee, Joon S.; Reis, Steven E.; Kip, Kevin E.; Kelsey, Sheryl F.; Williams, David O.; Marroquin, Oscar C.

    2011-01-01

    Patients with chronic kidney disease (CKD) have a disproportionate burden of coronary artery disease and commonly undergo revascularization. The role and safety of percutaneous coronary intervention (PCI) using drug eluting stents (DES) verses bare metal stents (BMS) in CKD patients not on renal replacement therapy has not been fully evaluated. This study investigated the efficacy and safety of DES in patients with CKD not on renal replacement therapy. Patients where drawn from the National Heart, Lung, and Blood Institute Dynamic Registry and were stratified by renal function based on estimated glomerular filtration rate (GFR). Of the 4157 participants, 1108 had CKD (“low-GFR” <60 ml/min/1.73m2), while 3049 patients had normal renal function (“normal-GFR”≥60 ml/min/1.73m2). For each strata of renal function, we compared the risk of death, myocardial infarction (MI), or repeat revascularization between subjects who received DES and BMS at the index procedure. Patients with low-GFR had higher one-year rates of death and MI and a decreased rate of repeat revascularization when compared to patients with a normal-GFR. The use of DES was associated with a decreased need for repeat revascularization in the normal-GFR group (adjusted hazard ratio [HR] 0.63, 95% CI 0.50–0.79, p<0.001) but not in the low-GFR group (HR 0.69, 95% CI 0.45–1.06, p=0.09). The risks of death and MI were not different between the two stents in either patient population. In conclusion, the presence of CKD predicted poor outcomes after PCI with high rates of mortality regardless of stent type. The effect of DES in reducing repeat revascularization appeared to be attenuated in these patients. PMID:21890077

  5. Impact of Age on Long-Term Outcome After Primary Angioplasty With Bare-Metal or Drug-Eluting Stent (From the DESERT Cooperation)

    DEFF Research Database (Denmark)

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

    2013-01-01

    Despite mechanical reperfusion, elderly patients with ST-segment elevation myocardial infarction (STEMI) still experience unsatisfactory outcomes. Drug-eluting stents (DES) have significantly reduced target-vessel revascularization (TVR), but concerns have emerged about the higher risk of late...... stent thrombosis, which may be more pronounced in elderly patients. Therefore, the aim of this study was to evaluate the impact of age on outcome in patients with STEMI who underwent primary angioplasty with bare-metal stents (BMS) or DES. Our population comprised 6,298 patients who underwent primary...

  6. Prospective, multi-center evaluation of a silicon carbide coated cobalt chromium bare metal stent for percutaneous coronary interventions: Two-year results of the ENERGY Registry

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-11-15

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

  7. Sirolimus-eluting stents for treatment of drug-eluting versus bare-metal stents restenosis: 42-month clinical outcomes from a Chinese single center

    Institute of Scientific and Technical Information of China (English)

    YAN Rong-qiang; LIU Hai-bo; WU Yong-jian; YUAN Jin-qing; CHEN Jue; YOU Shi-jie; DAI Jun; GAO Run-lin; CHEN Ji-lin; GAO Li-jian; YANG Yue-jin; LI Jian-jun; QIAO Shu-bin; XU Bo; YAO Min; QIN Xue-wen

    2012-01-01

    Background Restenosis of bare-metal stents (BMS) and drug-eluting stents (DES) has been increasingly treated with sirolimus-eluting stents (SES),but the long-term outcomes are unknown.Methods In our study,388 consecutive patients (144 DES restenosis and 244 BMS restenosis) with 400 lesions (147 DES restenosis and 253 BMS restenosis) treated with SES were included.The rates of target lesion revascularization (TLR) and major adverse cardiac events (MACE) at 42 months were analyzed.Results At the mean follow-up of 42 months,the rates of death (3.5% vs.3.3%,P=1.000) and myocardial infarction (2.8% vs.1.2%,P=0.431) in the DES group and BMS group were comparable.Compared with the BMS group,ischemia-driven TLR occurred with a higher frequency in the DES group (18.8% vs.10.7%,P=0.024).This translated into an increased rate of MACE in the DES group (22.2% vs.14.0%,P=0.034).Stent thrombosis occurred with a similar frequency in both groups (2.8% vs.1.6%,P=0.475).Multivariate analysis showed that DES restenosis (OR=1.907,95%Cl 1.108-3.285,P=0.020) and smoking (OR=2.069; 95% C/ 1.188-3.605; P=0.010) were independent predictors of MACE.Conclusions Although SES implantation appears to be safe and effective,it was associated with higher TLR recurrence for DES than BMS restenosis.

  8. Clinical outcomes of serolimus-eluting stents versus bare metal stents in ST-segment elevation myocardial infarction patients: a meta-analysis

    Institute of Scientific and Technical Information of China (English)

    PAN Xiao-hong; ZHONG Wen-zhao; XIANG Mei-xiang; XU Geng; SHAN Jiang; WANG Jia-nan

    2009-01-01

    Background The benefits and safety of sirolimus-eluting stent (SES) have not been systematically quantified in different trials in ST-segment elevation myocardial infarction (STEMI) patients with primary or rescue percutaneous coronary intervention (PCI). A meta-analysis of randomised trials comparing SES and bare-metal stent (BMS) was performed. Methods A systematic literature search was conducted to identify all randomized clinical trials. The primary outcome was the rate of major adverse cardiac events (MACEs). The secondary outcomes included death, recurrent myocardial infarction, recurrent revascularization, and stent thrombosis. Results Totally, 1973 STEMI patients were enrolled in seven eligible randomized trials comparing SES with BMS. The pooled rate of major adverse cardiac events was significantly lower in the SES group than in the BMS group (9.7% vs 20.3%, OR 2.45, 95% Cl 1.88-3.19, P < 0.00001). No significant difference in all causes of death was found between the SES and BMS groups, as well as in the pooled recurrent myocardial infarction rates. The pooled recurrent revascularization rate was significantly lower in the SES group than in the BMS group (5.1% vs 14.8%, OR 3.30, 95%Cl 2.37-4.60, P < 0.00001). No significant difference was found between the pooled rates of stent thrombosis (1.2% in the SES group and 2.0% in the BMS group, OR 1.61, 95%Cl 0.79-3.26, P=0.19). Conclusions SES is associated with a decreased risk of major adverse cardiac events compared with BMS by thegreater reduction in repeat revascularization in STEMI patients. Larger trials with longer follow up are warranted to betterdefine the role of SES in STEMI.

  9. Transjugular Insertion of Bare-Metal Biliary Stent for the Treatment of Distal Malignant Obstructive Jaundice Complicated by Coagulopathy

    Energy Technology Data Exchange (ETDEWEB)

    Tsauo Jiaywei, E-mail: 80732059@qq.com; Li Xiao, E-mail: simonlixiao@gmail.com; Li Hongcui, E-mail: lihongcui520@126.com; Wei Bo, E-mail: allyooking@tom.com; Luo Xuefeng, E-mail: luobo_913@126.com; Zhang Chunle, E-mail: sugar139000@163.com; Tang Chengwei, E-mail: 20378375@qq.com [West China Hospital of Sichuan University, Department of Gastroenterology and Hepatology (China); Wang Weiping, E-mail: irjournalclub@gmail.com [Section of Interventional Radiology, Cleveland Clinic, Imaging Institute (United States)

    2013-04-15

    This study was designed to investigate retrospectively the feasibility of transjugular insertion of biliary stent (TIBS) for the treatment of distal malignant obstructive jaundice complicated by coagulopathy. Between April 2005 and May 2010, six patients with distal malignant obstructive jaundice associated with coagulopathy that was unable to be corrected underwent TIBS at our institution for the palliation of jaundice. Patients' medical record and imaging results were reviewed to obtain information about demographics, procedure details, complications, and clinical outcomes. The intrahepatic biliary tract was successfully accessed in all six patients via transjugular approach. The procedure was technically successfully in five of six patients, with a bare-metal stent implanted after traversing the biliary strictures. One procedure failed, because the guidewire could not traverse the biliary occlusion. One week after TIBS, the mean serum bilirubin in the five successful cases had decreased from 313 {mu}mol/L (range 203.4-369.3) to 146.2 {mu}mol/L (range 95.8-223.3) and had further decreased to 103.6 {mu}mol/L (range 29.5-240.9) at 1 month after the procedure. No bleeding, sepsis, or other major complications were observed after the procedure. The mean survival of these five patients was 4.5 months (range 1.9-5.8). On imaging follow-up, there was no evidence of stent stenosis or migration, with 100 % primary patency. When the risks of hemorrhage from percutaneous transhepatic cholangiodrainage are high, TIBS may be an effective alternative for the treatment of distal malignant obstructive jaundice.

  10. Patency of paclitaxel-eluting versus bare metal stents long term after implantation in acute ST-segment elevation myocardial infarction.

    Science.gov (United States)

    Vink, Maarten A; Van Nooijen, Ferdinand C; Laarman, Gerrit J; Suttorp, Maarten J; Tijssen, Jan G; Slagboom, Ton; Patterson, Mark S; Van Der Schaaf, Rene J; Kiemeneij, Ferdinand; Amoroso, Giovanni; Dirksen, Maurits T

    2011-11-01

    Drug-eluting stents effectively inhibit neointimal hyperplasia within the first year, thereby reducing the need for repeat revascularization. However, a delayed pattern of restenosis might be more prominent in drug-eluting stents compared to bare metal stents (BMSs). The extent of restenosis of paclitaxel-eluting stents (PESs) long term after implantation in acute ST-segment elevation myocardial infarction is currently unknown. The present study was designed to evaluate very late luminal loss (VLLL) of PESs used in ST-segment elevation myocardial infarction compared to BMSs. A total of 116 patients (61 with PESs and 55 with BMSs) initially included in the Paclitaxel Eluting Stent Versus Conventional Stent in ST-segment Elevation Myocardial Infarction (PASSION) trial and who were free from previous lesion failure underwent angiographic follow-up. Off-line quantitative coronary analysis of the angiogram immediately after stent implantation and at follow-up was performed. The primary end point was VLLL within the stent. The presence of binary restenosis was defined as diameter stenosis >50% as a secondary end point. The mean interval between stent implantation and follow-up was 4.1 ± 0.5 years in both stent groups. In-stent VLLL was 0.12 mm (interquartile range -0.03 to 0.42) in the PES group versus 0.30 mm (interquartile range 0.08 to 0.69) in the BMS group (p = 0.011). In-segment binary restenosis was found in 4 patients (6.6%) with a PES and 6 patients (10.9%) with a BMS (p = 0.40). In conclusion, angiographic follow-up 4 years after implantation in ST-segment elevation myocardial infarction showed that in patients prospectively randomized to PESs or BMSs, VLLL was low in both stent groups. PESs were associated with lower VLLL than BMSs, and the observed rate of binary restenosis was not significantly different between the 2 stent groups.

  11. The Relationship Between Lymphocyte-to-Monocyte Ratio and Bare-Metal Stent In-Stent Restenosis in Patients With Stable Coronary Artery Disease.

    Science.gov (United States)

    Murat, Sani Namik; Yarlioglues, Mikail; Celik, Ibrahim Etem; Kurtul, Alparslan; Duran, Mustafa; Kilic, Alparslan; Oksuz, Fatih

    2017-04-01

    In-stent restenosis (ISR) is a common clinical problem in patients with coronary artery disease treated with percutaneous coronary intervention. Inflammatory process plays a pivotal role in the development of ISR. Both lymphocytes and monocytes are associated with inflammatory status. Recently, it has been shown that the lymphocyte-to-monocyte ratio (LMR) is a novel inflammatory marker. We aimed to investigate the association of serum LMR levels and ISR in patients undergoing bare-metal stent (BMS) implantation. The study included 273 patients (aged 61 ± 11 years, 66.5% men) with a history of BMS implantation and a further control coronary angiography due to stable angina pectoris. Patients were divided into 2 groups: patients with and without ISR. The LMR levels were significantly lower in patients with ISR than in those without ISR (2.50 ± 0.95 vs 3.87 ± 1.51, respectively, P ISR (odds ratio [OR]: 0.310, 95% confidence interval: 0.166-0.579, P ISR in patients treated with BMS implantation.

  12. Newest-generation drug-eluting and bare-metal stents combined with prasugrel-based antiplatelet therapy in large coronary arteries

    DEFF Research Database (Denmark)

    Jeger, Raban; Pfisterer, Matthias; Alber, Hannes

    2012-01-01

    In the BAsel Stent Kosten Effektivitäts Trial PROspective Validation Examination (BASKET-PROVE), drug-eluting stents (DESs) had similar 2-year rates of death and myocardial infarction but lower rates of target vessel revascularization and major adverse cardiac events compared with bare-metal sten...... (BMSs). However, comparative clinical effects of newest-generation DES with biodegradable polymers vs second-generation DES or newest-generation BMS with biocompatible coatings, all combined with a prasugrel-based antiplatelet therapy, on 2-year outcomes are not known....

  13. 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

  14. Sustained Benefit at 2 Years for Covered Stents Versus Bare-Metal Stents in Long SFA Lesions: The VIASTAR Trial

    Energy Technology Data Exchange (ETDEWEB)

    Lammer, Johannes, E-mail: jlammer@gmx.at, E-mail: johannes.lammer@meduniwien.ac.at [Medical University Vienna, The Department of Cardiovascular and Interventional Radiology, Department of Biomedical Imaging and Image-guided Therapy (Austria); Zeller, Thomas, E-mail: thomas.zeller@universitaets-herzzentrum.de [Universitaets-Herzzentrum Freiburg-Bad Krozingen, Department of Angiology (Germany); Hausegger, Klaus A., E-mail: klaus.hausegger@lkh-klu.at [Klinikum Klagenfurt, The Department of Diagnostic and Interventional Radiology (Austria); Schaefer, Philipp J., E-mail: jp.schaefer@rad.uni-kiel.de [University Clinics Schleswig-Holstein, The Department of Radiology (Germany); Gschwendtner, Manfred, E-mail: manfred.gschwendtner@elisabethinen.or.at [Elisabethinen Hospital, The Department of Diagnostic and Interventional Radiology (Austria); Mueller-Huelsbeck, Stefan, E-mail: muehue@diako.de [Diakonissen Hospital, The Department of Diagnostic and Interventional Radiology (Germany); Rand, Thomas, E-mail: thomas.rand@wienkav.at [Hietzing Hospital, The Department of Radiology (Austria); Funovics, Martin, E-mail: martin.funovics@meduniwien.ac.at; Wolf, Florian, E-mail: florian.wolf@meduniwien.ac.at [Medical University Vienna, The Department of Cardiovascular and Interventional Radiology, Department of Biomedical Imaging and Image-guided Therapy (Austria); Rastan, Aljoscha, E-mail: aljoscha.rastan@universitaets-herzzentrum.de [Universitaets-Herzzentrum Freiburg-Bad Krozingen, Department of Angiology (Germany); Gschwandtner, Michael, E-mail: michael.gschwandtner@meduniwien.ac.at [Medical University Vienna, The Department of Angiology (Austria); Puchner, Stefan, E-mail: stefan.puchner@meduniwien.ac.at [Medical University Vienna, The Department of Cardiovascular and Interventional Radiology, Department of Biomedical Imaging and Image-guided Therapy (Austria); and others

    2015-02-15

    PurposeThe hypothesis that covered stents are superior to bare-metal stents (BMS) in long femoropopliteal artery disease was tested. The one-year results of the VIASTAR trial revealed a patency benefit of covered stents in the treatment-per-protocol (TPP) analysis only.MethodsA prospective, randomized, single-blind, multicenter study evaluated 141 patients with symptomatic peripheral arterial disease (PAD) after treatment with heparin-bonded covered stents (VIABAHN{sup ®} Endoprosthesis) or BMS. Clinical outcomes and patency rates were assessed at 1, 6, 12, and 24 months. Mean lesion length was 19.0 ± 6.3 cm in the VIABAHN{sup ®} versus 17.3 ± 6.6 cm in the BMS group.ResultsThe 24-month primary patency rates in the VIABAHN{sup ®} and BMS group were: intention-to-treat 63.1 (95 % CI 0.52–0.76) versus 41.2 % (95 % CI 0.29–0.57; log rank p = 0.04) and TPP 69.4 (95 % CI 0.58–0.83) versus 40.0 % (95 % CI 0.28–0.56; log rank p = 0.004). Freedom from target-lesion-revascularization (TLR) was 79.4 (95 % CI 0.70–0.90) versus 73.0 % (95 % CI 0.63–0.85) for VIABAHN{sup ®} versus BMS (log rank p = 0.37). For the TPP group in lesions ≥20 cm, the 24-month patency rates were 65.2 (95 % CI 0.50–0.85) versus 26.7 % (95 % CI 0.12–0.59; log rank p = 0.004) for VIABAHN{sup ®} versus BMS, and freedom from TLR was 80.0 (95 % CI 0.68–0.94) versus 61.9 % (95 % CI 0.44–0.87; log rank p = 0.13). The ankle brachial index was 0.89 ± 0.18 versus 0.91 ± 0.17 (p = 0.76) at 24-month in the VIABAHN{sup ®} versus the BMS group, respectively.ConclusionAt 24-month, this trial in PAD patients with long femoropopliteal lesions demonstrated a significantly improved primary patency rate for heparin-bonded covered stents compared to BMS, however, without a significant impact on clinical outcomes and TLR rate (Reg. Nr. ISRCTN48164244)

  15. Comparison of bare-metal and drug-eluting stents in patients with chronic kidney disease (from the NHLBI Dynamic Registry).

    Science.gov (United States)

    Green, Sandy M; Selzer, Faith; Mulukutla, Suresh R; Tadajweski, Edward J; Green, Jamie A; Wilensky, Robert L; Laskey, Warren K; Cohen, Howard A; Rao, Sunil V; Weisbord, Steven D; Lee, Joon S; Reis, Steven E; Kip, Kevin E; Kelsey, Sheryl F; Williams, David O; Marroquin, Oscar C

    2011-12-01

    Patients with chronic kidney disease (CKD) have a disproportionate burden of coronary artery disease and commonly undergo revascularization. The role and safety of percutaneous coronary intervention (PCI) using drug-eluting stents (DESs) verses bare-metal stents in patients with CKD not on renal replacement therapy has not been fully evaluated. This study investigated the efficacy and safety of DES in patients with CKD not on renal replacement therapy. Patients were drawn from the National Heart, Lung, and Blood Institute Dynamic Registry and were stratified by renal function based on estimated glomerular filtration rate (GFR). Of the 4,157 participants, 1,108 had CKD ("low GFR" <60 ml/min/1.73 m(2)), whereas 3,049 patients had normal renal function ("normal GFR" ≥60 ml/min/1.73 m(2)). For each stratum of renal function we compared risk of death, myocardial infarction, or repeat revascularization between subjects who received DESs and bare-metal stents at the index procedure. Patients with low GFR had higher 1-year rates of death and myocardial infarction and a decreased rate of repeat revascularization compared to patients with normal GFR. Use of DESs was associated with a decreased need for repeat revascularization in the normal-GFR group (adjusted hazard ratio 0.63, 95% confidence interval 0.50 to 0.79, p <0.001) but not in the low-GFR group (hazard ratio 0.69, 95% confidence interval 0.45 to 1.06, p = 0.09). Risks of death and myocardial infarction were not different between the 2 stents in either patient population. In conclusion, presence of CKD predicted poor outcomes after PCI with high rates of mortality regardless of stent type. The effect of DES in decreasing repeat revascularization appeared to be attenuated in these patients.

  16. 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.

  17. Impact of the metabolic syndrome on angiographic and clinical events after coronary intervention using bare-metal or sirolimus-eluting stents.

    Science.gov (United States)

    Hoffmann, Rainer; Stellbrink, Ekaterina; Schröder, Jörg; Grawe, Armin; Vogel, Gunter; Blindt, Rüdiger; Kelm, Malte; Radke, Peter W

    2007-11-01

    Patients with metabolic syndrome (MS) are at increased risk for cardiovascular events. Although the number of patients with MS requiring coronary revascularization is increasing rapidly, the impact of MS on clinical events and restenosis in patients who undergo stent placement is not well defined. Seven hundred thirty-four consecutive patients with 734 de novo coronary lesions ( or =3 of the following criteria: obesity, hypertension, hypertriglyceridemia, low high-density lipoprotein cholesterol, and increased fasting glucose). Clinical follow-up was performed for > or =1 year (mean 27.5 +/- 18.1 months). One hundred sixty-four patients (22%) had DM, 180 patients (25%) had MS without DM, and 390 patients (53%) had no MS and no DM. Baseline clinical and angiographic parameters were comparable among the 3 groups, including lesion length and reference vessel diameter. In patients treated with bare-metal stents, the rates of major adverse cardiac events (MACEs) at 12 months were 14% in patients without DM or MS, 18% in those with MS but no DM, and 33% in those with DM (p = 0.046). In patients treated with sirolimus-eluting stents, the MACE rates were 3% in patients without DM or MS, 4% in those with MS, and 13% in those with DM (p = 0.034). DM (odds ratio 2.14, 95% confidence interval 1.48 to 3.07, p <0.001) and bare-metal stent (odds ratio 2.51, 95% confidence interval 1.49 to 4.22, p <0.001) implantation were independent predictors of MACEs during follow-up, whereas MS was not predictive. Similarly, MS was not a predictor of target lesion revascularization. In conclusion, patients with MS did not have an increased risk for target lesion revascularization or a greater MACE rate compared with control patients during a 12 month follow-up period after bare-metal or drug-eluting stent placement. In contrast, DM is associated with significantly increased event rates.

  18. Paclitaxel and sirolimus eluting stents versus bare metal stents: long-term risk of stent thrombosis and other outcomes. From the Western Denmark Heart Registry

    DEFF Research Database (Denmark)

    Jensen, Lisette Okkels; Tilsted, Hans Henrik; Thayssen, Per;

    2010-01-01

    AND RESULTS: All patients who underwent PES, SES or BMS implantation from January 2002 to June 2005 were identified in the population-based Western Denmark Heart Registry. All were followed for 36 months. Cox regression analysis was used to estimate relative risk (RR), controlling for covariates. A total...... (adjusted RR: 0.71, 95% CI: 0.63-0.81). CONCLUSIONS: An increased risk of very late definite stent thrombosis was observed in DES-treated patients compared with BMS-treated patients, but a similar mortality was detected. TLR continued to be lower among patients receiving DES....

  19. Long-term outcome of patients of over 85 years old with acute coronary syndrome undergoing percutaneous coronary stenting: a comparison of bare metal stent and drug eluting stent

    Institute of Scientific and Technical Information of China (English)

    MA Han-ying; ZHOU Yu-jie; Ronald J Dick; SHI Dong-mei; LIU Yu-yang; CHENG Wan-jun; GUO Yong-he; WANG Jian-long; GE Hai-long

    2008-01-01

    Background Patients aged over 85 years have been under-represented in percutaneous coronary intervention (PCI)trials despite an increase in referrals for PCI. The long-term safety and efficacy of percutaneous coronary stenting in patients aged over 85 years with acute coronary syndrome (ACS) remain unclear. Moreover it is unknown whether there are differences between bare metal stent (BMS) and drug eluting stent (DES) in this special population.Methods A total of 80 patients with ACS aged over 85 years undergoing stenting (BMS group n=21 vs DES group n=59)were retrospectively studied. In-hospital, one year and overall clinical follow-up (12-36 months) of major adverse cardiac events (MACEs) including cardiac deaths, myocardial infarction, target lesion revascularization (TLR) and target vessel revascularization (TVR) as well as stroke and other major bleeding were compared between the two groups.Results In the entire cohort, the procedure success rate was 93.8% with TIMI-3 coronary flow post-PCI in 93.8% of the vessels and the procedure related complication was 17.5%. The incidence of in-hospital MACEs in BMS group was higher (14.3% vs 6.8%, P=0.30). The 1-year incidence of MACEs in DES group was 7.0% while there was no MACE in the BMS group. Clinical follow-up for 12-36 months showed that the overall survival free from MACE was 82.9% and the incidence of MACE in the BMS group was lower (5.3% vs 21.1%, P=0.20). Multivariate regression analysis showed that the creatinine level (OR:1.013; 95%C1: 1.006-1.020; P=0.004) and hypertension (OR:3.201; 95%C1: 1.000-10.663;P=0.04) are two major factors affecting the long-term MACE.Conclusions Percutaneous coronary stenting in patients aged over 85 years is safe and provides good short and long-term efficacy. Patients with renal dysfunction and hypertension may have a relatively high incidence of MACE.

  20. Two-year clinical outcome after successful implantation of drug-eluting and bare metal stents in diabetic patients: results from a real-world single center registry

    Institute of Scientific and Technical Information of China (English)

    DOU Ke-fei; XU Bo; YANG Yue-jin; CHEN Ji-lin; QIAO Shu-bin; LI Jian-jun; QIN Xue-wen; LIU Hai-bo; WU Yong-jian; CHEN Jue; YAO Min; YOU Shi-jie; YUAN Jin-qing; DAI Jun; GAO Run-lin

    2009-01-01

    Background Drug-eluting stents (DES) have revolutionized the field of interventional cardiology by dramatically improving clinical and angiographic outcomes. Patients with diabetes mellitus (DM) are associated with an increased risk of adverse clinical outcomes after a percutaneous coronary intervention (PCI). Available information on the efficacy and safety of DES and bare metal stent (BMS) in diabetic patients remains scarce.Methods From April 2004 to October 2006, 1565 patients with diabetes, who successfully underwent elective stenting at Fu Wai Hospital in Beijing, China, were enrolled in this study. All enrolled patients were assigned to a drug eluting stent group and a bare metal stent group. We obtained follow-up data: death, myocardial infarction (MI), thrombus, target lesion revascularization (TLR), and target vessel revascularization (TVR) at 30 days and 12 and 24 months, as defined by the Academic Research Consortium (ARC). We calculated and compared all the unadjusted cumulative frequencies of the various adverse events in the two groups. Cox's proportional-hazards models adjusted with the propensity score were used to assess the relative risks of all the outcome measures at 24 months.Results At 24 months, all ARC defined stent thrombosis in the two groups were similar; at 30 days, a more definite thrombosis was found in the BES group (0.08% vs 0.81%, P=0.016). Patients treated with DES showed a significant lower risk of TLR (3.88% vs 10.89%; hazard ratio (HR) 0.159 (95% CI: 0.151-0.444), P<0.001), TVR (5.48% vs 11.69%; HR 0.383 (95% CI: 0.232-0.633), P <0.001), and any revascularization (12.47% vs 18.55%; HR 0.555 (95% CI: 0.370-0.831), P=0.0004) at 24 months. No significant difference was apparent in terms of all-cause mortality, MI, and all-cause mortality/MI.Conclusions In contemporary society's large, diabetic population, the use of DES is associated with long-term significant reductions in the risks of TLR, TVR, and any revascularization. There

  1. 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)....

  2. Drug-eluting or bare-metal stents for large coronary vessel stenting? The BASKET-PROVE (PROspective Validation Examination) trial: Study protocol and design

    DEFF Research Database (Denmark)

    Pfisterer, M.; Bertel, O.; Bonetti, P.O.;

    2008-01-01

    Background Based on a subgroup analysis of 18-month BAsel Stent Kosten Effektivitats Trial (BASKET) outcome data, we hypothesized that very late (>12 months) stent thrombosis occurs predominantly after drug-eluting stent implantation in large native coronary vessel stenting. Methods To prove...... stent use in patients with large native vessel stenting. The 2-year death/myocardial infarction-as well as target vessel revascularization-and bleeding rates in these patients with a first-versus second-generation drug-eluting stent should demonstrate the benefit or harm of these stents compared...

  3. Does intravascular ultrasound provide clinical benefits for percutaneous coronary intervention with bare-metal stent implantation? A meta-analysis of randomized controlled trials

    Directory of Open Access Journals (Sweden)

    Lodi-Junqueira Lucas

    2012-09-01

    Full Text Available Abstract Background The role of intravascular ultrasound (IVUS in percutaneous coronary interventions (PCI is still controversial despite several previously published meta-analyses. A meta-analysis to evaluate the controversial role of IVUS-guided PCI with bare-metal stenting was performed and a previous published meta-analysis was re-evaluated in order to clarify the discrepancy between results of these studies. Methods A systematic review was performed by an electronic search of the PubMed, Embase and Web of Knowledge databases and by a manual search of reference lists for randomized controlled trials published until April 2011, with clinical outcomes and, at least, six months of clinical follow-up. A meta-analysis based on the intention to treat was performed with the selected studies. Results Five studies and 1,754 patients were included. There were no differences in death (OR = 1.86; 95% CI = 0.88-3.95; p = 0.10, non-fatal myocardial infarction (OR = 0.65; 95% CI = 0.27-1.58; p = 0.35 and major adverse cardiac events (OR = 0.74; 95% CI = 0.49-1.13; p = 0.16. An analysis of the previous published meta-analysis strongly suggested the presence of publication bias. Conclusions There is no evidence to recommend routine IVUS-guided PCI with bare-metal stent implantation. This may be explained by the paucity and heterogeneity of the studies published so far.

  4. Influence of a pressure gradient distal to implanted bare-metal stent on in-stent restenosis after percutaneous coronary intervention

    DEFF Research Database (Denmark)

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

    2007-01-01

    BACKGROUND: Fractional flow reserve predicts cardiac events after coronary stent implantation. The aim of the present study was to assess the 9-month angiographic in-stent restenosis rate in the setting of optimal stenting and a persisting gradient distal to the stent as assessed by a pressure wire...... performed in the target vessel: (1) P(d)/P(a) as distal to the artery as possible (fractional flow reserve per definition); (2) P(d)/P(a) just distal to the stent; (3) P(d)/P(a) just proximal to the stent; and (4) P(d)/P(a) at the ostium. Residual abnormal P(d)/P(a) was defined as a pressure drop between P......(d)/P(a) measured at points 1 and 2. Fractional flow reserve distal to the artery after stenting was significantly lower (0.88+/-0.21 versus 0.97+/-0.05; P

  5. Usefulness of Drug-Eluting Balloons for Bare-Metal and Drug-Eluting In-Stent Restenosis (from the RIBS IV and V Randomized Trials).

    Science.gov (United States)

    Alfonso, Fernando; Pérez-Vizcayno, María José; García Del Blanco, Bruno; García-Touchard, Arturo; López-Mínguez, José-Ramón; Sabaté, Manel; Zueco, Javier; Melgares, Rafael; Hernández, Rosana; Moreno, Raul; Domínguez, Antonio; Sanchís, Juan; Moris, Cesar; Moreu, José; Cequier, Angel; Romaguera, Rafael; Rivero, Fernando; Cuesta, Javier; Gonzalo, Nieves; Jiménez-Quevedo, Pilar; Cárdenas, Alberto; Fernández, Cristina

    2017-01-05

    Treatment of patients with drug-eluting stent (DES) in-stent restenosis (ISR) is particularly challenging. We sought to compare results of drug-eluting balloons in patients with DES-ISR with those in patients with bare-metal stent (BMS) ISR. A pooled analysis of the Restenosis Intra-Stent: Drug-Eluting Balloon versus Everolimus-Eluting Stent IV and V randomized trials was performed. Both trials had identical inclusion and exclusion criteria. Results of drug-eluting balloons in 95 patients with BMS-ISR and 154 patients with DES-ISR were compared. Patients with DES-ISR were more frequently diabetics, presented more often as an acute coronary syndrome and had more severe lesions and more frequently a focal pattern, including edge-ISR. Late angiographic findings (92% of eligible patients), including minimal lumen diameter (1.80 ± 0.6 vs 2.01 ± 0.6 mm, p = 0.001; absolute mean difference 0.21 mm; 95% confidence interval 0.04 to 0.38; p = 0.014) and restenosis rate (19% vs 9.5%, p ISR. Results were consistent across 10 prespecified subgroups. Moreover, on multiple linear regression analysis, minimal lumen diameter at follow-up remained significantly smaller in patients with DES-ISR after adjusting for potential confounders (adjusted absolute mean difference 0.17 mm; 95% confidence interval 0.04 to 0.41; p = 0.019). Finally, at 1-year clinical follow-up (100% of patients), rates of target vessel revascularization (16% vs 6%, p = 0.02) and of the main combined clinical end point (18% vs 8%, p = 0.03) were significantly higher in patients treated for DES-ISR. In conclusion, this study confirms the efficacy of DEB for patients with ISR. However, the long-term clinical and angiographic results of DEB are poorer in patients with DES-ISR than in those with BMS-ISR. (ClinicalTrials.govIdentifier:NCT01239953&NCT01239940).

  6. 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

    Energy Technology Data Exchange (ETDEWEB)

    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, E-mail: ron.waksman@medstar.net

    2014-04-15

    Objective: 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). Background: Neoatherosclerosis in neointima has been reported in BMS and in DES. Methods: Thirty patients with 36 stented lesions [BMS (n = 17) or DES (n = 19)] > 3 years after implantation were prospectively enrolled. OCT and VH-IVUS were performed and analyzed independently. Stents with ≥ 70% diameter stenosis were excluded. Results: The median duration from implantation was 126.0 months in the BMS group and 60.0 months in the DES group (p < 0.001). Lipid-laden intima (58.8% vs. 42.1%, p = 0.317), thrombus (17.6% vs. 5.3%, p = 0.326), and calcification (35.3% vs. 26.3%, p = 0.559) did not show significant differences between BMS and DES. When divided into 3 time periods, the cumulative incidence of lipid-laden neointima from > 3 years to < 9 years was similar between BMS and DES (42.9% vs. 42.1%, p = 1.000). Furthermore, it continued to gradually increase over time in both groups. OCT-derived thin-cap fibroatheroma (TCFA) was observed in 17.6% of BMS- and 5.3% of DES-treated lesions (p = 0.326). No 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. Conclusion: At long-term follow-up beyond 3 years after implantation, the intra-stent neointimal tissue characteristics appeared similar for both BMS and DES.

  7. Ultra-thin strut cobalt chromium bare metal stent usage in a complex real-world setting. (SOLSTICE Registry)

    NARCIS (Netherlands)

    Suttorp, M. J.; Stella, P. R.; Dens, J.; McKenzie, J. M.; Park, K. S.; Frambach, P.

    2015-01-01

    Aim To report clinical follow-up at 6 months after implantation of the ultra-thin strut cobalt chromiumSolarFlex stent in a real-world setting. Methods and results Patients (n=240) with single or multiple vessel coronary artery disease undergoing percutaneous coronary intervention (PCI) at four site

  8. Usefulness of preprocedure high-sensitivity C-reactive protein to predict death, recurrent myocardial infarction, and stent thrombosis according to stent type in patients with ST-segment elevation myocardial infarction randomized to bare metal or drug-eluting stenting during primary percutaneous

    DEFF Research Database (Denmark)

    Schoos, Mikkel Malby; Kelbæk, Henning; Kofoed, Klaus F;

    2011-01-01

    It is unknown whether high-sensitivity C-reactive protein (hs-CRP) predicts outcome depending on implanted stent type. We investigated the prognostic value of hs-CRP in relation to type of stent implanted in patients with ST-segment elevation myocardial infarction (STEMI). Immediately before...... primary percutaneous coronary intervention (pPCI), 301 patients had blood drawn. Patients were categorized according to hs-CRP levels and combination of hs-CRP (≤2 vs >2 mg/L) and stent type (bare metal stent [BMS] vs drug-eluting stent [DES]). Hs-CRP >2 mg/L (median, hazard ratio 2.7, 95% confidence...... type. Survival analysis demonstrated significant differences for occurrence of death and MI: 4.8% in BMS + CRP ≤2 mg/L, 11.9% in DES + CRP ≤2 mg/L, 17.6% in DES + CRP >2 mg/L, and 27.9% in BMS + CRP >2 mg/L. None of the 14 stent thromboses occurred in patients with BMS + CRP ≤2 mg/L. In conclusion...

  9. One year cost effectiveness of sirolimus eluting stents compared with bare metal stents in the treatment of single native de novo coronary lesions: an analysis from the RAVEL trial

    Science.gov (United States)

    van Hout, B A; Serruys, P W; Lemos, P A; van den Brand, M J B M; Es, G-A van; Lindeboom, W K; Morice, M-C

    2005-01-01

    Objective: To assess the balance between costs and effects of the sirolimus eluting stent in the treatment of single native de novo coronary lesions in the RAVEL (randomised study with the sirolimus eluting Bx Velocity balloon expandable stent in the treatment of patients with de novo native coronary artery lesions) study. Design: Multicentre, double blind, randomised trial Setting: Percutaneous coronary intervention for single de novo coronary lesions Patients: 238 patients with stable or unstable angina. Interventions: Randomisation to sirolimus eluting stent or bare stent implantation. Main outcome measures: Patients were followed up to one year and the treatment effects were expressed as one year survival free of major adverse cardiac events (MACE). Costs were estimated as the product of resource utilisation and Dutch unit costs. Results: At one year, the absolute difference in MACE-free survival was 23% in favour of the sirolimus eluting stent group. At the index procedure, sirolimus eluting stent implantation had an estimated additional procedural cost of €1286. At one year, however, the estimated additional cost difference had decreased to €54 because of the reduction in the need for repeat revascularisations in the sirolimus group (0.8% v 23.6%; p < 0.01). After adjustment of actual results for the consequences of angiographic follow up (correction based on data from the BENESTENT (Belgium Netherlands stent) II study), the difference in MACE-free survival was estimated at 11.1% and the additional one year costs at €166. Conclusions: The one year data from RAVEL suggest an attractive balance between costs and effects for sirolimus eluting stents in the treatment of single native de novo coronary lesions. The cost effectiveness of drug eluting stents in more complex lesion subsets remains to be determined. PMID:15772214

  10. Firebird sirolimus eluting stent versus bare mental stent in patients with ST-segment elevation myocardial infarction

    Institute of Scientific and Technical Information of China (English)

    GAO Hai; YAN Hong-bing; ZHU Xiao-ling; LI Nan; AI Hui; WANG Jian; LI Shi-ying; YANG Duo

    2007-01-01

    Background There are few evidences about the value of drug eluting stent in patients with ST-segment elevation myocardial infarction (STEMI). We prospectively designed a randomized controlled trial to compare the safety and efficacy of Firebird sirolimus eluting stent (Firebird stent) and bare metal stent (BMS).Methods Patients with STEMI enrolled during one year period were randomized to undergo implantation of Firebird stent or BMS, and clinical and angiographic follow-up. The primary endpoint of the present study was in-lesion late lumen loss (LLL) at 6 months, and secondary endpoint includes stent thrombosis and major adverse cardiac events (MACE) at 6 months.Results During one year period, 156 patients were randomized into the Firebird stent group (101 patients with an average age of 57.8 years) or the BMS group (55 patients with 59.7 years on average). Six-month angiographic follow-up was available in 66.3% and 63.7% of patients assigned to Firebird stent and BMS, respectively. At 6-month follow-up,mortality, target vessel revascularization (TVR) and MACE were 2.0%, 6.9% and 9.9% in the Firebird stent group, while 3.6%, 30.9% and 36.4% in the BMS group (P<0.05). Subacute thrombosis occurred in 1 patient in both groups,respectively. The mean LLL was 0.18 mm in the Firebird stent group versus 0.72 mm in the BMS group.Conclusion Implantation of Firebird sirolimus eluting stent for STEMI may greatly reduce TVR and MACE at 6 months with low incidence of acute/subacute stent thrombosis compared with BMS.

  11. Construction of Transjugular Intrahepatic Portosystemic Shunt: Bare Metal Stent/Stent-graft Combination versus Single Stent-graft, a Prospective Randomized Controlled Study with Long-term Patency and Clinical Analysis

    Directory of Open Access Journals (Sweden)

    Chang-Ming Wang

    2016-01-01

    Conclusions: The construction of a TIPS with either the single stent-graft or BMS/stent-graft combination is effective for controlling variceal bleeding. The BMS/stent-graft combination technique is superior to the stent-graft technique in terms of hepatic function preservation indicated by the Child-Pugh score. However, considering the clinical results of the TIPS, the two techniques are comparable in their primary shunt patency, incidence of encephalopathy and patient survival during the long-term follow-up.

  12. Drug-eluting versus bare metal stents in patients with st-segment-elevation myocardial infarction: eight-month follow-up in the Drug Elution and Distal Protection in Acute Myocardial Infarction (DEDICATION) trial

    DEFF Research Database (Denmark)

    Kelbaek, Henning; Thuesen, Leif; Helqvist, Steffen

    2008-01-01

    BACKGROUND: Implantation of drug-eluting stents (DES) limits the rate of coronary restenosis in most patients with coronary artery disease, but data are scarce with regard to their use in patients with ST-segment-elevation myocardial infarction and in connection with distal protection of the micr......BACKGROUND: Implantation of drug-eluting stents (DES) limits the rate of coronary restenosis in most patients with coronary artery disease, but data are scarce with regard to their use in patients with ST-segment-elevation myocardial infarction and in connection with distal protection...... of the microvascular perfusion during primary percutaneous coronary intervention. METHODS AND RESULTS: We randomly assigned 626 patients referred within 12 hours from symptom onset of an ST-elevation myocardial infarction to have a DES or a bare metal stent implanted in the infarct-related lesion with or without...... distal protection during primary percutaneous coronary intervention. Quantitative coronary angiography was performed during the index treatment and 8 months later. The primary end point was loss of the lumen diameter in the infarct-related lesion induced by neointimal proliferation. Patients were...

  13. TAXUS VI 2-year follow-up: randomized comparison of polymer-based paclitaxel-eluting with bare metal stents for treatment of long, complex lesions

    DEFF Research Database (Denmark)

    Grube, Eberhard; Dawkins, Keith D; Guagliumi, Giulio;

    2007-01-01

    AIMS: Drug-eluting stents (DESs) have shown to be effective in reducing in-stent restenosis, although data relating to long-term experience in treating more complex lesion subsets are limited. In order to assess the long-term safety and clinical efficacy of the polymer-based moderate release (MR)...

  14. Expressão gênica de adiponectina no tecido adiposo epicárdico após intervenção coronária percutânea com implante de stent metálico Adiponectin expression in epicardial adipose tissue after percutaneous coronary intervention with bare-metal stent

    Directory of Open Access Journals (Sweden)

    Roberta França Spener

    2011-09-01

    intracoronary bare-metal stent (BMS, could promote inflammatory changes in the periadvential fat, contributing to vascular restenosis. OBJECTIVE: We sought to determine gene expression of inflammatory mediator in pericardial adipose tissue after bare-metal stent implantation and vascular restenosis that had been referred to operative treatment. METHODS: Paired samples of PAT were harvested at the time of elective coronary artery bypass surgery (CABG in 11 patients (n=22, one sample was obtained of the tissue around BMS area and another sample around coronary artery without stent. Local expression of adiponectin was determined by real-time polymerase chain reaction (RT-PCR using Taq DNA polymerase. RESULTS: In two samples, there was no gene expression of adiponectin. We are able to identify adiponectin in 20 samples, however, the pattern of gene expression were heterogeneous.We did not notice specificity when we compared PAT obtained near BMS area or far from BMS area. CONCLUSION: There were no correlation between adiponectin gene expression and presence of BMS

  15. Radial forces of stents used in thoracic endovascular aortic repair and bare self-expanding nitinol stents measured ex vivo - Rapid rescue for obstruction of the innominate artery using bare self-expanding nitinol stents.

    Science.gov (United States)

    Matsumoto, Takuya; Inoue, Kentaro; Tanaka, Shinichi; Aoyagi, Yukihiko; Matsubara, Yutaka; Matsuda, Daisuke; Yoshiya, Keiji; Yoshiga, Ryosuke; Ohkusa, Tomoko; Maehara, Yoshihiko

    2017-02-01

    Purpose Our objective was to compare the radial forces of several stents ex vivo to identify stents suitable for rescue of the unexpected coverage of aortic arch branches in thoracic endovascular aortic repair. Methods We measured the radial forces of two types of self-expanding bare nitinol stents (E-luminexx and Epic) used singly or as double-walled pairs, and of three endoprostheses used in thoracic endovascular aortic repair (TEVAR, Gore c-TAG, Relay, and Valiant) by compressing the stent using an MTS Instron universal testing machine (model #5582). We also examined the compressive effects of the TEVAR endoprostheses and the bare nitinol stents on each other. Results The radial force was greater in the center than at the edge of each stent. In all stents tested, the radial force decreased incrementally with increasing stent diameter. The radial force at the center was two times greater when using two stents than with a single stent. In the compression test, only E-luminexx used as a pair was not compressed after compressing a Relay endoprosthesis by 12 mm. Conclusion Two E-luminexx stents are appropriate to restore the blood flow if a TEVAR endoprosthesis covers the innominate artery following innominate-carotid-left subclavian arterial bypass.

  16. Treatment of splenic artery aneurysm with double overlapping bare stents: case report

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Hyo Sung; Han, Young Min; Jin, Gong Yong [School of Medicine, Chonbuk National Univ., Chonju (Korea, Republic of)

    2004-09-01

    The traditional treatment of splenic artery aneurysm (SAA) is generally surgery and/or transcatheter arterial embolization, but recently, the treatment of SAA using a stent graft has been reported. However, the acute angle of the celiac axis, as well as the tortuous path of the splenic artery makes the use of stent graft difficult for treatment of aneurysma. We report here a case of SAA treated with the technique of double overlapping metallic stents.

  17. Fabrication of nonbiofouling metal stent and in vitro studies on its hemocompatibility.

    Science.gov (United States)

    Wang, Xiaobo; Miao, Jingjing; Zhao, Haolin; Mao, Chun; Chen, Xiaoqiang; Shen, Jian

    2014-07-01

    In recent years, there has been increasing interest for the surface modification of biomaterials in order to improve their surface properties. The bare metal stents surface based on 3-dimethyl(methacryloyloxyethyl)ammonium propane sulfonate polymers has shown an excellent antifouling and blood compatibility by using surface-initiated atom transfer radical polymerization. Surface structure, morphology, wettability, and element content were characterized by scanning electronic microscope, static water contact angles measurement, X-ray photoelectron spectroscopy measurement, respectively. The results showed zwitterionic brushes were successfully fabricated on bare metal stents. The blood compatibility of bare metal stents before and after modification was evaluated by platelet adhesion tests, hemolysis assay, morphological changes of red blood cells, coagulation time tests, plasma recalcification time assay, complement activation, and platelet activation at molecular level. Moreover, the cytotoxicity was also to be characterized. All assays showed after the modification with zwitterionic brush the metal stents displayed a property of excellent blood compatibility and low cytotoxicity.

  18. The Relationships between Polymorphisms in Genes Encoding the Growth Factors TGF-β1, PDGFB, EGF, bFGF and VEGF-A and the Restenosis Process in Patients with Stable Coronary Artery Disease Treated with Bare Metal Stent.

    Directory of Open Access Journals (Sweden)

    Tadeusz Osadnik

    in patients with SCAD treated by PCI with a metal stent implantation.

  19. Cost comparison between two modes of Palmaz Schatz coronary stent implantation: transradial bare stent technique vs. transfemoral sheath-protected stent technique.

    Science.gov (United States)

    Kiemeneij, F; Hofland, J; Laarman, G J; van der Elst, D H; van der Lubbe, H

    1995-08-01

    Coronary Palmaz Schatz stent implantation is usually performed by using the sheath protected stent delivery system (SDS) via the percutaneous transfemoral route. However, downsizing of PTCA equipment made transradial coronary stenting feasible. Bare stent implantation, 6F technique, increased patient mobility, reduced vascular complications and reduced hospital stay may increase cost effectiveness of this novel technique. Two well-documented patient groups selected for elective single vessel and single lesion Palmaz Schatz stent implantation were retrospectively compared. Group A (transradial stenting; n = 35) was compared to Group B (transfemoral stenting; n = 25) derived from the Benestent population, included in our hospital. A comparison was made for three areas of interest: (1) procedural consumption of material (the number of guiding catheters, guidewires, balloon catheters and stents), (2) postprocedural need for diagnostic and therapeutic procedures for stent-related complications, and (3) duration of hospital stay. Differences between these subjects in Group A and B were translated to hospital costs. Although more guiding catheters were used in group A (1.69 +/- 0.87 vs. 1.08 +/- 0.28; P = 0.001), the use of the SDS contributed importantly to higher material costs in group B (cost reduction in group A; 13%). Less patients in group A required diagnostic (2 vs. 7; P = 0.027) and therapeutic (0 vs. 5; P = 0.01) procedures for bleeding complications (cost reduction; 93%). Hospitalization in Group A was shorter (6.4 +/- 4.7 vs. 11.6 +/- 9.9 days; P = 0.005), caused by early and safe mobilization, less vascular complications, and preprocedural adjustment on coumadin (cost reduction; 45%).(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Cobalt chromium stents versus stainless steel stents in diabetic patients

    Directory of Open Access Journals (Sweden)

    Mahmoud Ahmed Tantawy

    2014-03-01

    Conclusions: We concluded that no significant statistical difference was found between the two stents (cobalt-chromium alloy bare metal stent versus conventional bare metal stainless steel stent in diabetic patients regarding (initial procedural success, in-hospital complications, the incidence of ISR at follow up, event-free survival at follow up.

  1. Coronary aneurysm and very late stent thrombosis formation associated with sirolimus-eluting stent implantation

    Institute of Scientific and Technical Information of China (English)

    XIE Hong-zhi; ZHANG Shu-yang; ZENG Yong; SHEN Zhu-jun; FANG Quan

    2009-01-01

    @@ Since drug-eluting stents (DES) can significantly reduce the risk of instant restenosis compared with bare-metal stents, they have been widely used in interventional therapy for coronary heart disease. With bare-metal stents being rapidly replaced by DES there is a great concern about the safety of DES due to stent thrombosis.~(1,2)

  2. Expressions of matrix metalloproteinases and tissue inhibitor of metalloproteinases after bare and magnetic stent implantation in rabbits

    Institute of Scientific and Technical Information of China (English)

    Xinhong Guo; Guoliang Jia; Anlin Lu; Xinguo Zhao; Fei Li; Rongqing Zhang

    2008-01-01

    Objective We aimed to investigate whether magnetic stent has preventive effect on in-stent restenosis by observing expressions of matrix metalioproteinase (MMP)2,MMP9,tissue inhibitor of matrix metalloproteinase (TIMP)1 and TIMP2 after balloon angioplasty,bare and magnetic stent implantation in rabbits.Methods Rabbits underwent balloon angioplasty,bare and magnetic stent implantation in the left iliac arteries.The changes of MMPs and TIMPs were examined at various time points in the injured arteries using the methods of zymography,Western blot analysis,reverse transcription-polymerase chain reaction (RT-PCR) and morphometric analysis.Results Balloon angioplasty group (BA) and magnetic stent group (MS) showed lower intrinsic gelatinolytic activity and higher expression of TIMPs with less intimae hyperplasia;Whereas bare stent (BS) group exhibited higher intrinsic gelatinolytic activity and lower expression of TIMPs with significant intimae hyperplasia.Conclusion Magnetic stent probably has preventive effect on in-stent restenosis by changing intrinsic matrix metalloproteinases activity and expression of TIMPs.

  3. Everolimus-eluting coronary stents

    Directory of Open Access Journals (Sweden)

    Alejandro Saez

    2010-09-01

    Full Text Available Alejandro Saez, Raul MorenoDivision of Interventional Cardiology, University Hospital La Paz, Madrid, SpainAbstract: Bare metal stents enabled a reduction in the risk of early procedural complications and restenosis in comparison with balloon angioplasty alone, but introduced a new and device-specific iatrogenic condition, ie, in-stent restenosis due to increased neointimal hyperplasia. Sirolimus- and paclitaxel-eluting stents reduce restenosis and the need for new revascularizations in comparison with bare metal stents, although at the cost of a slight increase in the risk of late stent thrombosis and a need for prolonged dual antiplatelet therapy. Everolimus is an analog of sirolimus with an increased solubility. In this review, the currently available evidence for everolimus-eluting stents is revised, including randomized trials against bare metal stents, and head-to-head trials comparing this stent with other drug-eluting stents.Keywords: coronary stents, restenosis, everolimus, review

  4. Drug-eluting stents: current issues

    NARCIS (Netherlands)

    P.W.J.C. Serruys (Patrick); A.T.L. Ong (Andrew)

    2005-01-01

    textabstractEarly stent thrombosis occurs in about 1% to 1.5% of patients with drug-eluting stents, very similar to the rate with bare-metal stents. Late stent thrombosis is more of a concern with drug-eluting stents, with an incidence of at least 0.35%. I would urge caution if you feel you have to

  5. Percutaneous transluminal angioplasty and stenting of the vertebral artery ostium with balloon-mounted bare coronary stents

    Directory of Open Access Journals (Sweden)

    Javad Kojuri

    2011-01-01

    Full Text Available Background : Vertebral artery ostial stenosis (VAOS is one of the most frequent causes of posterior circulation stroke. Percutaneous angioplasty and stenting (PTAS is one of the treatment modalities. Patients and Methods : This is a longitudinal observational study from September 2006 to February 2009, conducted at hospitals affiliated with the Shiraz University of Medical Sciences, Shiraz, southern Iran. The patient cohort included patients with posterior circulation stroke or transient ischemic attack (TIA and more than 70% VAOS, and patients with asymptomatic VAOS of more than 70% and aplasia or total occlusion of the contralateral VA or subclavian artery. All the patients underwent PTAS with balloon-mounted bare coronary stents. Technical success, procedural complications, composite outcomes of death, stroke or TIA in the vertebrobasilar territory during the first 30 days, stroke or TIA in the vertebrobasilar territory, and restenosis during follow-up, were assessed. Results : During the study period, 81 patients (mean age 68 + 8.9 years, 63 (78% males, 71 symptomatic and 18 asymptomatic underwent the procedure. Technical success was achieved in 88 (99% patients. Procedure-related complications, other than puncture site complications, were seen in two patients (2.2%. The composite outcome of death, stroke or TIA in the vertebrobasilar territory during the first 30 days was 1%. None of the patients had clinical recurrence or restenosis during the follow-up (mean follow-up 14 months. Conclusion : Percutaneous transluminal angioplasty and stenting of the proximal VA was feasible and safe. The risk of restenosis should be analyzed in long-term studies with angiographic follow-up.

  6. Usefulness of preprocedure high-sensitivity C-reactive protein to predict death, recurrent myocardial infarction, and stent thrombosis according to stent type in patients with ST-segment elevation myocardial infarction randomized to bare metal or drug-eluting stenting during primary percutaneous

    DEFF Research Database (Denmark)

    Schoos, Mikkel Malby; Kelbæk, Henning; Kofoed, Klaus F;

    2011-01-01

    It is unknown whether high-sensitivity C-reactive protein (hs-CRP) predicts outcome depending on implanted stent type. We investigated the prognostic value of hs-CRP in relation to type of stent implanted in patients with ST-segment elevation myocardial infarction (STEMI). Immediately before...... interval 1.3 to 5.6, p = 0.007) and the combined variable of hs-CRP >2 mg/L and BMS (hazard ratio 2.4, 95% confidence interval 1.2 to 4.5, p = 0.006) independently predicted the composite end point of death and MI at 36-month follow-up. There was a significant interaction (p = 0.006) for hs-CRP and stent...

  7. Therapeutic effect and safety of bare metal stent in patients with coronary heart disease complicated im-paired glucose tolerance%冠心病合并糖耐量受损患者应用金属裸支架的疗效及安全性

    Institute of Scientific and Technical Information of China (English)

    王德伟; 黄洁; 杨海英

    2014-01-01

    Objective:To analyze the clinical therapeutic effect and safety of bare metal stent (BMS)application in patients with coronary heart disease (CHD)complicated impaired glucose tolerance (IGT).Methods:The data of 68 CHD + IGT patients undergoing stent implantation in our hospital were retrospectively analyzed.According to kind of implanted stents,they were divided into BMS group (n=36)and drug eluting stent (DES)group (n=32). Thrombolysis in myocardial infarction (TIMI)flow grade and Gensini score of coronary lesion were compared be-tween two groups via reviewing coronary angiography six months after operation.Incidence rates of re-stenosis,a-cute thrombosis,sub-acute thrombosis,revascularization and sudden death were compared between two groups after one year follow-up.Results:There were no significant difference in TIMI grade and Gensini score of coronary le-sion between two groups after operation (P>0.05).Compared with DES group after one-year follow-up,there were significant reductions in incidence rates of acute thrombosis (6.25% vs. 2.78%), sub-acute thrombosis (15.63% vs.5.56%)and sudden death (6.25% vs.2.78%)in BMS group (P0.05).Conclusion:Application of bare metal stent can reduce incidence rate of postoperative complications and possess better therapeu-tic effect in patients with coronary heart disease complicated impaired glucose tolerance.%目的:在冠心病(CHD)合并糖耐量受损患者应用金属裸支架的疗效及安全性。方法:回顾性分析68例CHD合并糖耐量受损患者在我院行支架植入术的资料,依据植入支架种类分为:金属裸支架(BMS)组(36例),药物涂层支架(DES)组(32例)。术后6月复查冠脉造影,比较两组的心肌梗死溶栓治疗(TIMI)临床试验血流分级及 Gensini冠脉病变积分的差异。随访1年,比较两组患者再狭窄发生率、急性血栓形成、亚急性血栓形成、血运重建率及猝死率等并发症的差异。

  8. 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.

  9. 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.

  10. 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

    2015-11-01

    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 6.5months. 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 6.5months 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.

  11. 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

  12. Incidence of definite stent thrombosis or in-stent restenosis after drug-eluting stent implantation for treatment of coronary in-stent restenosis

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  13. Influence of metal alloy and the profile of coronary stents in patients with multivessel coronary disease

    Directory of Open Access Journals (Sweden)

    Luciano Maurício de Abreu Filho

    2011-01-01

    Full Text Available BACKGROUND: In Brazil, despite the recommendations of the Brazilian Society of Hemodynamics and Interventional Cardiology, the National Health System has not yet approved the use of drug-eluting stents. In percutaneous coronary interventions performed in the public and part of the private health care system, bare metal stents are used as the only option. Therefore, new information on bare metal stents is of great importance. The primary endpoint was to evaluate the influence of the alloy and the profile of coronary stents on late loss and restenosis rates 6 months after implantation in patients with multivessel coronary disease. METHODS: Single center, randomized and prospective study comparison of cobalt-chromium versus stainless steel stent implantation in 187 patients with multivessel coronary disease. At least one cobalt-chromium and one stainless steel stent were implanted per patient. RESULTS: Mean age of patients was 59.5 + 10.1 years with a prevalence of males (66.3% and patients with acute coronary syndrome (56%. Baseline clinical characteristics were similar with hypertension in 146 (78%, dyslipidemia in 85 (45.5% and diabetes in 68 (36.4%. Two hundred and twenty-nine cobalt-chromium and 284 stainless steel stents were implanted. Angiographic variables showed no statistically significant difference. Angiographic follow-up to 6 months after implantation showed similar late loss and restenosis rates. CONCLUSION: The use of two different alloys, stainless steel and cobalt-chrome stents, in the same patient and in the same vessel produced similar 6-month restenosis and late loss rates.

  14. Comparison of visibility for four self-expanding nitinol bare stents in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Wiesinger, Benjamin; Stutz, Alexander; Schmehl, Joerg; Groezinger, Gerd; Claussen, Claus Detlef [Div. of Diagnostic Radiology, Dept. of Radiology, Univ. of Tubingen, Tubingen (Germany)], E-mail: Benjamin.wiesinger@med.uni-tuebingen.de; Wiskirchen, Jakub [Dept. of Radiology, Franziskus Krankenhaus, Bielefeld (Germany)

    2012-11-15

    Background Sufficient radiopacity of stents is a prerequisite for safe interventions and minimization of the radiation dose for the patient and the interventionist. Modern nitinol stents are considered less radiopaque compared to formerly used stents. Purpose To evaluate the objective detection rate (ODR) and the subjective radiopacity score (SRS) of four self-expanding nitinol stents with their markers on a phantom human pelvis. Material and Methods We evaluated the ODR (as a percentage of correctly identified stents) and the SRS (on a scale from 0 = not visible to 4 = excellent visibility) for four self-expanding nitinol stents (SinusSuperflex, SMART, Luminexx, Zilver) with 8 mm diameter and 40 mm length. Stents were placed on a phantom human pelvis and images of the stents were taken in four different positions (right and left lumbosacral joint and near the right and left limbus acetabuli) using the following modes: spotfilm, pulsed fluoroscopy (4, 7.5, 15, and 30 pulses/min) and at three different digital magnification modes. Dose area products (DAPs) were assessed. Results ODR and SRS, respectively, were significantly increased for the SMART stent compared to all other tested stents (P < 0.05): SMART 93.53% and 2.43, SinusSuperflex 90.81% and 2.21, Luminexx 90.39% and 2.20, and Zilver 89.28% and 2.21. ODR was significantly reduced in position 3 where the bone overlap was more pronounced for all stents (detection rates 77.14-79.56%). An increase in magnification significantly improved the ODR and SRS for all stents (70.33-99.25% and 1.07-3.28, respectively, P < 0.05). Increased pulsing frequency did not improve the ODR of the various stents but did increase the DAP. Conclusion The SMART stent had the best overall performance. In the presence of bone overlap, all self-expanding nitinol stents had poor results. Increased pulsing frequency did not improve ODR or SRS but did increase the DAP. Use of digital magnification modes had no effect on DAP increasing ODR

  15. Biodegradable Metals for Cardiovascular Stent Application: Interests and New Opportunities

    Directory of Open Access Journals (Sweden)

    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.

  16. Paraffin processing of stented arteries using a postfixation dissolution of metallic and polymeric stents.

    Science.gov (United States)

    Fishbein, Ilia; Welch, Tre; Guerrero, David T; Alferiev, Ivan S; Adamo, Richard F; Chorny, Michael; Gupte, Rohit K; Tang, Yanqing; Levy, Robert J

    Studying the morphology of the arterial response to endovascular stent implantation requires embedding the explanted stented artery in rigid materials such as poly(methyl methacrylate) to enable sectioning through both the in situ stent and the arterial wall, thus maintaining the proper anatomic relationships. This is a laborious, time-consuming process. Moreover, the technical quality of stained plastic sections is typically suboptimal and, in some cases, precludes immunohistochemical analysis. Here we describe a novel technique for dissolution of metallic and plastic stents that is compatible with subsequent embedding of "destented" arteries in paraffin, fine sectioning, major staining protocols, and immunohistochemistry.

  17. Patients with previous definite stent thrombosis have a larger fraction of immature platelets and a reduced antiplatelet effect of aspirin

    DEFF Research Database (Denmark)

    Würtz, Morten; Grove, Erik; Wulff, Lise Nielsen;

    turnover. Key Words: aspirin; immature platelets; platelet aggregation; platelet function tests; stent thrombosis Abbreviations: ARU, aspirin reaction units; AU, aggregation units; BMS, bare-metal stent(s); DES, drug-eluting stent(s); IPF, immature platelet fraction; MEA, multiple electrode aggregometry...

  18. Subacute coronary stent thrombosis in a patient with angina treated with double antiplatelet drugs for six days

    Institute of Scientific and Technical Information of China (English)

    XUE Feng; YANG Xiang-jun; CHENG Xu-jie; HUI Jie; JIANG Ting-bo; CHEN Tan; LIU Zhi-hua; SONG Jian-ping; JIANG Wen-ping

    2009-01-01

    @@ Stent implantation has been a great advance in percutaneous coronary intervention (PCI), decreasing the frequency of acute closure and restenosis. But stent thrombosis is a severe complication of this therapy regardless of the stent type: bare-metal stent (BMS) and drug-eluting stent (DES).

  19. 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.

  20. Hypersensitivity to drug-eluting stent and stent thrombosis: Kounis or not Kounis syndrome?

    Institute of Scientific and Technical Information of China (English)

    TAN Wei; CHENG Kang-lin; CHEN Qiu-xiong

    2009-01-01

    @@ With the utilization of coronary-stents, coronary remodeling and restenosis were reduced compared with balloon angioplasty alone.~1 However, the risk of restenosis is still in the range of 15% to 20%. Drug-eluting stents (DES), which could release antiproliferative pharmacological agents after deployment. were designed to inhibit the response to injury reaction after bare-metal stent (BMS) implantation.

  1. Very late coronary aneurysm formation with subsequent stent thrombosis secondary to drug-eluting stent

    Institute of Scientific and Technical Information of China (English)

    Ibrahim Akin,; Stephan Kische; Tim C Rehders; Henrik Schneider; G(o)kmen R Turan; Tilo Kleinfeldt; Jasmin Ortak; Christoph A. Nienaber; Hüseyin Ince

    2011-01-01

    Drug-eluting stents have changed the practice in interventional cardiology.With the widespread use of these stents important safety concerns regarding stent thrombosis and formation of coronary artery aneurysm have been expressed.While the majority of attention was focused on stent thrombosis,the formation of coronary aneurysm was only described in anecdotal reports.We report on a patient who suffered from very late stent thrombosis in association with coronary artery aneurysm formation secondary to drug-eluting stent but not to bare-metal stent.

  2. Neoatherosclerosis in the stent

    Directory of Open Access Journals (Sweden)

    A. A. Komkov

    2015-01-01

    Full Text Available Achievements of interventional cardiology in the treatment of coronary artery disease are based on coronary balloon angioplasty with implanting bare metal stents and drug eluting stents. Questions of complications such as early stent thrombosis and restenosis of stent were solved in a considerable degree. However, with the lengthening of the followup period, the problem of late complications became obvious. Except endothelization and fibromuscular proliferation in stented coronary arteries the process of plaque formation has an important influence on later complications in follow-up period more than one year. This process was defined as neoatherosclerosis. This is verified by clinical manifestations of the disease, histological studies, angioscopy, intravascular ultrasound and optical-coherence tomography in stented patients. Dynamic observation of the condition in stentedcoronary arteries showed multistep proliferation with restenosis, its regression, and neoatherosclerosis development. Evidences of neoatherosclerosis formation in stented coronary arteries are considered in this review.

  3. AMQ Protocol Based Performance Analysis of Bare Metal Hypervisors

    Directory of Open Access Journals (Sweden)

    Dr Deepak Arora

    2014-06-01

    Full Text Available Cloud computing is one of the most exciting technology because of its cost-reducing approach, flexibility, and scalability. Hypervisor is the essential part of cloud technology; it is a component of software that provides a virtualized hardware environment to support running multiple operating systems concurrently using one physical server. In this paper we took KVM, XEN, Hyper-V and ESXi as hypervisors. We have compared the performance of Virtual Machines (VMs by RabbitMQ message broker server that uses Advanced Message Queuing Protocol(AMQP for breaking messages. We establish the setup on bare metal hypervisor that is installed directly on the hardware of the system. We took SAN (Shared Storage Network server for maintaining the storage of all VMs. By the evaluation of these hyperviosrs we got a brief idea about their performance on different parameters. These results will be beneficial to small enterprise, social group or any private IT firm which is choosing to build small cloud infrastructure with optimal benefits. Experiment results of checking the performance of VMs for all the hypervisors shows that there is performance variation on different applications and workloads of the hypervisors. None of the hypervisors outperform another at every aspect of our comparison.

  4. Malignant Ureteral Obstruction: Functional Duration of Metallic versus Polymeric Ureteral Stents.

    Directory of Open Access Journals (Sweden)

    Po-Ming Chow

    Full Text Available Ureteral obstruction caused by extrinsic compression is often associated with intra-abdominal cancers. Internal drainage with ureteral stents is typically the first-line therapy to relieve such obstructions. Novel designs of ureteral stents made of different materials have been invented to achieve better drainage. In this study, we described the functional outcomes of a Resonance metallic ureteral stent (Cook Medical, Bloomington, Indiana, USA in patients with malignant ureteral obstruction and compare the functional duration of Resonance stents with regular polymeric stents in the same cohort.Cancer patients who received polymeric stents and subsequent Resonance stents for ureteral obstruction between July 2009 and November 2012 were included in a chart review. Stent failure was detected by clinical symptoms, imaging studies, and renal function tests. The functional durations of each stent were calculated, and possible factors affecting stent patency were investigated.A total of 50 stents were successfully inserted into 50 ureteral units in 42 patients with malignant ureteral obstruction. There were 7 antegrade stents and 43 retrograde stents. There were no major complications. Stent-related symptoms were similar in both kinds of stents. After polymeric stents were replaced with Resonance metallic stents, hydronephrosis subsided or remained stable in 90% (45/50 of the ureteral units. Serum creatinine decreased or remained stable in 90% (38/42 of these patients. The Resonance stent exhibited a mean increase in functional duration of 4 months compared with the polymeric stents (p<0.0001, and 50% (25/50 of the Resonance stents exhibited a significant increase in functional duration (more than 3 months. Pre-operative serum creatinine < 2 was associated with a substantial increase in stent duration.Resonance stents are effective and safe in relieving malignant ureteral obstructions after polymeric stents failure. Resonance stents can provide a

  5. Partial stent-in-stent placement of biliary metallic stents using a short double-balloon enteroscopy

    Institute of Scientific and Technical Information of China (English)

    Koichiro Tsutsumi; Hironari Kato; Takeshi Tomoda; Kazuyuki Matsumoto; Ichiro Sakakihara; Naoki Yamamoto; Yasuhiro Noma

    2012-01-01

    Endoscopic intervention is less invasive than percutaneous or surgical approaches and should be considered the primary drainage procedure in most cases with obstructive jaundice.Recently,therapeutic endoscopic retrograde cholangiopancreatography (ERCP) using double-balloon enteroscopy (DBE) has been shown to be feasible and effective,even in patients with surgically altered anatomies.On the other hand,endoscopic partial stent-in-stent (PSIS) placement of selfexpandable metallic stents (SEMSs) for malignant hilar biliary obstruction in conventional ERCP has also been shown to be feasible,safe and effective.We performed PSIS placement of SEMSs for malignant hilar biliary obstruction due to liver metastasis using a short DBE in a patient with Roux-en-Y anastomosis and achieved technical and clinical success.This procedure can result in quick relief from obstructive jaundice in a single session and with short-term hospitalization,even in patients with surgically altered anatomies.

  6. Stent Fracture after Everolimus-Eluting Stent Implantation

    Directory of Open Access Journals (Sweden)

    Ali S. Almasood

    2011-01-01

    Full Text Available Compared with bare-metal stents, drug-eluting stents (DES have greatly reduced the risk of in-stent restenosis (ISR by inhibiting neointimal growth. Nevertheless, DES are still prone to device failure, which may lead to cardiac events. Recently, stent fracture (SF has emerged as a potential mechanism of DES failure that is associated with ISR. Stent fracture is strongly related to stent type, and prior reports suggest that deployment of sirolimus eluting stents (SES may be associated with a higher risk of SF compared to other DES. Everolimus eluting stents (EESs represent a new generation of DES with promising results. The occurrence of SF with EES has not been well established. The present paper describes two cases of EES fracture associated with ISR.

  7. Biodegradable and Elastomeric Poly(glycerol sebacate as a Coating Material for Nitinol Bare Stent

    Directory of Open Access Journals (Sweden)

    Min Ji Kim

    2014-01-01

    Full Text Available We synthesized and evaluated biodegradable and elastomeric polyesters (poly(glycerol sebacate (PGS using polycondensation between glycerol and sebacic acid to form a cross-linked network structure without using exogenous catalysts. Synthesized materials possess good mechanical properties, elasticity, and surface erosion biodegradation behavior. The tensile strength of the PGS was as high as 0.28 ± 0.004 MPa, and Young's modulus was 0.122 ± 0.0003 MPa. Elongation was as high as 237.8 ± 0.64%, and repeated elongation behavior was also observed to at least three times the original length without rupture. The water-in-air contact angles of the PGS surfaces were about 60°. We also analyzed the properties of an electrospray coating of biodegradable PGS on a nitinol stent for the purpose of enhancing long-term patency for the therapeutic treatment of varicose veins disease. The surface morphology and thickness of coating layer could be controlled by adjusting the electrospraying conditions and solution parameters.

  8. Biodegradable and elastomeric poly(glycerol sebacate) as a coating material for nitinol bare stent.

    Science.gov (United States)

    Kim, Min Ji; Hwang, Moon Young; Kim, JiHeung; Chung, Dong June

    2014-01-01

    We synthesized and evaluated biodegradable and elastomeric polyesters (poly(glycerol sebacate) (PGS)) using polycondensation between glycerol and sebacic acid to form a cross-linked network structure without using exogenous catalysts. Synthesized materials possess good mechanical properties, elasticity, and surface erosion biodegradation behavior. The tensile strength of the PGS was as high as 0.28 ± 0.004 MPa, and Young's modulus was 0.122 ± 0.0003 MPa. Elongation was as high as 237.8 ± 0.64%, and repeated elongation behavior was also observed to at least three times the original length without rupture. The water-in-air contact angles of the PGS surfaces were about 60°. We also analyzed the properties of an electrospray coating of biodegradable PGS on a nitinol stent for the purpose of enhancing long-term patency for the therapeutic treatment of varicose veins disease. The surface morphology and thickness of coating layer could be controlled by adjusting the electrospraying conditions and solution parameters.

  9. Will absorbable metal stent technology change our practice?

    Science.gov (United States)

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

    2006-08-01

    Peripheral stents aim to support revascularization procedures of intravascular stenoses by mechanically preventing vessel recoil and counteracting pathophysiologic processes of luminal re-narrowing triggered by procedural injury of the vessel wall. Despite improvements in stenting techniques and concomitant medication, repeated intervention due to target lesion re-stenosis is necessary on a significant percentage of patients. The permanent presence of an artificial implant plays a prominent role in the discussion of mechanisms causing in-stent restenosis. Permanent metallic implants pose the risk of a continuous interaction between non-absorbable stent and surrounding tissue, leading to physical irritation, long-term endothelial dysfunction, or chronic inflammatory reactions. In addition, there is a risk of stent fracture due to external mechanical forces. To overcome these shortcomings, technology of stenting has moved towards the development of temporary implants composed of biocompatible materials which mechanically support the vessel during the period of high risk for recoil and then completely degrade in the long-term perspective. This removes a potential trigger for late restenosis.

  10. Self-expanding metallic esophageal stents: A long way to go before a particular stent can be recommended

    Institute of Scientific and Technical Information of China (English)

    Pankaj Jain

    2011-01-01

    We agree that the covered self-expanding metal stents (SEMSs) fare better than the uncovered stents as recurrent dysphagia due to tumor ingrowth is common with uncovered stent. Recent American College of Gastroenterology Practice Guideline on the Role of Esophageal Stents in Benign and Malignant Diseases concludes that SEMSs cannot be routinely recommended in conjunction with chemo-radiation. The comparison of ultraflex and choostent in the Italian study found no difference in the palliation of dysphagia, rate of complications and survival rate.

  11. Treatment of medium and late stage esophageal carcinoma with combined endoscopic metal stenting and radiotherapy

    Institute of Scientific and Technical Information of China (English)

    钟捷; 吴云林; 许帧; 刘晓天; 许斌; 翟祖康

    2003-01-01

    Objective To evaluate clinical feasibility and efficacy of endoscopic metal stenting combined with radiotherapy for treatment of medium and late stages of esophageal carcinoma. Methods Thirty-four patients of late stage esophageal carcinoma were treated with endoscopic stent implantation in combination with radiotherapy. Evaluations of CES stainless steel metal stent on the effect of radiation, clinical symptom alleviation and complication and survival rates in both groups were made. Conclusion Endoscopic metal stenting in combination with radiotherapy was a feasible and practical management in treating medium and late stages esophageal carcinoma and was superior to simple metal stent implantation.

  12. Comparison of Acute Recoil between Bioabsorbable Poly-L-lactic Acid XINSORB Stent and Metallic Stent in Porcine Model

    Directory of Open Access Journals (Sweden)

    Yizhe Wu

    2012-01-01

    Full Text Available Objective. To investigate acute recoil of bioabsorbable poly-L-lactic acid (PLLA stent. Background. As newly developed coronary stent, bioabsorbable PLLA stent still encountered concern of acute stent recoil. Methods. Sixteen minipigs were enrolled in our study. Eight PLLA XINSORB stents (Weite Biotechnology Co., Ltd., China and eight metallic stents (EXCEL, Jiwei Co., Ltd. China were implanted into coronary arteries. Upon quantitative coronary angiography analysis, acute absolute recoil was defined as the difference between mean diameter of inflated balloon (X and mean lumen diameter of stent immediately after deployment (Y, while acute percent recoil was defined as (X−Y/X and expressed as a percentage. Intravascular ultrasound (IVUS was performed immediately after implantation and 24 hours later to compare cross-sectional area (CSA between two groups and detect stent malapposition or collapse. Results. Acute absolute recoil in XINSORB and EXCEL was 0.02±0.13 mm and −0.08±0.08 mm respectively (P=0.19. Acute percent recoil in XINSORB and EXCEL was 0.66±4.32% and −1.40±3.83%, respectively (P=0.45. CSA of XINSORB was similar to that of EXCEL immediately after implantation, so was CSA of XINSORB at 24-hours followup. Within XINSORB group, no difference existed between CSA after implantation and CSA at 24-hours followup. No sign of acute stent malapposition was detected by IVUS. Conclusions. The acute stent recoil of XINSORB is similar to that of EXCEL. No acute stent malapposition or collapse appeared in both kinds of stent. This preclinical study was designed to provide preliminary data for future studies of long-term efficacy and safety of XINSORB stent.

  13. Percutaneous treatment of superior vena cava syndrome using metallic stents

    Energy Technology Data Exchange (ETDEWEB)

    De Gregorio Ariza, Miguel Angel; Gimeno, Maria Jose; Alfonso, Eduardo; Mainar, Antonio; Medrano, Joaquin; Lopez-Marin, Paloma [Department of Interventional Radiology, ' ' Lozano Blesa' ' University Hospital, Avda. San Juan Bosco 15, 50009 Zaragoza (Spain); Gamboa, Pablo [Division of Interventional Radiology, Ohio State University Hospital, Columbus, Ohio (United States); Tobio, Ricardo [Interventional Radiology, Clinica de la Zarzuela, Madrid (Spain); Herrera, Marcos [Division of Interventional Radiology, University of Minnesota, Minneapolis, Minnesota (United States)

    2003-04-01

    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.)

  14. The use of cold sprayed alloys for metallic stents

    Science.gov (United States)

    AL-Mangour, Bandar

    With the invention of the coronary stent, which is a wire metal mesh tube designed to keep the arteries open in the treatment of heart diseases, promising clinical outcomes were generated. However, the long term successes of stents have been delayed by significant in-stent restenosis (blockages) and stent fracture. In this research work, it has been proposed to use Cold Gas Dynamic Spraying (CGDS) coating material as an alternative choice to manufacture metallic stent. In CGDS, fine particles are accelerated to a high velocity and undergo solid-state plastic deformation upon impact on the substrate, which leads to particle-particle bonding. The feature of CGDS distinct from other thermal spray techniques is that the processing gas temperature is below the melting point of the feedstock. Therefore, unwanted effects of high temperatures, such as oxidation, grain growth and thermal stresses, are absent. In response to the fact that the majority of stents are made from stainless steel (316L) or Co-Cr alloy (L605), this study specifically addresses the development and characterization of 316L and 316L mixed with L605 coatings produced by the CGDS process. Scanning electron microscopy and electron backscatter diffraction were used to investigate the microstructural changes of these coatings before and after annealing. The effect of gas type on the microstructure of 316L coatings and the role of post-heat treatment in the microstructure and properties are also studied. Of particular interest are grain refinement, heat treatment, mechanical properties and corrosion behavior of the cold sprayed material.

  15. Late stent thrombosis: a not negligible issue after drug-eluting stent implantation

    Institute of Scientific and Technical Information of China (English)

    GAO Run-lin

    2007-01-01

    @@ Drug-eluting stent (DES) has markedly reduced restenosis and the need for target lesion revascularization (TLR). The safety profile of DES does not seem to differ from that of bare metal stent in the acute and subacute phases following coronary intervention.

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

    Science.gov (United States)

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

    2015-07-01

    Malignant gastric outlet obstruction is a late complication of intraabdominal malignancy. Self-expandable metallic stent placement has been a safe palliative treatment to relieve obstructive symptoms. We aimed to assess the efficacy and safety of metallic stents in our patients and analyzed the clinical outcome of different brands. Seventy-one patients with inoperable gastric outlet obstruction receiving WallFlex enteral stents (WallFlex group) or Bonastents (Bonastent group) since April 2010 were analyzed retrospectively. The overall technical and clinical success rates of stent placement were 100% and 93%, respectively. The baseline characteristics and clinical outcomes including procedure-related complications, restenosis, and reintervention rates were comparable between the 2 groups. However, the Bonastent group had a higher rate of stent fracture than the WallFlex group (13.3% vs 0%, P = 0.03). The mean duration of overall stent patency was 132.7 days. The mean duration of survival was 181.9 days. Resumption of regular diet or low residual diet at day 7 after stent insertion predicted stent patency (hazard ratio [HR]: 0.28, P = 0.01). Cancer with gastric origin (HR: 0.25, P = 0.045) and poststent chemotherapy (HR: 0.38, P = 0.006) predicted lower mortality; however, peritoneal carcinomatosis (HR: 3.09, P = 0.04) correlated with higher mortality. Metallic stent placement is a safe and effective method for relieving gastric outlet obstruction. Except higher rate of stent fracture in the Bonastent group, there is no significant difference in clinical outcomes between the Bonastent group and the WallFlex group.

  17. High flip angle imaging of metallic stents: Implications for MR angiography and intraluminal signal interpretation

    NARCIS (Netherlands)

    Brück, E.H.; van Holten, J.; Wielopolski, P.; Pattynama, P.M.T.; van Dijk, L.C.

    2003-01-01

    Intraluminal stent signal characterization by MRI is generally hampered by signal loss from the metallic stent material. This signal loss is related to magnetic susceptibility and RF shielding. Even when stent materials with low magnetic susceptibility are used, RF shielding can still be problematic

  18. ORSPHERE: CRITICAL, BARE, HEU(93.2)-METAL SPHERE

    Energy Technology Data Exchange (ETDEWEB)

    Margaret A. Marshall

    2013-09-01

    In the early 1970’s Dr. John T. Mihalczo (team leader), J.J. Lynn, and J.R. Taylor performed experiments at the Oak Ridge Critical Experiments Facility (ORCEF) with highly enriched uranium (HEU) metal (called Oak Ridge Alloy or ORALLOY) in an attempt to recreate GODIVA I results with greater accuracy than those performed at Los Alamos National Laboratory in the 1950’s (HEU-MET-FAST-001). The purpose of the Oak Ridge ORALLOY Sphere (ORSphere) experiments was to estimate the unreflected and unmoderated critical mass of an idealized sphere of uranium metal corrected to a density, purity, and enrichment such that it could be compared with the GODIVA I experiments. “The very accurate description of this sphere, as assembled, establishes it as an ideal benchmark for calculational methods and cross-section data files.” (Reference 1) While performing the ORSphere experiments care was taken to accurately document component dimensions (±0. 0001 in. for non-spherical parts), masses (±0.01 g), and material data The experiment was also set up to minimize the amount of structural material in the sphere proximity. A three part sphere was initially assembled with an average radius of 3.4665 in. and was then machined down to an average radius of 3.4420 in. (3.4425 in. nominal). These two spherical configurations were evaluated and judged to be acceptable benchmark experiments; however, the two experiments are highly correlated.

  19. A physical corrosion model for bioabsorbable metal stents.

    Science.gov (United States)

    Grogan, J A; Leen, S B; McHugh, P E

    2014-05-01

    Absorbable metal stents (AMSs) are an emerging technology in the treatment of heart disease. Computational modelling of AMS performance will facilitate the development of this technology. In this study a physical corrosion model is developed for AMSs based on the finite element method and adaptive meshing. The model addresses a gap between currently available phenomenological corrosion models for AMSs and physical corrosion models that have been developed for more simple geometries than those of a stent. The model developed in this study captures the changing surface of a corroding three-dimensional AMS structure for the case of diffusion-controlled corrosion. Comparisons are made between model predictions and those of previously developed phenomenological corrosion models for AMSs in terms of predicted device geometry and mechanical performance during corrosion. Relationships between alloy solubility and diffusivity in the corrosion environment and device performance during corrosion are also investigated.

  20. Bronchial stump fistula :treatment with covered retrievable hinged metallic stents-preliminary clinical experience

    Institute of Scientific and Technical Information of China (English)

    LI Yong-dong; HAN Xin-wei; WU Gang; LI Ming-hua

    2007-01-01

    Objective To evaluate the preliminaily clinical efficacy and retrievability of a retrievable hinged covered metallic stent in the treatment of the bronchial stump fistula (BSF). Methods Between April 2003 and March 2005, 8 patients with bronchial stump fistula after pneumonectomy or lobectomy were treated with two types (A and B) of retrievable hinged covered metallic stents. Type A stent was placed in 6 patients and type B in 2 under fluoroscopic guidance. The stent was removed with a retrieval set when BSF was healed or complications occurred. Results Stent placement in the bronchial tree was technically successful in all patients, without procedure-related complications. Immediate closure of the BSF was achieved in all patients after the procedure. Stents were removed from all patients but one. Removal of the stents was difficult in two patients due to tissue hyperplasia. Patients were followed up for 6 - 21 months. Placement of the stents remained stable in all patients except one due to severe cough. Permanent closure of BSF was achieved in 7(87.5%) of 8 patients. Conclusion Use of a retrievable hinged covered expandable metallic stent is a simple,safe, and effective procedure for closure of the BSF. Retrieval of the stent seems to be feasible. (J Intervent Radiol, 2007, 16: 253-257)[ Key words ] Fistula, pulmonary; Bronchialpleural fistula; Stents and prostheses; Computed tomography

  1. 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.

  2. Temporary partially-covered metal stent insertion in benign esophageal stricture

    Institute of Scientific and Technical Information of China (English)

    Ying-Sheng Cheng; Ming-Hua Li; Wei-Xiong Chen; Ni-Wei Chen; Qi-Xin Zhuang; Ke-Zhong Shang

    2003-01-01

    AIM: To study the therapeutic efficacy of temporary partiallycovered metal stent insertion on benign esophageal stricture.METHODS: Temporary partially-covered metal stent was inserted in 83 patients with benign esophageal stricture. All the patients had various dysphagia scores.RESULTS: Insertion of 85 temporary partially-covered metal stents was performed successfully in 83 patients with benign esophageal stricture and dysphagia was effectively remitted in all the 83 cases. The dysphagia score was 3.20±0.63(mean±SD) and 0.68±0.31 before and after stent insertion,and 0.86±0.48 after stent removal. The mean diameter of the strictured esophageal lumen was 3.37±1.23 mm and 25.77±3.89 mm before and after stent insertion, and 16.15±2.96 mm after stent removal. Follow-up time was from 1 week to 96 months (mean 54.26±12.75 months). The complications were chest pain (n=37) after stent insertion,and bleeding (n=12) and reflux (n=13) after stent removal.CONCLUSION: Temporary partially-covered metal stent insertion is one of the best methods for treatment of benign esophageal stricture.

  3. Biocompatibility of Coronary Stents

    Directory of Open Access Journals (Sweden)

    Thamarasee M. Jeewandara

    2014-01-01

    Full Text Available Cardiovascular disease is the dominant cause of mortality in developed countries, with coronary artery disease (CAD a predominant contributor. The development of stents to treat CAD was a significant innovation, facilitating effective percutaneous coronary revascularization. Coronary stents have evolved from bare metal compositions, to incorporate advances in pharmacological therapy in what are now known as drug eluting stents (DES. Deployment of a stent overcomes some limitations of balloon angioplasty alone, but provides an acute stimulus for thrombus formation and promotes neointimal hyperplasia. First generation DES effectively reduced in-stent restenosis, but profoundly delay healing and are susceptible to late stent thrombosis, leading to significant clinical complications in the long term. This review characterizes the development of coronary stents, detailing the incremental improvements, which aim to attenuate the major clinical complications of thrombosis and restenosis. Despite these enhancements, coronary stents remain fundamentally incompatible with the vasculature, an issue which has largely gone unaddressed. We highlight the latest modifications and research directions that promise to more holistically design coronary implants that are truly biocompatible.

  4. Prevention of stent thrombosis: challenges and solutions

    Directory of Open Access Journals (Sweden)

    Reejhsinghani R

    2015-01-01

    Full Text Available Risheen Reejhsinghani, Amir S LotfiDivision of Cardiology, Baystate Medical Center, Springfield, MA, USAAbstract: Stent thrombosis is an uncommon but serious complication which carries with it significant mortality and morbidity. This review analyzes the entity of stent thrombosis from a historical and clinical perspective, and chronicles the evolution of this condition through the various generations of stent development, from bare metal to first-generation, second-generation, and third-generation drug-eluting stents. It also delineates the specific risk factors associated with stent thrombosis and comprehensively examines the literature related to each of these risks. Finally, it highlights the preventative strategies that can be garnered from the existing data, and concludes that a multifactorial approach is necessary to combat the occurrence of stent thrombosis, with higher risk groups, such as patients with ST segment elevation myocardial infarction, meriting further research.Keywords: stent thrombosis, preventative strategies, post-procedural myocardial infarction

  5. 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.

  6. Obstructing fungal cholangitis complicating metal biliary stent placement in pancreatic cancer

    Institute of Scientific and Technical Information of China (English)

    Brian; Story; Michael; Gluck

    2010-01-01

    Biliary obstructions can lead to infections of the biliary system, particularly in patients with occluded biliary stents. Fungal organisms are frequently found in bili-ary aspirates of patients who have been on antibiotics and have stents; however, fungal masses, or "balls", that fully obstruct the biliary system are uncommon and exceedingly diff icult to eradicate. We present 4 cases of obstructing fungal cholangitis in patients who had metal biliary stents placed for pancreatic malignancies, and subsequen...

  7. Targeting In-Stent-Stenosis with RGD- and CXCL1-Coated Mini-Stents in Mice.

    Directory of Open Access Journals (Sweden)

    Sakine Simsekyilmaz

    Full Text Available 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.

  8. 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.

  9. Drug-eluting stents and acute myocardial infarction:A lethal combination or friends?

    Institute of Scientific and Technical Information of China (English)

    Shuji; Otsuki; Manel; Sabaté

    2014-01-01

    Primary percutaneous coronary intervention is the preferred reperfusion strategy for patients presenting with ST-segment elevation myocardial infarction(STEMI). First generation drug-eluting stents(DES),(sirolimus drug-eluting stents and paclitaxel drug-eluting stents), reduce the risk of restenosis and target vessel revascularization compared to bare metal stents. However, stent thrombosis emerged as a major safety concern with first generation DES. In response to these safety issues, second generation DES were developed with different drugs, improved stent platforms and more biocompatible durable or bioabsorbable polymeric coating. This article presents an overview of safety and efficacy of the first and second generation DES in STEMI.

  10. The first use of Resonance® metallic ureteric stent in a case of obstructed transplant kidney

    Science.gov (United States)

    Abdulmajed, Mohamed I.; Jones, Vaughan W.; Shergill, Iqbal S.

    2014-01-01

    INTRODUCTION To date, double JJ stent is the mainstay ureteric stent used in a transplant kidney. We herein report the first use of Resonance® metallic ureteric stent to manage ureteric obstruction in a transplant kidney. PRESENTATION OF CASE A 45-year-old lady underwent an uneventful living related donor renal transplantation. Due to post-operative pelvi-ureteric obstruction and recurrent obstruction following multiple distal stent migration and expulsion necessitated frequent nephrostomy insertion and antegrade stenting, she underwent challenging but successful retrograde insertion of a 12 centimetres long and size 6.0 French Cook Resonance® metallic ureteric stent which was performed under general anaesthesia. DISCUSSION Metallic ureteric stents are a fairly recent introduction to modern urology and they have been successfully used in the management of benign and malignant obstruction of ureter. CONCLUSION This is the first case of therapeutic metallic ureteric stent insertion in a transplant kidney. PMID:24858983

  11. Predictors for occlusion of the first inserted metallic stent in patients with malignant biliary obstruction

    Directory of Open Access Journals (Sweden)

    Wandong Hong

    2015-01-01

    Full Text Available Background/Aims: Endoscopic biliary stent drainage plays an important role in the palliative treatment of malignant biliary obstruction. The aim of this study was to investigate predictors of occlusion of first metal inserted stent in patients with malignant biliary obstruction. Patients and Methods: The retrospective analysis was performed in 178 patients with malignant biliary obstruction. Factors associated with stent occlusion were analyzed by Cox regression analysis. Results: Median overall stent patency was 178 days. Total cumulative obstruction rate of the first stents during the follow up was 33%, 57%, 83%, and 96% at 90, 180, 360, and 720 days. Multivariate analysis revealed that hilar obstruction (hazard ratio [HR] =3.26, 95% confidence interval [CI, 2.31–4.61, metastasis cancer (HR = 2.61, 95% CI, 1.79–3.80, and length of stent (HR = 1.74, 95% CI, 1.24–2.46 were independent predictors of stent occlusion. Conclusions: Hilar biliary stricture, metastatic cancer, and length of stent were important predictors of occlusion of first-inserted metal stent in patients with malignant biliary obstruction.

  12. Recent developments in drug-eluting coronary stents.

    Science.gov (United States)

    Yildiz, Mustafa; Yildiz, Banu Sahin; Gursoy, Mustafa Ozan; Akin, Ibrahim

    2014-01-01

    The interventional treatment of coronary artery disease was introduced in 1970`s by Andreas Grüntzig. The initial treatment strategy with plain old balloon angioplasty (POBA) was associated with high restenosis rates. The introduction of coronary stents, especially drug-eluting stents (DES) in 2002 has improved the results by lowering the rate of in-stent restenosis from 20-40% in the era of bare-metal stent (BMS) to 6-8%. However, in 2006 with the observation of late stent thrombosis the reputations of DES have decreased. However, improvements in stent design especially antiproliferative agents, polymeric agents as well as stent platforms improved newer generation DES. In controlled trials as well as registries the use of second-generation DES as compared to bare-metal stents (BMS) was associated with better clinical and angiographic results. A further development of these stents with use of biodegradable polymers, polymer-free stents, and biodegradable stents on the basis of poly L-lactide (PLLA) or magnesium resulted in third-generation DES and has been evaluated in preclinical and first clinical trials. However, to date, there is a lack of data comparing these third-generation DES with first- and second-generatrion DES in a large scale.

  13. A Nano-Inspired Multifunctional POSS-PCU Covered Stent: Endothelial Progenitor Cell Capture with Stealth Liposomal Drug Release

    OpenAIRE

    Tan, A. J. K.

    2014-01-01

    The 2 main unresolved issues inherent in coronary stents are in-stent restenosis (ISR) and late stent thrombosis (ST). ISR is largely due to vascular smooth muscle cell (VSMC) proliferation, and ST is attributed to a lack of re-endothelialization. This thesis describes the conceptualization and development of a biofunctionalized polyhedral oligomeric silsesquioxane poly(carbonate-urea) urethane (POSS-PCU) platform, for the express purpose of circumventing ISR and ST. A bare-metal stent is emb...

  14. Endoscopic stenting for hilar cholangiocarcinoma: efficacy of unilateral and bilateral placement of plastic and metal stents in a retrospective review of 480 patients

    Directory of Open Access Journals (Sweden)

    Liberato Manuel José

    2012-08-01

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

  15. Percutaneous Placement of Permanent Metallic Stents in the Cystic Duct to Treat Obstructive Cholecystitis.

    Science.gov (United States)

    Brown, Nicholas I; Jhamb, Ashu; Brooks, Duncan M; Little, Andrew F

    2015-12-01

    This report presents a series of five patients unsuitable for surgery who had nonretrievable self-expanding metallic stents deployed along the cystic duct as treatment for benign and malignant causes of gallbladder obstruction. Techniques are described for draining cholecystitis, removing gallstones, bypassing gallbladder obstructions, and inserting metallic stents across the cystic duct to restore permanent antegrade gallbladder drainage in acute and chronic cholecystitis. Symptoms resolved in all cases, and stents remained patent for as long as 22 months. This procedure may be an effective alternative to cholecystectomy or long-term gallbladder drainage for patients in inoperable condition.

  16. Two-Year Outcomes of High Bleeding Risk Patients after Polymer-Free Drug-Coated Stents

    DEFF Research Database (Denmark)

    Garot, Philippe; Morice, Marie-Claude; Tresukosol, Damras;

    2016-01-01

    BACKGROUND: For patients at high risk for bleeding, a polymer-free metallic stent coated with biolimus-A9 followed by one-month dual antiplatelet therapy was safer and more effective than a bare metal stent at one year. OBJECTIVES: Longer-term follow-up is needed to determine whether these benefi...

  17. Clinical evaluation of radiotherapy for advanced esophageal cancer after metallic stent placement

    Institute of Scientific and Technical Information of China (English)

    You-Tao Yu; Guang Yang; Yan Liu; Bao-Zhong Shen

    2004-01-01

    AIM: To evaluate the therapeutic effect of radiotherapy for esophageal cancer after expandable metallic stent placement.METHODS: Ten cases of advanced esophageal cancer were evaluated, 7 having complete obstruction and 3 with digestive-respiratory fistula. Ten nitinol stents were placed at the site of stenosis. Patients were treated with a total dose of 1 200 cGy divided into 3 fractions of 400 cGy 4-7 d after stents placement.RESULTS: All the 10 stents were placed successfully at one time. After radiotherapy for advanced esophageal cancer, the survival period of the cases ranged from 14 to 22 mo, with a mean survival of 17 mo. No re-stenosis occurred among all the 10 cases.CONCLUSION: Stent placement combined with radiotherapy for esophageal cancer is helpful to prolong patients' survival and reduce occurrence of re-stenosis.

  18. Five-Year Long-Term Clinical Follow-Up of the XIENCE V Everolimus Eluting Coronary Stent System in the Treatment of Patients With de novo Coronary Artery Lesions: The SPIRIT FIRST Trial

    NARCIS (Netherlands)

    M. Wiemer; P.W. Serruys; K. Miquel-Hebert; F.J. Neumann; J.J. Piek; E. Grube; J. Haase; L. Thuesen; C. Hamm

    2010-01-01

    Background: Drug-eluting stents have shown to be superior over bare metal stents in clinical and angiographic outcomes after percutaneous treatment of coronary artery stenosis. However, long-term follow-up data are scarce and only available for sirolimus- and paclitaxel-eluting stents. Aim: To asses

  19. Drug-eluting stents in renal artery stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Zaehringer, M. [Marienhospital Stuttgart, Department of Radiology, Stuttgart (Germany); Pattynama, P.M.T. [Erasmus MC-University Medical Center Rotterdam, Rotterdam (Netherlands); Talen, A. [genae associates nv, Antwerp (Belgium); Sapoval, M. [Hopital Europeen Georges Pompidou, Service de Radiologie Cardio-Vasculaire, Paris (France); Inserm U 780 epidemiologie Cardio Vasculaire, Paris (France)

    2008-04-15

    Because of higher acute and long-term success rates compared with balloon angioplasty alone, percutaneous stent implantation has become an accepted therapy for the treatment of atherosclerotic renal artery stenosis. Restenosis rates after successful renal stent placement vary from 6 up to 40%, depending on the definition of restenosis, the diameter of the treated vessel segment and comorbidities. The safety and efficacy of drug-eluting stents for the treatment of renal-artery stenosis is poorly defined. The recently published GREAT study is the only prospective study, comparing bare-metal and sirolimus-coated low profile stent systems in renal artery stenosis, showing a relative risk reduction of angiographic binary in-stent restenosis by 50%. This is an opinion paper on indications, current treatment options and restenosis rates following renal artery stenting and the potential use of drug-eluting stents for this indication. (orig.)

  20. Metallic Stents for Proximal Tracheal Stenosis: Is It Worth the Risk?

    Directory of Open Access Journals (Sweden)

    Sandeep Bansal

    2012-01-01

    Full Text Available Objective. To demonstrate the risk associated with blocked proximal tracheal stents when a patient presents with acute respiratory distress, with blockage of stent and what is the best management we can offer without damage to the stent and its associated complications. Case Report. A 22-yr-old, male patient, presented in severe respiratory distress. He had history of corrosive poisoning for which he was tracheotomised. A stainless steel wire mesh stent was placed in the trachea, from the subglottis, to just above the carina. One month later, he presented with a critically compromised airway with severe respiratory distress. Emergency tracheostomy was done and the metallic stent had to be cut open, in order to provide an airway. Conclusion. Management of blocked proximal stents with patient in respiratory distress remains a challenge. Formation of granulation tissue is common and fibreoptic bronchoscopic assisted intubation may not always be possible. A regular follow up of all patients with stents is essential. Placement of stents within a few centimetres of cricotracheal junction should not be encouraged for long term indications.

  1. The next generation of drug-eluting stents: What's on the horizon?

    NARCIS (Netherlands)

    S. Ramcharitar (Steve); S. Vaina (Sophia); P.W.J.C. Serruys (Patrick)

    2007-01-01

    textabstractDrug-eluting stents have radically changed the way we treat coronary artery disease. They offer lower restenotic rates compared with the bare metal stents and this enables more challenging and complex lesions to be treated. However, there are still limitations as restenosis has not been

  2. Polymer-free Drug-Coated Coronary Stents in Patients at High Bleeding Risk

    DEFF Research Database (Denmark)

    Urban, Philip; Meredith, Ian T; Abizaid, Alexandre;

    2015-01-01

    BACKGROUND: Patients at high risk for bleeding who undergo percutaneous coronary intervention (PCI) often receive bare-metal stents followed by 1 month of dual antiplatelet therapy. We studied a polymer-free and carrier-free drug-coated stent that transfers umirolimus (also known as biolimus A9),...

  3. Rapid development of late stent malappositon and coronary aneurysm following implantation of a paclitaxel-eluting coronary stent

    Institute of Scientific and Technical Information of China (English)

    ZHANG Feng; QIAN Ju-ying; GE Jun-bo

    2007-01-01

    @@ Late stent malapposition (LSM), an unusual intravascular ultrasound (IVUS) finding at follow-up, has been reported to be more common after drug-eluting stent (DES) implantation than after bare metal stent(BMS) implantation.1-3 However, there has been no clear elucidation of time course and mechanism. We reported a case who developed LSM and coronary aneurysm very early after paclitaxel-eluting stent (PES) implantation. A review of the literature reveals no previous report describing rapid development of LSM and coronary aneurysm after PES implantation.

  4. 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...... and one global, multicenter studies. Settings. 39 centers (22 academic, 17 community hospitals) from 13 countries. Patients. A total of 257 patients were enrolled, and 255 patients were treated with a WallFlex uncovered enteral colonic stent. Follow-up was up to 12 months or until death or retreatment...

  5. Oralloy (93.2 235U) Bare Metal Annuli And Disks

    Energy Technology Data Exchange (ETDEWEB)

    Hummel, Andrew John [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-01

    A multitude of critical experiments with highly enriched uranium metal were conducted in the 1960s and 1970s at the Oak Ridge Critical Experiments Facility (ORCEF) in support of criticality safety operations at the Y-12 Plant. These experiments served to evaluate the storage, casting, and handling limits for the Y-12 Plant while also providing data for verification of different calculation methods and associated cross-sections for nuclear criticality safety applications. These included both solid cylinders and annuli of various diameters, interacting cylinders of various diameters, parallelepipeds, and reflected cylinders and annuli. The experiments described here involve a series of delayed critical stacks of bare oralloy HEU annuli and disks. Three of these experiments consist of stacking bare HEU annuli of varying diameters to obtain critical configurations. These annuli have nominal inner and outer diameters (ID/OD) including: 7 inches (") ID – 9" OD, 9" ID – 11" OD, 11" ID – 13" OD, and 13? ID – 15" OD. The nominal heights range from 0.125" to 1.5". The three experiments themselves range from 7" – 13", 7" – 15", and 9" – 15" in diameter, respectively. The fourth experiment ranges from 7" – 11", and along with different annuli, it also includes an 11" disk and several 7" diameter disks. All four delayed critical experiments were configured and evaluated by J. T. Mihalczo, J. J. Lynn, and D. E. McCarty from December of 1962 to February 1963 with additional information in their corresponding logbook.

  6. Second- and third-generation drug-eluting coronary stents: progress and safety.

    Science.gov (United States)

    Akin, I; Schneider, H; Ince, H; Kische, S; Rehders, T C; Chatterjee, T; Nienaber, C A

    2011-05-01

    Drug-eluting stents (DES) have revolutionized the treatment of coronary artery disease by reducing the rate of in-stent restenosis from 20-40% with bare-metal stent (BMS) to 6-8% with DES. However, with widespread use of DES, safety concerns have risen due to the observation of late stent thrombosis. With this in mind and better understanding of mechanism and pathophysiology of stent thrombosis, the technological platform, especially innovative anti-restenotic agents, polymeric coatings, and stent platforms, improved with newer DES. Two second-generation DES, the Endeavor zotarolimus-eluting stent (ZES) and the Xience-V everolimus-eluting stent (EES), have provided promising results in both randomized controlled trials (SPIRIT and ENDEAVOR) and registries (E-Five, COMPARE) compared with bare-metal stents (BMS) and first-generation DES. Newer third-generation stent technology, especially biodegradable polymers, polymer-free stents, and biodegradable stents on the basis of poly-L-lactide (PLLA) or magnesium, has been evaluated in preclinical and initial clinical trials. However, despite encouraging initial results, long-term data of large-scale randomized trials as well as registries comparing them to currently approved first- and second-generation DES are still lacking.

  7. Sealing of Airway Fistulas for Metallic Covered Z-type Stents

    Directory of Open Access Journals (Sweden)

    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.

  8. Stone extraction balloon-guided repeat self-expanding metal stent placement

    Institute of Scientific and Technical Information of China (English)

    Hyung; Hun; Kim; Jeong; Seop; Moon; Soo; Hyung; Ryu; Jung; Hwan; Lee; You; Sun; Kim

    2010-01-01

    Self-expanding metal stent (SEMS) placement offers safe and effective palliation in patients with upper gastrointestinal obstruction due to a malignancy. Well described complications of SEMS placement include tumor growth, obstruction, and stent migration. SEMS occlusions are treated by SEMS redeployment, argon plasma coagulation application, balloon dilation, and surgical bypass. At our center, we usually place the second SEMS into the first SEMS if there is complete occlusion by the tumor. We discovered a...

  9. Self-Assembly of Graphene Nanoblisters Sealed to a Bare Metal Surface.

    Science.gov (United States)

    Larciprete, Rosanna; Colonna, Stefano; Ronci, Fabio; Flammini, Roberto; Lacovig, Paolo; Apostol, Nicoleta; Politano, Antonio; Feulner, Peter; Menzel, Dietrich; Lizzit, Silvano

    2016-03-09

    The possibility to intercalate noble gas atoms below epitaxial graphene monolayers coupled with the instability at high temperature of graphene on the surface of certain metals has been exploited to produce Ar-filled graphene nanosized blisters evenly distributed on the bare Ni(111) surface. We have followed in real time the self-assembling of the nanoblisters during the thermal annealing of the Gr/Ni(111) interface loaded with Ar and characterized their morphology and structure at the atomic scale. The nanoblisters contain Ar aggregates compressed at high pressure arranged below the graphene monolayer skin that is decoupled from the Ni substrate and sealed only at the periphery through stable C-Ni bonds. Their in-plane truncated triangular shapes are driven by the crystallographic directions of the Ni surface. The nonuniform strain revealed along the blister profile is explained by the inhomogeneous expansion of the flexible graphene lattice that adjusts to envelop the Ar atom stacks.

  10. Molecular modeling of organic corrosion inhibitors: why bare metal cations are not appropriate models of oxidized metal surfaces and solvated metal cations.

    Science.gov (United States)

    Kokalj, Anton

    2014-01-01

    The applicability of various models of oxidized metal surfaces - bare metal cations, clusters of various size, and extended (periodic) slabs - that are used in the field of quantum-chemical modeling of corrosion inhibitors is examined and discussed. As representative model systems imidazole inhibitor, MgO surface, and solvated Mg(2+) ion are considered by means of density-functional-theory calculations. Although the results of cluster models are prone to cluster size and shape effects, the clusters of moderate size seem useful at least for qualitative purposes. In contrast, the bare metal cations are useless not only as models of oxidized surfaces but also as models of solvated cations, because they bind molecules several times stronger than the more appropriate models. In particular, bare Mg(2+) binds imidazole by 5.9 eV, while the slab model of MgO(001) by only 0.35 eV. Such binding is even stronger for 3+ cations, e.g., bare Al(3+) binds imidazole by 17.9 eV. The reasons for these fantastically strong binding energies are discussed and it is shown that the strong bonding is predominantly due to electron charge transfer from molecule to metal cation, which stems from differences between molecular and metal ionization potentials.

  11. The Influence of a Metal Stent on the Distribution of Thermal Energy during Irreversible Electroporation.

    Directory of Open Access Journals (Sweden)

    Hester J Scheffer

    Full Text Available Irreversible electroporation (IRE uses short duration, high-voltage electrical pulses to induce cell death via nanoscale defects resulting from altered transmembrane potential. The technique is gaining interest for ablations in unresectable pancreatic and hepatobiliary cancer. Metal stents are often used for palliative biliary drainage in these patients, but are currently seen as an absolute contraindication for IRE due to the perceived risk of direct heating of the metal and its surroundings. This study investigates the thermal and tissue viability changes due to a metal stent during IRE.IRE was performed in a homogeneous tissue model (polyacrylamide gel, without and with a metal stent placed perpendicular and parallel to the electrodes, delivering 90 and 270 pulses (15-35 A, 90 μsec, 1.5 cm active tip exposure, 1.5 cm interelectrode distance, 1000-1500 V/cm, 90 pulses/min, and in-vivo in a porcine liver (4 ablations. Temperature changes were measured with an infrared thermal camera and with fiber-optic probes. Tissue viability after in-vivo IRE was investigated macroscopically using 5-triphenyltetrazolium chloride (TTC vitality staining.In the gel, direct stent-heating was not observed. Contrarily, the presence of a stent between the electrodes caused a higher increase in median temperature near the electrodes (23.2 vs 13.3°C [90 pulses]; p = 0.021, and 33.1 vs 24.8°C [270 pulses]; p = 0.242. In-vivo, no temperature difference was observed for ablations with and without a stent. Tissue examination showed white coagulation 1mm around the electrodes only. A rim of vital tissue remained around the stent, whereas ablation without stent resulted in complete tissue avitality.IRE in the vicinity of a metal stent does not cause notable direct heating of the metal, but results in higher temperatures around the electrodes and remnant viable tissue. Future studies should determine for which clinical indications IRE in the presence of metal stents is

  12. Covered metallic stents for the palliation of colovesical fistula.

    Science.gov (United States)

    Ahmad, Mukhtar; Nice, Colin; Katory, Mark

    2010-09-01

    Colovesical fistula is a distressing condition that is usually managed surgically. For some patients in whom surgery is not feasible, covered colonic stents offer palliation. We present two challenging cases with contrasting outcomes. The first case is a colovesical fistula secondary to malignancy with a successful outcome after stenting and the second a complex diverticular fistula with a poor outcome. From our limited experience, it is a useful technique but careful patient selection is essential to its safe application. There is little published experience of the use of these stents for colovesical fistula.

  13. [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

  14. Metallic stent placement in hemodialysis graft patients after insufficient balloon dilation

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Huei-Lung; Pan, Huay-Ben; Lin, Yih-Huie; Chen, Chiung-Yu; Lai, Pin-Hong; Yang, Chien-Fang [Kaohsiung Veterans General Hospital, Kaohsiung (China); Chung, Hsiao-Min; Wu, Tung-Ho; Chou, Kang-Ju [National Yangming University, Taipei (China)

    2006-06-15

    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 ({rho} = .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.

  15. Enteral metallic stenting by balloon enteroscopy for obstruction of surgically reconstructed intestine.

    Science.gov (United States)

    Nakahara, Kazunari; Okuse, Chiaki; Matsumoto, Nobuyuki; Suetani, Keigo; Morita, Ryo; Michikawa, Yosuke; Ozawa, Shun-ichiro; Hosoya, Kosuke; Kobayashi, Shinjiro; Otsubo, Takehito; Itoh, Fumio

    2015-06-28

    We present three cases of self-expandable metallic stent (SEMS) placement using a balloon enteroscope (BE) and its overtube (OT) for malignant obstruction of surgically reconstructed intestine. A BE is effective for the insertion of an endoscope into the deep bowel. However, SEMS placement is impossible through the working channel, because the working channel of BE is too small and too long for the stent device. Therefore, we used a technique in which the BE is inserted as far as the stenotic area; thereafter, the BE is removed, leaving only the OT, and then the stent is placed by inserting the stent device through the OT. In the present three cases, a modification of this technique resulted in the successful placement of the SEMS for obstruction of surgically reconstructed intestine, and the procedures were performed without serious complications. We consider that the present procedure is extremely effective as a palliative treatment for distal bowel stenosis, such as in the surgically reconstructed intestine.

  16. Green nanochemistry: metal oxide nanoparticles and porous thin films from bare metal powders.

    Science.gov (United States)

    Redel, Engelbert; Petrov, Srebri; Dag, Omer; Moir, Jonathon; Huai, Chen; Mirtchev, Peter; Ozin, Geoffrey A

    2012-01-01

    A universal, simple, robust, widely applicable and cost-effective aqueous process is described for a controlled oxidative dissolution process of micrometer-sized metal powders to form high-purity aqueous dispersions of colloidally stable 3-8 nm metal oxide nanoparticles. Their utilization for making single and multilayer optically transparent high-surface-area nanoporous films is demonstrated. This facile synthesis is anticipated to find numerous applications in materials science, engineering, and nanomedicine.

  17. Single-cycle surface plasmon polaritons on a bare metal wire excited by relativistic electrons

    Science.gov (United States)

    Op `T Root, W. P. E. M.; Brussaard, G. J. H.; Smorenburg, P. W.; Luiten, O. J.

    2016-12-01

    Terahertz (THz) pulses are applied in areas as diverse as materials science, communication and biosensing. Techniques for subwavelength concentration of THz pulses give access to a rapidly growing range of spatial scales and field intensities. Here we experimentally demonstrate a method to generate intense THz pulses on a metal wire, thereby introducing the possibility of wave-guiding and focussing of the full THz pulse energy to subwavelength spotsizes. This enables endoscopic sensing, single-shot subwavelength THz imaging and study of strongly nonlinear THz phenomena. We generate THz surface plasmon polaritons (SPPs) by launching electron bunches onto the tip of a bare metal wire. Bunches with 160 pC charge and ~6 ps duration yield SPPs with 6-10 ps duration and 0.4+/-0.1 MV m-1 electric field strength on a 1.5 mm diameter aluminium wire. These are the most intense SPPs reported on a wire. The SPPs are shown to propagate around a 90° bend.

  18. Bronchial stents

    Directory of Open Access Journals (Sweden)

    Ibrahim Emad

    2006-01-01

    Full Text Available Bronchial stents are mostly used as a Palliative relief of symptoms often caused by airway obstruction, It is also used for sealing of stump fistulas after pneumonectomy and dehiscence after bronchoplastic operations. Advances in airway prosthetics have provided a variety of silicone stents, expandable metal stents, and pneumatic dilators, enabling the correction of increasingly complex anatomical problems. Several series have been published describing the application and results of these techniques. This manuscript reviews the historical development of stents, types, indication, outcome, and complications. Alternative therapies for tracheobronchial stenting were also reviewed

  19. Percutaneous Intraductal Radiofrequency Ablation for Clearance of Occluded Metal Stent in Malignant Biliary Obstruction: Feasibility and Early Results

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-11

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

  20. 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.

  1. Role of Fully Covered Self-Expandable Metal Stent for Treatment of Benign Biliary Strictures and Bile Leaks

    Energy Technology Data Exchange (ETDEWEB)

    Pausawasadi, Nonthalee [Department of Medicine, Siriraj Hospital, Mahidol University, Bangkok (Thailand); Soontornmanokul, Tanassanee; Rerknimitr, Rungsun [Department of Medicine, Chulalongkorn University, Bangkok (Thailand)

    2012-02-15

    Endoscopic therapy by balloon dilation and placement of multiple large-bore plastic stents is the treatment of choice for benign biliary stricture. This approach is effective but it typically requires multiple endoscopic sessions given the short duration of stent patency. The endoscopic approach for treatment of bile leak involves the placement of a stent with or without biliary sphincterotomy. The self-expandable metal stent (SEMS) has traditionally been used for palliation of malignant biliary strictures given the long duration of stent patency owing to their larger stent diameter. Recently, SEMS has been used in a variety of benign biliary strictures and leaks, especially with the design of the covered self-expandable metal stent (CSEMS), which permits endoscopic-mediated stent removal. The use of CSEMS in benign biliary stricture could potentially result in a decrease in endoscopic sessions and it is technically easier when compared to placement of multiple plastic stents. However, complications such as cholecystitis due to blockage of cystic duct, stent migration, infection and pancreatitis have been reported. The potential subsegmental occlusion of contralateral intrahepatic ducts also limits the use of CSEMS in hilar stricture. Certain techniques and improvement of stent design may overcome these challenges in the future. Thus, CSEMS may be appropriate in only highly selected conditions, such as refractory benign biliary stricture, despite multiple plastic stent placement or difficult to treat bile duct stricture from chronic pancreatitis, and should not be used routinely. This review focuses on the use of fully covered self-expandable metal stent for benign biliary strictures and bile leaks.

  2. Efficacy of Self-Expandable Metallic Stent Inserted for Refractory Hemorrhage of Duodenal Cancer

    Directory of Open Access Journals (Sweden)

    Takashi Orii

    2016-05-01

    Full Text Available Because of advances in the technology of gastrointestinal endoscopy and improvements in the quality of stents, it has become routine to place a stent as palliative therapy for malignant gastrointestinal obstruction. On the other hand, stent placement for malignant gastrointestinal hemorrhage has scarcely been reported, although it may be performed for hemorrhage of the esophageal varicose vein. We recently experienced a patient with refractory hemorrhage from an unresectable duodenal cancer who underwent placement of a self-expandable metallic stent (SEMS and thereafter had no recurrence of the hemorrhage. A 46-year-old man underwent laparotomy to radically resect a cancer in the third portion of the duodenum, which invaded widely to the superior mesenteric vein and its branches and was considered unresectable. After stomach-partitioning gastrojejunostomy was performed, chemotherapy was initiated according to the regimen of chemotherapy of far advanced gastric cancer. One year and 4 months after induction of chemotherapy, gastrointestinal hemorrhage occurred. Upper gastrointestinal endoscopy revealed the hemorrhage oozing from the duodenal cancer, and endoscopic hemostasis, such as injection of hypertonic saline epinephrine and argon plasma coagulation, was unsuccessful. Twenty days after emergence of the hemorrhage, an endoscopic covered SEMS was placed with confirmation by fluoroscopy. Immediately after placement of the stent, the tarry stool stopped and the anemia ceased to progress. The recurrence of the hemorrhage has not been confirmed without migration of the stent. SEMS is an effective hemostatic procedure for malignant refractory hemorrhage.

  3. Treatment of gastric outlet and duodenal obstructions with uncovered expandable metal stents

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    AIM: To investigate and evaluate the technical feasibility and clinical effectiveness of fluoroscopically guided peroral uncovered expandable metal stent placement to treat gastric outlet and duodenal obstructions. METHODS: Fifteen consecutive patients underwent peroral placement of WallstentTM Enteral Endoprosthesis to treat gastric outlet and duodenal obstructions (14 malignant, 1 benign). All procedures were completed under fluoroscopic guidance without endoscopic assistance. Follow-up was completed until the patients died or were lost, and the clinical outcomes were analyzed. RESULTS: The technique success rate was 100%, and the oral intake was maintained in 12 of 14 patients varying from 7 d to 270 d. Two patients remained unable to resume oral intake, although their stents were proven to be patent with the barium study. One patient with acute necrotizing pancreatitis underwent enteral stenting to treat intestinal obstruction, and nausea and vomiting disappeared. Ten patients died during the followup period, and their mean oral intake time was 50 d. No procedure-related complications occurred. Stent migration to the gastric antrum occurred in one patient 1 year after the procedure, a tumor grew at the proximal end of the stent in another patient 38 d post-stent insertion. CONCLUSION: Fluoroscopically guided peroral metal stent implantation is a safe and effective method to treat malignant gastrointestinal obstructions, and complications can be ignored based on our short-term study. Indications for this procedure should be discreetly considered because a few patients may not benefit from gastrointestinal insertion, but some benign gastrointestinal obstructions can be treated using this procedure.

  4. Covered self-expandable metallic stent placement for a post-operative malignant anastomotic stricture secondary to recurrent gastric cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Woon Ha; Jung, Gyoo Sik; Kim, Kyu Jong; Lee, Sang Ho [Gospel Hospital, College of Medicine, Kosin University, Busan (Korea, Republic of); Ko, Ji Ho [Masan Samsung Medical Center, Sungkyunkwan University School of University, Masan (Korea, Republic of); Jeong, Kyung Soon [University of Ulsan Colleg of Medicine, Asan Medical Center, Seoul (Korea, Republic of)

    2007-09-15

    To evaluate the technical feasibility and clinical effectiveness of stent placement for the treatment of a post-operative malignant anastomotic stricture secondary to recurrent gastric cancer. Under fluoroscopic guidance, one or two covered stents were placed in 20 consecutive patients (age range, 44-75 years) with an anastomotic stricture due to a recurrent gastric malignancy. Before stent placement, all patients had severe nausea and recurrent vomiting after ingestion. Stent placement was technically successful for all patients, and no procedural complications occurred. After stent placement, 18 of 20 (90.0%) patients were able to ingest at least a liquid diet and had a markedly decreased incidence of vomiting. During the follow-up of 2-116 weeks (mean, 25.5 weeks), stent migration occurred in two patients (10.0%) on one day after the procedure. All patients with stent migration were treated successfully by means of placing a second stent. Three patients showed a recurrence of the stricture due to tumor overgrowth; two of the patients were treated with coaxial placement of a second stent. Another patient refused additional management. Covered self-expandable metallic stent placement seems to be technically feasible and effective for palliative treatment of a post-operative malignant anastomotic stricture secondary to recurrent gastric cancer.

  5. The influence of a metal stent on the distribution of thermal energy during irreversible electroporation

    OpenAIRE

    Scheffer, Hester J.; Vogel, Jantien A.; Willemien van den Bos; Neal, Robert E; Krijn P. van Lienden; Besselink, Marc G.H.; van Gemert, Martin J. C.; van der Geld, Cees W. M.; Meijerink, Martijn R.; Klaessens, John H; Rudolf M Verdaasdonk

    2016-01-01

    Purpose Irreversible electroporation (IRE) uses short duration, high-voltage electrical pulses to induce cell death via nanoscale defects resulting from altered transmembrane potential. The technique is gaining interest for ablations in unresectable pancreatic and hepatobiliary cancer. Metal stents are often used for palliative biliary drainage in these patients, but are currently seen as an absolute contraindication for IRE due to the perceived risk of direct heating of the metal and its sur...

  6. Broncho-vascular fistulas from self-expanding metallic stents: A retrospective case review

    Directory of Open Access Journals (Sweden)

    Chirag Choudhary

    2013-01-01

    Full Text Available To highlight a potentially fatal complication of broncho-vascular fistula arising from the self expanding metallic stent (SEMS placement. We retrospectively analyzed five patients with benign and malignant airway diseases, who developed tracheo/broncho-vascular fistulas following SEMS placement in our tertiary care setting. All patients received either Wallstent or Ultraflex® stent (Boston Scientific, Natick, MA between 1999 and 2007. All patients had received adjunct therapy such as balloon bronchoplasty, laser therapy or electrocautery. Most patients presented with massive hemoptysis. A total of 483 SEMS were placed during this period. SEMS placement can be complicated by Broncho-vascular fistula formation. True incidence and precise time interval between the insertion of stent and onset of this complication is unknown. Additional therapeutic modalities to maintain stent patency may enhance the risk of fistula formation. SEMS should only be used in a select sub-group of patients, after exhaustive evaluation of other treatment options. These cases provide evidence that broncho-vascular fistulas can develop at any time following SEMS placement, suggesting the need for a more cautious approach, especially while using them for a long term management. In benign airway disease, the stent should be removed as soon as healing has taken place.

  7. Double layered self-expanding metal stents for malignant esophageal obstruction, especially across the gastroesophageal junction

    Institute of Scientific and Technical Information of China (English)

    Min Dae Kim; Su Bum Park; Dae Hwan Kang; Jae Hyung Lee; Cheol Woong Choi; Hyung Wook Kim; Chung Uk Chung

    2012-01-01

    AIM:TO evaluate the clinical outcomes of double-layered self-expanding metal stents (SEMS) for treatment of malignant esophageal obstruction according to whether SEMS crosses the gastroesophageal junction (GEJ).METHODS:Forty eight patients who underwent the SEMS insertion for malignant esophageal obstruction were enrolled.Patients were classified as GEJ group (SEMS across GEHm 18 patients) and non-GEJ group (SEMS above GEJ,30 patients) according to SEMS position.Double layered (outer uncovered and inner covered stent) esophageal stents were placed.RESULTS:The SEMS insertion and the clinical improvement were achieved in all patients in both groups.Stent malfunction occurred in seven patients in the GEJ group and nine patients in the non-GEJ group.Tumor overgrowth occurred in five and eight patients,respectively,food impaction occurred in one patient in each group,and stent migration occurred in one and no patient,respectively.There were no significant differences between the two groups.Reflux esophagitis occurred more frequently in the GEJ group (eight vs five patients,P =0.036) and was controlled by proton pump inhibitor.Aspiration pneumonia occurred in zero and five patients,respectively,and tracheoesophageal fistula occurred in zero and two patients,respectively.CONCLUSION:Double-layered SEMS are a feasible and effective treatment when placed across the GEJ for malignant esophageal obstruction.Double-layered SEMS provide acceptable complications,especially migration,although reflux esophagitis is more common in the GEJ group.

  8. Gastroduodenal Outlet Obstruction and Palliative Self-Expandable Metal Stenting: A Dual-Centre Experience

    Directory of Open Access Journals (Sweden)

    Nik S. Ding

    2013-01-01

    Full Text Available Background. Self-expandable metal stents (SEMs are increasingly being utilised instead of invasive surgery for the palliation of patients with malignant gastroduodenal outlet obstruction. Aim. To review two tertiary centres’ experience with placement of SEMs and clinical outcomes. Methods. Retrospective analysis of prospectively collected data over 12 years. Results. Ninety-four patients (mean age, 68; range 28–93 years underwent enteral stenting during this period. The primary tumour was gastric adenocarcinoma in 27 (29% patients, pancreatic adenocarcinoma in 45 (48%, primary duodenal adenocarcinoma in 8 (9%, and cholangiocarcinoma and other metastatic cancers in 14 (16%. A stent was successfully deployed in 95% of cases. There was an improvement in gastric outlet obstruction score (GOOS in 84 (90% of patients with the ability to tolerate an enteral diet. Median survival was 4.25 months (range 0–49 without any significant differences between types of primary malignancy. Mean hospital stay was 3 days (range 1–20. Reintervention rate for stent related complications was 5%. Conclusion. The successful deployment of enteral stents achieves excellent palliation often resulting in the prompt reintroduction of enteral diet and early hospital discharge with minimal complications and reintervention.

  9. Interdisciplinary Canadian guidelines on the use of metal stents in the gastrointestinal tract for oncological indications

    Energy Technology Data Exchange (ETDEWEB)

    Baerlocher, M.O. [Dept. of Radiology, Univ. of Toronto, Toronto, Ontario (Canada)], E-mail: mark.baerlocher@utoronto.ca; Asch, M.R. [Dept. of Diagnostic Imaging, Lakeridge Health Corp., Oshawa, Ontario (Canada); Dixon, P. [Dept. of Radiation Oncology, Durham Regional Cancer Centre, Oshawa, Ontario (Canada); Dept. of Oncology, Queen' s Univ., Kingston, Ontario (Canada); Kortan, P. [Div. of Gastroenterology, Dept. of Medicine, St. Michael' s Hospital, Toronto, Ontario (Canada); Myers, A. [Dept. of Diagnostic Imaging, Lakeridge Health Corp., Oshawa, Ontario (Canada); Law, C. [Dept. of Surgical Oncology, Div. of General Surgery, Sunnybrook HSC, Toronto, Ontario (Canada)

    2008-06-15

    To provide evidence-based guidelines regarding the appropriate use of gastrointestinal stents for oncologic indications. This document describes the use of gastrointestinal stents by appropriately trained physicians. This document is based on a review of the published evidence and supplemented by consensus expert opinion. Gastrointestinal stenting has been evaluated in terms of technical success, complications, patient satisfaction, clinical outcome, and cost-benefit analysis. This document was approved by the Canadian Interventional Radiology Association; approval from the other relevant Canadian societies is pending. Gastrointestinal stenting has a valuable role in the management of the gastrointestinal malignancy. The decision to use such devices should be taken after comprehensive multidisciplinary clinical, endoscopic, and radiologic evaluation. This interdisciplinary Canadian guideline on the use of metal stents in the gastrointestinal tract for ontological indications is based on a scientific literature review and relevant clinical experience. This guideline attempts to define principles of practice for most circumstances, though adherence to this guideline will not, of course, produce successful outcomes in every case. (author)

  10. New stent developments for peripheral arterial occlusive disease; Neue Stententwicklungen fuer die periphere arterielle Verschlusskrankheit

    Energy Technology Data Exchange (ETDEWEB)

    Tepe, G. [Romed Kliniken, Klinikum Rosenheim, Institut fuer Diagnostische und Interventionelle Radiologie, Rosenheim (Germany)

    2010-01-15

    Infrainguinal peripheral occlusive disease is increasingly being treated by endovascular techniques. Bare metal stainless steel, self-expanding nitinol stents, drug-eluting and covered stents (stent grafts) are becoming increasingly more important adjuncts to percutaneous translumninal angioplasty in the treatment of peripheral artery disease. In this article the available evidence supporting the use of stents in the femoropopliteal and tibial arteries will be described as well as their limitations. Future stent developments will also be discussed. (orig.) [German] Die endovaskulaere Therapie spielt bei der Therapie der peripheren arteriellen Verschlusskrankheit (PAVK) eine wichtige Rolle. Unbeschichtete ballonexpandierbare Stahlstents, selbstexpandierende Nitinolstents sowie medikamentenbeschichtete und ''covered stents'' (Stentgrafts) haben eine zunehmende Bedeutung als Zusatztherapie zusammen mit der primaeren Ballonangioplastie gewonnen. In diesem Artikel wird die klinische Evidenz beschrieben, die die Anwendung von Stents im Bereich der femoropoplitealen und tibialen Strombahn unterstuetzt. Limitationen sowie zukuenftige Stententwicklungen werden ebenfalls diskutiert. (orig.)

  11. Stent-induced coronary artery stenosis characterized by multimodal nonlinear optical microscopy

    Science.gov (United States)

    Wang, Han-Wei; Simianu, Vlad; Locker, Mattew J.; Cheng, Ji-Xin; Sturek, Michael

    2011-02-01

    We demonstrate for the first time the applicability of multimodal nonlinear optical (NLO) microscopy to the interrogation of stented coronary arteries under different diet and stent deployment conditions. Bare metal stents and Taxus drug-eluting stents (DES) were placed in coronary arteries of Ossabaw pigs of control and atherogenic diet groups. Multimodal NLO imaging was performed to inspect changes in arterial structures and compositions after stenting. Sum frequency generation, one of the multimodalities, was used for the quantitative analysis of collagen content in the peristent and in-stent artery segments of both pig groups. Atherogenic diet increased lipid and collagen in peristent segments. In-stent segments showed decreased collagen expression in neointima compared to media. Deployment of DES in atheromatous arteries inhibited collagen expression in the arterial media.

  12. Advances in stent technologies and their effect on clinical efficacy and safety

    Directory of Open Access Journals (Sweden)

    Nikam N

    2014-06-01

    Full Text Available Navin Nikam, Toby B Steinberg, Daniel H SteinbergDivision of Cardiology, Medical University of South Carolina, Charleston, SC, USAAbstract: The introduction of intracoronary stents represented a major advance in interventional cardiology. While bare metal stents set the benchmark for improved safety over angioplasty, intimal hyperplasia and subsequent restenosis were important limitations. First-generation drug-eluting stents demonstrated significant improvements in efficacy, but not necessarily safety, and further technologic developments have focused on optimizing both. Current advances and understanding in stent design continue to improve on these concepts. This review summarizes past and present technology with particular emphasis on the principles underlying the efficacy and safety of drug-eluting stents, and offers a glimpse into the next generations of stents aimed at treating symptomatic coronary artery disease.Keywords: drug-eluting stents percutaneous coronary intervention, coronary artery disease, bioabsorbable polymers, bioabsorbable struts, polymer free

  13. Endoscopic multiple metal stenting for the treatment of enteral leaks near the biliary orifice: A novel effective rescue procedure

    Institute of Scientific and Technical Information of China (English)

    Massimiliano Mutignani; Lorenzo Dioscoridi; Stefanos Dokas; Paolo Aseni; Pietro Carnevali; Edoardo Forti; Raffaele Manta; Mariano Sica; Alberto Tringali; Francesco Pugliese

    2016-01-01

    Between April 2013 and October 2015, 6 patients developed periampul ary duodenal or jejunal/biliary leaks after major abdominal surgery. In all patients, percutaneous drainage of the collection or re-operation with primary surgical repair was attempted at first but failed. A fully covered enteral metal stent was placed in all patients to seal the leak. Subsequently, we cannulated the common bile duct and, in some cases, and the main pancreatic duct inserting hydrophilic guidewires through the stent after dilating the stent mesh with a dilatation balloon or breaking the meshes with Argon Plasma Beam. Finally, we inserted a fully covered biliary metal stent to drain the bile into the lumen of the enteral stent. In cases of normal proximal upper gastrointestinal anatomy, a pancreatic plastic stent was also inserted. Oral food intake was initiated when the abdominal drain outflow stopped completely. Stent removal was scheduled four to eight weeks later after a CT scan to confirm the complete healing of the fistula and the absence of any perilesional residual fluid collection. The leak resolved in five patients. One patient died two days after the procedure due to severe, pre-existing, sepsis. The stents were removed endoscopically in four weeks in four patients. In one patient we experiencedstent migration causing small bowel obstruction. In this case, the stents were removed surgically. Four patients are still alive today. They are still under follow-up and doing well. Bilio-enteral fully covered metal stenting with or without pancreatic stenting was feasible, safe and effective in treating postoperative enteral leaks near the biliopancreatic orifice in our small series. This minimally invasive procedure can be implemented in selected patients as a rescue procedure to repair these challenging leaks.

  14. Fabrication of a silver particle-integrated silicone polymer-covered metal stent against sludge and biofilm formation and stent-induced tissue inflammation

    Science.gov (United States)

    Lee, Tae Hoon; Jang, Bong Seok; Jung, Min Kyo; Pack, Chan Gi; Choi, Jun-Ho; Park, Do Hyun

    2016-01-01

    To reduce tissue or tumor ingrowth, covered self-expandable metal stents (SEMSs) have been developed. The effectiveness of covered SEMSs may be attenuated by sludge or stone formation or by stent clogging due to the formation of biofilm on the covering membrane. In this study, we tested the hypothesis that a silicone membrane containing silver particles (Ag-P) would prevent sludge and biofilm formation on the covered SEMS. In vitro, the Ag-P-integrated silicone polymer-covered membrane exhibited sustained antibacterial activity, and there was no definite release of silver ions from the Ag-P-integrated silicone polymer membrane at any time point. Using a porcine stent model, in vivo analysis demonstrated that the Ag-P-integrated silicone polymer-covered SEMS reduced the thickness of the biofilm and the quantity of sludge formed, compared with a conventional silicone-covered SEMS. In vivo, the release of silver ions from an Ag-P-integrated silicone polymer-covered SEMS was not detected in porcine serum. The Ag-P-integrated silicone polymer-covered SEMS also resulted in significantly less stent-related bile duct and subepithelium tissue inflammation than a conventional silicone polymer-covered SEMS. Therefore, the Ag-P-integrated silicone polymer-covered SEMS reduced sludge and biofilm formation and stent-induced pathological changes in tissue. This novel SEMS may prolong the stent patency in clinical application. PMID:27739486

  15. The Supralimus sirolimus-eluting stent.

    Science.gov (United States)

    Lemos, Pedro A; Bienert, Igor

    2013-05-01

    The use of biodegradable polymeric coatings has emerged as a potential bioengineering target to improve the vascular compatibility of coronary drug-eluting stents (DESs). This review summarizes the main features and scientific facts about the Supralimus sirolimus-eluting stent (Sahajanand Medical Technologies Ltd, Surat, India), which is a biodegradable polymer-based, sirolimus-eluting metallic stent that was recently introduced for routine use in Europe. The novel stent is built on a stainless steel platform, coated with a blend of biodegradable polymers (poly-l-lactide, poly-dl-lactide-co-glycolide and polyvinyl pyrrolidone; coating thickness is 4-5 µm). The active agent is the antiproliferative sirolimus in a dose load of 1.4 µg/mm(2), which is released within 48 days. The Supralimus stent was initially evaluated in the single-arm SERIES-I study, which showed binary angiographic restenosis rates of 0% (in-stent) and 1.7% (in-segment) and an in-stent late lumen loss of 0.09 ± 0.28 mm. The multicenter randomized PAINT trial compared two DESs with identical metallic platforms and biodegradable polymer carriers, but different agents (Infinnium [Sahajanand Medical Technologies Pvt Ltd] paclitaxel-eluting stent or Supralimus sirolimus-eluting stent) against bare stents. After 3 years, the pooled DES population had similar rates of cardiac death or myocardial infarction (9 vs 7.1%; p = 0.6), but a lower risk of repeat interventions (10 vs 29.9%; p < 0.01) than controls with bare stents. The incidence of definite or probable stent thrombosis in the pooled DES group was 2.3% (1st year: 1.8%; 2nd year: 0.4% and 3rd year: 0%). These results demonstrate that the novel Supralimus stents are effective in reducing reintervention, while potentially improving the safety profile by decreasing the risk of late-term thrombosis, even though further studies would be necessary to confirm these findings.

  16. Interventional Management of Delayed and Massive Hemobilia due to Arterial Erosion by Metallic Biliary Stent

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hee Seok [Dept. of Radiology, Gyeongsang National University Hospital, Jinju (Korea, Republic of); Shin, Tae Beom [Dept. of Diagnostic Radiology, Kimhae Jung Ang Hospital, Kimhae (Korea, Republic of); Hwang, Jae Cheol [Dept. of Radiology, Ulsan Hospital, Ulsan (Korea, Republic of); Bae, Jae Ik [Dept. of Radiology, Ajou University Hospital, Suwon (Korea, Republic of); Kim, Chang Won [Dept. of Radiology, Busan National University Hospital, Busan (Korea, Republic of)

    2012-01-15

    To evaluate the effectiveness of interventional management for delayed and massive hemobilia secondary to arterial erosion self expandable metallic stent (SES) in with biliary duct malignancy. Over 8-year period, eight patients who suffered from delayed massive hemobilia after SES placement for malignant biliary obstruction as palliative procedure, were included. The mean period between SES placement and presence of massive gastrointestinal hemorrhage was 66.5 days (15-152 days), pancreatic cancer (n = 2), Klatskin tumor (n = 2), common bile duct cancer (n = 2), intrahepatic cholangiocarcinoma (n = 1), and gastric cancer with ductal invasion (n = 1). Angiographic findings were pseudoaneurysm (n = 6), contrast extravasation (n = 1) and arterial spasm at segment (n = 1). Six patients underwent embolization of injured vessels using microcoils and N-butyl cyanoacrylate. Two patients underwent stent graft placement at right hepatic artery to prevent ischemic hepatic damage because of the presence of portal vein occlusion. Massive hemobilia was successfully controlled by the embolization of arteries (n = 6) and stent graft placement (n = 2) without related complications. The delayed massive hemobilia to arterial erosion metallic biliary stent is rare this complication be successfully treated by interventional management.

  17. Titanium-nitride-oxide-coated coronary stents: insights from the available evidence.

    Science.gov (United States)

    Karjalainen, Pasi P; Nammas, Wail

    2016-11-12

    Coating of stent surface with a biocompatible material is suggested to improve stent safety profile. A proprietary process was developed to coat titanium-nitride-oxide on the stent surface, based on plasma technology that uses the nano-synthesis of gas and metal. Preclinical in vitro and in vivo investigation confirmed blood compatibility of titanium (nitride-) oxide films. Titanium-nitride-oxide-coated stents demonstrated a better angiographic outcome, compared with bare-metal stents at mid-term follow-up; however, they failed to achieve non-inferiority for angiographic outcome versus second-generation drug-eluting stents. Observational studies showed adequate clinical outcome at mid-term follow-up. Non-randomized studies showed an outcome of titanium-nitride-oxide-coated stents comparable to - or better than - first-generation drug-eluting stents at long-term follow-up. Two randomized controlled trials demonstrated comparable efficacy outcome, and a better safety outcome of titanium-nitride-oxide-coated stents versus drug-eluting stents at long-term follow-up. Evaluation by optical coherence tomography at mid-term follow-up revealed better neointimal strut coverage associated with titanium-nitride-oxide-coated stents versus drug-eluting stents; yet, neointimal hyperplasia thickness was greater. Key messages Stents coated with titanium-nitride-oxide demonstrated biocompatibility in preclinical studies: they inhibit platelet and fibrin deposition, and reduce neointimal growth. In observational and non-randomized studies, titanium-nitride-oxide-coated stents were associated with adequate safety and efficacy outcome. In randomized trials of patients with acute coronary syndrome, titanium-nitride-oxide-coated stents were associated with a better safety outcome, compared with drug-eluting stents; efficacy outcome was comparable.

  18. Flexible Yttrium Coordination Geometry Inhibits “Bare-Metal” Guest Interactions in the Metal-Organic Framework Y(btc

    Directory of Open Access Journals (Sweden)

    Josie E. Auckett

    2016-10-01

    Full Text Available Y(btc (btc = 1,3,5-benzenetricarboxylate is a metal-organic framework that exhibits significant adsorption of industrially-relevant gases such as H2, CH4, and O2. Previous studies have noted a surprising lack of close interactions between the adsorbed guest molecules and Y, despite the apparent availability of a “bare-metal” binding site. We have extended our previous work in a detailed investigation of the adsorption behaviours of CO2, CD4, and O2 in Y(btc over a range of concentrations using in situ neutron powder diffraction methods. The O–Y–O bond angles enclosing the bare-metal site are found to change considerably depending on the type and quantity of guest molecules present. Multiple binding sites are found for each guest species, and the largest changes in O–Y–O angles are accompanied by changes in the filling sequences of the binding sites, pointing to an important interplay between guest-induced framework distortions and binding site accessibility. These results suggest the potential for coordinatively flexible rare-earth metal centres to promote guest-selective binding in metal-organic frameworks.

  19. Self-expandable metallic stents for palliation of patients with malignant gastric outlet obstruction caused by stomach cancer

    Institute of Scientific and Technical Information of China (English)

    Tae Oh Kim; Dae Hwan Kang; Gwang Ha Kim; Jeong Heo; Geun Am Song; Mong Cho; Dong Heon Kim; Mun Sup Sim

    2007-01-01

    AIM: To ascertain clinical outcome and complications of self-expandable metal stents for endoscopic palliation of patients with malignant obstruction of the gastrointestinal (GI) tract.METHODS: A retrospective review was performed throughout August 2000 to June 2005 of 53 patients with gastric outlet obstruction caused by stomach cancer. All patients had symptomatic obstruction including nausea, vomiting, and decreased oral intake. All received self-expandable metallic stents.RESULTS: Stent implantation was successful in all 53 (100%) patients. Relief of obstructive symptoms was achieved in 43 (81.1%) patients. No immediate stent-related complications were noted. Seventeen patients had recurrent obstruction (tumor ingrowth in 14 patients, tumor overgrowth in 1 patient, and partial distal stent migration in 2 patients). The mean survival was 145 d. Median stent patency time was 187 d.CONCLUSION: Endoscopic placement of self-expandable metallic stents is a safe and effective treatment for the palliation of patients with inoperable malignant gastric outlet obstruction caused by stomach cancer.

  20. Clinical benefit of radiation therapy and metallic stenting for unresectable hilar cholangiocarcinoma

    Institute of Scientific and Technical Information of China (English)

    Hiroyuki Isayama; Takeshi Tsujino; Yousuke Nakai; Takashi Sasaki; Keiichi Nakagawa; Hideomi Yamashita; Taku Aoki; Kazuhiko Koike

    2012-01-01

    AIM:To determine the efficacy of external beam radiotherapy (EBRT),with or without intraluminal brachytherapy (ILBT),in patients with non-resected locally advanced hilar cholangiocarcinoma.METHODS:We analyzed 64 patients with locally advanced hilar cholangiocarcinoma,including 25 who underwent resection (17 curative and 8 non-curative),28 treated with radiotherapy,and 11 who received best supportive care (BSC).The radiotherapy group received EBRT (50 Gy,30 fractions),with 11 receiving an additional 24 Gy (4 fractions) ILBT by iridium-192 with remote after loading.ILBT was performed using percutaneous transhepatic biliary drainage (PTBD) route.Uncovered metallic stents (UMS) were inserted into nonresected patients with obstructive jaundice,with the exception of four patients who received percutaneous transhepatic biliary drainage only.UMS were placed endoscopically or percutaneously,depending on the initial drainage procedure.The primary endpoints were patient death or stent occlusion.Survival time of patients in the radiotherapy group was compared with that of patients in the resection and BSC groups.Stent patency was compared in the radiotherapy and BSC groups.RESULTS:No statistically significant differences in patient characteristics were found among the resection,radiotherapy,and BSC groups.Three patients in the radiotherapy group and one in the BSC group did not receive UMS insertion but received PTBD alone;cholangitis occurred after endoscopic stenting,and patients were treated with PTBD.A total of 16 patients were administered additional systemic chemotherapy (5-fluorouracil-based regimen in 9,S-1 in 6,and gemcitabine in 1).Overall survival varied significantly among groups,with median survival times of 48.7 mo in the surgery group,22.1 mo in the radiotherapy group,and 5.7 mo in the BSC group.Patients who underwent curative resection survived significantly longer than those who were not candidates for surgery (P =0.0076).Cumulative survival in the

  1. In vivo Evaluation of Cenderitide-Eluting Stent (CES) II.

    Science.gov (United States)

    Huang, Yingying; Ng, Xu Wen; Lim, Soon Ghim; Chen, Horng Haur; Burnett, John C; Boey, Yin Chiang Freddy; Venkatraman, Subbu S

    2016-02-01

    The use of drug-eluting coronary stents has led to significant reduction in in-stent restenosis (ISR), but led to delayed endothelialization, necessitating the prolonged use of expensive anti-thrombotic drugs with their side-effects. Cenderitide (CD-NP) is a novel anti-proliferative chimeric peptide of semi-endothelial origin. Our previous work in vitro has demonstrated; that the smooth muscle cells were inhibited significantly more than endothelial cells which is the desirable feature of an anti-restenosis drug. This work reports the effects of implantation of a centeritide-eluting stent (CES) on ISR and endothelialization in an in vivo model. CESs were produced by coating bare metallic stents with CD-NP entrapped in biodegradable poly(ε-caprolactone) using an ultrasonic spray coater. A total of 32 stents were successfully implanted into 16 pigs, and all animal survived for 28 days. The plasma levels of CD-NP were significantly higher in the CES group than in the control group (bare metal stents and polymer-coated stent) at post-stenting, indicating the successful release of CD-NP from the stent in vivo. Furthermore, SEM analysis results showed the greater endothelial coverage of the stent struts, as well as between the struts in CES group. Moreover, histological results showed mild inflammation, and low fibrin score at 28 days. However, plasma cGMP (second messenger, cyclic 3',5' guanosine monophosphate) does not show a significant difference, and the CES is also unable to show significant difference in terms on neointimal area and stenosis, in comparison to BMS at 28 days.

  2. Long-term safety and efficacy of percutaneous coronary intervention with stenting and coronary artery bypass surgery for multivessel coronary artery disease: A meta-analysis with 5-year patient-level data from the ARTS, ERACI-II, MASS-II, and SoS trials

    NARCIS (Netherlands)

    J. Daemen (Joost); H. Boersma (Eric); M. Flather (Marcus); J. Booth (Jean); R.H. Stables (Rodney); A. Rodriguez (Alfredo Chapin); G.A. Rodriguez-Granillo (Gaston); W.A. Hueb (Whady Armindo); P.A. Lemos Neto (Pedro); P.W.J.C. Serruys (Patrick)

    2008-01-01

    textabstractBackground - Randomized trials that studied clinical outcomes after percutaneous coronary intervention (PCI) with bare metal stenting versus coronary artery bypass grafting (CABG) are underpowered to properly assess safety end points like death, stroke, and myocardial infarction. Pooling

  3. Clinical outcomes of self-expandable metal stents in palliation of malignant anastomotic strictures caused by recurrent gastric cancer

    Institute of Scientific and Technical Information of China (English)

    Yu Kyung Cho; Sang Woo Kim; Kwan Woo Nam; Jae Hyuck Chang; Jae Myung Park; Jeong-Jo Jeong; In Seok Lee; Myung-Gyu Choi; In-Sik Chung

    2009-01-01

    AIM: To examine the technical feasibility and clinical outcomes of the endoscopic insertion of a selfexpandable metal stent (SEMS) for the palliation of a malignant anastomotic stricture caused by recurrent gastric cancer. METHODS: The medical records of patients, who had obstructive symptoms caused by a malignant anastomotic stricture after gastric surgery and underwent endoscopic insertion of a SEMS from January 2001 to December 2007 at Kangnam St Mary's Hospital, were reviewed retrospectively. RESULTS: Twenty patients (15 male, mean age 63 years) were included. The operations were a total gastrectomy with esophagojejunostomy ( n = 12), subtotal gastrectomy with Billroth-Ⅰ reconstruction ( n = 2) and subtotal gastrectomy with Billroth- Ⅱ reconstruction ( n = 8). The technical and clinical success rates were 100% and 70%, respectively. A small bowel or colon stricture was the reason for a lack of improvement in symptoms in 4 patients. Two of these patients showed improvement in symptoms after another stent was placed. Stent reobstruction caused by tumor ingrowth or overgrowth occurred in 3 patients (15%) within 1 mo after stenting. Stent migration occurred with a covered stent in 3 patients who underwent a subtotal gastrectomy with Billroth-Ⅱ reconstruction. Two cases of partial stent migration were easily treated with a second stent or stent repositioning. The median stent patency was 56 d (range, 5-439 d). The median survival was 83 d (range, 12-439 d). CONCLUSION: Endoscopic insertion of a SEMS provides safe and effective palliation of a recurrent anastomotic stricture caused by gastric cancer. A meticulous evaluation of the presence of other strictures before inserting the stent is essential for symptom improvement.

  4. Role of self-expanding metal stents in the management ofvariceal haemorrhage: Hype or hope?

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    Despite the advances of medical, endoscopic andradiological therapy over recent years the mortality ratesof acute variceal haemorrhage are still 16%-20% and themedium term outcome has not improved in the last 25years. Early transjugular intrahepatic portosystemic shunthas proved to be an effective therapy for selected groupsof patients with a high risk of re-bleeding and moderateliver disease. However, there is an unmet need for atherapy that can be applied in patients with a high risk ofre-bleeding and advanced liver disease either as definitivetherapy or as a bridge to permanent therapy. Selfexpandingmetal stents can be placed without the needfor endoscopic or fluoroscopic control and, once in place,will provide effective haemostasis and allow a routefor oral fluids and nutrition. They can remain in placewhilst liver function recovers and secondary prophylaxisis initiated. We review the results of 6 case seriesincluding a total of 83 patients and the first randomisedcontrolled trial of self-expanding metal stents vs balloontamponade (BT) in the management of refractory varicealhaemorrhage. We report that self-expanding metal stentsprovide effective haemostasis and perform better thanBT in refractory bleeding, where they are associated withfewer complications. Whilst the most effective place forself-expanding metal stents in the management algorithmneeds to be determined by further randomised controlledtrials, currently they provide an effective alternative to BTin selected patients.

  5. A Double-Layered Covered Biliary Metal Stent for the Management of Unresectable Malignant Biliary Obstruction: A Multicenter Feasibility Study

    Science.gov (United States)

    Park, Jin-Seok; Jeong, Seok; Lee, Don Haeng; Moon, Jong Ho; Lee, Kyu Taek; Dong, Seok Ho

    2016-01-01

    Background/Aims The covered self-expandable metal stent (CMS) was developed to prevent tumor ingrowth-induced stent occlusion during the treatment of malignant biliary obstruction. However, complications such as cholecystitis, pancreatitis, and stent migration can occur after the endoscopic insertion of CMSs. The aim of the present study was to assess the efficacy and safety of a double-layered CMS (DCMS) for the management of malignant bile duct obstruction. Methods DCMSs were endoscopically introduced into 59 patients with unresectable malignant extrahepatic biliary obstruction at four tertiary referral centers, and the patient medical records were retrospectively reviewed. Results Both the technical and functional success rates were 100%. Procedure-related complications including pancreatitis, cholangitis, stent migration, and liver abscess occurred in five patients (8.5%). The median follow-up period was 265 days (range, 31 to 752 days). Cumulative stent patency rates were 68.2% and 40.8% at 6 and 12 months, respectively. At the final follow-up, the rate of stent occlusion was 33.9% (20/59), and the median stent patency period was 276 days (range, 2 to 706 days). Conclusions The clinical outcomes of DCMSs were comparable to the outcomes previously reported for CMSs with respect to stent patency period and complication rates. PMID:27172927

  6. Endoscopic ultrasound-guided biliary drainage with placement of a fully covered metal stent for malignant biliary obstruction

    Institute of Scientific and Technical Information of China (English)

    Tae Hyeon Kim; Seong Hun Kim; Hyo Jeong Oh; Young Woo Sohn; Seung Ok Lee

    2012-01-01

    AIM:To determine the utility of endoscopic ultrasoundguided biliary drainage (EUS-BD) with a fully covered self-expandable metal stent for managing malignant biliary stricture.METHODS:We collected data from 13 patients who presented with malignant biliary obstruction and underwent EUS-BD with a nitinol fully covered selfexpandable metal stent when endoscopic retrograde cholangiopancreatography (ERCP) fails.EUS-guided choledochoduodenostomy (EUS-CD) and EUS-guided hepaticogastrostomy (EUS-HG) was performed in 9 patients and 4 patients,respectively.RESULTS:The technical and functional success rate was 92.3% (12/13) and 91.7% (11/12),respectively.Using an intrahepatic approach (EUS-HG,n =4),there was mild peritonitis (n =1) and migration of the metal stent to the stomach (n =1).With an extrahepatic approach (EUS-CD,n =10),there was pneumoperitoneum (n =2),migration (n =2),and mild peritonitis (n =1).All patients were managed conservatively with antibiotics.During follow-up (range,1-12 mo),there was re-intervention (4/13 cases,30.7%) necessitated by stent migration (n =2) and stent occlusion (n =2).CONCLUSION:EUS-BD with a nitinol fully covered self-expandable metal stent may be a feasible and effective treatment option in patients with malignant biliary obstruction when ERCP fails.

  7. Delayed ischemic cecal perforation despite optimal decompression after placement of a self-expanding metal stent: report of a case

    DEFF Research Database (Denmark)

    Knop, Filip Krag; Pilsgaard, Bo; Meisner, Søren;

    2004-01-01

    condition. Three days after stent deployment, x-ray examinations revealed a small-bowel obstruction and emergency surgery was performed. Intraoperative findings demonstrated a segment of ileum fixated to the tumor in the small pelvis, resulting in the obstructive condition. Furthermore, a cecal perforation...... to this specific treatment. We conclude that although a patient is eligible for treatment with self-expanding metal stents, large-bowel obstruction can be too "old" for stent-decompression, causing ischemic perforation of the colon. Furthermore, we underline the need to focus on the possibility of obstructions...

  8. [Safety of magnetic resonance imaging after coronary stenting].

    Science.gov (United States)

    Sinitsyn, V E; Stukalova, O V; Kupriianova, O M; Ternovoĭ, S K

    2007-01-01

    Magnetic resonance imaging (MRI) is contraindicated to some patients with certain types of metallic devices and implants (e.g. cerebral surgical clips, defibrillators). There are some controversies concerning safety of MRI in patients with metallic coronary stents in cases when MRI examination is performed earlier then one month after stent implantation. Analysis of published data has shown that MRI performed with systems having field strength up to 3 Tesla does not cause migration and heating of both bare and coated stent and is not associated with increased risk of coronary artery thrombosis. MRI can be performed safely in first days after coronary stent implantation. Small local artifacts on MRI images do not influence interpretation of the data (except for cases of coronary magnetic resonance angiography).

  9. Percutaneous expandable metallic stent biliary endoprostheses used inmalignant and benign obstructive jaundice

    Institute of Scientific and Technical Information of China (English)

    Hai Ying Liu; Wei Hua Tong; Wei Min Hu; Huai Ren Li; Zhe Sheng Wen; Jia Kang Wang; Wan Xi Huang; Shu Liu

    2000-01-01

    AIM To evaluate the effects of expandable metallic stent biliary endoprostheses (EMSBE) viaultrasonographic guided percutaneous transhepatic approach on the treatment of benign and malignantobstructive jaundice.METHODS Thirty-eight patients with obstructive jaundice (29 males and 9 females) aged 27 to 69 years(mean 54.7 years) were studied. Of them, 4 were benign and 34 malignant obstructions. Percutaneoustranshepatic cholangiography (PTC) was performed under ultrasonic guidance. A catheter was introducedinto the dilated bile duct via the introducer. A guide wire was inserted through the occlusive part of biliary duct after dilating with a double-lumen balloon catheter. A self-expandable metallic stent was inserted intcthe occlusive bile duct under fluoroscopic control.RESULTS The success rate of sonographic guided PTC was 100% (38/38) and the success rate of stentimplantation was 86.8% (33/ 38). Biliary obstruction was eliminated immediately, jaundice subsidedgradually and symptoms relieved after the procedure. During the 3 to 28 months fellow-up, re-occlusionoccurred in 4 malignant cases which were corrected by balloon catheter dilation and/or by stent, one patienthad secondary cholangitis and fifteen died without jaundice 6 - 28 months after the procedure. The otherswere alive with no jaundice. No severe complications or side effects were observed.CONCLUSION EMSBE via sonographic guided percutaneous transhepatic approach is a reliable and safepalliative therapy for malignant jaundice and an ideal nonoperative method for benign biliary obstruction. Ithas a definite positive impact on the quality of patient life.

  10. Fe-Mn alloys for metallic biodegradable stents: degradation and cell viability studies.

    Science.gov (United States)

    Hermawan, Hendra; Purnama, Agung; Dube, Dominique; Couet, Jacques; Mantovani, Diego

    2010-05-01

    Biodegradable stents have shown their potential to be a valid alternative for the treatment of coronary artery occlusion. This new class of stents requires materials having excellent mechanical properties and controllable degradation behaviour without inducing toxicological problems. The properties of the currently considered gold standard material for stents, stainless steel 316L, were approached by new Fe-Mn alloys. The degradation characteristics of these Fe-Mn alloys were investigated including in vitro cell viability. A specific test bench was used to investigate the degradation in flow conditions simulating those of coronary artery. A water-soluble tetrazolium test method was used to study the effect of the alloy's degradation product to the viability of fibroblast cells. These tests have revealed the corrosion mechanism of the alloys. The degradation products consist of metal hydroxides and calcium/phosphorus layers. The alloys have shown low inhibition to fibroblast cells' metabolic activities. It is concluded that they demonstrate their potential to be developed as degradable metallic biomaterials.

  11. Expandable metallic stent in the treatment of subglottic tracheal stenosis: Report of long-term failure in 4 cases

    Energy Technology Data Exchange (ETDEWEB)

    Han, Young Min; Hong, Ki Whan; Chung, Kyung Ho; Kim, Chong Soo; Sohn, Myung He; Choi, Ki Chul [Chonbuk National University Medical School, Chunju (Korea, Republic of); Song, Ho Young [Ulsan University, Medical School, Seoul (Korea, Republic of)

    1994-06-15

    Subglottic stenosis is more likely to develop secondary to endotracheal intubation if one or more traumarelated risk factors are involved. Subglottic stenosis have been dealt with many medicosurgical procedures such as dilatation, stent, laryngofissure with or without skin of mucosal graft, and segmental resection. We report long-term failure of expandable metallic stent in the treatment of subglottic tracheal stenosis in 4 cases which had been presented with respiration difficulty due to framework problem of subglottic trachea after surgical operation.

  12. Role of Self-Expandable Metal Stents in Acute Variceal Bleeding

    Directory of Open Access Journals (Sweden)

    Fuad Maufa

    2012-01-01

    Full Text Available Acute variceal bleeding continues to be associated with significant mortality. Current standard of care combines hemodynamic stabilization, antibiotic prophylaxis, pharmacological agents, and endoscopic treatment. Rescue therapies using balloon tamponade or transjugular intrahepatic portosystemic shunt are implemented when first-line therapy fails. Rescue therapies have many limitations and are contraindicated in some cases. Placement of fully covered self-expandable metallic stent is a promising therapeutic technique that can be used to control bleeding in cases of refractory esophageal bleeding as an alternative to balloon tamponade. These stents can be left in place for as long as two weeks, allowing for improvement in liver function and institution of a more definitive treatment.

  13. The electronic properties of bare and alkali metal adsorbed two-dimensional GeSi alloy sheet

    Science.gov (United States)

    Qiu, Wenhao; Ye, Han; Yu, Zhongyuan; Liu, Yumin

    2016-09-01

    In this paper, the structural and electronic properties of both bare and alkali metal (AM) atoms adsorbed two-dimensional GeSi alloy sheet (GeSiAS) are investigated by means of first-principles calculations. The band gaps of bare GeSiAS are shown slightly opened at Dirac point with the energy dispersion remain linear due to the spin-orbit coupling effect at all concentrations of Ge atoms. For metal adsorption, AM atoms (including Li, Na and K) prefer to occupy the hexagonal hollow site of GeSiAS and the primary chemical bond between AM adatom and GeSiAS is ionic. The adsorption energy has an increase tendency with the increase of the Ge concentration in supercell. Besides, single-side adsorption of AM atoms introduces band gap at Dirac point, which can be tuned by the Ge concentration and the species of AM atoms. The strong relation between the band gaps and the distribution of Si and Ge atoms inside GeSiAS are also demonstrated. The opened band gaps of AM covered GeSiAS range from 14.8 to 269.1 meV along with the effective masses of electrons ranging from 0.013 to 0.109 me, indicating the high tunability of band gap as well as high mobility of carriers. These results provide a development in two-dimensional alloys and show potential applications in novel micro/nano-electronic devices.

  14. Successful management of a benign anastomotic colonic stricture with self-expanding metallic stents:A case report

    Institute of Scientific and Technical Information of China (English)

    Yong-Song Guan; Long Sun; Xiao Li; Xiao-Hua Zheng

    2004-01-01

    AIM: To assess the effectiveness of and complications associated with metallic stent placement for treatment of anastomotic colonic strictures.METHODS: A 46-year-old man underging two procedures of surgery for perforation of descending colon due to a traffic accident presented with pain, abdominal distention,and inability to defecate. Single-contrast barium enema radiograph showed a severe stenosis in the region of surgical anastomosis and the patient was too weak to accept another laparotomy. Under fluoroscopic and endoscopic guidance, we placed two metallic stents in the stenosis site of the anastomosis of the patient with anastomotic colonic strictures.RESULTS: In this case of postsurgical stenosis, the first stent relieved the symptoms of obstruction, but stent migration happened on the next day so an additional stent was required to deal with the stricture and relieve the symptoms.CONCLUSION: This case confirms that metallic stenting may represent an effective treatment for anastomotic colonic strictures in the absence of other therapeutic alternatives.

  15. A Comparison of Y-Type and T-Type Metallic Bilateral Biliary Stents in Patients with Malignant Hilar Biliary Obstruction

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Esther; Jin, Gong Yong; Hwang, Seung Bae; Choi, Eun Jung; Song, Ji Soo; Han, Young Min; Kwon, Keun Sang [Dept. of Chonbuk National University Hospital and Medical School, Jeonju (Korea, Republic of)

    2013-04-15

    To compare the Y type (side-by-side) and T type (stent-in-stent) bilateral biliary metal stenting in malignant hilar obstruction in terms of treatment outcomes, including post-stenting serum bilirubin level and stent patency. 41 consecutive patients with advanced hilar malignancies who underwent percutaneous placement of bilateral metallic stents - Y (n = 23) and T types (n = 18) - were retrospectively reviewed. We evaluated stent patency after the procedure by cholangiogram and abdominal CT. Pre- and post-stenting serum bilirubin level (total, direct bilirubin) at 1 week and at 1 month were compared. Student t-test and Kaplan-Meier method were used in the statistical analysis. After comparing the median stent patency according to both types, they did not differ significantly (Y: 38 days, T: 61 days; p 0.141). There was a more decrease in the total and direct bilirubin of the T type compared to the Y type after 1 week (p = 0.013, 0.025). However, no significant difference existed between the decreasing bilirubin rates of both types after 1 month (p = 0.923, 0.742). In patients with malignant hilar obstruction, both Y and T type bilateral metallic biliary stents are effective methods. Stent patency and bilirubin decrease rates were not significantly different.

  16. Firebird stent for the treatment of patients with coronary heart disease: short-term clinical outcome

    Institute of Scientific and Technical Information of China (English)

    Hai-Ying Wang; Jin-Bo Wang; Feng Liang; Da-Yi Hu; Ming-Ying Wu; Tian-Chang Li; Chu-Zhong Tang; Ji-Yun Wang; Chang-Lin Lu

    2009-01-01

    Objective The sirolimus-eluting stent (SES) has dramatically reduced the rate ofrestenosis in comparison to that with the bare-metal stent (BMS).This study aimed to evaluate the short-term efficacy and safety of Firebird stent implantation for patients with coronary heart disease (CHD). Methods From Apri12006 through July 2007, 155 patients (mean age 58.93~10.27 years) with CHD were implanted with Firebird stent or Cypher select stent at Daxing Hospital. Patients were followed up for one year. All-cause mortality, major adverse cardiac events (MACE, including cardiac death, myocardial infarction, recurrence of angina pectoris, heart failure, revascularization, and adverse arrhythmia) and stent thrombosis were compared between the 2 groups. Results Of the 155 consecutive patients, 147 patients were revascularized completely. Of these patients, 48 (with 59 lesions) were treated with Firebird stent, 59 patients (with 75 lesions) with Cypher select stent. The demographic characteristics were similar in the 2 groups. All the angiographic and procedural results were not significantly different between the 2 groups. All-cause mortality, myocardial infarction, recurrence of angina pectoris, MACE and stent thrombosis were almost identical between the 2 groups before discharge, at 6 months and at one year .Conclusion The short-term efficacy and safety of Firebird stent are similar to that of the cypher select stent for the treatment of patients with CHD.

  17. Factors Associated with In-stent Restenosis in Patients Following Percutaneous Coronary Intervention

    Directory of Open Access Journals (Sweden)

    Dedi Wihanda

    2015-07-01

    Full Text Available Aim: to determine factors associated with In-Stent Restenosis (ISR in patients following Percutaneous Coronary Intervention (PCI. Methods: a retrospective cross-sectional study was conducted using secondary information from medical records of post-PCI patients who underwent follow-up of angiography PCI between January 2009 and March 2014 at The Integrated Cardiovascular Service Unit, Cipto Mangunkusumo Hospital, Jakarta. Angiographic ISR was defined when the diameter of stenosis ≥50% at follow-up angiography including the diameter inside the stent and diameter with five-mm protrusion out of the proximal and distal ends of the stent. Results: there were 289 subjects including 133 subjects with and 156 subjects without ISR. The incidence of ISR in patients using of bare-metal stent (BMS and drug-eluting stent (DES were 61.3% and 40.7%, respectively. Factors associated with ISR are stent-type (OR=4.83, 95% CI 2.51-9.30, stent length (OR=3.71, 95% CI 1.99-6.90, bifurcation lesions (OR=2.43, 95% CI 1.16-5.10, smoking (OR=2.30, 95% CI 1.33-3.99, vascular diameter (OR=2.18, 95% CI 1.2-3.73, hypertension (OR=2.16, 95% CI 1.16-4.04 and diabetes mellitus (OR=2.14, 95% CI 1.23-3.70. Conclusion: stent type, stent length, bifurcation lesions, smoking, vascular diameter, hypertension and DM are factors associated with ISR in patients following PCI. Key words: bare-metal stent; drug-eluting stent; in-stent restenosis.

  18. First principles study of the electron density distribution in a pair of bare metallic electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Chun-Lan [Suzhou University of Science and Technology, School of Mathematics and Physics, Suzhou (China); Chen, Yu-Chang; Nghiem, Diu; Tseng, Allen; Huang, Pao-Chieh [National Chiao Tung University, Department of Electrophysics, Hsinchu (China)

    2011-07-15

    Self-consistent calculations of electron density distribution from first principles for a series of semi-infinite metals show that the electron density almost drops to zero at 8.5 a.u. away from a metal surface. The electron densities in a series of bimetallic-electrode systems with a distance between the two electrodes of 21.7 a.u. are further investigated. Spin-polarized calculations of electron density for nonmagnetic and magnetic bimetallic-electrode systems are compared. Our work is helpful for first principles investigation of spin-dependent metal-molecule-metal tunneling junctions. (orig.)

  19. Malignant tracheal-mediastinal-parenchymal-pleural fistula after chemoradiation plus bevacizumab: management with a Y-silicone stent inside a metallic covered stent.

    Science.gov (United States)

    Machuzak, Michael S; Santacruz, Jose F; Jaber, Wissam; Gildea, Thomas R

    2015-01-01

    Tracheal or bronchial-mediastinal fistulas are a rare entity associated to high mortality. We report a case of a 58-year-old man with an unresectable non-small cell carcinoma of the lung, treated with chemoradiation followed by bevacizumab. Approximately, 6 weeks after starting bevacizumab he developed a severe cough with copious secretions He could not lie supine due to the feeling of drowning. Investigations revealed a large tracheo-mediastinal-parenchymal-pleural fistula. Palliative management was offered with interventional bronchoscopic techniques. He was found to have a large central airway defect that obliterated almost 40% of the trachea. Under general anesthesia and positive pressure ventilation, a unique approach was used to rebuild an eroded tracheal and right main stem bronchial wall. A self-expanding metallic stent (SEMS) was placed to provide a scaffold of support, whereas a Dumon Y-stent was placed inside the SEMS. This combination allowed for a patent, stable airway; recreating the normal anatomy in a minimally invasive manner walling off the fistula. The patient was discharged 2 days after the bronchoscopic intervention, with significant palliation of his symptomatology. Eighteen months later, the upper lobe cavity persists with a stable airway and stents perfectly positioned with clinically insignificant evidence of stent related granulation in the upper trachea.

  20. Biliary Leak in Post-Liver-Transplant Patients: Is There Any Place for Metal Stent?

    Directory of Open Access Journals (Sweden)

    Fernanda P. Martins

    2012-01-01

    Full Text Available Objectives. Endoscopic management of bile leak after orthotopic liver transplant (OLT is widely accepted. Preliminary studies demonstrated encouraging results for covered self-expandable metal stents (CSEMS in complex bile leaks. Methods. Thirty-one patients with post-OLT bile leaks underwent endoscopic temporary placement of CSEMS (3 partially CSEMS , 18 fully CSEMS with fins and 10 fully CSEMS with flare ends between December 2003 and December 2010. Long-term clinical success and safety were evaluated. Results. Median stent indwelling and follow-up were 89 and 1,353 days for PCSEMS, 102 and 849 for FCSEMS with fins and 98 and 203 for FCSEMS with flare ends. Clinical success was achieved in 100%, 77.8%, and 70%, respectively. Postplacement complications: cholangitis (1 and proximal migration (1, both in the FCSEMS with fins. Postremoval complications were biliary strictures requiring drainage: PCSEMS (1, FCSEMS with fins (6 and with flare ends (1. There was no significant differences in the FCSEMS groups regarding clinical success, age, gender, leak location, previous treatment, stent indwelling, and complications. Conclusion. Temporary placement of CSEMS is effective to treat post-OLT biliary leaks. However, a high number of post removal biliary strictures occurred especially in the FCSEMS with fins. CSEMS cannot be recommended in this patient population.

  1. Drug-eluting stents, restenosis and revascularization.

    Science.gov (United States)

    Ramcharitar, Steve; Gaster, Anne Louise; Daemen, Joost; Serruys, Patrick

    2007-06-01

    Several meta-analyses have demonstrated the superiority of drug-eluting stents (DES) in reducing the incidence of restenosis, target vessel revascularization and target lesion revascularization compared to their predecessor, the bare-metal stent. In comparing Cypher and Taxus stents, the two most recent meta-analyses have given the edge to the Cypher. However, it must be stressed that the superiority of one DES over another remains debatable due to ever changing "real-world data" compared to those attained from randomized trials. The newer sirolimus analogs and selective inhibitors are challenging the old guard in their quest to further limit restenosis. So too are the newer "high-tech" polymers and additionally by using more biodegradable material in the stent's design. Stents aimed at targeting lesions are a new armament in the battle against restenosis and together with combination therapies are exciting key areas to watch. The ideal way to treat a DES in-stent restenosis is still a challenge and hence the impetus is to avoid it from happening in the first place.

  2. Long-term outcome of endoscopic metallic stenting for benign biliary stenosis associated with chronic pancreatitis

    Institute of Scientific and Technical Information of China (English)

    Taketo Yamaguchi; Takeshi Ishihara; Katsutoshi Seza; Akihiko Nakagawa; Kentarou Sudo; Katsuyuki Tawada; Teruo Kouzu; Hiromitsu Saisho

    2006-01-01

    AIM: Endoscopic metal stenting (EMS) offers good results in short to medium term follow-up for bile duct stenosis associated with chronic pancreatitis (CP);however, longer follow-up is needed to determine if EMS has the potential to become the treatment of first choice.METHODS: EMS was performed in eight patients with severe common bile duct stenosis due to CR After the resolution of cholestasis by endoscopic naso-biliary drainage three patients were subjected to EMS while,the other five underwent EMS following plastic tube stenting. The patients were followed up for more than5 years through periodical laboratory tests and imaging techniques.RESULTS: EMS was successfully performed in all the patients. Two patients died due to causes unrelated to the procedure: one with an acute myocardial infarction and the other with maxillary carcinoma at 2.8 and 5.5years after EMS, respectively. One patient died with cholangitis because of EMS clogging 3.6 years after EMS.None of these three patients had showed symptoms of cholestasis during the follow-up period. Two patients developed choledocholithiasis and two suffered from duodenal ulcers due to dislodgement of the stent between 4.8 and 7.3 years after stenting; however, they were successfully treated endoscopically. Thus, five of eight patients are alive at present after a mean follow-up period of 7.4 years.CONCLUSION: EMS is evidently one of the very promising treatment options for bile duct stenosis associated with CP, provided the patients are closely followed up; thus setting a system for their prompt management on emergency is desirable.

  3. Fully biodegradable coronary stents : progress to date.

    Science.gov (United States)

    Ramcharitar, Steve; Serruys, Patrick W

    2008-01-01

    The limitations of currently available metallic drug-eluting stents have renewed interest in biodegradable stents (BDS). Apart from removing the (offending) foreign material that may potentiate a thrombotic event, BDS have the advantage of avoiding 'full metal jackets,' and thus can preclude subsequent coronary surgery. In addition, they do not interfere with the diagnostic evaluation of non-invasive imaging such as cardiac magnetic resonance and CT. There are now several BDS in development or in clinical trials that incorporate a variety of biodegradable polymer technologies. Two broad categories of materials are generally used: those made from organic biopolymers and those made from corrodible metals. However, to date, none of the materials/stents tested have been able to establish a perfect balance between biocompatibility, the kinetics of degradation needed to maintain mechanical strength to limit recoil, and inflammation. However, studies, such as the ABSORB trial with the everolimus eluting poly-L-lactide stent, which demonstrated comparable restenotic rates with bare metallic stents and a low incidence of major adverse cardiac events (MACE) at 12 months of 3.3%, with only one patient having a non-Q-wave myocardial infarction and no target lesion revascularization, suggest that there has been significant progress with respect to the earlier prototypes. The acute recoil observed could potentially be addressed with the polytyrosine REVA stent currently being evaluated in the RESORB trial, which incorporates a novel locking mechanism within its design. Alternative BDS designs include the combination of an antiproliferative drug with endothelial progenitor cell capturing antibodies to facilitate epithelialization and/or dual eluting having, in addition to the antiproliferative drug, polymeric salicyclic acid to limit inflammation. Compared with biodegradable polymers, there are fewer metals used in the manufacture of BDS. The only metal BDS in trials is the

  4. Vessel healings after stenting with different polymers in STEMI patients

    Science.gov (United States)

    Jin, Qin-Hua; Chen, Yun-Dai; Tian, Feng; Guo, Jun; Jing, Jing; Sun, Zhi-Jun

    2016-01-01

    Background Different stents implantation in ST-segment elevation myocardial infarction (STEMI) patients may influence the long term prognosis by affecting vessel healings after stenting. The aim of this study was to evaluate the vessel healings after implantation of drug eluting stents (DES) with biodegradable or durable polymer or of bare-metal stents (BMS) in patients with acute STEMI. Methods This study included 50 patients, who underwent follow up angiogram and optical coherence tomography (OCT) assessment about one year after percutaneous coronary intervention (PCI) for STEMI. According to the initial stents types, these patients were classified to durable (n = 19) or biodegradable polymer sirolimus-eluting stents (n = 15), or BMS (n = 16) groups. The conditions of stent struts coverage and malapposition were analyzed with OCT technique. Results A total of 9003 struts were analyzed: 3299, 3202 and 2502 from durable or biodegradable polymer DES, or BMS, respectively. Strut coverage rate (89.0%, 94.9% and 99.3%, respectively), malapposition presence (1.7%, 0.03% and 0 of struts, respectively) and average intimal thickness over struts (76 ± 12 µm, 161 ± 30 µm and 292 ± 29 µm, respectively) were significantly different among different stent groups (all P < 0.001). Conclusions Vessel healing status in STEMI patients is superior after implantation of biodegradable polymer DES than durable polymer DES, while both are inferior to BMS. PMID:27403139

  5. Comparison of plastic and self-expandable metal stents in the palliative treatment of malignant biliary obstruction:a meta-analysis

    Institute of Scientific and Technical Information of China (English)

    Kui Li; Zhongyin Zhou; Ximing Xu; Hesheng Luo

    2014-01-01

    Stent-placement-is-one-of-the-main-methods-in-the-pal-iative-treatment-of-malignant-biliary-obstruc-tion,-including-plastic-and-self-expandable-metal-stents.-The-comparison-of-stent-patency-between-self-expandable-metal-and-plastic-stents-in-pal-iation-of-malignant-biliary-obstruction-is-meaningful.-We-carried-out-a-meta-analysis-to-summarize-current-evidence-for-clinical-ef-icacy-of-self-expandable-metal-and-plastic-stents-in-the-treatment-of-malignant-biliary-obstruc-tion.-Methods:A-comprehensive-search-of-several-databases-including-CNKI,-Wanfang-Data,-Sino-MED.-A-fixed-ef-ects-or-random-ef-ects-model-was-used-to-pool-data-of-al-study-endpoint.-Sensitivity-analysis-was-also-performed.-Results:Eight-randomized-clinical-trials-were-identified,-including-633-patients.-These-results-suggested-that-the-self-expandable-metal-stents-were-associated-with-a-significantly-longer-stent-patency-(OR=8.15;95%CI:2.80-23.76;I2=85%).-No-publication-bias-was-observed.-Conclusion:Self-expanding-metal-stents-have-a-longer-patency-than-plastic-stents-and-of-er-adequate-pal-iation-in-patients-with-malignant-biliary-obstruction.

  6. Configuration of SoC FPGA, Booting of HPS and running Bare Metal Application from SD card.

    CERN Document Server

    Zahid Rasheed, Awais

    2016-01-01

    First, a hardware design is created using Qsys in Quartus 16.0. Creation of the hardware design consists of configuring Hard Processor System (HPS) inside FPGA and adding necessary hardware blocks to the design. After generating the Qsys design, it is then instantiated in top level module in Verilog or VHDL. After setting up all pin assignments and adding all necessary files in the design, project is compiled to have a complete hardware design. Second part comprises full software design in correspondence with the hardware design and booting the HPS from SD card. Software includes enabling the different bridges used by HPS to communicate with FPGA, configuring FPGA from HPS and embedded application itself. Finally, everything is added in the SD card to get a complete automatic bare metal application running on the host board without any configuration what so ever.

  7. Coronary Stents: The Impact of Technological Advances on Clinical Outcomes.

    Science.gov (United States)

    Mennuni, Marco G; Pagnotta, Paolo A; Stefanini, Giulio G

    2016-02-01

    Percutaneous coronary interventions (PCI) were proposed in the late 1970s as an alternative to surgical coronary artery bypass grafting for the treatment of coronary artery disease. Important technological progress has been made since. Balloon angioplasty was replaced by bare metal stents, which allowed to permanently scaffold the coronary vessel avoiding acute recoil and abrupt occlusion. Thereafter, the introduction of early generation drug-eluting stents (DES) has significantly improved clinical outcomes, primarily by markedly reducing the risk of restenosis. New generation DES with thinner stent struts, novel durable or biodegradable polymer coatings, and new limus antiproliferative agents, have further improved upon the safety and efficacy profile of early generation DES. The present article aims to review the impact of technological advances on clinical outcomes in the field of PCI with coronary stents, and to provide a brief overview on clinical margins of improvement and unmet needs of available DES.

  8. Everolimus-eluting bioresorbable stent vs. durable polymer everolimus-eluting metallic stent in patients with ST-segment elevation myocardial infarction

    DEFF Research Database (Denmark)

    Sabaté, Manel; Windecker, Stephan; Iñiguez, Andres

    2015-01-01

    AIMS: Patients with ST-segment elevation myocardial infarction (STEMI) feature thrombus-rich lesions with large necrotic core, which are usually associated with delayed arterial healing and impaired stent-related outcomes. The use of bioresorbable vascular scaffolds (Absorb) has the potential...... to overcome these limitations owing to restoration of native vessel lumen and physiology at long term. The purpose of this randomized trial was to compare the arterial healing response at short term, as a surrogate for safety and efficacy, between the Absorb and the metallic everolimus-eluting stent (EES......) in patients with STEMI. METHODS AND RESULTS: ABSORB-STEMI TROFI II was a multicentre, single-blind, non-inferiority, randomized controlled trial. Patients with STEMI who underwent primary percutaneous coronary intervention were randomly allocated 1:1 to treatment with the Absorb or EES. The primary endpoint...

  9. A new approach to endoscopic treatment of tumors of the esophagogastric junction with individually designed self-expanding metal stents

    Institute of Scientific and Technical Information of China (English)

    Serhat Aymaz; Arno J Dormann

    2008-01-01

    The incidence of adenocarcinoma of the esophagogastric junction is constantly increasing.Curative treatment is no longer possible at the time of diagnosis in more than 50% of patients with esophageal carcinoma,and palliative treatment focusing on eliminating dysphagia is required.Endoscopic therapy with stent implantation is an established method of achieving this.It can be carried out quickly,with a low rate of early complications,and leads to fast symptomatic improvement,assessed using the dysphagia score.The relatively high rate of late complications such as stent migration,hemorrhage,and gastroesophageal mucosal prolapse has led to recent debate on the role of metal stents in palliative therapy.We present here a new type of stent design for transcardial application,which is intended to prevent bleeding due to mechanical mucosal lesions caused by the distal end of the stent extending into the stomach.The further intention of this case report is to force the discussion on individually designed nitinol stents in special anatomic conditions.

  10. Coronary Stent Materials and Coatings: A Technology and Performance Update.

    Science.gov (United States)

    O'Brien, Barry; Zafar, Haroon; Ibrahim, Ahmad; Zafar, Junaid; Sharif, Faisal

    2016-02-01

    This paper reviews the current state of the art for coronary stent materials and surface coatings, with an emphasis on new technologies that followed on from first-generation bare metal and drug-eluting stents. These developments have been driven mainly by the need to improve long term outcomes, including late stent thrombosis. Biodegradable drug-eluting coatings aim to address the long term effects of residual durable polymer after drug elution; the SYNERGY, BioMatrix, and Nobori stents are all promising devices in this category, with minimal polymer through the use of abluminal coatings. Textured stent surfaces have been used to attached drug directly, without polymer; the Yukon Choice and BioFreedom stents have some promising data in this category, while a hydroxyapatite textured surface has had less success. The use of drug-filled reservoirs looked promising initially but the NEVO device has experienced both technical and commercial set-backs. However this approach may eventually make it to market if trials with the Drug-Filled Stent prove to be successful. Non-pharmacological coatings such as silicon carbide, carbon, and titanium-nitride-oxide are also proving to have potential to provide better performance than BMS, without some of the longer term issues associated with DES. In terms of biological coatings, the Genous stent which promotes attachment of endothelial progenitor cells has made good progress while gene-eluting stents still have some practical challenges to overcome. Perhaps the most advancement has been in the field of biodegradable stents. The BVS PLLA device is now seeing increasing clinical use in many complex indications while magnesium stents continue to make steady advancements.

  11. Quality of life after PCI with drug-eluting stents or coronary-artery bypass surgery

    NARCIS (Netherlands)

    D.J. Cohen (David J.); B.A. van Hout (Ben); P.W.J.C. Serruys (Patrick); F.W. Mohr (Friedrich); C.M. Miguel (Carlos); P. den Heijer (Peter); M.M. Vrakking (M. M.); K.K. Wang (Kenneth); E.M. Mahoney (Elizabeth M.); S. Audi (Salma); K. Leadly (Katrin); K.D. Dawkins (Keith); A.P. Kappetein (Arie Pieter)

    2011-01-01

    textabstractBACKGROUND: Previous studies have shown that among patients undergoing multivessel revascularization, coronary-artery bypass grafting (CABG), as compared with percutaneous coronary intervention (PCI) either by means of balloon angioplasty or with the use of bare-metal stents, results in

  12. A new dextran-graft-polybutylmethacrylate copolymer coated on 316L metallic stents enhances endothelial cell coverage.

    Science.gov (United States)

    Derkaoui, S M; Labbé, A; Chevallier, P; Holvoet, S; Roques, C; Avramoglou, T; Mantovani, D; Letourneur, D

    2012-09-01

    Amphiphilic copolymers based on the copolymerization of hydrophilic and hydrophobic moieties offer versatility in various biomedical material applications. Here, a new biocompatible copolymer of dextran-graft-polybutylmethacrylate is synthesized for the coating of metallic endovascular stents. Coating of metallic surfaces is performed and analyzed by X-ray photoelectron spectroscopy, attenuated total reflection Fourier transform infrared spectroscopy, contact angle measurement, atomic force microscopy and scanning electron microscopy before and after deformation corresponding to stent deployment by a balloon catheter. In the conditions described here, the resulting coating is smooth and uniform with neither cracks nor detachment after stent expansion. Interestingly, surfaces coated with the copolymer greatly improve in vitro adhesion and growth of endothelial cells. This copolymer provides new opportunities for implanted biomaterials.

  13. Insertion of self-expanding metal stent for treatment of malignant obstruction in a pregnant woman

    Directory of Open Access Journals (Sweden)

    Noelia Alonso-Lázaro

    2014-03-01

    Full Text Available Colorectal cancer (CRC is the second most frequent cancer both in incidence and mortality in women, especially in those over 60 years of age. Diagnosis in women at gestational age is rare, so its incidence during pregnancy is low. However, an increase in its diagnosis is expected during the next years because of the raise in the average age of pregnancy. In most cases, the diagnosis is delayed because symptoms related to CRC can be attributed to pregnancy itself. Up to 30 % of CRC cases may present as an intestinal obstruction. In this situation, the main objective is to solve the clinical emergency in the safest way for mother and fetus, together with performing an accurate diagnostic approach to offer the best possible therapeutic management knowing the limitations and difficulties related to pregnancy. The self-expanding metallic stent (SEMS can be particularly useful in colon obstruction in a pregnant patient with CRC because it allows solving the acute condition providing time to perform a more accurate staging study and to prepare the patient for surgery, thus reducing both post-surgical morbidity and mortality. We report on the case of a patient who early in the second trimester of pregnancy presented with an acute colonic obstruction due to CRC which was successfully managed with the placement of a self-expanding metal stent.

  14. The qualitative assessment of biodegradable coronary stents with the use of intravascular ultrasound, optical coherence tomography and histology

    OpenAIRE

    Burcu GÜL

    2014-01-01

    Percutaneous coronary intervention (PCI) is the most common treatment for coronary artery disease (CAD). The first form of PCI introduced was balloon angioplasty. After that, the advent of coronary stents (tubular wire mesh for intravascular mechanical support) led to a new era in interventional cardiology. Through the implantation of bare metal stents (BMS), all three limitations of balloon angioplasty – coronary artery dissection, elastic recoil and negative remodelling – are prevented. Unf...

  15. Management of late/very late stent thrombosis: Utility of ıntravenous ultrasonography (IVUS) in clinical practise

    OpenAIRE

    Emre Yalçınkaya; Barış Bugan; Yalçın Gökoğlan; Erkan Yıldırım

    2013-01-01

    To the editor We read with great interest the article by Aksu et al. [1] on the management of very late bare metal stent thrombosis. They performed intracoronary thrombus aspiration and inflated balloon in-stent for restenosis. During percutaneous coronary interventions, interventionalists have often to deal with thrombus-laden lesions in coronary vessels. Plaque characteristics and distribution, severity and extent of calcification, arterial remodeling and the presence of dissection or throm...

  16. SU-E-T-115: Dose Perturbation Study of Self-Expandable Metal and Polyester Esophageal Stents in Proton Therapy Beams

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S; Li, Z [University of Florida Proton Therapy Institute, Jacksonville, FL (United States); Jalaj, S; McGaw, C; B K, John; J S, Scolapio; J C, Munoz [Division of Gastoenterology, Department of Medicine, University of Florida, Jacksonville, FL (United States)

    2014-06-01

    Purpose: This work investigates dose perturbations due to Self-expandable metal and polyester esophageal stents undergoing proton radiotherapy for esophageal cancer. Methods: Five commercially available esophageal stents made of nitinol (Evolution, Wallflex and Ultraflex), stainless steel (Z-Stent) and polyester (Polyflex) were tested. Radiochromic film (GafChromic EBT3 film, Ashland, Covington, KY) wrapped around a stent and a 12cc syringe was irradiated with 2CGE (Cobalt Gray Equivalent) of proton beam in a custom fabricated acrylic phantom. An air-hollow syringe simulates the esophagus. Results: The Z-stent created the largest dose perturbations ranges from -14.5% to 6.1% due to the steel composition. The WallFlex, Evolution and Ultraflex stents produced the dose perturbation ranges of (−9.2%∼8.6%), (−6.8%∼5.7%) and (−6.2%∼6.2%), respectively. The PolyFlex stent contains the radiopaque tungsten markers located top, middle and bottom portions. When the focal cold spots induced by the markers were excluded in the analysis, the dose perturbation range was changed from (−11.6%∼6.4%) to (−0.6%∼5.0%). Conclusion: The magnitude of dose perturbation is related to material of a metallic stent. The non-metallic stent such as PolyFlex shows relatively lower dose perturbation than metallic stents except a radiopaque marker region. Overall Evolution and Ultraflex stent appear to be less dose perturbations. The largest dose perturbations (cold spots) were located at both edges of stents in distal area for the single proton beam irradiation study. The analysis of more than two proton beam which is more typical clinical beam arrangement would be necessary to minimize the doe perturbation effect in proton ratiotherapy.

  17. Marble waste and pig manure amendments decrease metal availability, increase soil quality and facilitate vegetation development in bare mine soils

    Science.gov (United States)

    Zornoza, Raúl; Faz, Ángel; Martínez-Martínez, Silvia; Acosta, José A.; Gómez, M. Dolores; Ángeles Muñoz, M.

    2013-04-01

    In order to bring out a functional and sustainable land use in a highly contaminated mine tailing, firstly environmental risks have to be reduced or eliminated by suitable reclamation activities. Tailing ponds pose environmental hazards, such as acidity and toxic metals reaching to waters through wind and water erosions and leaching. As a consequence, soils have no vegetation and low soil organic matter and nutrients. Various physicochemical and biochemical properties, together with exchangeable metals were measured before, 6 months and 12 months after the application of marble waste and pigs manure as reclamation strategy in a tailing pond from SE Spain to reduce hazards for environment and human health. Three months after the last addition of amendments, eight different native shrub species where planted for phytostabilization. Results showed the pH increased up to neutrality. Aggregates stability, organic carbon, total nitrogen, cation exchange capacity, bioavailable phosphorus and potassium, microbial biomass and microbial activity increased with the application of the amendments, while exchangeable metals drastically decreased (~90%). After one year of plantation, only 20% planted species died, with a high growth of survivals reaching flowering and fructification. This study confirms the high effectiveness of initial applications of marble wastes together with pig manure and plantation of shrub species to initialize the recovery of the ecosystem in bare mine soils under Mediterranean semiarid conditions. Key Words: pig manure, marble waste, heavy metals, mine soil. Acknowledgements This work has been funded by the European Union LIFE+ project MIPOLARE (LIFE09 ENV/ES/000439). J.A. Acosta acknowledges a "Saavedra Fajardo" contract from Comunidad Autónoma de Murcia (Spain)

  18. ISR II study: a long-term evaluation of sirolimus-eluting stent in the treatment of patients with in-stent restenotic native coronary artery lesions.

    Science.gov (United States)

    Commeau, Philippe; Barragan, Paul T; Roquebert, Pierre O; Siméoni, Jean B

    2005-10-01

    The aim of this pilot study was to determine the safety and long-term efficacy of treating intrastent restenosis (ISR) with the slow-release sirolimus-eluting stent Bx Velocity (Cypher stent) without intravascular ultrasound (IVUS) guidance. Of patients who received a bare metal stent implantation and presented an ISR, 30-80% of the patients will develop a second restenosis within the stent, at the stent edges or both. To date, intravascular brachytherapy using beta- and gamma-radiation has been the only effective treatment for ISR. Twenty-three patients with ISR and evidence of ischemia were treated with Cypher stent. Clinical information was collected 1, 8, 12, and 24 months after stent implantation. During the first 8 months of the study, in-stent lumen diameter remained essentially unchanged from postprocedure in 80% of the case. The target lesion repeat revascularization (TLR) was 17%, of which 50% were oculostenotic reflexes. Only one patient presented a restenosis greater than 70%. During the 2-year study period, the TLR rate was 17%; the major adverse coronary event rate was 26%, and the non-Q-wave myocardial infarction (MI) rate was 9%. There were no reports of death, coronary artery bypass grafting, or Q-wave MI during the study. This study demonstrates the feasibility of using sirolimus-eluting stents without IVUS guidance for the treatment of ISR, providing long-term stability of immediate results.

  19. Domestic coronary drug-eluting stents on a new horizon

    Institute of Scientific and Technical Information of China (English)

    SHEN Wei-feng

    2012-01-01

    Supported by growing evidence from randomized clinical trials and observational or registry studies,percutaneous coronary intervention (PCI) with implantation of drug-eluting stents (DES) has become the standard of care for coronary artery disease,because of reduced repeat intervention and improved clinical outcomes in comparison with bare metal stent.1-3Currently,majority of coronary artery disease patients with complicated lesion subsets or clinical conditions can be successfully treated with DES-based PCI with favorable results.4-6 In 2011,around 300000 PCI procedures have been performed in China,with the penetration rate of DES reaching beyond 90% in most of the centers.

  20. Orsphere: Physics Measurments For Bare, HEU(93.2)-Metal Sphere

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, Margaret A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bess, John D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Briggs, J. Blair [Idaho National Lab. (INL), Idaho Falls, ID (United States); White, Christine E. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Dyrda, James P. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Tancock, Nigel P. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mihalczo, John [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-03-01

    In the early 1970s Dr. John T. Mihalczo (team leader), J.J. Lynn, and J.R. Taylor performed experiments at the Oak Ridge Critical Experiments Facility (ORCEF) with highly enriched uranium (HEU) metal (called Oak Ridge Alloy or ORALLOY) in an attempt to recreate GODIVA I results with greater accuracy than those performed at Los Alamos National Laboratory in the 1950s (HEU-MET-FAST-001). The purpose of the Oak Ridge ORALLOY Sphere (ORSphere) experiments was to estimate the unreflected and unmoderated critical mass of an idealized sphere of uranium metal corrected to a density, purity, and enrichment such that it could be compared with the GODIVA I experiments. “The very accurate description of this sphere, as assembled, establishes it as an ideal benchmark for calculational methods and cross-section data files” (Reference 1). While performing the ORSphere experiments care was taken to accurately document component dimensions (±0.0001 inches), masses (±0.01 g), and material data. The experiment was also set up to minimize the amount of structural material in the sphere proximity. Two, correlated spheres were evaluated and judged to be acceptable as criticality benchmark experiments. This evaluation is given in HEU-MET-FAST-100. The second, smaller sphere was used for additional reactor physics measurements. Worth measurements (Reference 1, 2, 3 and 4), the delayed neutron fraction (Reference 3, 4 and 5) and surface material worth coefficient (Reference 1 and 2) are all measured and judged to be acceptable as benchmark data. The prompt neutron decay (Reference 6), relative fission density (Reference 7) and relative neutron importance (Reference 7) were measured, but are not evaluated. Information for the evaluation was compiled from References 1 through 7, the experimental logbooks 8 and 9 ; additional drawings and notes provided by the experimenter; and communication with the lead experimenter, John T. Mihalczo.

  1. ORSPHERE: PHYSICS MEASUREMENTS FOR BARE, HEU(93.2)-METAL SPHERE

    Energy Technology Data Exchange (ETDEWEB)

    Margaret A. Marshall

    2014-03-01

    In the early 1970s Dr. John T. Mihalczo (team leader), J.J. Lynn, and J.R. Taylor performed experiments at the Oak Ridge Critical Experiments Facility (ORCEF) with highly enriched uranium (HEU) metal (called Oak Ridge Alloy or ORALLOY) in an attempt to recreate GODIVA I results with greater accuracy than those performed at Los Alamos National Laboratory in the 1950s (HEU-MET-FAST-001). The purpose of the Oak Ridge ORALLOY Sphere (ORSphere) experiments was to estimate the unreflected and unmoderated critical mass of an idealized sphere of uranium metal corrected to a density, purity, and enrichment such that it could be compared with the GODIVA I experiments. “The very accurate description of this sphere, as assembled, establishes it as an ideal benchmark for calculational methods and cross-section data files” (Reference 1). While performing the ORSphere experiments care was taken to accurately document component dimensions (±0.0001 inches), masses (±0.01 g), and material data. The experiment was also set up to minimize the amount of structural material in the sphere proximity. Two, correlated spheres were evaluated and judged to be acceptable as criticality benchmark experiments. This evaluation is given in HEU-MET-FAST-100. The second, smaller sphere was used for additional reactor physics measurements. Worth measurements (Reference 1, 2, 3 and 4), the delayed neutron fraction (Reference 3, 4 and 5) and surface material worth coefficient (Reference 1 and 2) are all measured and judged to be acceptable as benchmark data. The prompt neutron decay (Reference 6), relative fission density (Reference 7) and relative neutron importance (Reference 7) were measured, but are not evaluated. Information for the evaluation was compiled from References 1 through 7, the experimental logbooks 8 and 9 ; additional drawings and notes provided by the experimenter; and communication with the lead experimenter, John T. Mihalczo.

  2. Percutaneous unilateral biliary metallic stent placement in patients with malignant obstruction of the biliary hila and contralateral portal vein steno-occlusion

    Energy Technology Data Exchange (ETDEWEB)

    Son, Rak Chae; Gwon, Dong Il; Ko, Heung Kyu; Kim, Jong Woo; Ko, Gi Young [Dept. of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2015-06-15

    To investigate the outcomes of percutaneous unilateral metallic stent placement in patients with a malignant obstruction of the biliary hila and a contralateral portal vein steno-occlusion. Sixty patients with a malignant hilar obstruction and unilobar portal vein steno-occlusion caused by tumor invasion or preoperative portal vein embolization were enrolled in this retrospective study from October 2010 to October 2013. All patients were treated with percutaneous placement of a biliary metallic stent, including expanded polytetrafluoroethylene (ePTFE)-covered stents in 27 patients and uncovered stents in 33 patients. A total of 70 stents were successfully placed in 60 patients. Procedural-related minor complications, including self-limiting hemobilia (n = 2) and cholangitis (n = 4) occurred in six (10%) patients. Acute cholecystitis occurred in two patients. Successful internal drainage was achieved in 54 (90%) of the 60 patients. According to a Kaplan-Meier analysis, median survival time was 210 days (95% confidence interval [CI], 135-284 days), and median stent patency time was 133 days (95% CI, 94-171 days). No significant difference in stent patency was observed between covered and uncovered stents (p = 0.646). Stent dysfunction occurred in 16 (29.6%) of 54 patients after a mean of 159 days (range, 65-321 days). Unilateral placement of ePTFE-covered and uncovered stents in the hepatic lobe with a patent portal vein is a safe and effective method for palliative treatment of patients with a contralateral portal vein steno-occlusion caused by an advanced hilar malignancy or portal vein embolization. No significant difference in stent patency was detected between covered and uncovered metallic stents.

  3. A novel lumen-apposing metal stent for endoscopic ultrasound-guided drainage of pancreatic fluid collections

    DEFF Research Database (Denmark)

    Walter, Daisy; Will, Uwe; Sanchez-Yague, Andres;

    2015-01-01

    BACKGROUND AND STUDY AIMS: A novel large-diameter, lumen-apposing, self-expanding metal stent with bilateral flanges was recently developed for endoscopic ultrasound (EUS)-guided transmural drainage of symptomatic pancreatic fluid collections (PFCs). The aim of this study was to evaluate the effi...

  4. Improvement of quality of life and survival using self-expandable metal stent placement for severe malignant stenosis of the gastric body: a case report

    Directory of Open Access Journals (Sweden)

    Kumagai Hozumi

    2012-09-01

    Full Text Available Abstract Introduction Advanced gastric carcinoma often decreases quality of life because of upper gastrointestinal tract stenosis. Self-expandable metal stents have been thought to be an effective, minimally invasive treatment for stenosis. However, the effectiveness of self-expandable metal stent placement for carcinomatous stenosis of the gastric body and antrum has not been clarified, and there have been few reports of such cases. Case presentation A 74-year-old Japanese woman developed stenosis of the gastric body and antrum caused by advanced gastric cancer during first-line chemotherapy. She developed weight loss and poor nutrition due to inadequate intake. Self-expandable metal stent placement for stenosis of the gastric body and antrum ameliorated her symptoms rapidly and improved her general condition and quality of life. Eight days after self-expandable metal stent placement, second-line chemotherapy could be administered safely. Oral intake and nutritional status were maintained for 117 days after self-expandable metal stent placement, and she died of gastric cancer 176 days after self-expandable metal stent placement and initiation of second-line chemotherapy. Conclusions Self-expandable metal stent placement for carcinomatous stenosis in the gastric body and antrum could be an effective therapeutic strategy for patients with inadequate oral uptake. It may provide rapid improvement of the patient’s general condition and oral intake with minimal complications, comparatively long-term symptom relief, and a survival benefit by allowing second-line chemotherapy.

  5. Temporary self-expanding metallic stents for achalasia: A prospective study with a long-term follow-up

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    AIM: To compare the efficacy of self-expanding metallic stents (SEMSs) for the long-term clinical treatment of achalasia. METHODS: Ninety achalasic patients were treated with a temporary SEMS with a diameter of 20 mm (n = 30, group A), 25 mm (n = 30, group B) or 30 mm (n = 30, group C). Data on clinical symptoms, complications and treatment outcomes were collected, and follow-up was made at 6 mo and at 1, 3-5, 5-8, 8-10 and > 10 years, postoperatively.RESULTS: Stent placement was successful in all patients....

  6. Effectiveness and Safety of Endoscopic Treatment of Benign Biliary Strictures Using a New Fully Covered Self Expandable Metal Stent

    Directory of Open Access Journals (Sweden)

    Mihir S. Wagh

    2013-01-01

    Full Text Available Background. In patients with benign biliary strictures, the use of fully covered self-expandable metal stents (SEMS has been proposed as an alternative to plastic stenting, but high quality prospective data are sparse. This study was performed to evaluate the long-term effectiveness and safety of a new fully covered SEMS for benign biliary strictures. Methods. All consecutive patients with benign biliary strictures were treated with placement of a fully covered SEMS (WallFlex for 6 months. Short- and long-term stricture resolution, adverse events, and ease of stent removal were recorded. Results. 23 patients were enrolled. Stricture etiology was chronic pancreatitis (14, postorthotopic liver transplant (4, idiopathic (4, and biliary stones (1. All ERCPs were technically successful. All stents were successfully removed. Short-term stricture resolution was seen in 22/23 (96% patients. Long-term success was 15/18 (83.3%. All 3 failures were patients with biliary strictures in the setting of chronic calcific pancreatitis. Conclusions. The use of the new SEMS for the treatment of benign biliary strictures led to short-term stricture resolution in the vast majority of patients. Over a long-term followup the success rate appears favorable compared to historical results achieved with multiple plastic stenting, particularly in patients with chronic pancreatitis. The study was registered with ClinicalTrials.gov (NCT01238900.

  7. Patient with Recent Coronary Artery Stent Requiring Major Non Cardiac Surgery

    Directory of Open Access Journals (Sweden)

    Usha Kiran

    2009-01-01

    Full Text Available Anaesthesiologists are increasingly confronted with patients who had a recent coronary artery stent implanta-tion and are on dual anti-platelet medication. Non cardiac surgery and most invasive procedures increase the risk of stent thrombosis especially when procedure is performed early after stent implantation. Anaesthesiologist faces the dilemma of stopping the antiplatelet therapy before surgery to avoid bleeding versus perioperative stent thrombosis. Individualized approach should be adopted with following precautions. i In a surgical patient with a history of percu-taneous coronary intervention (PCI and coronary stent, determine the date of the procedure, the kind of the stent inserted and the possibility of complications during the procedure. ii Consider all patents with a recent stent implan-tation (e.g. less than three months for bare metal stents and less than one year for brachytherapy or drug eluting stents as high risk and consult an interventional cardiologist. iii Any decision to postpone surgery, continue, modify or discontinue antiplatelet regimes must involve the cardiologist, anaesthesiologist, surgeon, haematologist and the intensivist to balance the risk and benefit of each decision.

  8. Time course, predictors and clinical implications of stent thrombosis following primary angioplasty. Insights from the DESERT cooperation

    DEFF Research Database (Denmark)

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

    2013-01-01

    on the timing of stent thrombosis (ST) with both DES and bare metal stents (BMS) and its prognostic significance in patients undergoing pPCI. The Drug-Eluting Stent in Primary Angioplasty (DESERT) cooperation is based on a pooled database including individual data of randomised trials that evaluate the long...... angioplasty with BMS or DES. At 1201 ± 440 days, ST occurred in 267 patients (4.25%). Most of the events were acute or subacute (within 30 days) and very late (> 1 years), with different distribution between DES vs BMS. Patients with ST were more often diabetic (21.7% vs 15.1%, p=0.005), more frequently had...

  9. 5-aminolevulinic acid-incorporated poly(vinyl alcohol nanofiber-coated metal stent for application in photodynamic therapy

    Directory of Open Access Journals (Sweden)

    Kang DH

    2012-05-01

    Full Text Available Jin Ju Yoo*, Chan Kim*, Chung-Wook Chung, Young-Il Jeong, Dae Hwan KangNational Research and Development Center for Hepatibiliary Disease, Pusan National University Yangsan Hospital, Gyeongnam 626-770, Korea *These authors contributed equally to this work.Background: The study investigated the use of combined photodynamic therapy (PDT and stent placement for the treatment of cholangiocarcinoma (CC. For this purpose, 5-aminolevulinic acid (ALA was incorporated into poly(vinyl alcohol (PVA nanofiber, and coated onto metal stents. Their efficacy was assessed in PDT towards HuCC-T1 CC cells.Methods: Fabrication of ALA-PVA nanofiber, and simultaneous coating onto metal stents, was performed through electrospinning. The dark-toxicity, generation of protoporphyrin IX (PpIX, and PDT effect of ALA and ALA-PVA nanofiber were studied in vitro, using HuCC-T1 CC cells.Results: The ALA-PVA nanofibers were coated onto metal stents less than 1000 nm in diameter. ALA-only displayed marginal cytotoxicity; ALA-PVA nanofiber showed less cytotoxicity. PpIX generation was not sigficantly different between ALA and ALA-PVA nanofiber treatments. PVA itself did not generate PpIX in tumor cells. ALA and ALA-PVA nanofiber displayed a similar PDT effect on tumor cells. Cell viability was decreased, dose-dependently, until ALA concentration reached 100 µg/mL. Necrosis and apoptosis of tumor cells occurred similarly for ALA and ALA- PVA nanofiber treatments.Conclusion: The ALA-PVA nanofiber-coated stent is a promising candidate for therapeutic use with cholangiocarcinoma.Keywords: nanofiber, photodynamic therapy, 5-aminolevulinic acid, poly(vinyl alcohol

  10. 支架植入术治疗上腔静脉综合征:金属支架的选择%Stent implantation for the treatment of superior vena cava syndrome:Selection of metallic stents

    Institute of Scientific and Technical Information of China (English)

    杨维竹; 潘恒; 黄兢姚; 江娜; 郑曲彬; 林俊清

    2013-01-01

    目的 探讨支架植入术治疗上腔静脉综合征(SVCS)中选择金属支架的要点.方法 收集51例SVCS,CT均显示上腔静脉(SVC)明显狭窄或闭塞;经股静脉穿刺插管,以球囊扩张狭窄或闭塞段后植入1枚或多枚金属内支架(Smart支架、Z-Stent支架、Fluency支架),直至复查造影显示SVC血流通畅.术后评价疗效.结果 51例SVCS中,50例双侧头臂静脉汇合处受累.支架植入术均获成功,28例植入Smart支架,17例植入Z-Stent,4例植入Fluency支架,2例为Smart支架内套Fluency支架;31例植入1枚支架,12例植入2枚支架,8例植入3枚支架.支架植入后48例临床症状明显改善,上腔静脉压显著下降.术中无SVC破裂等严重并发症发生.46例接受随访,其中18例于随访期内重现SVC阻塞症状,包括11例植入Smart支架、7例植入Z-Stent支架者,植入Fluency支架者未见复发.结论 根据SVC病变程度、位置,选择植入结构和特性适当的金属支架可使介入治疗SVCS安全、有效.%Objective To investigate the elective points of different types of metallic stents for implantation in patients with superior vena cava syndrome (SVCS).Methods Fifty-one patients with SVCS were enrolled.Enhanced CT showed obvious stenosis or occlusion of the superior vena cava (SVC) in all patients.Stent implantation was performed after balloon dilatation through femoral vein.One or more stents (Smart stent,Z-Stent and Fluency stent) were positioned till the obstruction of SVC flow was relieved.The therapeutic effects of stent implantation were evaluated.Results Among all 51 patients,invasion of bilateral brachiocephalic veins were observed in 50 patients.Technical success of stent implantation was achieved in all patients including 28 patients with Smart stent,17 with Z-Stent,4 with Fluency stent and 2 patients with Fluency+Smart stent.Significant improvements of SVCS symptoms was noticed in 48 patients after stent implantation,and the pressure of SVC

  11. Y-Shaped Bilateral Self-Expandable Metallic Stent Placement for Malignant Hilar Biliary Obstruction: Data from a Referral Center for Palliative Care

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    R. Di Mitri

    2014-01-01

    Full Text Available Background and Aim. Malignant hilar strictures are a clinical challenge because of the current therapeutic approach and the poor prognosis. In recent years, self-expandable metallic stents have proven more effective than plastic stents for palliation of malignant hilar strictures, with the bilateral stent-in-stent technique registering a high success rate. We report our experience with Y-shaped endoscopic self-expandable metallic stents placement for treatment of advanced malignant hilar strictures. Methods. From April 2009 to August 2012, we prospectively collected data on patients treated with Y-shaped SEMS placement for advanced malignant hilar carcinoma. Data on technical success, clinical success, and complications were collected. Results. Twenty patients (9 males were treated (mean age 64.2 ± 15.3 years. The grade of malignant hilar strictures according to the Bismuth classification was II in 5 patients (25%, IIIa in 1 (5%, and IV in 14 (70%. The mean bilirubin level was 14.7 ± 4.9 mg/dL. Technical success was achieved in all patients, with a significant reduction in bilirubin levels (2.9 ± 1.7 mg/dL. One patient experienced cholangitis as early complication, while in 2 patients stent ingrowth was observed. No stents migration was recorded. There was no procedure-related mortality. At the end of the follow-up (7.1 ± 3.1 months, 13 of the 20 patients (65% had died. Conclusions. Our experience confirms endoscopic bilateral self-expandable metallic stents placement with stent-in-stent technique (Y-shaped configuration as a feasible, effective, and safe procedure for palliation of unresectable malignant hilar strictures.

  12. Prospective multi-center registry to evaluate efficacy and safety of the newly developed diamond-like carbon-coated cobalt-chromium coronary stent system.

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    Ando, Kenji; Ishii, Katsuhisa; Tada, Eiji; Kataoka, Kazuaki; Hirohata, Atsushi; Goto, Kenji; Kobayashi, Katsuyuki; Tsutsui, Hiroshi; Nakahama, Makoto; Nakashima, Hitoshi; Uchikawa, Shinichiroh; Kanda, Junji; Yasuda, Satoshi; Yajima, Junji; Kitabayashi, Hiroshi; Sakurai, Shumpei; Nakanishi, Keita; Inoue, Naoto; Noike, Hirofumi; Hasebe, Terumitsu; Sato, Tetsuya; Yamasaki, Masao; Kimura, Takeshi

    2016-07-22

    The purpose of this multi-center, non-randomized, and open-label clinical trial was to determine the non-inferiority of diamond-like carbon (DLC)-coated cobalt-chromium coronary stent, the MOMO DLC coronary stent, relative to commercially available bare-metal stents (MULTI-LINK VISION(®)). Nineteen centers in Japan participated. The study cohort consisted of 99 patients from 19 Japanese centers with single or double native coronary vessel disease with de novo and restenosis lesions who met the study eligibility criteria. This cohort formed the safety analysis set. The efficacy analysis set consisted of 98 patients (one case was excluded for violating the eligibility criteria). The primary endpoint was target vessel failure (TVF) rate at 9 months after stent placement. Of the 98 efficacy analysis set patients, TVF occurred in 11 patients (11.2 %, 95 % confidence interval 5.7-19.2 %) at 9 months after the index stent implantation. The upper 95 % confidence interval for TVF of the study stent was lower than that previously reported for the commercially available MULTI-LINK VISION(®) (19.6 %), demonstrating non-inferiority of the study stent to MULTI-LINK VISION(®). All the TVF cases were related to target vascular revascularization. None of the cases developed in-stent thrombosis or myocardial infarction. The average in-stent late loss and binary restenosis rate at the 6-month follow-up angiography were 0.69 mm and 10.5 %, respectively, which are lower than the reported values for commercially available bare-metal stents. In conclusion, the current pivotal clinical study evaluating the new MOMO DLC-coated coronary stent suggested its low rates of TVF and angiographic binary restenosis, and small in-stent late loss, although the data were considered preliminary considering the small sample size and single arm study design.

  13. Longitudinal stent elongation during retraction of entrapped jailed guidewire in a side branch with balloon catheter support: a case report

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    Taniguchi, Norimasa; Mizuguchi, Yukio; Takahashi, Akihiko, E-mail: a-takahashi@wine.ocn.ne.jp

    2015-01-15

    A 72-year-old man underwent primary percutaneous coronary intervention for a subtotal occlusion in the mid-portion of the left anterior descending artery involving a large diagonal branch. After successful stenting with a 3.0/24 mm bare metal stent, during which, the diagonal branch was protected with a coronary guidewire, conventional retrieval of the jailed guide wire was impossible. Subsequently, several attempts at a strong retraction of the wire with the support of a balloon catheter enabled retrieval of the trapped wire. Optical coherence tomography performed after post-dilatation, revealed that the stent was elongated to the left main coronary artery, and the structure of the strut had become coarse in the proximal portion. The stent was believed to have become entangled with the balloon catheter when the guidewire was being pulled. This case suggests that retrieving the jailed guidewire with a balloon catheter carries a potential risk of entrapment in the deformed stent.

  14. Mechanisms of Biliary Plastic Stent Occlusion and Efforts at Prevention

    Science.gov (United States)

    Kwon, Chang-Il; Lehman, Glen A.

    2016-01-01

    Biliary stenting via endoscopic retrograde cholangiopancreatography has greatly improved the quality of patient care over the last 30 years. Plastic stent occlusion limits the life span of such stents. Attempts to improve plastic stent patency duration have mostly failed. Metal stents (self-expandable metal stents [SEMSs]) have therefore replaced plastic stents, especially for malignant biliary strictures. SEMS are at least 10 times more expensive than plastic stents. In this focused review, we will discuss basic mechanisms of plastic stent occlusion, along with a systematic summary of previous efforts and related studies to improve stent patency and potential new techniques to overcome existing limitations. PMID:27000422

  15. Computational Bench Testing to Evaluate the Short-Term Mechanical Performance of a Polymeric Stent.

    Science.gov (United States)

    Bobel, A C; Petisco, S; Sarasua, J R; Wang, W; McHugh, P E

    2015-12-01

    Over the last decade, there has been a significant volume of research focussed on the utilization of biodegradable polymers such as poly-L-lactide-acid (PLLA) for applications associated with cardiovascular disease. More specifically, there has been an emphasis on upgrading current clinical shortfalls experienced with conventional bare metal stents and drug eluting stents. One such approach, the adaption of fully formed polymeric stents has led to a small number of products being commercialized. Unfortunately, these products are still in their market infancy, meaning there is a clear non-occurrence of long term data which can support their mechanical performance in vivo. Moreover, the load carry capacity and other mechanical properties essential to a fully optimized polymeric stent are difficult, timely and costly to establish. With the aim of compiling rapid and representative performance data for specific stent geometries, materials and designs, in addition to reducing experimental timeframes, Computational bench testing via finite element analysis (FEA) offers itself as a very powerful tool. On this basis, the research presented in this paper is concentrated on the finite element simulation of the mechanical performance of PLLA, which is a fully biodegradable polymer, in the stent application, using a non-linear viscous material model. Three physical stent geometries, typically used for fully polymeric stents, are selected, and a comparative study is performed in relation to their short-term mechanical performance, with the aid of experimental data. From the simulated output results, an informed understanding can be established in relation to radial strength, flexibility and longitudinal resistance, that can be compared with conventional permanent metal stent functionality, and the results show that it is indeed possible to generate a PLLA stent with comparable and sufficient mechanical performance. The paper also demonstrates the attractiveness of FEA as a tool

  16. Clinical application of self-expanding metallic stent in the management of acute left-sided colorectal malignant obstruction

    Institute of Scientific and Technical Information of China (English)

    You-Ben Fan; Ying-Sheng Cheng; Ni-Wei Chen; Hui-Min Xu; Zhe Yang; Yue Wang; Yu-Yao Huang; Qi Zheng

    2006-01-01

    AIM: To summarize our experience with the application of self-expanding metallic stent (SEMS) in the management of acute left-sided colorectal malignant obstruction.METHODS: A retrospective chart review of all patients undergoing placement of SEMS between April 2000 and January 2004 was performed.RESULTS: Insertion of SEMS was attempted in 26patients under fluoroscopic guidance with occasional endoscopic assistance. The sites of lesions were located in splenic flexure of two patients, left colon of seven patients, sigmoid colon of eight patients and rectum of nine patients. The intended uses of SEMS were for palliation in 7 patients and as a bridge to elective surgery in 19 patients. In the latter group, placement of SEMS allowed for preoperative systemic and bowel preparation and the following one-stage anastomosis. Successful stent placement was achieved in 22 (85%) of the 26patients. The clinical bowel obstruction resolved 24 hours after successful stent placement in 21 (95%) patients.Three SEMS-related minor complications occurred, two stents migrated and one caused anal pain.CONCLUSION: SEMS represents an effective and safe tool in the management of acute malignant colorectal obstruction. As a bridge to surgery, SEMS can provide time for systematic support and bowel preparation and obviate the need for fecal diversion or on-table lavage.As a palliative measure, SEMS can eliminate the need for emergent colostomy.

  17. The Control of Drug Release and Vascular Endothelialization after Hyaluronic Acid-Coated Paclitaxel Multi-Layer Coating Stent Implantation in Porcine Coronary Restenosis Model

    Science.gov (United States)

    Bae, In-Ho; Jeong, Myung Ho; Park, Yong Hwan; Lim, Kyung Seob; Park, Dae Sung; Shim, Jae Won; Kim, Jung Ha; Ahn, Youngkeun; Hong, Young Joon; Sim, Doo Sun

    2017-01-01

    Background and Objectives Hyaluronic acid (HA) is highly biocompatible with cells and the extracellular matrix. In contrast to degradation products of a synthetic polymer, degradation products of HA do not acidify the local environment. The aim of this study was to fabricate an HA-coated paclitaxel (PTX)-eluting stent via simple ionic interactions and to evaluate its effects in vitro and in vivo. Materials and Methods HA and catechol were conjugated by means of an activation agent, and then the stent was immersed in this solution (resulting in a HA-coated stent). After that, PTX was immobilized on the HA-coated stent (resulting in a hyaluronic acid-coated paclitaxel-eluting stent [H-PTX stent]). Study groups were divided into 4 groups: bare metal stent (BMS), HA, H-PTX, and poly (L-lactide)-coated paclitaxel-eluting stent (P-PTX). Stents were randomly implanted in a porcine coronary artery. After 4 weeks, vessels surrounding the stents were isolated and subjected to various analyses. Results Smoothness of the surface was maintained after expansion of the stent. In contrast to a previous study on a PTX-eluting stent, in this study, the PTX was effectively released up to 14 days (a half amount of PTX in 4 days). The proliferation of smooth muscle cells was successfully inhibited (by 80.5±12.11% at 7 days of culture as compared to the control) by PTX released from the stent. Animal experiments showed that the H-PTX stent does not induce an obvious inflammatory response. Nevertheless, restenosis was clearly decreased in the H-PTX stent group (9.8±3.25%) compared to the bare-metal stent group (29.7±8.11%). Conclusion A stent was stably coated with PTX via simple ionic interactions with HA. Restenosis was decreased in the H-PTX group. These results suggest that HA, a natural polymer, is suitable for fabrication of drug-eluting stents (without inflammation) as an alternative to a synthetic polymer.

  18. EUS-Guided Antegrade Transhepatic Placement of a Self-Expandable Metal Stent in Hepatico-Jejunal Anastomosis

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    Everson LA Artifon

    2011-11-01

    Full Text Available Context To demonstrate an EUS-guided biliary drainage in patient with gastrointestinal tract modified surgically. Case report An EUS guided access to the left intra hepatic duct, followed by an antegrade passage of a partially self-expandable metal stent that was removed by using an enteroscope, in one patient with hepatico-jejunal anastomosis. There were no early or delayed complications and the procedure was effective in relieving jaundice until the self-expandable metal stent was removed, 3 months later. A cholangiogram was obtained via enteroscopy, after removal of self-expandable metal stent, and found to be normal. The patient had an uneventful evaluation afterwards. Conclusion The indication of these procedures must be made under a multidisciplinary view while sharing information with the patient or legal guardian. EUS-guided biliary drainage is feasible when performed by professionals with expertise in biliopancreatic endoscopy and advanced echo-endoscopy and should be performed currently under rigorous protocol in educational institutions.

  19. A Multicenter, Prospective Study of a New Fully Covered Expandable Metal Biliary Stent for the Palliative Treatment of Malignant Bile Duct Obstruction

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    Bret T. Petersen

    2013-01-01

    Full Text Available Background and Study Aims. Endoscopic placement of self-expanding metal stents (SEMSs is indicated for palliation of inoperable malignant biliary obstruction. A fully covered biliary SEMS (WallFlex Biliary RX Boston Scientific, Natick, USA was assessed for palliation of extrahepatic malignant biliary obstruction. Patients and Methods. 58 patients were included in this prospective, multicenter series conducted under an FDA-approved IDE. Main outcome measurements included (1 absence of stent occlusion within six months or until death, whichever occurred first and (2 technical success, need for reintervention, bilirubin levels, stent patency, time to stent occlusion, and adverse events. Results. Technical success was achieved in 98% (57/58, with demonstrated acute removability in two patients. Adequate clinical palliation until completion of followup was achievedin 98% (54/55 of evaluable patients, with 1 reintervention due to stent obstruction after 142 days. Mean total bilirubin decreased from 8.9 mg/dL to 1.2 mg/dL at 1 month. Device-related adverse events were limited and included 2 cases of cholecystitis. One stent migrated following radiation therapy. Conclusions. The WallFlex Biliary fully covered stent yielded technically successful placement with uncomplicated acute removal where required, appropriate reduction in bilirubin levels, and low rates of stent migration and occlusion. This SEMS allows successful palliation of malignant extrahepatic biliary obstruction.

  20. Meta-analysis of stent thrombosis after drug-eluting stent implantation: 4-year follow-up

    Institute of Scientific and Technical Information of China (English)

    Nata(s)a M Mili(c); Biljana J Parapid; Miodrag (C) Ostoji(c); Milan A Nedeljkovi(c); Jelena M Marinkovi(c)

    2010-01-01

    Background Drug-eluting stents (DES) are the most common device used in percutaneous treatment of coronary artery disease. Recently, there has been an increased concern regarding their safety profile, in particular the late and very late stent thrombosis rate compared to bare metal stents (BMS). The aim of the study was to compare the reported incidence of late and very late stent thrombosis of DES and BMS in patients from published clinical studies with an extended follow-up period to four years.Methods A search strategy was developed to identify publications reporting on late or very late thrombosis of BMS and DES available through MEDLINE and Cochrane Library databases. Two independent reviewers appraised eligible studies and extracted data. Odds ratios (OR) were calculated for each outcome and presented with 95% confidence intervals (CI).Results Fourteen randomized controlled trials, which were at least single blinded, were identified. There was no difference in the incidence of late and very late stent thrombosis in patients treated with DES compared with patients treated with BMS (late OR 0.55, 95%Cl 0.23-1.31 and late/very late OR=1.08, 95%CI 0.61-1.91).Conclusions The safety profile of DES was similar to BMS in terms of stent thrombosis. We found no evidence of increased risk of late and very late thrombosis for DES.

  1. Management of malignant biliary obstruction: Technical and clinical results using an expanded polytetrafluoroethylene fluorinated ethylene propylene (ePTFE/FEP)-covered metallic stent after 6-year experience

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    Fanelli, Fabrizio; Orgera, Gianluigi; Bezzi, Mario; Rossi, Plinio; Allegritti, Massimiliano; Passariello, Roberto [University of Rome, Department of Radiological Sciences, Rome (Italy)

    2008-05-15

    To evaluate the efficacy and safety of an expanded polytetrafluoroethylene-fluorinated ethylene-propylene (ePTFE/FEP)-covered metallic stent in the management of malignant biliary obstruction. Eighty consecutive patients with malignant common bile duct strictures were treated by placement of 83 covered metallic stents. The stent-graft consists of an inner ePTFE/FEP lining and an outer supporting structure of nitinol wire. Clinical evaluation, assessment of serum bilirubin and liver enzyme levels were analyzed before biliary drainage, before stent-graft placement and during the follow-up period at 1, 3, 6, 9 and 12 months. Technical success was obtained in all cases. After a mean follow-up of 6.9{+-}4.63 months, the 30-day mortality rate was 14.2%. Survival rates were 40% and 20.2% at 6 and 12 months, respectively. Stent-graft patency rates were 95.5%, 92.6% and 85.7% at 3, 6 and 12 months, respectively. Complications occurred in five patients (6.4%); among these, acute cholecystitis was observed in three patients (3.8%). A stent-graft occlusion rate of 9% was observed. The percentage of patients undergoing lifetime palliation (91%) and the midterm patency rate suggest that placement of this ePTFE/FEP-covered stent-graft is safe and highly effective in achieving biliary drainage in patients with malignant strictures of the common bile duct. (orig.)

  2. Stent graft implantation in an aortic pseudoaneurysm associated with a fractured Cheatham-Platinum stent in aortic coarctation.

    Science.gov (United States)

    Kuhelj, Dimitrij; Berden, Pavel; Podnar, Tomaž

    2016-03-01

    We report a case of aortic pseudoaneurysm associated with a fractured bare Cheatham-Platinum stent following stenting for aortic coarctation. These complications were recognised 6 years after the implantation procedure and were successfully managed by percutaneous stent graft implantation. Staged approach for stent dilatation might prevent development of aortic pseudoaneurysms. In addition, careful follow-up is warranted after stenting for aortic coarctation, particularly in patients with recognised aortic wall injury.

  3. Self-Expandable Metal Stents for Persisting Esophageal Variceal Bleeding after Band Ligation or Injection-Therapy: A Retrospective Study.

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    Martin Müller

    Full Text Available Despite a pronounced reduction of lethality rates due to upper gastrointestinal bleeding, esophageal variceal bleeding remains a challenge for the endoscopist and still accounts for a mortality rate of up to 40% within the first 6 weeks. A relevant proportion of patients with esophageal variceal bleeding remains refractory to standard therapy, thus making a call for additional tools to achieve hemostasis. Self-expandable metal stents (SEMS incorporate such a tool.We evaluated a total number of 582 patients admitted to our endoscopy unit with the diagnosis "gastrointestinal bleeding" according to our documentation software between 2011 and 2014. 82 patients suffered from esophageal variceal bleeding, out of which 11 cases were refractory to standard therapy leading to SEMS application. Patients with esophageal malignancy, fistula, or stricture and a non-esophageal variceal bleeding source were excluded from the analysis. A retrospective analysis reporting a series of clinically relevant parameters in combination with bleeding control rates and adverse events was performed.The initial bleeding control rate after SEMS application was 100%. Despite this success, we observed a 27% mortality rate within the first 42 days. All of these patients died due to non-directly hemorrhage-associated reasons. The majority of patients exhibited an extensive demand of medical care with prolonged hospital stay. Common complications were hepatic decompensation, pulmonary infection and decline of renal function. Interestingly, we found in 7 out of 11 patients (63.6% stent dislocation at time of control endoscopy 24 h after hemostasis or at time of stent removal. The presence of hiatal hernia did not affect obviously stent dislocation rates. Refractory patients had significantly longer hospitalization times compared to non-refractory patients.Self-expandable metal stents for esophageal variceal bleeding seem to be safe and efficient after failed standard therapy

  4. Treatment of Esophageal Variceal Hemorrhage with Self-Expanding Metal Stents as a Rescue Maneuver in a Swiss Multicentric Cohort

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    Fabienne C. Fierz

    2013-03-01

    Full Text Available Acute esophageal variceal bleeding in patients with portal hypertension remains a complication with a high mortality today. In cases refractory to standard therapy including endoscopic band ligation and pharmacological therapy, traditionally balloon tamponade has been used as salvage therapy. However, these techniques show several important limitations. Self-expanding metal stents (SEMS have been proposed as an alternative rescue treatment. The use of variceal stenting in 7 patients with a total of 9 bleeding episodes in three different Swiss hospitals is demonstrated. While immediate bleeding control is achieved in a high percentage of cases, the 5-day and 6-week mortality rate remain high. Mortality is strongly influenced by the severity of the underlying liver disease. Accordingly, our data represent a high-risk patient collective. Thanks to their safety and easy handling, SEMS are an interesting alternative to balloon tamponade as a bridging intervention to definitive therapy including the pre-hospital setting.

  5. Association between cholesterol efflux capacity and coronary restenosis after successful stent implantation.

    Science.gov (United States)

    Imaizumi, Satoshi; Miura, Shin-Ichiro; Takata, Kohei; Takamiya, Yosuke; Kuwano, Takashi; Sugihara, Makoto; Ike, Amane; Iwata, Atsushi; Nishikawa, Hiroaki; Saku, Keijiro

    2016-08-01

    The measurement of high-density lipoprotein (HDL) functionality could be useful for identifying patients who have an increased risk of coronary restenosis after stent implantation. In the present study, we elucidates whether HDL functionality can predict restenosis. The participants included 48 consecutive patients who had stable angina and were successfully implanted with a drug-eluting stent (DES) or bare-metal stent. Follow-up coronary angiography was performed after 6-8 months of stenting. Cholesterol efflux and the anti-inflammatory capacity of HDL were measured before stenting (at baseline) and at follow-up. The mean age was 64 ± 11 years and the body mass index was 24 ± 3 kg/m(2). While HDL cholesterol (HDL-C) significantly increased from baseline to follow-up, there was no significant association between HDL-C level at baseline and in-stent late loss. Cholesterol efflux capacity was significantly increased from baseline to follow-up. The efflux capacity at baseline was negatively correlated with in-stent late loss, whereas the anti-oxidative activity of HDL at baseline was not associated with in-stent late loss. We analyzed the predictors of in-stent late loss using independent variables (efflux capacity and anti-oxidative capacity at baseline in addition to age, gender, HDL-C and low-density lipoprotein cholesterol at baseline, hypertension, diabetes mellitus, smoking, lesion length and DES implantation, history of myocardial infarction and prior percutaneous coronary intervention) by a multiple regression analysis. The efflux capacity at baseline was only independently associated with in-stent late loss. In conclusion, cholesterol efflux capacity at baseline could predict coronary restenosis in patients with successful stent implantation.

  6. In vitro hemocompatibility and cytocompatibility of dexamethasone-eluting PLGA stent coatings

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jiang; Liu, Yang; Luo, Rifang; Chen, Si; Li, Xin; Yuan, Shuheng; Wang, Jin, E-mail: jinxxwang@263.net; Huang, Nan

    2015-02-15

    Highlights: • Biodegradable dexamethasone-eluting PLGA stent coatings were developed. • Stent coatings can withstand the compressive and tensile strains without cracking. • Stent coatings presented favorable release kinetic for the lesion site. • Stent coatings can effectively inhibit the adhesion and activation of platelets. • Stent coatings can effectively inhibit the proliferation of SMC. - Abstract: Drug-eluting stents (DESs) have been an important breakthrough for interventional cardiology applications since 2002. Though successful in reducing restenosis, some adverse clinical problems still emerged, which were mostly caused by the bare-metal stents and non-biodegradable polymer coatings, associated with the delayed endothelialization process. In this study, dexamethasone-loaded poly (lactic-co-glycolic acid) (PLGA) coatings were developed to explore the potential application of dexamethasone-eluting stents. Dexamethasone-eluting PLGA stents were prepared using ultrasonic atomization spray method. For other tests like stability and cytocompatibility and hemocompatibility tests, dexamethasone loaded coatings were deposited on 316L SS wafers. Fourier transform-infrared spectroscopy (FT-IR) results demonstrated that there was no chemical reaction between PLGA and dexamethasone. The balloon expansion experiment and surface morphology observation suggested that the stent coatings were smooth and uniform, and could also withstand the compressive and tensile strains imparted without cracking after stent expansion. The drug release behavior in vitro indicated that dexamethasone existed burst release within 1 day, but it presented linear release characteristics after 6 days. In vitro platelets adhesion, activation test and APTT test were also done, which showed that after blending dexamethasone into PLGA, the hemocompatibility was improved. Besides, dexamethasone and dexamethasone-loaded PLGA coatings could significantly inhibit the attachment and

  7. Self-Expanding Metal Stenting for Palliation of Patients with Malignant Colonic Obstruction: Effectiveness and Efficacy on 255 Patients with 12-Month's Follow-up

    Science.gov (United States)

    Meisner, Søren; González-Huix, Ferran; Vandervoort, Jo G.; Repici, Alessandro; Xinopoulos, Dimitrios; Grund, Karl E.; Goldberg, Paul; Registry Group, The WallFlex Colonic

    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 and one global, multicenter studies. Settings. 39 centers (22 academic, 17 community hospitals) from 13 countries. Patients. A total of 257 patients were enrolled, and 255 patients were treated with a WallFlex uncovered enteral colonic stent. Follow-up was up to 12 months or until death or retreatment. 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 5.1%. Overall migration rate was 5.5%. Overall death rate during follow-up was 48.6% (124), with 67.7% of deaths related to the patient's colorectal cancer, unrelated in 32.3%. Only 2 deaths were related to the stent or procedure. Limitations. No control group. Conclusions. The primary palliative option 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. PMID:22761609

  8. Self-Expanding Metal Stenting for Palliation of Patients with Malignant Colonic Obstruction: Effectiveness and Efficacy on 255 Patients with 12-Month's Follow-up

    Directory of Open Access Journals (Sweden)

    Søren Meisner

    2012-01-01

    Full Text Available 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 and one global, multicenter studies. Settings. 39 centers (22 academic, 17 community hospitals from 13 countries. Patients. A total of 257 patients were enrolled, and 255 patients were treated with a WallFlex uncovered enteral colonic stent. Follow-up was up to 12 months or until death or retreatment. 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 5.1%. Overall migration rate was 5.5%. Overall death rate during follow-up was 48.6% (124, with 67.7% of deaths related to the patient’s colorectal cancer, unrelated in 32.3%. Only 2 deaths were related to the stent or procedure. Limitations. No control group. Conclusions. The primary palliative option 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Successful retrieval of an unexpanded coronary stent from the left main coronary artery during primary percutaneous coronary intervention

    Directory of Open Access Journals (Sweden)

    Šalinger-Martinović Sonja

    2011-01-01

    Full Text Available Introduction. Dislodgement and embolization of the new generation of coronary stents before their deployment are rare but could constitute a very serious complication. Case Outline. We report a case of a stent dislodgement into the left main coronary artery during the primary coronary intervention of infarct related left circumflex artery in a patient with acute myocardial infarction. The dislodged and unexpanded bare-metal stent FlexMaster 3.0x19 mm (Abbot Vascular was stranded and bended in the left main coronary artery (LMCA, probably by the tip of the guiding catheter, but stayed over the guidewire. It was successfully retrieved using a low-profile Ryujin 1.25x15 balloon catheter (Terumo that was passed through the stent, inflated and then pulled back into the guiding catheter. After that, the whole system was withdrawn through the 6 F arterial sheath via the transfemoral approach. After repeated cannulation via the 6F arterial sheath, additional BMW and ATW guidewires were introduced into the posterolateral and obtuse marginal branches and a bare-metal stent Driver (Medtronic Cardiovascular Inc 3.0x18 mm was implanted in the target lesion. Conclusion. Stent dislodgement is a rare but potentially life-threatening complication of the percutaneous coronary intervention. This incident occurring in the LMCA in particular during an acute myocardial infarction requires to be urgently resolved. The avoidance of rough manipulation with the guiding catheter and delivery system may help in preventing this kind of complications.

  11. Impact of the distance from the stent edge to the residual plaque on edge restenosis following everolimus-eluting stent implantation.

    Directory of Open Access Journals (Sweden)

    Masao Takahashi

    Full Text Available OBJECTIVES: This study aimed to assess the relation between stent edge restenosis (SER and the distance from the stent edge to the residual plaque using quantitative intravascular ultrasound. BACKGROUND: Although percutaneous coronary intervention with drug-eluting stents has improved SER rates, determining an appropriate stent edge landing zone can be challenging in cases of diffuse plaque lesions. It is known that edge vascular response can occur within 2 mm from the edge of a bare metal stent, but the distance to the adjacent plaque has not been evaluated for drug-eluting stents. METHODS: A total of 97 proximal residual plaque lesions (plaque burden [PB] >40% treated with everolimus-eluting stents were retrospectively evaluated to determine the distance from the stent edge to the residual plaque. RESULTS: The SER group had significantly higher PB (59.1 ± 6.1% vs. 51.9 ± 9.1% for non-SER; P = 0.04. Higher PB was associated with SER, with the cutoff value of 54.74% determined using receiver operating characteristic (ROC curve analysis. At this cutoff value of PB, the distance from the stent edge to the lesion was significantly associated with SER (odds ratio = 2.05, P = 0.035. The corresponding area under the ROC curve was 0.725, and the cutoff distance value for predicting SER was 1.0 mm. CONCLUSION: An interval less than 1 mm from the proximal stent edge to the nearest point with the determined PB cutoff value of 54.74% was significantly associated with SER in patients with residual plaque lesions.

  12. Comparison of the Efficacy of Everolimus-Eluting Stents Versus Drug-Eluting Balloons in Patients With In-Stent Restenosis (from the RIBS IV and V Randomized Clinical Trials).

    Science.gov (United States)

    Alfonso, Fernando; Pérez-Vizcayno, María José; García Del Blanco, Bruno; García-Touchard, Arturo; Masotti, Mónica; López-Minguez, José R; Iñiguez, Andrés; Zueco, Javier; Velazquez, Maite; Cequier, Angel; Lázaro-García, Rosa; Martí, Vicens; Moris, César; Urbano-Carrillo, Cristobal; Bastante, Teresa; Rivero, Fernando; Cárdenas, Alberto; Gonzalo, Nieves; Jiménez-Quevedo, Pilar; Fernández, Cristina

    2016-02-15

    Treatment of patients with in-stent restenosis (ISR) remains a challenge. This study sought to compare the efficacy of everolimus-eluting stents (EESs) and drug-eluting balloons (DEBs) with paclitaxel in patients with ISR. A pooled analysis of the Restenosis Intra-Stent of Drug-Eluting Stents: Drug-Eluting Balloon vs Everolimus-Eluting Stent (RIBS IV) and Restenosis Intra-Stent of Bare-Metal Stents: Drug-Eluting Balloon vs Everolimus-Eluting Stent (RIBS V) randomized trials was performed using patient-level data. In both trials, EESs were compared with DEBs in patients with ISR (RIBS V included 189 patients with bare-metal ISR; RIBS IV included 309 patients with drug-eluting ISR). Inclusion and exclusion criteria were identical in both trials. A total of 249 patients were allocated to EES and 249 to DEB. Clinical follow-up at 1 year was obtained in all (100%) patients and late angiography (median 249 days) in 91% of eligible patients. Compared with patients treated with DEBs, patients treated with EESs obtained better short-term results (postprocedural minimal lumen diameter 2.28 ± 0.5 vs 2.12 ± 0.4 mm, p stent type and treatment effects. At 1-year clinical follow-up, the composite of cardiac death, myocardial infarction, and target vessel revascularization was significantly reduced in the EES arm (8.8% vs 14.5%, p = 0.03; hazard ratio 0.59, 95% CI 0.31 to 0.94) mainly driven by a lower need for target vessel revascularization (6% vs 12.4%, p = 0.01, hazard ratio 0.46, 95% CI 0.25 to 0.86). This pooled analysis of the RIBS IV and RIBS V randomized trials demonstrates the superiority of EES over DEB in the treatment of patients with ISR.

  13. Treatment of malignant gastric outlet obstruction with endoscopically placed self-expandable metal stents

    Institute of Scientific and Technical Information of China (English)

    Jill KJ Gaidos; Peter V Draganov

    2009-01-01

    Malignant gastroduodenal obstruction can occur in up to 20% of patients with primary pancreatic, gastric or duodenal carcinomas. Presenting symptoms include nausea, vomiting, abdominal distention, pain and decreased oral intake which can lead to dehydration, malnutrition, and poor quality of life. Endoscopic stent placement has become the primary therapeutic modality because it is safe, minimally invasive, and a cost-effective option for palliation. Stents can be successfully deployed in the majority of patients. Stent placement appears to lead to a shorter time to symptomatic improvement, shorter time to resumption of an oral diet, and shorter hospital stays as compared with surgical options. Recurrence of the obstructive symptoms resulting from stent occlusion, due to tumor ingrowth or overgrowth, can be successfully treated with repeat endoscopic stent placement in the majority of the cases. Both endoscopic stenting and surgical bypass are considered palliative treatments and, to date, no improvement in survival with either modality has been demonstrated. A tailored therapeutic approach, taking into consideration patient preferences and involving a multidisciplinary team including the therapeutic endoscopist, surgeon, medical oncologist, radiation therapist, and interventional radiologist, should be considered in all cases.

  14. Application of rotational atherectomy in the drug-eluting stent era

    Institute of Scientific and Technical Information of China (English)

    Chun-Chi Chen; I-Chang Hsieh

    2013-01-01

    Rotational atherectomy (RA) was introduced in the interventional arena in 1988 as a dedicated device for calcified lesions. Due to the complexity of the technique, the development of alternative methods such as the cutting balloon procedure, and the high restenosis rate of subsequent bare metal stenting in long lesions, its use had later declined. However, with the increasing use of drug-eluting stents (DES) and the aggressive treatment of longer lesions, the number of procedure performed with RA has increased significantly again in recent years. In this article, we reviewed the application of RA in DES era.

  15. 不同金属胆道支架对恶性梗阻性黄疸疗效比较%Biliary stenting for the treatment of malignant obstructive jaundice:comparison study of different metallic stents

    Institute of Scientific and Technical Information of China (English)

    路绪龙; 白旭明; 程龙; 顾星石; 靳勇

    2014-01-01

    目的:评估两类常用金属支架治疗不同位置的恶性胆道梗阻支架通畅率及患者生存率。方法对126例因恶性胆道梗阻接受经皮经胆道金属支架植入治疗的患者进行回顾性分析,共植入金属胆道支架167枚,其中70例患者植入网状编织型支架92枚,56例患者植入激光雕刻型支架75枚。术后随访并比较患者支架通畅时间及生存时间。结果支架植入成功率为100%(126/126),网状型与激光型中位通畅时间分别为182 d、196 d,术后患者的中位生存时间分别为179 d、186 d。两组患者术后通畅率及生存率进行对比分析差异均无统计学意义(P >0.05)。结论网状型与激光型支架在治疗恶性胆道梗阻效果上基本等效。在一定程度上前者可起到替代作用。%Objective To evaluate the patency rate of two types of metallic biliary stent in treating malignant biliary stenosis, and to discuss the patient’s survival rate. Methods A total of 126 patients with malignant biliary stenosis were treated with percutaneous implantation of biliary stent. The clinical data were retrospectively analyzed. A total of 167 metallic biliary stents were used in 126 patients. Ninety - two metal stents of mesh type were employed in 70 cases, while 75 metal stents of laser engraving type were adopted in 56 cases. After the treatment all patients were followed up, and the stent patency time as well as the median survival time was determined. The results were analyzed and compared between the two types of stents. Results Technical success rate was 100% (126/126). The median patency rate time of mesh type and laser type was 182 days and 196 days respectively, the patient’s median survival time of mesh type group and laser type group was 179 days and 186 days respectively. No statistically significant differences in the stent patency time and in the median survival time existed between the two groups (P > 0.05). Conclusion In

  16. Future developments in biliary stenting

    Directory of Open Access Journals (Sweden)

    Hair CD

    2013-06-01

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

  17. Physical and histopathological assessment of the effects of metallic stents on radiation therapy.

    Science.gov (United States)

    Tsuji, Yoshihiko; Yoshimura, Hitoshi; Uto, Fumiaki; Tamada, Toshiaki; Iwata, Kazuro; Tamamoto, Tetsuro; Asakawa, Isao; Shinkai, Takayuki; Kichikawa, Kimihiko; Hasegawa, Masatoshi

    2007-11-01

    To evaluate whether simultaneous metallic stent (MS) placement and radiotherapy are feasible, phantom and animal experiments were performed. The interface dose by external irradiation (EI) or intracavity irradiation (II) to 5 kinds of MS was measured using the charge-coupled device (CCD) camera with a thermoluminescent (TL) sheet, and backscatter and absorption were evaluated using composite method. Lineac 10 MV X-ray irradiated the MS in close contact with the TL sheet. II was performed using (192)Ir, and the irradiation dose transmitted through the MS was measured using the TL sheet. The ratio of the CCD value of the MS wire region to that of the MS non-wire region was defined as the dose perturbation factor (DPF). Furthermore, the effects of a combination of (60)Co gamma-ray EI and MS placement in the normal common bile duct were histopathologically evaluated in dogs. In the phantom experiments of EI, in backscatter by the MS, the DPF was 1.09 for CZ, and 1.03 for Pal, but no backscatter was detected in the remaining 3 MS. In absorption by the MS, the DPF was 0.92, 0.97, 0.97, and 0.98 for CZ, Wall, Pal, and Vel, respectively, but no absorption was detected in U. Flex. In those of II, the DPF of absorption was 0.91, 0.98, and 0.98 for CZ, U. Flex, and Wall, respectively, but no absorption was detected in Pal and Vel. The animal experiments showed infiltration of inflammatory cells and fibrosis in the case of both MS placement and EI. These changes were marked in EI treating after MS placement, but neither severe ulcer nor perforation was found. In conclusion, these results suggested that the effect of MS should be considered carefully when simultaneous MS placement and EI is performed clinically.

  18. Use of a novel covered self-expandable metal stent with an anti-migration system for endoscopic ultrasound-guided drainage of a pseudocyst.

    Science.gov (United States)

    Téllez-Ávila, Félix Ignacio; Villalobos-Garita, Alvaro; Ramírez-Luna, Miguel Ángel

    2013-06-16

    The development of pseudocysts in patients with chronic pancreatitis has been reported in 23%-60% of cases and drainage is indicated when they become symptomatic. Endoscopic ultrasound-guided drainage with the placement of plastic or metallic stents to create a cystogastric anastomosis has been shown to be a reliable and efficacious maneuver. Metallic stent use appears to be a safe and effective alternative that shortens the length of time of the procedure and maintains a greater diameter in the cystogastric communication. However, important migration rates have been reported. The use of new metallic stents that are specially designed to prevent migration represents a promising development in the treatment of these group of patients that appears to be safe and effective for pseudocyst drainage and could importantly reduce migration rates, while at the same time having the advantage of a single step procedure and a larger fistula diameter in the endoscopic cystogastric anastomosis.

  19. Blood-Flow Modelling Along and Trough a Braided Multi-Layer Metallic Stent

    CERN Document Server

    Milisic, Vuk

    2009-01-01

    In this work we study the hemodynamics in a stented artery connected either to a collateral artery or to an aneurysmal sac. The blood flow is driven by the pressure drop. Our aim is to characterize the flow-rate and the pressure in the contiguous zone to the main artery: using boundary layer theory we construct a homogenized first order approximation with respect to epsilon, the size of the stent's wires. This provides an explicit expression of the velocity profile through and along the stent. The profile depends only on the input/output pressure data of the problem and some homogenized constant quantities: it is explicit. In the collateral artery this gives the flow-rate. In the case of the aneurysm, it shows that : (i) the zeroth order term of the pressure in the sac equals the averaged pressure along the stent in the main artery, (ii) the presence of the stent inverses the rotation of the vortex. Extending the tools set up in [Bonnetier et al, Adv. Math. Fluids, 2009, Milisic, Meth. Apl. Ann., 2009] we pro...

  20. Novel A20-gene-eluting stent inhibits carotid artery restenosis in a porcine model

    Directory of Open Access Journals (Sweden)

    Zhou ZH

    2016-08-01

    Full Text Available Zhen-hua Zhou,1 Jing Peng,1 Zhao-you Meng,1 Lin Chen,1 Jia-Lu Huang,1 He-qing Huang,1 Li Li,2 Wen Zeng,2 Yong Wei,2 Chu-Hong Zhu,2 Kang-Ning Chen1 1Department of Neurology, Cerebrovascular Disease Research Institute, Southwest Hospital, 2Department of Anatomy, Key Laboratory for Biomechanics of Chongqing, Third Military Medical University, Chongqing, People’s Republic of China Background: Carotid artery stenosis is a major risk factor for ischemic stroke. Although carotid angioplasty and stenting using an embolic protection device has been introduced as a less invasive carotid revascularization approach, in-stent restenosis limits its long-term efficacy and safety. The objective of this study was to test the anti-restenosis effects of local stent-mediated delivery of the A20 gene in a porcine carotid artery model.Materials and methods: The pCDNA3.1EHA20 was firmly attached onto stents that had been collagen coated and treated with N-succinimidyl-3-(2-pyridyldithiolpropionate solution and anti-DNA immunoglobulin fixation. Anti-restenosis effects of modified vs control (the bare-metal stent and pCDNA3.1 void vector stents were assessed by Western blot and scanning electron microscopy, as well as by morphological and inflammatory reaction analyses.Results: Stent-delivered A20 gene was locally expressed in porcine carotids in association with significantly greater extent of re-endothelialization at day 14 and of neointimal hyperplasia inhibition at 3 months than stenting without A20 gene expression.Conclusion: The A20-gene-eluting stent inhibits neointimal hyperplasia while promoting re-endothelialization and therefore constitutes a novel potential alternative to prevent restenosis while minimizing complications. Keywords: restenosis, A20, gene therapy, stent, endothelialization

  1. PTA and stent placement distal to the superficial femoral artery; PTA und Stent distal der AFS

    Energy Technology Data Exchange (ETDEWEB)

    Rand, T.; Stadler, A.; Schoder, M.; Kettenbach, J. [Medizinische Universitaet Wien, Klinische Abteilung fuer Angiographie und Interventionelle Radiologie, Wien (Austria); Haumer, M. [Klinik fuer Innere Medizin II des Universitaetsklinikums Wien, Klinische Abteilung fuer Angiologie, Wien (Austria)

    2006-11-15

    Although angioplasty and stent applications in the iliac vessels and the superficial femoral artery have become routine procedures, their usefulness for the treatment of lesions of the popliteal artery and the lower leg arteries is still under discussion. For the popliteal artery, limitations are mainly due to the high mechanical stress in this area, causing high traction forces. Moreover, beyond the occlusive atherosclerotic changes, specific pathological entities such as aneurysms, emboli, entrapment syndromes, and cystic adventitial disease have to be differentiated. There is hope that the development of innovative stent designs with high flexibility might overcome the limitations. For lesions of the lower leg arteries treatment with percutaneous transluminal angioplasty (PTA) has become the method of choice. However, stent designs as used for cardiac interventions have been adapted for their application below the knee, and first encouraging results may help to justify their broad use in the future. Regarding PTA, innovative equipment and techniques for the treatment of arterial lesions below the knee include dedicated, long, and very flexible balloons, cutting balloon cryoplasty, and laser angioplasty. Regarding stents, bare metal stents, stents with passive or active coatings, and bioabsorbable stents have all been successfully used. (orig.) [German] Waehrend Angioplastie (PTA) und Stentbehandlung im Bereich der Beckengefaesse sich zu etablierten interventionellen Standardverfahren entwickelt haben, ist die endovaskulaere Behandlung von Laesionen der A. poplitea und auch der Unterschenkelgefaesse noch in Diskussion. Gruende hierfuer sind bei der A. poplitea v. a. die unguenstigen mechanischen Faktoren, die hohe Traktionskraefte am Gefaess wirken lassen und besonders die Gefaesspathologien, die neben der stenosierenden Atherosklerose auch andere spezifische Auspraegungen wie Aneurysmen, Embolien, Entrapmentsyndrome und die zystische Adventitianekrose umfassen

  2. 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.

  3. A novel polymer-free ciglitazone-coated vascular stent: in vivo and ex vivo analysis of stent endothelialization in a rabbit iliac artery model

    Science.gov (United States)

    Otto, Sylvia; Jaeger, Kristin; Kolodgie, Frank D.; Muehlstaedt, Diana; Franz, Marcus; Bischoff, Sabine; Schubert, Harald; Figulla, Hans R.; Virmani, Renu; Poerner, Tudor C.

    2016-01-01

    Aim Peroxisome proliferator-activated receptor-gamma (PPARg) agonists have known pleiotropic cardiovascular effects with favourable properties in vascular remodeling, and specifically in suppression of vascular smooth muscle cell proliferation. A novel vascular stent coating using the PPARg ligand ciglitazone (CCS) was investigated regarding its effects on endothelialization after 7 and 28 days. Methods Microporous bare metal stents (BMS) were coated with ciglitazone by ultrasonic flux with a load of 255 μg ciglitazone/stent. SixteenNew Zealand white rabbits, fed a with high cholesterol diet, underwent stent implantation in both iliac arteries. Everolimus-eluting stents (EES) and BMS were comparators. Histology (CD 31 immunostaining, confocal and scanning electron microscopy, morphometry) was performed after 7 and 28 days and by OCT (optical coherence tomography) in vivo after 28 days. Results Microscopy showed comparable results with near complete endothelialization in CCS and BMS (%CD31 above stent struts after 7 days: 67.92±36.35 vs. 84.48±23.86; p = 0.55; endothel % above stent struts: 77.22±27.9 vs. 83.89±27.91; p = 0.78). EES were less endothelialized with minimal fibrin deposition, not found in BMS and CCS (% CD 31 above struts after 28 days, BMS: 100.0±0.0 vs. EES: 95.9±3.57 vs. CCS: 100.0±0.0; p = 0.0292). OCT revealed no uncovered struts in all stents after 28 days. Conclusions Polymer-free coating with ciglitazone, a PPARg agonist is feasible and stable over time. Our data prove unimpaired endothelial coverage of a ciglitazone-coated vascular stent system by histology and OCT. Thus, this PPARg agonist coating deserves further investigation to evaluate its potency on local neointimal suppression. PMID:27613845

  4. New stent design for use in small coronary arteries during percutaneous coronary intervention

    Directory of Open Access Journals (Sweden)

    Juan F Granada

    2010-10-01

    Full Text Available Juan F Granada1, Barbara A Huibregtse2, Keith D Dawkins21The Jack H Skirball Center for Cardiovascular Research, Cardiovascular Research Foundation, Columbia University Medical Center, New York, NY, USA; 2Boston Scientific Corporation, Natick, MA, USAAbstract: Patients with diabetes mellitus, of female gender, increased age, and/or with peripheral vascular disease often develop coronary stenoses in small caliber vessels. This review describes treatment of these lesions with the paclitaxel-eluting 2.25 mm TAXUS® Liberté® Atom™ stent. Given the same stent composition, polymer, antirestenotic drug (paclitaxel, and release kinetics as the first-generation 2.25 mm TAXUS® Express® Atom™ stent, the second-generation TAXUS Liberté Atom stent incorporates improved stent design characteristics, including thinner struts (0.0038 versus 0.0052 inches, intended to increase conformability and deliverability. In a porcine noninjured coronary artery model, TAXUS Liberté Atom stent implantation in small vessels demonstrated complete strut tissue coverage compared with the bare metal stent control, suggesting a similar degree of tissue healing between the groups at 30, 90, and 180 days. The prospective, single-armed TAXUS ATLAS Small Vessel trial demonstrated improved instent late loss (0.28 ± 0.45 versus 0.84 ± 0.57 mm, P < 0.001, instent binary restenosis (13.0% versus 38.1%, P < 0.001, and target lesion revascularization (5.8% versus 17.6%, P < 0.001 at nine months with the TAXUS Liberté Atom stent as compared with the bare metal Express stent control, with similar safety measures between the two groups. The TAXUS Liberté Atom also significantly reduced nine-month angiographic rates of both instent late loss (0.28 ± 0.45 versus 0.44 ± 0.61 mm, P = 0.03 and instent binary restenosis (13.0% versus 25.9%, P = 0.02 when compared with the 2.25 mm TAXUS Express Atom control. The observed reduction in target lesion revascularization with the TAXUS

  5. Self-Expandable Metal Stents for Colorectal Cancer: From Guidelines to Clinical Practice

    Directory of Open Access Journals (Sweden)

    Maria Pia Costa Santos

    2016-11-01

    Conclusions: In this study, stent placement was an effective procedure in obstructive colorectal cancer. It was mainly used as a bridge to elective surgery. However, a significant rate of silent perforation was observed, which may compromise the oncological outcome of these potentially curable patients. Prospective real life studies are warranted for a better definition of actual recommendations.

  6. A novel lumen-apposing metal stent for endoscopic ultrasound-guided drainage of pancreatic fluid collections : a prospective cohort study

    NARCIS (Netherlands)

    Walter, Daisy; Will, Uwe; Sanchez-Yague, Andres; Brenke, Dirk; Hampe, Jochen; Wollny, Helge; López-Jamar, Jose Miguel Esteban; Jechart, Gertrud; Vilmann, Peter; Gornals, Joan B; Ullrich, Sebastian; Fähndrich, Martin; de Tejada, Alberto Herreros; Junquera, Félix; Gonzalez-Huix, Ferran; Siersema, Peter D; Vleggaar, FP

    2015-01-01

    BACKGROUND AND STUDY AIMS: A novel large-diameter, lumen-apposing, self-expanding metal stent with bilateral flanges was recently developed for endoscopic ultrasound (EUS)-guided transmural drainage of symptomatic pancreatic fluid collections (PFCs). The aim of this study was to evaluate the efficac

  7. Application of 64 slice spiral CT in evaluating the patency of coronary artery after stent implantation

    Institute of Scientific and Technical Information of China (English)

    Yong-Shu Gao; Xing-Can Ma

    2015-01-01

    Objective:To explore the feasibility and effectiveness of 64 slice spiral CT in evaluating the patency of coronary artery after stent implantation.Methods:The 64 slice spiral CT image data of 125 patients after coronary artery stent implantation were collected, meanwhile, the image data of 25 patients underwent coronary angiography were also collected. The feasibility and accuracy of 64 slice spiral CT coronary artery stent imaging were comparatively analyzed. Results: The 64 slice spiral CT imaging quality with a stent diameter greater than 3.00 mm was significantly superior to that with a diameter of 2.25-3.00 mm. The CT imaging quality in the left main coronary artery and anterior descending artery was significantly higher than that in the left circumflex coronary artery. The CT imaging quality in the left main coronary artery was significantly higher than that in the right coronary artery. The CT reconstruction imaging quality in the drug coating stent was significantly superior to that in the bare metal stent. The sensitivity of 64 slice spiral CT was 100.00%, and the accuracy was 100.00%. In detecting the coronary artery with occlusion and stenosis (stent stenosis greater than 50%), the sensitivity was 90.00%, the false negative rate was 10.00%, and the positive predicative value was 100.00%.Conclusions:The effect of 64 slice spiral CT coronary imaging in evaluating the patency of coronary artery after stent implantation is highly consistent with that by coronary angiography, with a simple operation, less risk, and low cost, and thus, it can be completely taken as the imaging method in evaluating the patency of coronary artery after stent implantation.

  8. Y-configured metallic stent combined with (125)I seed strands cavity brachytherapy for a patient with type IV Klatskin tumor.

    Science.gov (United States)

    Dechao, Jiao; Han, Xinwei; Yanli, Wang; Zhen, Li

    2016-08-01

    We report a case in an inoperable patient with type IV Klatskin tumor treated by the use of a novel, two piece, Y-configured self-expandable metallic stent (SEMS) combined with two (125)I seed strands via bilateral approach. The placement of the Y-shaped SEMS was successful and resulted in adequate biliary drainage. After 2 months of intraluminal brachytherapy (ILBT), both (125)I seed strands and temporary drainage catheter were removed after patency of the expanded stents was confirmed by the cholangiogram. This technique was feasible and could be considered for the treatment of patients with Bismuth type IV Klatskin tumors.

  9. Y-configured metallic stent combined with 125I seed strands cavity brachytherapy for a patient with type IV Klatskin tumor

    Science.gov (United States)

    Dechao, Jiao; Yanli, Wang; Zhen, Li

    2016-01-01

    We report a case in an inoperable patient with type IV Klatskin tumor treated by the use of a novel, two piece, Y-configured self-expandable metallic stent (SEMS) combined with two 125I seed strands via bilateral approach. The placement of the Y-shaped SEMS was successful and resulted in adequate biliary drainage. After 2 months of intraluminal brachytherapy (ILBT), both 125I seed strands and temporary drainage catheter were removed after patency of the expanded stents was confirmed by the cholangiogram. This technique was feasible and could be considered for the treatment of patients with Bismuth type IV Klatskin tumors. PMID:27648091

  10. Self-expandable metal stents for achalasia: Thinking out ofthe box!

    Institute of Scientific and Technical Information of China (English)

    Athanasios D Sioulas; Chrysoula Malli; George D Dimitriadis; Konstantinos Triantafyllou

    2015-01-01

    Achalasia is a primary motor disorder of the esophagusdiagnosed manometrically in the clinical settingof dysphagia to both solids and liquids. Currentlyestablished treatment options include pneumaticdilation, laparoscopic Heller myotomy, botulinumtoxin injection performed endoscopically, oral agentsthat relax the lower esophageal sphincter andesophagectomy for refractory, end-stage disease.Despite their effectiveness, a significant proportion ofpatients eventually relapses and needs retreatment.In this setting, several new techniques are underinvestigation promising future enrichment of ourtherapeutic armamentarium for achalasic patients.Among them, peroral endoscopic myotomy and selfexpandablemetal stents placed across the gastroesophagealjunction represent the most encouragingmodalities, as initial studies assessing their efficacy andsafety indicate. This review highlights the role of selfexpandablemetal stents in the management of patientswith achalasia. Their possible position in the therapeuticalgorithm of achalasia along with established and noveltechniques is also assessed. Finally, the need for largeprospective randomized trials is underlined in order toelucidate the numerous relevant issues.

  11. Self-expandable metallic stents in the treatment of post-esophagogastrostomy/post-esophagoenterostomy fistula.

    Science.gov (United States)

    Nowakowski, P; Ziaja, K; Ludyga, T; Kuczmik, W; Biolik, G; Cwik, P; Ziaja, D

    2007-01-01

    Esophageus or gaster resection in patients with malignant disease is still a treatment of choice. It is obvious that each surgical procedure in these patients carries some possibility of complications. Esophageo-gastric or esophageo-jejuno anastomosis has a 4-27% frequency of fistula occurrence. All these result in 65% mortality in cases of poorer prognosis. The aim of this paper is not to present all types of complications but to objectively analyse the usefulness of the covered stent placement in the treatment of anastomotic fistulas. We present six patients who were treated for postoperative fistula of esophageo-gastric anastomosis (1 case) or esophageo-jejuno anastomosis (5 cases). All patients were treated with stapler suture for digestive tract reconstruction after malignancy removal during the primary surgical procedure. Signs and symptoms of suture leak between 5-8 days post-surgery were observed. Conservative therapy was not effective. Thus a new method of treatment was employed - covered stent placement. The procedure was performed under X-ray control. In all treated patients there was change for the better and quick reduction of secretion from the fistulas was observed. All patients were discharged from the department after several days and all had survived at 30 days follow-up. Covered esophageal stent placement seems to be a safe and promising method of treatment for patients with anastomotic fistula which significantly reduces mortality and improves quality of live. Our experiences confirms that of other investigators.

  12. Development of epigallocatechin gallate-eluting polymeric stent and its physicochemical, biomechanical and biological evaluations

    Energy Technology Data Exchange (ETDEWEB)

    Han, Dong-Wook [Department of Nanomedical Engineering, College of Nanoscience and Nanotechnology, Pusan National University, Busan 609-735 (Korea, Republic of); Lee, Jun Jae [Division of Advanced Fibro-Science, Kyoto Institute of Technology, Kyoto 606-8585 (Japan); Jung, Duk-Young [Senior Products Industrial Center, Busan Techno-Park, Busan-617-030 (Korea, Republic of); Park, Jong-Chul [Cellbiocontrol Laboratory, Department of Medical Engineering, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Hyon, Suong-Hyu, E-mail: nanohan@pusan.ac.k, E-mail: biogen@frontier.kyoto-u.ac.j [Department of Medical Simulation Engineering, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606-8507 (Japan)

    2009-08-15

    Localized drug delivery from drug-eluting stents has been accepted as one of the most promising treatment methods for preventing restenosis after stenting. However, hypersensitivity reactions caused by their nonresorbable polymer coatings and bare-metal stents may result in serious clinical sequelae. Epigallocatechin-3-O-gallate (EGCG), the predominant catechin from tea, has been shown to exert anti-thrombotic, anti-inflammatory and anti-proliferative activities. In this study, it was hypothesized that sustainedly released EGCG from biodegradable poly(lactide-co-epsilon-caprolactone, PLCL) would suppress the proliferation of vascular smooth muscle cells (VSMCs). EGCG-releasing PLCL (E-PLCL) was prepared by blending PLCL with EGCG. The surface morphology, roughness and melting temperature of PLCL were not changed despite EGCG addition. EGCG was uniformly dispersed into E-PLCL and sustainedly released for periods up to 7 days by controlled diffusion rather than PLCL degradation. Moreover, EGCG did not affect tensile strength at break, but significantly increased the elastic modulus of PLCL. The proliferation of VSMCs onto E-PLCL was significantly suppressed although the cell attachment onto E-PLCL had been higher than that onto PLCL. On the other hand, EGCG-eluting polymeric stents were prepared with neither cracks nor webbings between struts, and their structural integrity was maintained without delamination or destruction. These results suggest that E-PLCL can be potentially applied for fabricating an EGCG-eluting vascular stent, namely an EGCG-eluting polymeric stent, or even an EGCG-releasing polymer-coated metal stent, to prevent thrombosis, inflammation and in-stent restenosis.

  13. Cost-Effectiveness Analysis of Infrapopliteal Drug-Eluting Stents

    Energy Technology Data Exchange (ETDEWEB)

    Katsanos, Konstantinos, E-mail: katsanos@med.upatras.gr; Karnabatidis, Dimitris; Diamantopoulos, Athanasios; Spiliopoulos, Stavros; Siablis, Dimitris [Patras University Hospital, Department of Interventional Radiology, School of Medicine (Greece)

    2013-02-15

    IntroductionThere are no cost-utility data about below-the-knee placement of drug-eluting stents. The authors determined the cost-effectiveness of infrapopliteal drug-eluting stents for critical limb ischemia (CLI) treatment. The event-free individual survival outcomes defined by the absence of any major events, including death, major amputation, and target limb repeat procedures, were reconstructed on the basis of two published infrapopliteal series. The first included spot Bail-out use of Sirolimus-eluting stents versus bare metal stents after suboptimal balloon angioplasty (Bail-out SES).The second was full-lesion Primary Everolimus-eluting stenting versus plain balloon angioplasty and bail-out bare metal stenting as necessary (primary EES). The number-needed-to-treat (NNT) to avoid one major event and incremental cost-effectiveness ratios (ICERs) were calculated for a 3-year postprocedural period for both strategies. Overall event-free survival was significantly improved in both strategies (hazard ratio (HR) [confidence interval (CI)]: 0.68 [0.41-1.12] in Bail-out SES and HR [CI]: 0.53 [0.29-0.99] in Primary EES). Event-free survival gain per patient was 0.89 (range, 0.11-3.0) years in Bail-out SES with an NNT of 4.6 (CI: 2.5-25.6) and a corresponding ICER of 6,518 Euro-Sign (range 1,685-10,112 Euro-Sign ). Survival gain was 0.91 (range 0.25-3.0) years in Primary EES with an NNT of 2.7 (CI: 1.7-5.8) and an ICER of 11,581 Euro-Sign (range, 4,945-21,428 Euro-Sign ) per event-free life-year gained. Two-way sensitivity analysis showed that stented lesion length >10 cm and/or DES list price >1000 Euro-Sign were associated with the least economically favorable scenario in both strategies. Both strategies of bail-out SES and primary EES placement in the infrapopliteal arteries for CLI treatment exhibit single-digit NNT and relatively low corresponding ICERs.

  14. In vitro hemocompatibility and cytocompatibility of dexamethasone-eluting PLGA stent coatings

    Science.gov (United States)

    Zhang, Jiang; Liu, Yang; Luo, Rifang; Chen, Si; Li, Xin; Yuan, Shuheng; Wang, Jin; Huang, Nan

    2015-02-01

    Drug-eluting stents (DESs) have been an important breakthrough for interventional cardiology applications since 2002. Though successful in reducing restenosis, some adverse clinical problems still emerged, which were mostly caused by the bare-metal stents and non-biodegradable polymer coatings, associated with the delayed endothelialization process. In this study, dexamethasone-loaded poly (lactic-co-glycolic acid) (PLGA) coatings were developed to explore the potential application of dexamethasone-eluting stents. Dexamethasone-eluting PLGA stents were prepared using ultrasonic atomization spray method. For other tests like stability and cytocompatibility and hemocompatibility tests, dexamethasone loaded coatings were deposited on 316L SS wafers. Fourier transform-infrared spectroscopy (FT-IR) results demonstrated that there was no chemical reaction between PLGA and dexamethasone. The balloon expansion experiment and surface morphology observation suggested that the stent coatings were smooth and uniform, and could also withstand the compressive and tensile strains imparted without cracking after stent expansion. The drug release behavior in vitro indicated that dexamethasone existed burst release within 1 day, but it presented linear release characteristics after 6 days. In vitro platelets adhesion, activation test and APTT test were also done, which showed that after blending dexamethasone into PLGA, the hemocompatibility was improved. Besides, dexamethasone and dexamethasone-loaded PLGA coatings could significantly inhibit the attachment and proliferation of smooth muscle cells.

  15. Clinical safety of cardiac magnetic resonance imaging at 3 T early after stent placement for acute myocardial infarction

    Energy Technology Data Exchange (ETDEWEB)

    Jehl, Jerome; Comte, Alexandre; Aubry, Sebastien; Kastler, Bruno [Hopital Jean Minjoz, Service de Radiologie A and C, Centre Hospitalier Universitaire de Besancon, Besancon (France); Meneveau, Nicolas; Schiele, Francois [Hopital Jean Minjoz, Service de Cardiologie, Centre Hospitalier Universitaire de Besancon, Besancon (France)

    2009-12-15

    The purpose of this study was to prospectively evaluate the safety of cardiac magnetic resonance (CMR) imaging at 3 T performed early (less than 14 days) after bare metal or drug-eluting coronary stent implantation in patients with acute myocardial infarction (AMI). Seventy-two consecutive patients with AMI treated by percutaneous revascularisation with a stent underwent CMR examination with a median delay of 6 days. Patients were followed-up for major adverse cardiac events, during hospitalisation and at 6 months. After CMR imaging, no acute stent thrombosis, death or repeated AMI were recorded at 6-month follow-up. Two symptomatic in-stent restenoses and two silent in-stent restenoses were recorded, at a mean delay of 106 days. In our population, we found a target revascularisation rate of 5.6%. This is consistent with the 6-month event rates after coronary artery stent (CAS) placement for AMI, evaluated by several studies. This preliminary clinical study supports the safety of 3-T CMR imaging performed early after coronary stent placement. (orig.)

  16. EFFICACY AND SAFETY OF GLYCOPROTEIN IIB/IIIA BLOCKER MONOFRAM IN CORONARY STENTING IN PATIENTS WITH ACUTE MYOCARDIAL INFARCTION

    Directory of Open Access Journals (Sweden)

    E. I. Makhiyanova

    2011-01-01

    Full Text Available  Aim. To study of efficacy and safety of glycoprotein IIb/IIIa blocker monafram in acute ST-segment elevation myocardial infarction (STEMI patients, underwent coronary stenting. Material and methods. 220 STEMI patients were included in the trial; they were split into two groups. 109 patients of the first group were underwent coronary stenting with i/v monafram therapy. Coronary stenting without monafram therapy was performed in 111 patients of the second group. Bare metal stents were used in all patients. Deaths, stent thrombosis, individual intolerance, allergic reactions, bleeding were registered during hospitalization. Results. There were 3 (2.75% cases of stent thrombosis in monafram group and 4 (3.6% ones - in the control group. Good tolerance of monafram was observed in all patients. There were no allergic reactions, major and minor bleedings. Reinfarction rate was similar in both groups during 30 days observational period. Conclusions. Monafram therapy is effective and safe in acute STEMI patients underwent coronary stenting.  

  17. A randomized multicenter comparison of hybrid sirolimus-eluting stents with bioresorbable polymer versus everolimus-eluting stents with durable polymer in total coronary occlusion: rationale and design of the Primary Stenting of Occluded Native Coronary Arteries IV study

    Directory of Open Access Journals (Sweden)

    Teeuwen Koen

    2012-12-01

    Full Text Available Abstract Background Percutaneous recanalization of total coronary occlusion (TCO was historically hampered by high rates of restenosis and reocclusions. The PRISON II trial demonstrated a significant restenosis reduction in patients treated with sirolimus-eluting stents compared with bare metal stents for TCO. Similar reductions in restenosis were observed with the second-generation zotarolimus-eluting stent and everolimus-eluting stent. Despite favorable anti-restenotic efficacy, safety concerns evolved after identifying an increased rate of very late stent thrombosis (VLST with drug-eluting stents (DES for the treatment of TCO. Late malapposition caused by hypersensitivity reactions and chronic inflammation was suggested as a probable cause of these VLST. New DES with bioresorbable polymer coatings were developed to address these safety concerns. No randomized trials have evaluated the efficacy and safety of the new-generation DES with bioresorbable polymers in patients treated for TCO. Methods/Design The prospective, randomized, single-blinded, multicenter, non-inferiority PRISON IV trial was designed to evaluate the safety, efficacy, and angiographic outcome of hybrid sirolimus-eluting stents with bioresorbable polymers (Orsiro; Biotronik, Berlin, Germany compared with everolimus-eluting stents with durable polymers (Xience Prime/Xpedition; Abbott Vascular, Santa Clara, CA, USA in patients with successfully recanalized TCOs. In total, 330 patients have been randomly allocated to each treatment arm. Patients are eligible with estimated duration of TCO ≥4 weeks with evidence of ischemia in the supply area of the TCO. The primary endpoint is in-segment late luminal loss at 9-month follow-up angiography. Secondary angiographic endpoints include in-stent late luminal loss, minimal luminal diameter, percentage of diameter stenosis, in-stent and in-segment binary restenosis and reocclusions at 9-month follow-up. Additionally, optical coherence

  18. Biodegradable polymer Biolimus-eluting stent (Nobori® for the treatment of coronary artery lesions: review of concept and clinical results

    Directory of Open Access Journals (Sweden)

    Schurtz G

    2014-02-01

    Full Text Available Guillaume Schurtz,1,2 Cédric Delhaye,1 Christopher Hurt,1,2 Henri Thieuleux,1,2 Gilles Lemesle1–3 1Centre Hémodynamique et Unité des Soins Intensifs de Cardiologie, Hôpital Cardiologique, Centre Hospitalier Régional et Universitaire de Lille, Lille, France; 2Faculté de Médecine de Lille, Lille, France; 3Unité INSERM UMR744, Institut Pasteur de Lille, Lille, France Abstract: First-generation drug-eluting stents have raised concerns regarding the risk of late and very late stent thrombosis compared with bare metal stents and require prolonged dual antiplatelet therapy. Despite extensive investigations, the physiopathology of these late events remains incompletely understood. Aside from patient- and lesion-related risk factors, stent polymer has been cited as one of the potential causes. In fact, the persistence of durable polymer after complete drug release has been shown to be responsible for local hypersensitivity and inflammatory reactions. Third-generation drug-eluting stents with more biocompatible or biodegradable polymers have subsequently been developed to address this problem. In this article, we evaluate and discuss the concept and clinical results (safety and efficacy of a third-generation drug-eluting stent with biodegradable polymer: the Nobori® stent. Keywords: percutaneous coronary intervention, stent thrombosis, antiplatelet therapy

  19. 内镜置入胆道金属支架治疗肝门部胆管癌%Endoscopic metal stent implantation for hilar cholangiocarcinoma

    Institute of Scientific and Technical Information of China (English)

    庞勇; 田伏洲; 张炳印; 汤礼军

    2010-01-01

    Objective To investigate the therapeutic effectiveness of endoscopic self-expandable metal stent implantation for hilar cholangiocarcinoma. Methods The clinical data of 73 patients with hilar cholangiocar-cinoma who had received endoscopic metal stent implantation at the General Hospital of PLA Chengdu Command from July 2004 to July 2009 were retrospectively analyzed. The success rate of stent implantation, effective rate of jaundice release, duration of patency of the stent, survival time and postoperative complications were analyzed. Results Among the patients, 70 were successfully implanted with the stents. Unilateral metal stents were implan-ted in 62 patients, bilateral metal stents in three patients, and metal + plastic stents in five patients. The effective rate of jaundice release was 87% (61/70), the median duration of patency of the stent was 190 days, and the median survival time was 246 hours. Seven patients had complications of cholangitis, three had pancreatitis and two had bleeding. Conclusions The advantages of endoscopic metal stent implantation include minimal trauma and good efficacy in alleviating jaundice. It is the option of choice for the treatment of malignant biliary obstruction in patients with inoperable hilar cholangiocarcinoma.%目的 探讨通过内镜置入自膨式胆道金属支架治疗肝门部胆管癌的疗效.方法 回顾性分析2004年7月至2009年7月成都军区总医院收治的73例肝门部胆管癌患者行内镜胆道金属支架置入术的操作成功率、减黄有效率、支架通畅时间和生存时间以及术后并发症.结果 支架置入成功70例,3例失败.其中单金属支架置入62例,双侧金属支架置入3例,金属支架+塑料支架置人5例.减黄有效率为87%(61/70),中位支架通畅时间为190 d,中位生存时间为246 d.术后发生胆管炎7例,胰腺炎3例,出血2例.结论 内镜置入自膨式胆道金属支架治疗肝门部胆管癌创伤小、减黄效果好,可作为无法

  20. A prospective evaluation of the safety and efficacy of the TAXUS Element paclitaxel-eluting coronary stent system for the treatment of de novo coronary artery lesions: Design and statistical methods of the PERSEUS clinical program

    Directory of Open Access Journals (Sweden)

    Wehrenberg Scott

    2010-01-01

    Full Text Available Abstract Background Paclitaxel-eluting stents decrease angiographic and clinical restenosis following percutaneous coronary intervention compared to bare metal stents. TAXUS Element is a third-generation paclitaxel-eluting stent which incorporates a novel, thinner-strut, platinum-enriched metal alloy platform. The stent is intended to have enhanced radiopacity and improved deliverability compared to other paclitaxel-eluting stents. The safety and efficacy of the TAXUS Element stent are being evaluated in the pivotal PERSEUS clinical trials. Methods/Design The PERSEUS trials include two parallel studies of the TAXUS Element stent in single, de novo coronary atherosclerotic lesions. The PERSEUS Workhorse study is a prospective, randomized (3:1, single-blind, non-inferiority trial in subjects with lesion length ≤28 mm and vessel diameter ≥2.75 mm to ≤4.0 mm which compares TAXUS Element to the TAXUS Express2 paclitaxel-eluting stent system. The Workhorse study employs a novel Bayesian statistical approach that uses prior information to limit the number of study subjects exposed to the investigational device and thus provide a safer and more efficient analysis of the TAXUS Element stent. PERSEUS Small Vessel is a prospective, single-arm, superiority trial in subjects with lesion length ≤20 mm and vessel diameter ≥2.25 mm to Discussion The TAXUS PERSEUS clinical trial program uses a novel statistical approach to evaluate whether design and metal alloy iterations in the TAXUS Element stent platform provide comparable safety and improved procedural performance compared to the previous generation Express stent. PERSEUS trial enrollment is complete and primary endpoint data are expected in 2010. PERSEUS Workhorse and Small Vessel are registered at http://www.clinicaltrials.gov, identification numbers NCT00484315 and NCT00489541.

  1. Lethal post-endoscopic retrograde cholangiopancreatography pancreatitis following fully covered metal stent placement in distal biliary obstruction due to unresectable cholangiocarcinoma.

    Science.gov (United States)

    Itoi, Takao; Tsuchiya, Takayoshi; Tanaka, Reina; Ikeuchi, Nobuhito; Sofuni, Atsushi

    2013-05-01

    Biliary self-expandable metallic stent (SEMS) is the preferred and first-line therapy for unresectable malignant biliary obstruction. To date, several reports have revealed the relatively high incidence of acute complications such as pancreatitis and cholecystitis due to mechanical stent compression. In the present case, we encountered fatal pancreatitis following fully covered metal stent placement. An 85-year-old man had middle bile duct strictures due to cholangiocarcinoma. A 10-mm diameter fully covered SEMS was placed across the papilla for biliary decompression. Laboratory data and physical evidence the following day revealed acute pancreatitis. Therefore, antibiotics and protein degeneration enzyme inhibitors were given. However, his condition did not improve. Two days after the procedure, we removed the stent and returned him to his original hospital. Serum amylase level decreased below 400 mg/dL 6 h after the procedure. However, the acute pancreatitis worsened. Although we treated the patient in the intensive care unit, he died 32 days after the second admission.

  2. Nanotextured stainless steel for improved corrosion resistance and biological response in coronary stenting

    Science.gov (United States)

    Mohan, Chandini C.; Prabhath, Anupama; Cherian, Aleena Mary; Vadukumpully, Sajini; Nair, Shantikumar V.; Chennazhi, Krishnaprasad; Menon, Deepthy

    2014-12-01

    Nanosurface engineering of metallic substrates for improved cellular response is a persistent theme in biomaterials research. The need to improve the long term prognosis of commercially available stents has led us to adopt a `polymer-free' approach which is cost effective and industrially scalable. In this study, 316L stainless steel substrates were surface modified by hydrothermal treatment in alkaline pH, with and without the addition of a chromium precursor, to generate a well adherent uniform nanotopography. The modified surfaces showed improved hemocompatibility and augmented endothelialization, while hindering the proliferation of smooth muscle cells. Moreover, they also exhibited superior material properties like corrosion resistance, surface integrity and reduced metal ion leaching. The combination of improved corrosion resistance and selective vascular cell viability provided by nanomodification can be successfully utilized to offer a cell-friendly solution to the inherent limitations pertinent to bare metallic stents.

  3. A Budget Impact Model for Paclitaxel-eluting Stent in Femoropopliteal Disease in France

    Energy Technology Data Exchange (ETDEWEB)

    De Cock, Erwin, E-mail: erwin.decock@unitedbiosource.com [United BioSource Corporation, Peri- and Post-Approval Services (Spain); Sapoval, Marc, E-mail: Marc.sapoval2@egp.aphp.fr [Hopital Europeen Georges Pompidou, Universite Rene Descartes, Department of Cardiovascular and Interventional Radiology (France); Julia, Pierre, E-mail: pierre.julia@egp.aphp.fr [Hopital Europeen Georges Pompidou, Universite Rene Descartes, Cardiovascular Surgery Department (France); Lissovoy, Greg de, E-mail: gdelisso@jhsph.edu [Johns Hopkins Bloomberg School of Public Health, Department of Health Policy and Management (United States); Lopes, Sandra, E-mail: Sandra.Lopes@CookMedical.com [Cook Medical, Health Economics and Reimbursement (Denmark)

    2013-04-15

    The Zilver PTX drug-eluting stent (Cook Ireland Ltd., Limerick, Ireland) represents an advance in endovascular treatments for atherosclerotic superficial femoral artery (SFA) disease. Clinical data demonstrate improved clinical outcomes compared to bare-metal stents (BMS). This analysis assessed the likely impact on the French public health care budget of introducing reimbursement for the Zilver PTX stent. A model was developed in Microsoft Excel to estimate the impact of a progressive transition from BMS to Zilver PTX over a 5-year horizon. The number of patients undergoing SFA stenting was estimated on the basis of hospital episode data. The analysis from the payer perspective used French reimbursement tariffs. Target lesion revascularization (TLR) after primary stent placement was the primary outcome. TLR rates were based on 2-year data from the Zilver PTX single-arm study (6 and 9 %) and BMS rates reported in the literature (average 16 and 22 %) and extrapolated to 5 years. Net budget impact was expressed as the difference in total costs (primary stenting and reinterventions) for a scenario where BMS is progressively replaced by Zilver PTX compared to a scenario of BMS only. The model estimated a net cumulative 5-year budget reduction of Euro-Sign 6,807,202 for a projected population of 82,316 patients (21,361 receiving Zilver PTX). Base case results were confirmed in sensitivity analyses. Adoption of Zilver PTX could lead to important savings for the French public health care payer. Despite higher initial reimbursement for the Zilver PTX stent, fewer expected SFA reinterventions after the primary stenting procedure result in net savings.

  4. Outcome of endoscopic self-expandable metal stents in acute malignant colorectal obstruction at a tertiary center

    Directory of Open Access Journals (Sweden)

    Eduardo Rodrigues-Pinto

    2015-09-01

    Full Text Available Background: Malignant colorectal obstruction (MCRO by advanced colonic cancer occurs in 8-13% of colonic cancer patients. Emergent surgery carries a high mortality and morbidity risk. Endoscopic self-expanding metal stents (SEMS may be used in acute MCRO. Aim: Evaluate clinical outcome of SEMS in acute MCRO and efficacy of SEMS placement considering fluoroscopy guidance. Methods: Retrospective study of patients with acute MCRO that placed SEMS in a 3 years period. Results: SEMS were placed in 47 patients, followed-up for a median time of 150 days. The intent of stenting was bridge to definitive surgery in 40% of the patients (n = 19 and palliation in the remaining 60% (n = 28. The location of the tumor did not influence the presence of lymph node involvement (p = 0.764 nor metastasis (p = 0.885. Mortality rate at year 1 was 61%. Survival was significantly higher in patients submitted later to combination therapy compared to chemotherapy, surgery or symptomatic treatment (p < 0.001. Fluoroscopy was used in 57% of the procedures. Clinical success was 79%. A second SEMS was needed during the procedure in 6% of the patients. Rate of early and late complications was 11% and 5%, respectively. Fluoroscopy guidance did not influence the occurrence of immediate (p = 0.385, early (p = 0.950 or late complications (p = 0.057. Thirty-three percent of patients underwent surgery at a later stage, with neo-adjuvant therapy in 18%. Conclusions: SEMS provide a relative safe and successful treatment in a palliative or bridge-to-surgery indication. No significant differences were found in SEMS placement success, early complications or late complications considering fluoroscopy guidance.

  5. Percutaneous placement of self-expandable metallic stents in patients with obstructive janudice secondary to metastalic gastric cancer after gastrectomy

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Hyun Pyo [Dept. of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Seo, In Ho; Yu, Jung Rim; Mok, Young Jae; Oh, Joo Hyeong [Korea University Guro Hospital, Korea University College of Medicine, Seoul (Korea, Republic of); Kwon, Se Hwan [Dept. of Radiology, Kyung Hee University Medical Center, Seoul (Korea, Republic of); Kim, Sam Soo [Dept. of Radiology, Kangwon National University College of Medicine, Chuncheon (Korea, Republic of); Kim, Seung Kwon [Division of Interventional Radiology, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis (United States)

    2013-10-15

    To evaluate the outcomes of patients undergoing percutaneous placements of a biliary stent for obstructive jaundice secondary to metastatic gastric cancer after gastrectomy. Fifty patients (mean age, 62.4 years; range, 27-86 years) who underwent percutaneous placements of a biliary stent for obstructive jaundice secondary to metastatic gastric cancer after gastrectomy were included. The technical success rate, clinical success rate, complication rate, stent patency, patient survival and factors associated with stent patency were being evaluated. The median interval between the gastrectomy and stent placement was 23.1 months (range, 3.9-94.6 months). The 50 patients received a total of 65 stents without any major procedure-related complications. Technical success was achieved in all patients. The mean total serum bilirubin level, which had been 7.19 mg/dL ± 6.8 before stent insertion, decreased to 4.58 mg/dL ± 5.4 during the first week of follow-up (p < 0.001). Clinical success was achieved in 42 patients (84%). Percutaneous transhepatic biliary drainage catheters were removed from 45 patients (90%). Infectious complications were noted in two patients (4%), and stent malfunction occurred in seven patients (14%). The median stent patency was 233 ± 99 days, and the median patient survival was 179 ± 83 days. Total serum bilirubin level after stenting was an independent factor for stent patency (p = 0.009). Percutaneous transhepatic placement of a biliary stent for obstructive jaundice secondary to metastatic gastric cancer after gastrectomy is a technically feasible and clinically effective palliative procedure.

  6. Visualization of Stent Lumen in MR Imaging: Relationship with Stent Design and RF Direction

    Directory of Open Access Journals (Sweden)

    Ohno,Seiichiro

    2012-06-01

    Full Text Available Magnetic resonance imaging (MRI visualization of metallic stent lumens is possible if the stent structure counteracts eddy currents in the lumen induced by the radio frequency magnetic field, B1. To examine the effectiveness of various stent designs in counteracting eddy currents, we anchored eight copper stent models and 2 commercially available nickel-titanium alloy (Nitinol stents in a gel phantom, perpendicular or parallel to the direction of B1. A mesh stent lumen showed hypointensity irrespective of its alignment relative to B1. A solenoid stent lumen showed hypointensity with the stent axis parallel to B1, but it had the same signal intensity as outside the lumen when perpendicular to B1. A Moebius stent lumen showed no signal reduction, irrespective of alignment relative to B1. Lumens of the commercially available stents showed hypointensity regardless of alignment relative to B1. Computer simulation revealed that the signal intensities of the stents corresponded to magnetic flux densities of B1 in the stents, which are modified by the structure of the stent. While in vivo MRI viewing of a Moebius stent lumen is likely possible regardless of axis alignment, inherent structural weakness may be problematic. As a more practical choice, the solenoid stent is easier to manufacture and generates no hypointensive signal when the axis is parallel to B0.

  7. Efficacy and safety of a novel nano-porous polymer-free sirolimuseluting stent in pigs

    Institute of Scientific and Technical Information of China (English)

    CHEN Ming; ZHENG Bo; WU Zheng; PENG Hong-yu; WANG Xin-gang; ZHANG bin; HUO Yong

    2013-01-01

    Background Drug-eluting stents represent a major advance in interventional cardiology.However,the current drugeluting stents have significant limitations.One of the major problems is very late stent thrombosis,which is likely caused by inflammation and a hypersensitivity reaction related to a polymer on the stent.A polymer-free sirolimus-eluting stent with a unique nano-porous surface has been developed.This study aimed to evaluate this novel polymer-free sirolimuseluting stent for its efficacy and safety in a pig model.Methods Stents were directly coated with sirolimus (a drug concentration of 2.2 μg/mm2 on the stent surface).The polymer-free sirolimus-eluting stents (PFSES) were compared to standard polymer-coated sirolimus-eluting stents (PCSES) and bare-metal stents (BMS) in 18 pigs.Results At one month the degree of neointimal hyperplasia was similar between the two sirolimus-eluting stent groups and was significantly less compared to BMS ((1.93±0.51) mm2,(1.57±0.69) mm2 vs.(4.45±1.05) mm2,P <0.05) At three months,PFSES maintained the low level of neointima ((2.41±0.99) mm2 vs.(4.32±1.16) mm2,P <0.05),whereas PCSES had developed significant neointimal proliferation similar to BMS.The inflammation level was significantly higher in PCSES when compared with BMS three months post-implantation (2.50±0.55 vs.0.83±0.75,P <0.05) whereas PFSES showed a low level of inflammation comparable to PCSES (1.33±0.52 vs.2.50±0.55,P <0.05).Conclusion The PFSES is effective and safe,and appears to be superior to standard PCSEs.

  8. Paclitaxel Drug-eluting Tracheal Stent Could Reduce Granulation Tissue Formation in a Canine Model

    Institute of Scientific and Technical Information of China (English)

    Ting Wang; Jie Zhang; Juan Wang; Ying-Hua Pei; Xiao-Jian Qiu; Yu-Ling Wang

    2016-01-01

    Background:Currently available silicone and metallic stents for tracheal stenosis are associated with many problems.Granulation proliferation is one of the main complications.The present study aimed to evaluate the efficacy of paclitaxel drug-eluting tracheal stent in reducing granulation tissue formation in a canine model,as well as the pharmacokinetic features and safety profiles of the coated drug.Methods:Eight beagles were randomly divided into a control group (bare-metal stent group,n =4) and an experimental group (paclitaxel-eluting stent group,n =4).The observation period was 5 months.One beagle in both groups was sacrificed at the end of the 1st and 3rd months,respectively.The last two beagles in both groups were sacrificed at the end of 5th month.The proliferation of granulation tissue and changes in tracheal mucosa were compared between the two groups.Blood routine and liver and kidney function were monitored to evaluate the safety of the paclitaxel-eluting stent.The elution method and high-performance liquid chromatography were used to characterize the rate of in vivo release of paclitaxel from the stent.Results:Compared with the control group,the proliferation of granulation tissue in the experimental group was significantly reduced.The drug release of paclitaxel-eluting stent was the fastest in the 1st month after implantation (up to 70.9%).Then,the release slowed down gradually.By the 54 month,the release reached up to 98.5%.During the observation period,a high concentration of the drug in the trachea (in the stented and adjacent unstented areas) and lung tissue was not noted,and the blood test showed no side effect.Conclusions:The paclitaxel-eluting stent could safely reduce the granulation tissue formation after stent implantation in vivo,suggesting that the paclitaxel-eluting tracheal stent might be considered for potential use in humans in the future.

  9. 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......This Guideline is an official statement of the European Society of Gastrointestinal Endoscopy (ESGE). This Guideline was also reviewed and endorsed by the Governing Board of the American Society for Gastrointestinal Endoscopy (ASGE). The Grading of Recommendations Assessment, Development......, 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...

  10. CFD simulations in heavy liquid metal flows for square lattice bare rod bundle geometries with a four parameter heat transfer turbulence model

    Energy Technology Data Exchange (ETDEWEB)

    Manservisi, Sandro, E-mail: sandro.manservisi@unibo.it; Menghini, Filippo, E-mail: filippo.menghini3@unibo.it

    2015-12-15

    Highlights: • Turbulent heat transfer with a κ–ϵ–κ{sub θ}–ϵ{sub θ} turbulence model is investigated. • Numerical simulations with different pitch-to-diameter ratios are performed. • The results are compared with SED model and a few available experimental correlations. - Abstract: The study of heat transfer in heavy liquid metals has gained more attention in the last several years due to their applications in new advanced nuclear reactors. These fluids are characterized by low Prandtl numbers and a peculiar heat transfer that cannot be accurately reproduced with standard turbulence approximations, such as the Simple Eddy Diffusivity model (SED), commonly used in commercial codes. In this paper we report the results obtained for the SED and a more advanced κ–ϵ–κ{sub θ}–ϵ{sub θ} four parameter turbulence model for simulations in square lattice bare rod bundle geometries with different pitch-to-diameter ratios. We compare these numerical results with the available experimental data and correlations for the prediction of the Nusselt number.

  11. The back-diffusion effect of air on the discharge characteristics of atmospheric-pressure radio-frequency glow discharges using bare metal electrodes

    Science.gov (United States)

    Sun, Wen-Ting; Liang, Tian-Ran; Wang, Hua-Bo; Li, He-Ping; Bao, Cheng-Yu

    2007-05-01

    Radio-frequency (RF), atmospheric-pressure glow discharge (APGD) plasmas using bare metal electrodes have promising prospects in the fields of plasma-aided etching, deposition, surface treatment, disinfection, sterilization, etc. In this paper, the discharge characteristics, including the breakdown voltage and the discharge voltage for sustaining a stable and uniform α mode discharge of the RF APGD plasmas are presented. The experiments are conducted by placing the home-made planar-type plasma generator in ambient and in a vacuum chamber, respectively, with helium as the primary plasma-forming gas. When the discharge processes occur in ambient, particularly for the lower plasma-working gas flow rates, the experimental measurements show that it is the back-diffusion effect of air in atmosphere, instead of the flow rate of the gas, that results in the obvious decrease in the breakdown voltage with increasing plasma-working gas flow rate. Further studies on the discharge characteristics, e.g. the luminous structures, the concentrations and distributions of chemically active species in plasmas, with different plasma-working gases or gas mixtures need to be conducted in future work.

  12. The back-diffusion effect of air on the discharge characteristics of atmospheric-pressure radio-frequency glow discharges using bare metal electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Sun Wenting; Liang Tianran; Wang Huabo; Li Heping; Bao Chengyu [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China)

    2007-05-15

    Radio-frequency (RF), atmospheric-pressure glow discharge (APGD) plasmas using bare metal electrodes have promising prospects in the fields of plasma-aided etching, deposition, surface treatment, disinfection, sterilization, etc. In this paper, the discharge characteristics, including the breakdown voltage and the discharge voltage for sustaining a stable and uniform {alpha} mode discharge of the RF APGD plasmas are presented. The experiments are conducted by placing the home-made planar-type plasma generator in ambient and in a vacuum chamber, respectively, with helium as the primary plasma-forming gas. When the discharge processes occur in ambient, particularly for the lower plasma-working gas flow rates, the experimental measurements show that it is the back-diffusion effect of air in atmosphere, instead of the flow rate of the gas, that results in the obvious decrease in the breakdown voltage with increasing plasma-working gas flow rate. Further studies on the discharge characteristics, e.g. the luminous structures, the concentrations and distributions of chemically active species in plasmas, with different plasma-working gases or gas mixtures need to be conducted in future work.

  13. Mechanical characteristics of novel polyester/NiTi wires braided composite stent for the medical application

    Science.gov (United States)

    Zou, Qiuhua; Xue, Wen; Lin, Jing; Fu, Yijun; Guan, Guoping; Wang, Fujun; Wang, Lu

    Stents have been widely used in percutaneous surgery to treat stenosis diseases. The braided NiTi stent, as a promising prototype, still has limitations of low radial force and loose structure. In the present study, a newly integrated composite stent was designed and braided with NiTi wires and polyester multifilament yarns by textile technology. The mechanical properties of four composite stents and the control bare NiTi stent were evaluated by in vitro compression, bending and anti-torsion tests. The results showed that integrated polyester/NiTi composite stents were superior in radial support. The stents could keep patency even when highly curved and had lower stent straightening force. Composite stents with certain structure stayed stable under twisting. The configuration of NiTi wires in composite stents could significantly impact stent deformation under twisting.

  14. Diphenylalanine peptide nanotubes self-assembled on functionalized metal surfaces for potential application in drug-eluting stent.

    Science.gov (United States)

    Zohrabi, Tayebeh; Habibi, Neda; Zarrabi, Ali; Fanaei, Maryam; Lee, Lai Yeng

    2016-09-01

    This study focuses on the potential of diphenylalanine self-assembled peptide nanotubes (FF Nts) for delivery of flufenamic acid (FA) from metal implants. Self-assembly of FF Nts was studied in solution and on surfaces of glass, silicone and gold substrates. FA was loaded inside the shell of FF Nts and subsequently FF/FA Nts were attached to gold surfaces. The substrate were characterized by Field Emission Scanning Electron Microscopy (FESEM), fluorescence microscopy, confocal microscopy, and UV-vis spectroscopy. Release of FA from FF Nts were investigated by immersing coated metal substrates in phosphate-buffered saline for 12 days. Self-assembly of FF in water and solvent resulted in formation of nanotubes, which efficiently loaded 98% of FA with concentration of 20 µg/mL. FESEM images confirmed successful attachment of FF/FA Nts to functionalized gold substrates. In vitro release studies indicated using FF Nts has prolonged the release rate of FA for several days. Biocompatibility studied confirmed more than 50% of the cells were alive in concentration of 250-1000 µg/mL of FF Nts thus suggesting the potential of peptide based self-assemble nanostructures as an alternate system for polymer coating in drugs eluting stents. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2280-2290, 2016.

  15. A Dual Expandable Nitinol Stent: The Long-term Results in Patients with Malignant Gastroduodenal Strictures

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hee; Jung, Gyoo Sik; Oh, Kyeung Seung [Kosin University College of Medicine, Busan (Korea, Republic of)

    2009-12-15

    We wanted to evaluate the long-term results of a dual expandable nitinol stent for the palliative treatment of malignant gastroduodenal strictures. The dual stent consists of two stents; an outer partially nylon covered stent and an inner bare nitinol stent. The outer stent was placed into the stricture and this was followed by coaxial placement of the inner bare stent. Using fluoroscopic guidance, dual expandable stents were placed in 86 patients with inoperable malignant gastroduodenal strictures. The technical and clinical success, the complication, survival and the stent patency were evaluated during the follow-up period. Stent placement was technically successful in 83 of the 86 patients. After stent placement, 74 of the 85 patients showed improvement of their symptoms. During the mean follow-up period of 133 days, 24 patients (28%) developed recurrent symptoms due to incomplete expansion (n=1), stent migration (n=4), food impaction (n=2), granulation tissue formation (n=2), tumor overgrowth (n=6), tumor ingrowth (n=1) and stent collapse (n=8). Eleven of them were successfully treated by means of placing a second stent. The median period of stent patency was 212 days (mean, 299 days). The 30-day, 60-day, 90-day and 180-day patency rates were 93%, 84%, 81% and 53%, respectively. The dual expandable nitinol stent seems to be effective for the palliation of malignant gastroduodenal strictures

  16. The immobilization of recombinant human tropoelastin on metals using a plasma-activated coating to improve the biocompatibility of coronary stents.

    Science.gov (United States)

    Waterhouse, Anna; Yin, Yongbai; Wise, Steven G; Bax, Daniel V; McKenzie, David R; Bilek, Marcela M M; Weiss, Anthony S; Ng, Martin K C

    2010-11-01

    Current endovascular stents have sub-optimal biocompatibility reducing their clinical efficacy. We previously demonstrated a plasma-activated coating (PAC) that covalently bound recombinant human tropoelastin (TE), a major regulator of vascular cells in vivo, to enhance endothelial cell interactions. We sought to develop this coating to enhance its mechanical properties and hemocompatibility for application onto coronary stents. The plasma vapor composition was altered by incorporating argon, nitrogen, hydrogen or oxygen to modulate coating properties. Coatings were characterized for 1) surface properties, 2) mechanical durability, 3) covalent protein binding, 4) endothelial cell interactions and 5) thrombogenicity. The N(2)/Ar PAC had optimal mechanical properties and did not delaminate after stent expansion. The N(2)/Ar PAC was mildly hydrophilic and covalently bound the highest proportion of TE, which enhanced endothelial cell proliferation. Acute thrombogenicity was assessed in a modified Chandler loop using human blood. Strikingly, the N(2)/Ar PAC alone reduced thrombus weight by ten-fold compared to 316L SS, a finding unaltered with immobilized TE. Serum soluble P-selectin was reduced on N(2)/Ar PAC and N(2)/Ar PAC + TE (p < 0.05), consistent with reduced platelet activation. We have demonstrated a coating for metal alloys with multifaceted biocompatibility that resists delamination and is non-thrombogenic, with implications for improving coronary stent efficacy.

  17. Evaluation of bimetal doped TiO2 in dye fragmentation and its comparison to mono-metal doped and bare catalysts

    Science.gov (United States)

    Malika, Manjakuppam; Rao, Ch. Venkatanarasimha; Das, Raj Kumar; Giri, Ardhendu Sekhar; Golder, Animes Kumar

    2016-04-01

    There are instances that bimetal doped semiconductor materials impart superior photocatalytic activity than bare and mono-metal doping. In this study, visible light responsive mono- (Cu/TiO2 and Ni/TiO2) and bi-metal doped (Cu-Ni/TiO2) TiO2 photocatalysts with wide band gap energy were synthesized via co-precipitation method with an equal mass ratio of Cu and Ni. The catalyst characterization was performed using Diffuse Reflectance UV-visible (DR-UV-vis) spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, X-ray Diffraction (XRD), zeta-potential and Transmission Electron Microscopy (TEM) analyzes. The charge balancing effect of Cu and Ni caused a notable reduction in the optical band gap of TiO2 to 2.91 eV with Cu-Ni/TiO2. The synthesis method increased the anatase phase significantly along with the crystallite size. Cu-Ni/TiO2 displayed a lesser destabilization tendency, and the absolute value of zeta-potentials increased much at pH > pHzpc resulted from the higher oxygen vacancies. The activity of Ni/TiO2, Cu/TiO2, and Cu-Ni/TiO2 was tested for the degradation dynamics and kinetics of Eriochrome Cyanine Red (ECR), an anionic dye. Cu doping exhibited a better dye decomposition because of the low recombination rate of electron/hole pair as a full 3d sub-level of Cu is energetically more favorable than a full 4s sub-level of Ni. The mechanism of dye decomposition releasing inorganic ions is also proposed and validated from the mass spectra.

  18. Evaluation of bimetal doped TiO{sub 2} in dye fragmentation and its comparison to mono-metal doped and bare catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Malika, Manjakuppam; Rao, Ch. Venkatanarasimha; Das, Raj Kumar [Department of Chemical Engineering, Indian Institute of Technology Guwahati, Assam 781 039 (India); Giri, Ardhendu Sekhar [Department of Chemical Engineering, National Institute of Technology Jalandhar, Punjab 144 011 (India); Golder, Animes Kumar, E-mail: animes@iitg.ernet.in [Department of Chemical Engineering, Indian Institute of Technology Guwahati, Assam 781 039 (India)

    2016-04-15

    Graphical abstract: - Highlights: • Bimetal doped TiO{sub 2} showed a higher reduction in band gap than mono-metal doping. • Lower zeta-potential for bimetal doped TiO{sub 2} improved its stability in the aqueous media. • Metal doping increased crystallite sizes and also the anatase phase of doped TiO{sub 2}. • Dye degradation even up to 99% through decarboxylation and sulphonation reactions. - Abstract: There are instances that bimetal doped semiconductor materials impart superior photocatalytic activity than bare and mono-metal doping. In this study, visible light responsive mono- (Cu/TiO{sub 2} and Ni/TiO{sub 2}) and bi-metal doped (Cu–Ni/TiO{sub 2}) TiO{sub 2} photocatalysts with wide band gap energy were synthesized via co-precipitation method with an equal mass ratio of Cu and Ni. The catalyst characterization was performed using Diffuse Reflectance UV–visible (DR-UV–vis) spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, X-ray Diffraction (XRD), zeta-potential and Transmission Electron Microscopy (TEM) analyzes. The charge balancing effect of Cu and Ni caused a notable reduction in the optical band gap of TiO{sub 2} to 2.91 eV with Cu–Ni/TiO{sub 2}. The synthesis method increased the anatase phase significantly along with the crystallite size. Cu–Ni/TiO{sub 2} displayed a lesser destabilization tendency, and the absolute value of zeta-potentials increased much at pH > pH{sub zpc} resulted from the higher oxygen vacancies. The activity of Ni/TiO{sub 2}, Cu/TiO{sub 2}, and Cu–Ni/TiO{sub 2} was tested for the degradation dynamics and kinetics of Eriochrome Cyanine Red (ECR), an anionic dye. Cu doping exhibited a better dye decomposition because of the low recombination rate of electron/hole pair as a full 3d sub-level of Cu is energetically more favorable than a full 4s sub-level of Ni. The mechanism of dye decomposition releasing inorganic ions is also proposed and validated from the mass spectra.

  19. Stents for malignant ureteral obstruction

    Directory of Open Access Journals (Sweden)

    Kristina Pavlovic

    2016-07-01

    Full Text Available Malignant ureteral obstruction can result in renal dysfunction or urosepsis and can limit the physician's ability to treat the underlying cancer. There are multiple methods to deal with ureteral obstruction including regular polymeric double J stents (DJS, tandem DJS, nephrostomy tubes, and then more specialized products such as solid metal stents (e.g., Resonance Stent, Cook Medical and polyurethane stents reinforced with nickel-titanium (e.g., UVENTA stents, TaeWoong Medical. In patients who require long-term stenting, a nephrostomy tube could be transformed subcutaneously into an extra-anatomic stent that is then inserted into the bladder subcutaneously. We outline the most recent developments published since 2012 and report on identifiable risk factors that predict for failure of urinary drainage. These failures are typically a sign of cancer progression and the natural history of the disease rather than the individual type of drainage device. Factors that were identified to predict drainage failure included low serum albumin, bilateral hydronephrosis, elevated C-reactive protein, and the presence of pleural effusion. Head-to-head studies show that metal stents are superior to polymeric DJS in terms of maintaining patency. Discussions with the patient should take into consideration the frequency that exchanges will be needed, the need for externalized hardware (with nephrostomy tubes, or severe urinary symptoms in the case of internal DJS. This review will highlight the current state of diversions in the setting of malignant ureteral obstruction.

  20. Endoscopic ultrasound-guided gallbladder drainage for acute cholecystitis: Long-term outcomes after removal of a self-expandable metal stent

    Science.gov (United States)

    Kamata, Ken; Takenaka, Mamoru; Kitano, Masayuki; Omoto, Shunsuke; Miyata, Takeshi; Minaga, Kosuke; Yamao, Kentaro; Imai, Hajime; Sakurai, Toshiharu; Watanabe, Tomohiro; Nishida, Naoshi; Kudo, Masatoshi

    2017-01-01

    AIM To assess the long-term outcomes of this procedure after removal of self-expandable metal stent (SEMS). The efficacy and safety of endoscopic ultrasound-guided gallbladder drainage (EUS-GBD) with SEMS were also assessed. METHODS Between January 2010 and April 2015, 12 patients with acute calculous cholecystitis, who were deemed unsuitable for cholecystectomy, underwent EUS-GBD with a SEMS. EUS-GBD was performed under the guidance of EUS and fluoroscopy, by puncturing the gallbladder with a needle, inserting a guidewire, dilating the puncture hole, and placing a SEMS. The SEMS was removed and/or replaced with a 7-Fr plastic pigtail stent after cholecystitis improved. The technical and clinical success rates, adverse event rate, and recurrence rate were all measured. RESULTS The rates of technical success, clinical success, and adverse events were 100%, 100%, and 0%, respectively. After cholecystitis improved, the SEMS was removed without replacement in eight patients, whereas it was replaced with a 7-Fr pigtail stent in four patients. Recurrence was seen in one patient (8.3%) who did not receive a replacement pigtail stent. The median follow-up period after EUS-GBD was 304 d (78-1492). CONCLUSION EUS-GBD with a SEMS is a possible alternative treatment for acute cholecystitis. Long-term outcomes after removal of the SEMS were excellent. Removal of the SEMS at 4-wk after SEMS placement and improvement of symptoms might avoid migration of the stent and recurrence of cholecystitis due to food impaction. PMID:28216973

  1. A case of rectovagino-vesical fistula due to radiation therapy for uterine cancer treated with covered expandable metallic stent

    Energy Technology Data Exchange (ETDEWEB)

    Ohtsukasa, Shunroh; Okabe, Satoshi; Tanami, Hideaki [Tokyo Medical and Dental Univ. (Japan). School of Medicine] (and others)

    2002-04-01

    A 65-year-old woman had received a panhysterectomy and radiation therapy for a uterine cancer in 1974 and underwent a drainage operation for a peritonitis due to rupture of the bladder associated with radiation cystitis in 1983. A rectovesical fistula was revealed and partial resection of the bladder and rectum was performed in 1996. In 1998, rectovesical fistula recurred and symptom of fecaluria and contact-type dermatitis at perineal region subsequently worsened. In February, 2000, colonoscopy and gastrograffin-enema revealed a giant recto-vagino-vesical fistula. Although we recommended ileostomy, the patient refused our offer. She gave informed consent to our proposal about the insertion of a covered expandable metallic stent (EMS) into the rectum to treat for fecaluria. After insertion of a covered EMS, fecaluria and contact-type dermatitis at perineal region subsequently improved. Three months later, fecaluria appeared again. Finally, seven months later, severe inflammation occurred at perineal and pubic region because of migration of the covered EMS into the bladder, then we removed the covered EMS and performed ileostomy. It is difficult to use the covered EMS treatment for benign rectovesical or rectovaginal fistula for a long term. (author)

  2. Prognosis of unprotected left main coronary artery stenting and the factors affecting the outcomes in Chinese

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Background The long term prognosis of unprotected left main coronary artery (LMCA) stenting is controversial This study was conducted to evaluate the immediate and long term outcomes of LMCA stenting in Chinese patients and to determine which factors affect the outcomes. Methods From May 1997 to March 2003,224 patients in 23 hospitals underwent elective unprotected LMCA stenting with bare metal stents. Their clinical records were analysed to ascertain immediate and long term outcomes of LMCA stenting as well as factors influencing the prognosis .Results Stents were implanted into LMCA successfully in 223 cases (99.6 %). One death (0.5%) and one case of non-Q wave nonfatal myocardial infarction (MI) occurred in hospital. The mean follow-up time was (15.6±12.3) months. Cardiac death developed in 10 cases (4.5%), noncardiac death in 2 cases (0.9%), nonfatal MI in 4 cases (1.8%), target lesion revascularization (TLR) of LMCA in 26 cases (11.7%) and TLR of nonLMCA in 37 cases (16.5%). Univariate analysis showed that cardiac death correlated with left ventricular ejection fraction (LVEF < 40%), female gender and LMCA combined with multivessel disease; that major adverse cardiac events (MACE) correlated with LVEF < 40%, bifurcation lesion and incomplete revascularization. Logistic regression analysis revealed that LVEF < 40% and female gender were independent predictors of cardiac death and MACE. Follow-up angiography was performed in 102 cases (45.7%). The restenosis rate was 31.4%. Conclusions Long-term outcomes of stenting for selected patients with unprotected LMCA stenosis is acceptable. It should be performed in inoperable or low risk patients with LVEF ≥ 40% and isolated LMCA disease or LMCA combined with multivessel diseases in whom complete revascularization can be obtained.

  3. A Covered Nitinol Stent Fracture in a Patient with a Malignant Esophageal Stricture: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hee Jin; Cho, Yun Ku; Kim, Wan Tae [Seoul Veterans Hospital, Seoul (Korea, Republic of)

    2008-11-15

    Self-expanding metallic stent insertion has been widely applied for the palliative treatment of malignant esophageal strictures. Although it is known as an easy, safe, and effective procedure, complications are well known and include things such as stent migration and esophageal stent occlusion caused by tumor in growth. However, metallic stent fractures have been rarely reported in the esophagus, especially for nitinol stents. We report a case of a stent fracture associated with migration in a patient with a malignant esophageal stricture near the gastroesophageal junction. It is highly probable that the stent fracture was due to chemical erosion of the stent caused by gastric juice

  4. A new removable airway stent

    Directory of Open Access Journals (Sweden)

    Tore Amundsen

    2016-09-01

    Full Text Available Background: Malignant airway obstruction is a feared complication and will most probably occur more frequently in the future because of increasing cancer incidence and increased life expectancy in cancer patients. Minimal invasive treatment using airway stents represents a meaningful and life-saving palliation. We present a new removable airway stent for improved individualised treatment. Methods: To our knowledge, the new airway stent is the world's first knitted and uncovered self-expanding metal stent, which can unravel and be completely removed. In an in vivo model using two anaesthetised and spontaneously breathing pigs, we deployed and subsequently removed the stents by unravelling the device. The procedures were executed by flexible bronchoscopy in an acute and a chronic setting – a ‘proof-of-principle’ study. Results: The new stent was easily and accurately deployed in the central airways, and it remained fixed in its original position. It was easy to unravel and completely remove from the airways without clinically significant complications. During the presence of the stent in the chronic study, granulation tissue was induced. This tissue disappeared spontaneously with the removal. Conclusions: The new removable stent functioned according to its purpose and unravelled easily, and it was completely removed without significant technical or medical complications. Induced granulation tissue disappeared spontaneously. Further studies on animals and humans are needed to define its optimal indications and future use.

  5. Polymeric Biodegradable Stent Insertion in the Esophagus

    Directory of Open Access Journals (Sweden)

    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.

  6. 金属冠脉支架磁共振适用性检测方法%Methods of Magnetic Resonance Compatibility Testing for Metal Coronary Stents

    Institute of Scientific and Technical Information of China (English)

    王迎; 刘丽; 王硕; 尚汝瑶; 王春仁

    2015-01-01

    Objective:To establish an experimental platform for magnetic resonance compatibility for mental coronary stents and to study the magnetic resonance compatibility based on laboratory testing. Methods:The magnetic resonance compatibility testing for metal coronary stents was divided into four parts, which was conducted in the 3T magnetic resonance imaging environment, including magnetically induced displacement force test, magnetically induced torque test, heating test and image interference test. Results:For metal coronary stents with good demagnetization effect, the magnetically induced displacement force was lower than its own gravity, the magnetically induced torque was lower than its gravity-induced torque, its temperature increased in low amplitude, and the value of image distortion was small. By contrast for metal coronary stents with poor demagnetization effect, the magnetically induced displacement force was higher than its own gravity, the increase amplitude of its temperature was high, and the value of image distortion was large. Conclusion:The experimental platform can be applied to test magnetic resonance compatibility for coronary mental stents and evaluate its demagnetization effect.%目的:建立金属冠脉支架磁共振适用性实验平台,以实验室测试为基础,研究金属冠脉支架的磁共振适用性。方法:金属冠脉支架磁共振适用性试验分为四个部分,在3T磁共振环境下,分别进行磁位移力试验、磁扭矩试验、致热试验和图像干扰试验。结果:退磁效果好的金属冠脉支架,磁位移力小于其自身重力,磁扭矩小于其自身重力扭矩,温度升高值小,图像畸变值小。退磁效果不好的支架,磁位移力大于其自身重力,温度升高多,图像畸变值大。结论:实验平台可以对金属冠脉支架磁共振适用性进行检测,并对其退磁效果进行评价。

  7. The New Nitinol Conformable Self-Expandable Metal Stents for Malignant Colonic Obstruction: A Pilot Experience as Bridge to Surgery Treatment

    Directory of Open Access Journals (Sweden)

    Roberto Di Mitri

    2014-01-01

    Full Text Available Introduction. Self-expandable metal stents (SEMS are a nonsurgical option for treatment of malignant colorectal obstruction also as a bridge to surgery approach. The new nitinol conformable stent has improved clinical outcomes in these kinds of patients. We report a pilot experience with nitinol conformable SEMS placement as bridge to surgery treatment in patients with colorectal obstruction. Materials and Methods. Between April and August 2012, we collected data on colonic nitinol conformable SEMS placement in a cohort of consecutive symptomatic patients, with malignant colorectal obstruction, who were treated as a bridge to surgery. Technical success, clinical success, and adverse events were recorded. Results. Ten patients (7 male (70%, with a mean age of 69.2 ± 10.1, were evaluated. The mean length of the stenosis was 3.6 ± 0.6 cm. Five patients (50% were treated on an emergency basis. The median time from stent placement to surgery was 16 days (interquartile range 7–21. Technical and clinical success was achieved in all patients with a significant early improvement of symptoms. No adverse events due to the SEMS placement were observed. Conclusion. This pilot study confirmed the important role of nitinol conformable SEMS as a bridge to surgery option in the treatment of symptomatic malignant colorectal obstruction.

  8. Multi-link Vision and MiniVision stent registry in Asian patients with coronary artery disease: a prospective, multi-center study

    Institute of Scientific and Technical Information of China (English)

    XU Ya-wei; HOU Yu-qing; Ashok Jain; Parvez Grant; Gudapati Ramesh; Basavappa Ramesh; Chumpol Piamsomboon; Srun Kuanprasert; Hyeon-Cheol Gwon; Yoon Haeng Cho; Haizal Haroon Kamar; WEI Yi-dong; HUANG Cong-xin; TANG Kai; CHEN Yan-qing; LI Wei-ming; YU Xue-jing; QIN Yong-wen; QI Guo-xian; QU Peng

    2007-01-01

    Background Recent studies have showed that the fine mesh stents are associated with a significant reduction in both clinical and angiographic re-stenosis of the coronary arteries. To maintain a very satisfactory radio-opacity using the stents, Guidant of the USA has designed a new type of bare metal stents (BMS)-Multi-link (ML) Vision / ML MiniVision stents. The clinical outcomes of Asian patients with coronary artery disease (CAD) after implanting the Multi-link Vision or MiniVision stent were investigated in this study.Methods An observational, prospective, multi-center, non-randomized post marketing registry was conducted to demonstrate the efficacy of the BMS- ML Vision / ML MiniVision stents. The primary end point of the registry was clinical target lesion revascularization (TLR) at a 6-month follow-up. The major secondary end points included the rate of major adverse cardiac events (MACE) and serious adverse events (SAE) in hospital and at 6 months; and the rate of clinical TLR as a function of the type of angina. A total of 429 Asian people with 449 lesions from 14 centers were selected for this study. The average reference diameter of the lesions was (3.0±0.5) mm, and the mean length was (15.7±5.0) mm.Results The successful rate of the procedure was 99.3%. Twenty-five percent of the lesions were treated by direct stenting without pre-dilation. Eighty-six percent of the lesions were implanted with ML Vision stent. After the 6-month follow-up, the rate of clinical TLR was 1.4%. The MACE, SAE and target vessel revascularization (TVR) were 6.8%, 3.5%and 1.4% respectively.Conclusion The current registry showed the excellent 6-month clinical outcomes of ML Vision/ML MiniVision stents in Asian patients with CAD.

  9. Local sustained delivery of acetylsalicylic acid via hybrid stent with biodegradable nanofibers reduces adhesion of blood cells and promotes reendothelialization of the denuded artery.

    Science.gov (United States)

    Lee, Cheng-Hung; Lin, Yu-Huang; Chang, Shang-Hung; Tai, Chun-Der; Liu, Shih-Jung; Chu, Yen; Wang, Chao-Jan; Hsu, Ming-Yi; Chang, Hung; Chang, Gwo-Jyh; Hung, Kuo-Chun; Hsieh, Ming-Jer; Lin, Fen-Chiung; Hsieh, I-Chang; Wen, Ming-Shien; Huang, Yenlin

    2014-01-01

    Incomplete endothelialization, blood cell adhesion to vascular stents, and inflammation of arteries can result in acute stent thromboses. The systemic administration of acetylsalicylic acid decreases endothelial dysfunction, potentially reducing thrombus, enhancing vasodilatation, and inhibiting the progression of atherosclerosis; but, this is weakened by upper gastrointestinal bleeding. This study proposes a hybrid stent with biodegradable nanofibers, for the local, sustained delivery of acetylsalicylic acid to injured artery walls. Biodegradable nanofibers are prepared by first dissolving poly(D,L)-lactide-co-glycolide and acetylsalicylic acid in 1,1,1,3,3,3-hexafluoro-2-propanol. The solution is then electrospun into nanofibrous tubes, which are then mounted onto commercially available bare-metal stents. In vitro release rates of pharmaceuticals from nanofibers are characterized using an elution method, and a highperformance liquid chromatography assay. The experimental results suggest that biodegradable nanofibers release high concentrations of acetylsalicylic acid for three weeks. The in vivo efficacy of local delivery of acetylsalicylic acid in reducing platelet and monocyte adhesion, and the minimum tissue inflammatory reaction caused by the hybrid stents in treating denuded rabbit arteries, are documented. The proposed hybrid stent, with biodegradable acetylsalicylic acid-loaded nanofibers, substantially contributed to local, sustained delivery of drugs to promote re-endothelialization and reduce thrombogenicity in the injured artery. The stents may have potential applications in the local delivery of cardiovascular drugs. Furthermore, the use of hybrid stents with acetylsalicylic acid-loaded nanofibers that have high drug loadings may provide insight into the treatment of patients with high risk of acute stent thromboses.

  10. Arterial healing following primary PCI using the Absorb everolimus-eluting bioresorbable vascular scaffold (Absorb BVS) versus the durable polymer everolimus-eluting metallic stent (XIENCE) in patients with acute ST-elevation myocardial infarction

    DEFF Research Database (Denmark)

    Räber, Lorenz; Onuma, Yoshinobu; Brugaletta, Salvatore

    2015-01-01

    Aims: The Absorb bioresorbable vascular scaffold (Absorb BVS) provides similar clinical outcomes compared with a durable polymer-based everolimus-eluting metallic stent (EES) in stable coronary artery disease patients. ST-elevation myocardial infarction (STEMI) lesions have been associated...... with delayed arterial healing and impaired stent-related outcomes. The purpose of the present study is to compare directly the arterial healing response, angiographic efficacy and clinical outcomes between the Absorb BVS and metallic EES. Methods and results: A total of 191 patients with acute STEMI were...... randomly allocated to treatment with the Absorb BVS or a metallic EES 1:1. The primary endpoint is the neointimal healing (NIH) score, which is calculated based on a score taking into consideration the presence of uncovered and malapposed stent struts, intraluminal filling defects and excessive neointimal...

  11. Updates on the use of ureteral stents: focus on the Resonance® stent

    Directory of Open Access Journals (Sweden)

    Thomas MT Turk

    2010-12-01

    Full Text Available Manoj V Rao, Anthony J Polcari, Thomas MT TurkDepartment of Urology, Loyola University Medical Center, Maywood, IL, USAAbstract: The Resonance® metallic ureteral stent is one of the latest additions to the urologist’s armamentarium in managing ureteral obstruction. One advantage of this stent over traditional polymer-based stents is resistance to encrustation with stone material, which allows longer dwell times and less frequent exchange procedures. Although exchanging a metallic stent is slightly more complicated than exchanging a polymer stent, the fluoroscopic techniques required are familiar to most urologists. The Resonance stent is also more resistant to compression by external forces, potentially allowing greater applicability in patients with metastatic cancer. Furthermore, the use of this stent in patients with benign ureteral obstruction is shown to be associated with significant cost reduction. Clinical studies on the use of this stent are accumulating and the results are mixed, although Level 1 evidence is lacking. In this article we present a comprehensive review of the available literature on the Resonance metallic ureteral stent.Keywords: resonance, metallic, ureteral, stent, obstruction

  12. In vitro, time-resolved PIV comparison of the effect of stent design on wall shear stress.

    Science.gov (United States)

    Charonko, John; Karri, Satyaprakash; Schmieg, Jaime; Prabhu, Santosh; Vlachos, Pavlos

    2009-07-01

    The effect of stent design on wall shear stress (WSS) and oscillatory shear index (OSI) was studied in vitro using time-resolved digital particle image velocimetry (DPIV). Four drug-eluting stents [XIENCE V (Abbott Vascular), TAXUS Liberté (Boston Scientific), Endeavor (Medtronic), and Cypher (J&J Cordis)] and a bare-metal stent [VISION (Abbott Vascular)] were implanted into compliant vessel models, and the flow was measured in physiologically accurate coronary conditions featuring reversal and realistic offsets between pressure and flowrate. DPIV measurements were made at three locations under two different flow rates (resting: Re = 160, f = 70 bpm and exercise: Re = 300, f = 120 bpm). It was observed that design substantially affected the WSS experienced at the vessel walls. Averaged values between struts ranged from 2.05 dynes/cm(2) (Cypher) to 8.52 dynes/cm(2) (XIENCE V) in resting conditions, and from 3.72 dynes/cm(2) (Cypher) to 14.66 dynes/cm(2) (VISION) for the exercise state. Within the stent, the WSS dropped and the OSI increased immediately distal to each strut. In addition, an inverse correlation between average WSS and OSI existed. Comparisons with recently published results from animal studies show strong correlation between the measured WSS and observed endothelial cell coverage. These results suggest the importance of stent design on the WSS experienced by endothelial cells in coronary arteries.

  13. Material characteristics and biocompatibility of plastic and metal biliary stents%塑料与金属胆管支架的材料特征及其生物相容性

    Institute of Scientific and Technical Information of China (English)

    赵冬梅; 蒋丹娜; 刘侠

    2011-01-01

    BACKGROUND: Implantation of plastic and metal biliary stent under digestive endoscopy is an effective means in the treatment of benign and malignant bile duct obstruction. Particularly stent implantation provides great clinical application value for high biliary obstruction in biliary cancer patients who are not suitable for surgical treatment and need to eliminate jaundice,accommodate physiologic d rainage, prolong survival, and improve quality of life.OBJECTIVE: To compare the clinical effects of endoscopic implantation of plastic and metal biliary stents in the treatment of benign and malignant bile duct obstruction, and to explore the biocompatibility of plastic and metal biliary stents with the host.METHODS: Using "bile duct obstruction, plastic biliary stent, metal biliary stent, biocompatibility" in Chinese and "cerebrovascular disease, stent, biocompatibility" in English as the key words, China Academic Journal Full-text Database (CNKI:1989/2009) and Medline (1989/2009) database were searched online by the first author. Meta analysis and repeatable studies were excluded. Totally 35 studies were screened and evaluated, focusing on the research progress, complications, and biocompatibility in treatment of plastic and metal biliary stent.RESULTS AND CONCLUSION: Endoscopic biliary stent implantation is the principal means in the treatment of benign and malignant biliary obstruction. Biliary stent includes metal stent and plastic stent. Metal stents have exhibited great advantages in preventing the growth of bacteria and maintaining stent patency, but the price is expensive. Plastic stents are easy for bacterial attachment, biliary sludge deposition causes stent obstruction, but they are easy to replace and low price. The biocompatibility of plastic and metal biliary stents needs to be improved, for patients with malignant biliary obstruction, bile duct stent implantation in combined with radiation therapy will help to prevent stent obstruction. Further

  14. FACTORES CLÍNICOS Y DEL PROCEDIMIENTO RELACIONADOS CON LA TROMBOSIS DE STENT / Clinical and procedural factors related to stent thrombosis

    Directory of Open Access Journals (Sweden)

    Ronald Aroche Aportela

    2012-03-01

    this research was to determine the risk factors for thrombosis of the bare metal stents. Method: A retrospective descriptive study was performed. Out of the 2,014 revascularized arteries at the Medical-Surgical Research Center in Havana, Cuba, between August 1997 and February 2009, the 289 redo ones were selected. Results: thrombosis of the conventional metal stents was present in 20 arteries, of which 11 corresponded to the anterior descending artery, and the highest incidence occurred in the first 24 hours and after 30 days. Diabetes mellitus was a risk factor for thrombosis (OR = 3.06 and the release pressure of less than 10 atmospheres (OR = 3.70 and complex lesions of types B2 and C (OR = 8.80, all with statistical significance (p <0.05. Conclusions: The highest incidence of bare metal stent thrombosis was on the first day of revascularization after the termination of dual antiplatelet therapy and located in the anterior descending artery. Diabetes mellitus, complex lesions and low pressures of stent release, behaved as risk factors for thrombosis with statistically significant results.

  15. Effect of oral sirolimus therapy on inflammatory biomarkers following coronary stenting

    Directory of Open Access Journals (Sweden)

    W.C.M. Rosa

    2010-08-01

    Full Text Available We studied the effect of oral sirolimus, administered to prevent and treat in-stent restenosis (ISR, on the variation of serum levels of inflammatory markers following coronary stenting with bare metal stents. The mean age of the patients was 56 ± 13 years, 65% were males and all had clinically manifested ischemia. Serum levels of high sensitivity C-reactive protein (hs-CRP concentration were determined by chemiluminescence and serum levels of all other biomarkers by ELISA. One group of patients at high risk for ISR received a loading oral dose of 15 mg sirolimus and 5 mg daily thereafter for 28 days after stenting (SIR-G. A control group (CONT-G was submitted to stenting without sirolimus therapy. The increase in hs-CRP concentration was highest at 24 h after stenting in both groups. A significant difference between SIR-G and CONT-G was observed at 4 weeks (-1.50 ± 5.0 vs -0.19 ± 0.4, P = 0.008 and lost significance 1 month after sirolimus discontinuation (-1.73 ± 4.3 vs -0.01 ± 0.7, P = 0.0975. A continuous fall in MMP-9 concentration was observed in SIR-G, with the greatest reduction at 4 weeks (-352.9 ± 455 vs +395.2 ± 377, P = 0.0004, while a positive variation was noted 4 weeks after sirolimus discontinuation (227 ± 708 vs 406.2 ± 472.1, P = 0.0958. SIR-G exhibited a higher increase in P-selectin after sirolimus discontinuation at week 8 (46.1 ± 67.9 vs 5.8 ± 23.7, P = 0.0025. These findings suggest that the anti-restenotic actions of systemic sirolimus include anti-proliferative effects and modulation of the inflammatory response with inhibition of adhesion molecule expression.

  16. A Novel High Nitrogen Nickel-free Coronary Stents System:Evaluation in a Porcine Model

    Institute of Scientific and Technical Information of China (English)

    ZHANG Bin; CHEN Ming; ZHENG Bo; WANG Xin Gang; WANG Xi Ting; FAN Yuan Yuan; HUO Yong

    2014-01-01

    Objective To study the safety of the novel high nitrogen nickel-free austenitic stainless steel bare metal stents (BMS) in a recognized porcine coronary model and to select a better grid structure of it. Methods Three types of stents were randomly implanted in different coronary arteries of the same pig: 316L stainless steel BMS (316L-BMS) (n=12), novel high nitrogen nickel-free stents Grid A (NF-A-BMS) (n=12) and novel high nitrogen nickel-free stents Grid B (NF-B-BMS) (n=12). In total, eighteen animals underwent successful random placement of 36 oversized stents in the coronary arteries. Coronary angiography was performed after 36 d of stents implantation. Nine animals were respectively sacrificed after 14 d and 36 d for histomorphologic analysis. Results Quantitative coronary angiography (QCA) showed similar luminal loss (LL) in the three groups:(0.21±0.17) mm for 316L-BMS, (0.16±0.12) mm for NF-A-BMS, (0.24±0.15) mm for NF-B-BMS (P>0.05). Histomorphomeric analysis after 15 d and 36 d revealed that there was also no significant difference among the three groups in neointimal area (NA) with similar injury scores respectively. High magnification histomorphologic examination showed similar inflammation scores in the three groups, but NF-A-BMS group had poorer endothelialization scores compared with NF-B-BMS group, 2.00±0.63 vs. 2.83±0.41 (P=0.015) at 15 d, which also could be proved by the scanning electron microscope. However, the difference could not been observed at 36 d. Conclusion The novel NF-BMS showed similar safety as 316L-BMS during the short-term study. NF-B-BMS had better endothelialization than NF-A-BMS and this may owe to the specific strut units.

  17. Extending surface Raman spectroscopy to transition metals for practical applications IV. A study on corrosion inhibition of benzotriazole on bare Fe electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Yao, J.L.; Ren, B.; Huang, Z.F.; Cao, P.G.; Gu, R.A.; Tian, Z.-Q

    2003-04-20

    The emphasis in the present study was placed on developing Raman spectroscopy into a versatile technique, which offers an opportunity for investigating the inhibition effect on the corrosion process of bare Fe surfaces. Several surface pretreatments have been developed to bare Fe electrodes in order to obtain a surface of optimal surface-enhanced Raman scattering (SERS). It has been shown that the surface enhancement factor (SEF) of a bare Fe electrode can reach about two to three orders, depending on the roughening procedure. Therefore, SERS can be extended successfully to study some Fe electrode systems of practical importance. Here we present a study on the film formation process and inhibition effect of benzotriazole (BTA) on Fe surfaces. The results show that BTA interacts with Fe surface through its two N atoms of the triazole ring and surface complex polymer of [Fe{sub n}(BTA){sub p}]{sub m} is formed, which may suppress the dissolution and oxidation of Fe effectively. In addition, the solution pH, the synergetic effect of I{sup -} with BTA was revealed to have a significant influence on the inhibition efficiency.

  18. The Globe laid bare

    CERN Multimedia

    Fortunati, Lucien

    2015-01-01

    If you’re at CERN at the moment, you will certainly have noticed the work under way on the Globe. The structure, which has been in pride of place opposite the Laboratory for over ten years, has never been so completely laid bare. But, as we explained in a previous article (see here), it is all for a good cause. The Globe is built entirely from wood and certain parts of it need to be replaced.

  19. Stent placement for esophageal strictures : an update

    NARCIS (Netherlands)

    Hirdes, Meike Madeleine Catharine; Vleggaar, Frank Paul; Siersema, Peter Derk

    2011-01-01

    The use of stents for esophageal strictures has evolved rapidly over the past 10 years, from rigid plastic tubes to flexible self-expanding metal (SEMS), plastic (SEPS) and biodegradable stents. For the palliative treatment of malignant dysphagia both SEMS and SEPS effectively provide a rapid relief

  20. Delayed ischemic cecal perforation despite optimal decompression after placement of a self-expanding metal stent: report of a case

    DEFF Research Database (Denmark)

    Knop, Filip Krag; Pilsgaard, Bo; Meisner, Søren;

    2004-01-01

    condition. Three days after stent deployment, x-ray examinations revealed a small-bowel obstruction and emergency surgery was performed. Intraoperative findings demonstrated a segment of ileum fixated to the tumor in the small pelvis, resulting in the obstructive condition. Furthermore, a cecal perforation...

  1. Esophageal stent migration leads to intestinal obstruction

    Directory of Open Access Journals (Sweden)

    Oguzhan Karatepe

    2009-07-01

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

  2. Drug-eluting stents in percutaneous coronary intervention: a benefit-risk assessment.

    Science.gov (United States)

    Byrne, Robert A; Sarafoff, Nikolaus; Kastrati, Adnan; Schömig, Albert

    2009-01-01

    Drug-eluting stent (DES) therapy has represented a very significant milestone in the evolution of percutaneous coronary intervention (PCI) therapy. This review attempts to provide a balanced overview of the unprecedented wealth of data generated on this new technology, by examining the evidence bases for anti-restenotic efficacy, safety and cost effectiveness. The performance of a DES may be related to each of its three components: stent backbone; carrier polymer (to control drug-release kinetics); and active drug. In terms of anti-restenotic efficacy, the most appropriate parameters to examine are target lesion revascularization, angiographic restenosis and late luminal loss. The principal safety parameters are overall mortality, myocardial infarction (MI) and stent thrombosis. Anti-restenotic superiority of DES over bare metal stents (BMS) has been demonstrated across a spectrum of disease from straightforward 'vanilla lesions' through higher disease complexity in pivotal clinical trials to phase IV studies of efficacy in 'off-label' populations. The treatment effect of DES versus BMS is consistent in terms of a reduction in the need for repeat intervention of the order of 35-70%. Regarding differential efficacy of first-generation DES, a benefit may exist in favour of the Cypher (sirolimus-eluting) stent over Taxus (paclitaxel-eluting), particularly in high-risk lesion subsets. The second-generation approved devices are the Endeavor (zotarolimus-eluting) and Xience (everolimus-eluting) DES. While all four of these stents are permanent polymer-based, the current focus of development is towards DES platforms that are devoid of durable polymer, the presence of which has been implicated in late adverse events. In terms of safety concerns raised in relation to DES therapy, it is reasonable to conclude the following at 4- to 5-year post-stent implantation: (i) that there is no increased risk of death or MI with DES (neither is there a general signal of mortality

  3. Secreted Matrix Metalloproteinase-9 of Proliferating Smooth Muscle Cells as a Trigger for Drug Release from Stent Surface Polymers in Coronary Arteries.

    Science.gov (United States)

    Gliesche, Daniel G; Hussner, Janine; Witzigmann, Dominik; Porta, Fabiola; Glatter, Timo; Schmidt, Alexander; Huwyler, Jörg; Meyer Zu Schwabedissen, Henriette E

    2016-07-01

    Cardiovascular diseases are the leading causes of death in industrialized countries. Atherosclerotic coronary arteries are commonly treated with percutaneous transluminal coronary intervention followed by stent deployment. This treatment has significantly improved the clinical outcome. However, triggered vascular smooth muscle cell (SMC) proliferation leads to in-stent restenosis in bare metal stents. In addition, stent thrombosis is a severe side effect of drug eluting stents due to inhibition of endothelialization. The aim of this study was to develop and test a stent surface polymer, where cytotoxic drugs are covalently conjugated to the surface and released by proteases selectively secreted by proliferating smooth muscle cells. Resting and proliferating human coronary artery smooth muscle cells (HCASMC) and endothelial cells (HCAEC) were screened to identify an enzyme exclusively released by proliferating HCASMC. Expression analyses and enzyme activity assays verified selective and exclusive activity of the matrix metalloproteinase-9 (MMP-9) in proliferating HCASMC. The principle of drug release exclusively triggered by proliferating HCASMC was tested using the biodegradable stent surface polymer poly-l-lactic acid (PLLA) and the MMP-9 cleavable peptide linkers named SRL and AVR. The specific peptide cleavage by MMP-9 was verified by attachment of the model compound fluorescein. Fluorescein release was observed in the presence of MMP-9 secreting HCASMC but not of proliferating HCAEC. Our findings suggest that cytotoxic drug conjugated polymers can be designed to selectively release the attached compound triggered by MMP-9 secreting smooth muscle cells. This novel concept may be beneficial for stent endothelialization thereby reducing the risk of restenosis and thrombosis.

  4. The Coordination and Care of Endoscopic Metal Stenting%内镜下食管金属支架置入术的配合及护理

    Institute of Scientific and Technical Information of China (English)

    唐娟

    2011-01-01

    Objective: The aim of this study was to discuss the coordination and care of metal stenting under the endoscopy,and to improve the quality of life of patients. Methods: Retrospective analysis of the 48 cases of patients with advanced esophageal cancer endoscopic stenting in perioperative care, nursing care of the main points of their analysis and results. Results: The food situation of the 48 patients after the esophagus stenting were improved,the treatment effect was obvious,and the perioperative care plays an important role for the success of surgery. Conclusion: Good preoperative psychological care and adequate preparation, accurate surgery with, close observation afterward, was a key factor in successful treatment.%目的:探讨内镜下食管金属支架置入术的配合及护理要点,提高患者的生活质量.方法:回顾性分析48 例中晚期食管癌患者经内镜下食管支架置入术的围手术期的护理,探讨分析其护理措施的要点和效果.结果:食道支架置入后48 例患者的进食情况均得到改善,治疗效果明显,围手术期的护理对于手术的成败起着重要的作用.结论:术前良好的心理护理和充分的准备,术中精确的配合,术后密切观察,是治疗成功的关键因素.

  5. Dual role of circulating endothelial progenitor cells in stent struts endothelialisation and neointimal regrowth: A substudy of the IN-PACT CORO trial

    Energy Technology Data Exchange (ETDEWEB)

    De Maria, Giovanni Luigi [Institute of Cardiology, Catholic University of the Sacred Heart, Rome (Italy); Porto, Italo, E-mail: italo.porto@gmail.com [Institute of Cardiology, Catholic University of the Sacred Heart, Rome (Italy); Interventional Cardiology Unit, San Donato Hospital, Arezzo (Italy); Burzotta, Francesco; Brancati, Marta Francesca; Trani, Carlo; Pirozzolo, Giancarlo; Leone, Antonio Maria; Niccoli, Giampaolo [Institute of Cardiology, Catholic University of the Sacred Heart, Rome (Italy); Prati, Francesco [Department of Interventional Cardiology, San Giovanni Hospital, Rome (Italy); Crea, Filippo [Institute of Cardiology, Catholic University of the Sacred Heart, Rome (Italy)

    2015-01-15

    Background: Endothelialisation is a crucial event after percutaneous coronary intervention (PCI). Endothelial progenitor cells (EPCs) are bone marrow derived elements with reparative properties. We aimed to assess the relationship between circulating EPC levels and stent neointimal hyperplasia (NIH) using frequency domain optical coherence tomography (FD-OCT). Methods: Patients undergoing elective PCI to native vessels and randomised to bare metal stent (BMS) alone versus BMS plus drug coated balloon (DCB) were included. At six months, angiographic follow-up and FD-OCT were performed to measure percentage neointimal hyperplasia volume obstruction (%NIHV), and percentage of uncovered stent struts (%US). Venous blood samples were obtained before the procedure and at six months to detect CD34+CD45dimKDR + EPC levels. Results: Twenty patients were enrolled. A significant relationship was observed between baseline EPC levels and %NIHV (R: 0.63, p: 0.03) and %US (R: − 0.56, p: 0.01) at follow-up. Both EPC levels and DCB use were independently related to %NIHV (β: 0.55; p < 0.001 and β: − 0.51; p: 0.001, respectively), while only EPC levels were independently associated to %US (β: − 0.52; p: 0.01). Higher %NIHV (p: 0.004) and lower %US (p: 0.005) were observed in patients with stable or increasing EPC level. Conclusion: Our study shows a relationship between EPC levels and stent strut coverage, supporting a dual role for these cells in favouring stent endothelialisation but also NIH growth. - Highlights: • Substudy of IN-PACT CORO trial comparing, by adoption of optical coherence tomography, the amount of neointimal growth and stent struts coverage at six months of follow up, in elective patients randomised to conventional PCI with bare metal stent implantation (BMS group) or to stent implantation with pre or postdilation with a drug coated balloon (BMS + DCB group) • Lower neointimal regrowth observed in BMS + DCB group • First in vivo demonstration that

  6. Influence of Simvastatin for In-stent Restenosis Rate and Blood Lipid Level and Inflammation Actor after Coronary Artery Stent Implantation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    To investigate the effect of simvastatin on the probability of restenosis after stent implantation and serum level of lipids as well as high-sensitivity C-reactive protein (hs-CRP) in patients with coronary heart disease (CHD).Methods 118 patients with CHD after stenting therapy were divided into treatment group (n = 62) and control group(n =56) randomly. All patients were treated withaspirin (100 mg/d) and clopidogrel (75 mg/d) while treatment group patients took simvastatin (40 mg qn) additionally. All patients underwent coronary angiography (CAG) to compare the difference of restenosis and the serum level of total cholesterol (TC), low-density lipoprotein cholesterol(LDL-c), high-density lipoprotein cholesterol (HDL-c), triglyceride (TG) as well as hs-CRP after the drug treatment for 6 months. Results The probability of restenosis was significantly lower in the treatment group than that of control group ( P < 0.01 ) and the results were similar between the patients with bare metal stent ( P < 0.01 ) and those with sirolimus-eluting stent ( P<0.01 ). The serum levels of TC (P<0.01 ), LDL-c( P<0.01 ), TG (P<0.05 ) and hsCRP (P<0.01) were obviously lower while the HDL-c (P<0.05 ) level was higher in the treatment group than those of control group. There was no death case. Conclusions Simvastatin could decrease the probability of restenosis significantly after coronary stent implantation with dose of 40 mg/d. It also has good performance on lipids control and lightening inflammatory reactions with its undoubtedly safety.

  7. 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

    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......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...

  8. Gender differences in patients undergoing coronary stenting in current stent era

    Institute of Scientific and Technical Information of China (English)

    Max Woo; FAN Chang-qing; Chen Yung-Lung; Hesham Husein; Fang Hsiu-Yu; Lin Cheng-Jui; Wu Chiung-Jen

    2011-01-01

    Background Prior studies have demonstrated worse results of women in both hospital and short-term outcomes post-percutaneous coronary intervention. However, with advanced devices like drug-eluting stents (DESs) available,there are no consistent data revealing gender impact in outcome. This study examined whether gender affected hospital outcome and showed one-year single-center patient results of coronary stenting.Methods The study group included 969 consecutive patients (250 women and 719 men) undergoing coronary stenting for stable or unstable angina. Clinical events were assessed for at least 1 year post-procedure.Results Compared to men, women were older, presented more often with diabetes, hypertension, dyslipidemia, and lower creatinine clearance rate (Ccr); they had less percutaneous transluminal coronary angioplasty (PTCA) history,smaller vessel size, and shorter lesions. The hospital major adverse cardiovascular event (MACE) rate was 2.8% of women and 0.97% of men (P=0.037). The one-year MACE rate was 10.0% of women and 10.4% of men (P=0.874). After adjusting other covariates, women still had significantly higher hospital MACE rates (P=0.034) and odds ratios (0.18;95% confidence interval: 0.036-0.874). In women (n=250), there was no statistically significant difference in hospital or one-year MACE between bare metal stent (BMS) and DES groups. Meanwhile, in men (n=719), DES had a significant one-year improvement of MACE compared to BMS (P=0.004). The female hospital MACE rate was five times greater than male results. However, there were similar one-year outcomes between women and men. DES currently have an advantage in long-term outcome.Conclusions Currently, with the use of BMS and DES, adverse hospital post-procedure cardiovascular event rate has occurred more often in women than in men. However, the MACE rate differences between women and men resolved with one year follow-up.

  9. 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.

  10. Symptomatic stent cast.

    LENUS (Irish Health Repository)

    Keohane, John

    2012-02-03

    Biliary stent occlusion is a major complication of endoscopic stent insertion and results in repeat procedures. Various theories as to the etiology have been proposed, the most frequently studied is the attachment of gram negative bacteria within the stent. Several studies have shown prolongation of stent patency with antibiotic prophylaxis. We report the case of stent occlusion from a cast of a previously inserted straight biliary stent; a "stent cast" in an 86-year-old woman with obstructive jaundice. This was retrieved with the lithotrypter and she made an uneventful recovery. This is the first reported case of a biliary stent cast.

  11. Symptomatic stent cast.

    Science.gov (United States)

    Keohane, John; Moore, Michael; O'Mahony, Seamus; Crosbie, Orla

    2008-02-01

    Biliary stent occlusion is a major complication of endoscopic stent insertion and results in repeat procedures. Various theories as to the etiology have been proposed, the most frequently studied is the attachment of gram negative bacteria within the stent. Several studies have shown prolongation of stent patency with antibiotic prophylaxis. We report the case of stent occlusion from a cast of a previously inserted straight biliary stent; a "stent cast" in an 86-year-old woman with obstructive jaundice. This was retrieved with the lithotrypter and she made an uneventful recovery. This is the first reported case of a biliary stent cast.

  12. A Case of Successful Placement of a Fully Covered Metallic Stent for Hemobilia Secondary to Hepatocellular Carcinoma with Bile Duct Invasion

    Directory of Open Access Journals (Sweden)

    Yoshiaki Kawaguchi

    2012-12-01

    Full Text Available Hemobilia represents gastrointestinal bleeding that develops as a result of communication between blood vessels and the biliary tract, which causes the blood to reach the duodenal papilla. It is characterized by biliary colic as the initial symptom, and the complications of cholangitis, obstructive jaundice and/or anemia. In general, definitive diagnosis is made by esophagogastroduodenoscopy which confirms bleeding from the duodenal papilla. Abdominal US and abdominal enhanced CT are performed to identify the source of the bleeding, as well as ERCP for biliary drainage to control the comorbid cholangitis. If active hemorrhage accompanied by worsening of the anemia is suspected, abdominal angiography is performed to selectively image the hepatic artery. Then, embolization of the culprit vessel is recommended. In our patients with difficult hemostasis, because of the direct compression hemostasis to the tumor site achieved with the fully covered metallic stent and secondary compression hemostasis due to blood clots, the bleeding could be controlled.

  13. Cyclic strain amplitude dictates the growth response of vascular smooth muscle cells in vitro: role in in-stent restenosis and inhibition with a sirolimus drug-eluting stent.

    Science.gov (United States)

    Colombo, Alberto; Guha, Shaunta; Mackle, Joseph N; Cahill, Paul A; Lally, Caitríona

    2013-08-01

    The putative effects of changes in mean strain and cyclic strain amplitude on vascular smooth muscle cell (vSMC) growth (proliferation and apoptosis) were examined. Subsequently, a quantitative measure of vSMC growth was obtained to determine the prolonged effect of changes in mechanical burden following bare-metal stent (BMS) and sirolimus drug-eluting stent (DES) deployment in vitro. Bovine aortic vSMCs were exposed to prolonged cyclic strain using a Flexercell(TM) Tension system and a novel Sylgard(TM) phantom vessel following stent implantation before the level of vSMC proliferation and apoptosis was assessed by FACS analysis, cell counting, and immunocytochemistry. Physiological cyclic strain (5%) decreased vSMC proliferation and increased apoptosis in a temporal manner. There was no significant difference in cell growth following exposure to varying mean strains with similar amplitude. In contrast, exposure to varying strain amplitudes with similar mean strains resulted in significant differences in cell proliferation and apoptosis. In parallel studies, the level of vSMC proliferation and cell survival was significantly increased within low amplitude, high mean strain regions of a phantom vessel following BMS implantation when compared to regions of higher strain amplitude upstream and downstream of the stent, respectively. Moreover, the level of vSMC growth within the stented region was significantly attenuated following implantation of a sirolimus-coated DES independent of significant changes in cell survival. Cyclic strain amplitude is an important regulator of vSMC growth capacity within a stent and is a target for inhibition using a sirolimus-coated DES.

  14. Early local intracoronary platelet activation after drug-eluting stent placement

    Institute of Scientific and Technical Information of China (English)

    Ailiman Mahemuti; Nicolas Meneveau; Marie-France Seronde; Francois Schiele; Mariette Mercier; Evelyne Racadot; Jean-Pierre Bassand

    2007-01-01

    Background Early local platelet activation after coronary intervention identifies patients at increased risk of acute stent thrombosis (AST). However, early changes in platelet activation in coronary circulation following drug-eluting stent (DES) implantation have never been reported.Methods In a prospective study of 26 consecutive elective stable angina patients, platelet activation was analyzed by measuring soluble glycoprotein V (sGPV) and P-selectin (CD62P) before and after implantation of either DES or bare metal stent (BMS). All patients were pretreated with clopidogrel (300 mg loading dose) and aspirin (75 mg orally) the day before the procedure. Blood samples were drawn from the coronary ostium and 10 - 20 mm distal to the lesion site.Results Consistent with the lower baseline clinical risk, the levels of CD62P and sGPV were within normal reference range, both in the coronary ostium and distal to the lesion before percutaneous coronary intervention (PCl) procedure.The levels of CD62P and sGPV did not change significantly (CD62P: (31.1 ± 9.86) ng/ml vs (29.5 ± 9.02) ng/ml, P=0.319and sGPV: (52.4 ± 13.5) ng/ml vs (51.8 ± 11.7) ng/ml, P=0.674, respectively) after stent implantation when compared with baseline. Changes in these platelet activation markers did not differ between stent types.Conclusions Intracoronary local platelet activation does not occur in stable angina patients before and immediately following DES implantation when dual anti-platelet is administered.

  15. Radiation dose distribution of implanted metal stent%金属植入物对放射治疗剂量影响的研究

    Institute of Scientific and Technical Information of China (English)

    熊霏; 李兆斌; 姜瑞瑶; 黄国锋; 崔绍祥; 傅深

    2011-01-01

    Objective : To determine the scattering effect of implanted metal stent on radiation dose distribution and define the mathematical correction parameters for post - implantation irradiation dose calculation.Methods: The phantom with nickel - titanium alloy stent was scanned by CT - sim with 5mm slice.The CT images were transferred to TPS ( treatment planning system) by LANTIS network, and the interest point dose was calculated.According to the scan condition, the radiation was done with 6 MV and 15 MV X - ray.The dose was measured by TLD and FAMAR irradiation chamber.The result calculated from the TPS was compared with the measurement datum.Results: The measurements showed an increase in absorbed dose of up to 3.9% in 6 MV and 6.6% in 15 MV x - rays before the surface of stent, up to 2.8% in 6 MV and 6.3% in 15 MV x - rays after the surface of stent.The errors become smaller with the distance increase.Conclusion : The presence of stent increased the dose, which could lead to radiation damage , so the radiation dose should be amended while making radiotherapy planning.%目的:测量金属内固定支架对放射治疗剂量的影响,对采用金属内固定的肿瘤患者放射治疗提供剂量修正的临床数据.方法: 按照测量条件,将带有金属内固定支架的体模在螺旋CT下进行扫描,层厚为5mm,图像通过LANTIS网络传输系统传入放射治疗计划系统(treatment planning system,TPS)中进行模拟计算.按照相同条件,分别用6MV和15 MV X线照射,用热释光剂量仪和FAMER型电离室对钛镍合金支架界面以及界面上下一定深度分别测量,并与放射治疗计划系统计算结果比较.结果: 实际测量与TPS计算存在一定误差,实测值明显大于TPS计算值,支架前表面的误差最大可达3.9% (6MV)和6.6%(15MV),支架后表面的误差最大为2.8%(6MV)和6.3%(15MV),距表面距离越远,误差越小.结论: 镍钛合金支架患者放射治疗时,实际测量剂量比TPS计算剂量

  16. The Globe laid bare

    CERN Multimedia

    Anaïs Schaeffer

    2015-01-01

    If you’re at CERN at the moment, you will certainly have noticed the work under way on the Globe. The structure, which has been in pride of place opposite the Laboratory for over ten years, has never been so completely laid bare. But, as we explained in a previous article (see here), it is all for a good cause. The Globe is built entirely from wood and certain parts of it need to be replaced.   The Globe after the removal of all the sun baffles. Image: Lucien Fortunati. Picture the general structure of the Globe. In simple terms, the building consists of two spheres, one inside the other. The inner sphere houses the Universe of Particles exhibition and the conference room and is connected to the outer sphere by two access ramps. “Each of these two spheres is made up of eighteen large supporting arcs,” explains Amaya Martínez García of the GS department, who is supervising the Globe renovation project. “These eighteen arcs are ...

  17. A novel biodegradable esophageal stent: results from mechanical and animal experiments.

    Science.gov (United States)

    Liu, Jin; Shang, Liang; Liu, Jiyong; Qin, Chengyong

    2016-01-01

    Biodegradable esophageal stents eliminate stent retrieval, but usually induce hyperplasia. This study investigated the properties of a novel biodegradable stent in vitro and in vivo. The degradation of the novel stent was observed in phosphate buffered saline (PBS) for 8 weeks. The radial forces, pH values, morphology, and retention rate of the intrinsic viscosity (R[η]) of the new biodegradable stent were all evaluated. In vitro, the pH values remained constant for 4 weeks and declined from weeks 4 to 8. The biodegradable threads degraded and ruptured at 6 weeks. Consequently, the radial force of the stent decreased to zero at that time. The curve of R[η] decreased with time linearly in PBS. To study the stents in vivo, we used a stricture model in which the middle esophagus of rabbits was damaged by alkali burn. Stents were inserted 2 weeks after injury and observed for 8 weeks. We assessed complications related to stent insertion, degradation of the stent, and survival of the rabbits. Two stents migrated, and one rabbit died. In the other rabbits, two stents degraded and moved into the stomach during the sixth week, five during the seventh week and one during the eighth week, respectively. One stent remained in position until the end of the study. In conclusion, our newly designed stent retained the strong radial force of self-expandable metal stents (SEMSs) and maintained the biodegradable properties of biodegradable (BD) stents.

  18. Investigation of long-term implantation of BuMA stent in a porcine coronary model

    Institute of Scientific and Technical Information of China (English)

    CHEN Ming; WANG Xin-gang; ZHENG Bo; PENG Hong-yu; Zhang Xiao-yan; ZHANG Bin; HUO Yong

    2012-01-01

    Background Stent-based delivery of sirolimus has been shown to reduce neointimal hyperplasia significantly.However,the long-term effect of the polymer is thought to initiate and sustain an inflammatory response and contribute to the occurrence of late complications.Our study aimed to evaluate the efficacy and safety of the BuMA biodegradable drug-coated sirolimus-eluting stent(BSES)for inhibiting neointimal hyperplasia in a porcine coronary model.Methods Four types of stents were implanted at random in different coronary arteries of the same pig:BSES(n=24),bare metal stent(BMS)(n=24),biodegradable polymer coated stent without drug(PCS)(n=24)and only poly(n-butyl methacrylate)base layer coated stent(EGS)(n=23).In total,26 animals underwent successful random placement of 95 oversized stents in the coronary arteries.Coronary angiography was performed after 28 days,90 days and 240 days of stent implantation.After 14 days,28 days,90 days and 240 days,6 animals at each timepoint were sacrificed for histomorphologic analysis.Results The 28-day,90-day and 240-day results of quantitative coronary angiography(QCA)showed reduction in luminal loss(LL)in the BSES group when compared with the BMS group;(0.20±0.35)mm vs.(0.82±0.51)mm(P=0.035),(0.20±0.30)mm vs.(0.93±0.51)mm(P=0.013),and(0.18±0.16)mm vs.(0.19±0.24)mm(P=0.889),respectively.By 28-day,90-day and 240-day histomorphomeric analysis results,there was also a corresponding significant reduction in neointimal tissue proliferation with similar injury scores of BSES compared with the BMS control;average neointimal area(0.90±0.49)mm2 vs.(2.16±1.29)mm2(P=0.049),(1.53±0.84)mm2 vs.(3.41±1.55)mm2(P=0.026),and(2.43±0.95)mm2 vs.(3.12±1.16)mm2(P=0.228),respectively.High magnification histomorphologic examination revealed similar inflammation scores and endothelialization scores in both the BSES and BMS groups.Conclusions The BuMA biodegradable drug-coated sirolimus-eluting stents can significantly reduce neointimal

  19. The experimental study on intracoronary native metallic balloon-expandable stent%冠状动脉内置入国产支架的动物实验研究

    Institute of Scientific and Technical Information of China (English)

    朱锐; 江洪; 李庚山; 漆曙辉; 王小红; 王洪如; 叶泽兵

    2001-01-01

    目的 观察国产支架置入犬冠状动脉后的生物、血液相容性、支架开通率及其内皮化情况。方法 将16个国产支架置入8只犬的冠状动脉内,分别于1、2、3、6个月进行观察。结果 支架置入术后冠脉通畅,无明显狭窄。支架贴内膜良好,血管内腔表面光滑。术后2个月时支架覆盖的新生内膜最厚,其主要为平滑肌细胞和细胞外基质,未见明显炎性细胞浸润。支架置入1个月时,支架表面覆盖的内皮细胞排列不规则;置入2、3、6个月时,其沿血流方向排列规则。支架表面未见明显腐蚀。结论 该国产支架置入后有良好的生物和血液相容性,理化性能稳定,迅速重新内皮化,有良好的开通率。%Objective To investigate the biocompatibility, bloodcompatibility, the patency rates and reendothelialization of native coronary metallic stent after being implanted into canine coronary artery. Methods Sixteen stents were implanted into eight canine coronary artery through femoral artery aproach. The pathological examination was taken at 1 to 6 months after coronary angiography. Results Thirteen stents were successfully implanted into target vessels of six dogs. Two dogs died of coronary spasm and acute stent thrombosis respectively. Coronary angiography demonstrated all vessles patency after intracoronary stenting (ICS). Macroscopy of stented arteries demonstrated complete incorparation of stent wires into the arterial wall and smooth vessle lumens. Light microscope demonstrated the neointima was the thickest at two months and consisted mainly of smooth muscle cells and extracellular matrix. The findings also included slight to moderate media oppression localized to areas of stent wires and no significant inflammatory raction. Scanning electron mcroscope demonstrated the endotheliocytes covering on stents oriented irregularly at one month and regularly at two and three as well as six months

  20. Current status of infrapopliteal artery stenting in patients with critical limb ischemia Estado atual do uso de stents na artéria infrapolítea em pacientes com isquemia crítica do membro

    Directory of Open Access Journals (Sweden)

    Marc Bosiers

    2008-09-01

    Full Text Available Due to the fear that early thrombosis and late luminal loss resulting from intimal hyperplasia might impede sustained patency of small-caliber arteries, such as those of the infrapopliteal bed, stent implantation in below-knee vessels remains controversial and is generally reserved for cases with a suboptimal outcome after percutaneous transluminal angioplasty (i.e. > 50% residual stenosis, flow-limiting dissection. Although evidence starts to build, favoring the use of stenting in the tibial area, results of well-conducted randomized controlled trials have to be awaited to change this strategy. Because of diameter similarities with coronary arteries, the first stents applied in the infrapopliteal vessels were all coronary devices. Once the feasibility of the stenting approach with these coronary products was shown, device manufacturers started to develop a dedicated infrapopliteal product range. To date, a broad spectrum of stent types has been used and investigated for the given indication. This article overviews the available literature and results of different balloon-expandable (bare metal, passive coated, drug eluting, self-expanding and absorbable stent types available for below-the-knee application and gives recommendations for future device technology advancements.Devido ao receio de que a trombose precoce ou a estenose tardia por hiperplasia intimal possam impedir a manutenção da perviedade em vasos de pequeno calibre, o uso de stents pós-angioplastia no leito arterial infrapoplíteo permanece controverso e geralmente é reservado aos casos de resultado subótimo após angioplastia transluminal percutânea (isto é, estenose residual > 50% ou dissecção com limitação do fluxo. Apesar de evidências começarem a favorecer o uso de stents no segmento tibial, é necessário aguardar o resultado de ensaios controlados, randomizados e bem conduzidos para mudar esta estratégia. Sendo estes vasos infrapoplíteos de diâmetro similar

  1. Partially uncovered Cheatham platinum-covered stent to treat complex aortic coarctation associated with aortic wall aneurysm.

    Science.gov (United States)

    Butera, Gianfranco; Piazza, Luciane

    2015-04-01

    Percutaneous treatment of aortic coarctation is a widely used option. Covered stents have increased the profile of efficacy and safety of this procedure. Here we report on a 32-year-old woman with significant aortic recoarctation associated with aortic wall aneurysm and close proximity of both lesions to the origin of both the subclavian arteries. It was decided to manually and partially uncover the proximal part of the stent to have a hybrid stent that could act as a bare stent at the level of the origin of the subclavian arteries and as a covered stent at the level of the aneurysm.

  2. Local sustained delivery of acetylsalicylic acid via hybrid stent with biodegradable nanofibers reduces adhesion of blood cells and promotes reendothelialization of the denuded artery

    Directory of Open Access Journals (Sweden)

    Lee CH

    2014-01-01

    Full Text Available Cheng-Hung Lee,1,2 Yu-Huang Lin,3 Shang-Hung Chang,1 Chun-Der Tai,3 Shih-Jung Liu,2 Yen Chu,4 Chao-Jan Wang,5 Ming-Yi Hsu,5 Hung Chang,6 Gwo-Jyh Chang,7 Kuo-Chun Hung,1 Ming-Jer Hsieh,1 Fen-Chiung Lin,1 I-Chang Hsieh,1 Ming-Shien Wen,1 Yenlin Huang81Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Linkou, 2Department of Mechanical Engineering, 3Graduate Institute of Medical Mechatronics, Chang Gung University, 4Laboratory of Cardiovascular Physiology, Division of Thoracic and Cardiovascular Surgery, 5Department of Medical Imaging and Intervention, 6Hematology-Oncology Division, Department of Internal Medicine, Chang Gung Memorial Hospital, Linkou, 7Graduate Institute of Clinical Medicinal Sciences, Chang Gung University College of Medicine, Linkou, 8Department of Anatomical Pathology, Chang Gung Memorial Hospital, Linkou, Tao-Yuan, TaiwanAbstract: Incomplete endothelialization, blood cell adhesion to vascular stents, and inflammation of arteries can result in acute stent thromboses. The systemic administration of acetylsalicylic acid decreases endothelial dysfunction, potentially reducing thrombus, enhancing vasodilatation, and inhibiting the progression of atherosclerosis; but, this is weakened by upper gastrointestinal bleeding. This study proposes a hybrid stent with biodegradable nanofibers, for the local, sustained delivery of acetylsalicylic acid to injured artery walls. Biodegradable nanofibers are prepared by first dissolving poly(D,L-lactide-co-glycolide and acetylsalicylic acid in 1,1,1,3,3,3-hexafluoro-2-propanol. The solution is then electrospun into nanofibrous tubes, which are then mounted onto commercially available bare-metal stents. In vitro release rates of pharmaceuticals from nanofibers are characterized using an elution method, and a high-performance liquid chromatography assay. The experimental results suggest that biodegradable nanofibers

  3. Balloon Angioplasty and Drug Eluting Stenting for Treatment of Peripheral Arterial Occlusive Disease

    Directory of Open Access Journals (Sweden)

    Akın İzgi

    2010-08-01

    Full Text Available Peripheral arterial disease is one of the manifestations of systemic atherosclerosis. In the last decade, remarkable technological advances, especially in the stent area, have shifted revascularization strategies from traditional open surgical approaches toward less morbide percutaneous endovascular treatments. However, even with new designed nitinol bare stents, restenosis remains as the major obstacle of this procedures. More recently, drug eluting stent platforms have been used to treat atherosclerotic peripheral arterial disease. In this article, we reviewed new studies relevant to drug eluting stents for lower extremity peripheral arterial occlusive disease.

  4. Solid Bare Strange Quark Stars

    CERN Document Server

    Xu, R X

    2003-01-01

    The reason, we need three terms of `strange', `bare', and `solid' before quark stars, is presented concisely though some fundamental issues are not certain. Observations favoring these stars are introduced.

  5. Cell Area and Strut Distribution Changes of Bent Coronary Stents: A Finite Element Analysis

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yang; WU Wei; YANG Da-zhi; QI Min

    2009-01-01

    Coronary stents are metal coils or mesh tubes delivered to blocked vessels through catheters, which are expanded by balloons to reopen and scaffold target vessels. Recently,special drugs are carried by stents (drug-eluting stents) to further reduce in-stent restenosis rate after stenting procedure. However,continual study on biomechanical characteristics of stents is necessary for better interactions between stents and tissue, or to provide a more suitable drug loading platform for drug-eluting stents. The purpose of this paper is to show how finite element methods can be used to study cell area and strut distribution changes of bent coronary stents. A same bending deformation was applied to two commercial coronary stent models by a rigid curved vessel. Results show that the stent design influenced the changes of cell area and strut distribution under bending situation. The stent with links had more cell area changes at outer curvature, and the stent with peak-peak (><) strut design could have strut contact and overlapping at inner curvature. In conclusion, this finite element method can be used to study and compare cell area and strut distribution changes of bent stents,and to provide a convenient tool for designers in testing and improving biomechanical characteristics of new stents.

  6. Next generation coronary CT angiography: in vitro evaluation of 27 coronary stents

    Energy Technology Data Exchange (ETDEWEB)

    Gassenmaier, Tobias; Bley, Thorsten A. [University Hospital Wuerzburg, Department of Diagnostic and Interventional Radiology, Wuerzburg (Germany); Petri, Nils; Voelker, Wolfram [University Hospital Wuerzburg, Department of Internal Medicine I, Wuerzburg (Germany); Allmendinger, Thomas; Flohr, Thomas [Siemens Healthcare, Forchheim (Germany); Maintz, David [University of Cologne, Department of Radiology, Cologne (Germany)

    2014-11-15

    To evaluate in-stent lumen visibility of 27 modern and commonly used coronary stents (16 individual stent types, two stents at six different sizes each) utilising a third-generation dual-source CT system. Stents were implanted in a plastic tube filled with contrast. Examinations were performed parallel to the system's z-axis for all stents (i.e. 0 ) and in an orientation of 90 for stents with a diameter of 3.0 mm. Two stents were evaluated in different diameters (2.25 to 4.0 mm). Examinations were acquired with a collimation of 96 x 0.6 mm, tube voltage of 120 kVp with 340 mAs tube current. Evaluation was performed using a medium-soft (Bv40), a medium-sharp (Bv49) and a sharp (Bv59) convolution kernel optimised for vascular imaging. Mean visible stent lumen of stents with 3.0 mm diameter ranged from 53.3 % (IQR 48.9 - 56.7 %) to 73.9 % (66.7 - 76.7 %), depending on the kernel used at 0 , and was highest at an orientation of 90 with 80.0 % (75.6 - 82.8 %) using the Bv59 kernel, strength 4. Visible stent lumen declined with decreasing stent size. Use of third-generation dual-source CT enables stent lumen visibility of up to 80 % in metal stents and 100 % in bioresorbable stents. (orig.)

  7. 雷帕霉素与紫杉醇洗脱支架置入治疗冠状动脉病变的有效性%Efficacy of rapamycin and paclitaxel eluting stent implantation in treatment of coronary artery disease

    Institute of Scientific and Technical Information of China (English)

    杨俊; 陈冬林; 陈银朝; 陈新敬

    2015-01-01

    背景:药物洗脱支架置入治疗冠状动脉病变具有良好的临床效果,但不同支架的治疗效果可能存在一定差异。目的:比较不同支架置入治疗冠状动脉病变的临床效果。方法:纳入278例冠状动脉病变患者,均接受冠状动脉支架置入治疗,其中91例置入雷帕霉素洗脱支架,92例置入紫杉醇洗脱支架,95例置入裸金属支架。支架置入后随访12个月,记录死亡和心肌梗死等不良心脏事件发生情况,以及冠状动脉再狭窄发生情况及材料宿主反应。结果与结论:雷帕霉素洗脱支架组与紫杉醇洗脱支架组冠状动脉再狭窄率、急性心肌梗死发生率、冠状动脉旁路移植或再次经皮冠状动脉介入治疗率均低于裸金属支架组(P0.05)。3组死亡率比较差异无显著性意义(P>0.05)。3组均未发生支架移位、脱落、断裂、置入位置不良及白细胞增多和血小板减少、溶血等情况。表明两种药物洗脱支架的治疗效果相当,均优于裸金属支架。%BACKGROUND: The clinical effect of drug-eluting stent implantation in treatment of coronary artery disease is good, but there may be some differences in the therapeutic effect between different stents. OBJECTIVE:To compare the clinical effect of different stent implantation in treatment of coronary artery disease. METHODS:A total of 278 patients with coronary artery disease were enroled and al underwent coronary artery stent implantation treatment, of which 91 patients underwent implanted rapamycin eluting stent, 92 patients underwent implanted paclitaxel eluting stent, and 95 patients underwent implanted bare metal stents. Al the patients were folowed up for 12 months after stents implantation. The occurrence of adverse cardiac events such as death, myocardial infarction, and the occurrence of coronary restenosis and host reaction were recorded. RESULTS AND CONCLUSION:The rates of coronary artery stenosis, acute

  8. Uso de stents farmacológicos na "vida real": a importância dos registros Uso de stents farmacológicos en la "vida real": la importancia de los registros Real-world use of drug-eluting stents: the importance of registries

    Directory of Open Access Journals (Sweden)

    Expedito E. Ribeiro

    2010-07-01

    Full Text Available Nas últimas décadas, a eficácia e a segurança dos stents não-farmacológicos (SNF e dos stents farmacológicos (SF têm sido demonstradas em muitos ambientes clínicos diferentes, levando ao seu uso em mais de 75% de procedimentos no mundo todo. Comparados aos SNF, os SF mostraram menores taxas de reestenose angiográfica e revascularização do vaso-alvo. Esse benefício foi inicialmente demonstrado em estudos que excluíram pacientes com lesões mais complexas, tais como aquelas com vasos mais calibrosos ou finos, oclusão crônica, lesões bifurcadas, reestenose de stent, lesões longas e do tronco da coronária esquerda. Essa população do "mundo real" tem sido recentemente avaliada em muitos registros e meta-análises que são aqui revisados.En las últimas décadas, la eficacia de la seguridad de los stents no-farmacológicos (SNF y de los stents farmacológicos (SF ha sido demostrada en muchos ambientes clínicos diferentes, llevando a su uso en más de 75% de los procedimientos en todo el mundo. Comparados a los SNF, los SF mostraron menores tasas de reestenosis angiográfica y revascularización del vaso a tratar. Ese beneficio fue inicialmente demostrado en estudios que excluyeron a pacientes con lesiones más complejas, tales como aquellas con vasos más dilatados o finos, oclusión crónica, lesiones bifurcadas, reestenosis de stent, lesiones largas y del tronco de la coronaria izquierda. Esa población del "mundo real" ha sido recientemente evaluada en muchos registros y meta-análisis que son aquí revisados.over the last decades the efficacy and safety of bare metal (BMS and drug eluting stents (DES have been demonstrated in many different clinical scenarios, leading to their use in more than 75% of the procedures worldwide. Compared to BMS, DES have shown lower rates of angiographic restenosis and target-vessel revascularization. This benefit was initially demonstrated in trials that excluded patients with more complex

  9. Clinical Coronary In-Stent Restenosis Follow-Up after Treatment and Analyses of Clinical Outcomes

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    Barbara Campos Abreu Marino

    2015-05-01

    Full Text Available Background: Clinical in-stent restenosis (CISR is the main limitation of coronary angioplasty with stent implantation. Objective: Describe the clinical and angiographic characteristics of CISR and the outcomes over a minimum follow-up of 12 months after its diagnosis and treatment. Methods: We analyzed in 110 consecutive patients with CISR the clinical presentation, angiographic characteristics, treatment and combined primary outcomes (cardiovascular death, nonfatal acute myocardial infarction [AMI] and combined secondary (unstable angina with hospitalization, target vessel revascularization and target lesion revascularization during a minimal follow-up of one year. Results: Mean age was 61 ± 11 years (68.2% males. Clinical presentations included acute coronary syndrome (ACS in 62.7% and proliferative ISR in 34.5%. CISR was treated with implantation of drug-eluting stents (DES in 36.4%, Bare Metal Stent (BMS in 23.6%, myocardial revascularization surgery in 18.2%, balloon angioplasty in 15.5% and clinical treatment in 6.4%. During a median follow-up of 19.7 months, the primary outcome occurred in 18 patients, including 6 (5.5% deaths and 13 (11.8% AMI events. Twenty-four patients presented a secondary outcome. Predictors of the primary outcome were CISR with DES (HR = 4.36 [1.44–12.85]; p = 0.009 and clinical treatment for CISR (HR = 10.66 [2.53–44.87]; p = 0.001. Treatment of CISR with BMS (HR = 4.08 [1.75–9.48]; p = 0.001 and clinical therapy (HR = 6.29 [1.35–29.38]; p = 0.019 emerged as predictors of a secondary outcome. Conclusion: Patients with CISR present in most cases with ACS and with a high frequency of adverse events during a medium-term follow-up.

  10. Long-term effect of stenting in unprotected left main coronary artery disease in the elderly

    Institute of Scientific and Technical Information of China (English)

    Caiyi LU; Pinfa LIU; Jicai ZANG; Shiwen WANG; Lingling LIU; Qiao XUE; Xinli WU; Taohong HU; Pingshuan DONG; Zhiping WANG; Shenfang TIAN

    2005-01-01

    To evaluate the feasibility, safety and efficacy of percutaneous stent implantation for treating left main coronary artery (LMCA) stenosis. Methods Consecutive patients with unprotected left main coronary artery disease treated by stent-based percutaneous intervention (PCI) at 6 medical centers in China were enrolled. Procedural data and clinical outcomes were obtained from all patients. Results From January 2001 to December 2004, 138 patients (79 males and 59 females; mean age: 69.7±5.8 years)underwent PCI for LMCA stenosis. Bare metal stents (BMS) were implanted in 51 patients with non-bifurcational lesions and in 5 patients with bifurcational lesions from January of 2001 to June of 2003 (BMS group);. Drug eluting stents (DES) were used unselectively to cover both bifurcational and non-bifurcational lesions in 86 patients from July of 2003 to December of 2004 (DES group). Procedural success rate of the 138 cases was 98% (135/138). One patient (0.7%) with bifurcation lesion who was treated with DES died from severe heart failure 2 weeks after the procedure. During a mean follow up period of 21.3 ± 5.6 months, one patient died from renal failure, one from sudden cardiac death, 4 underwent target lesion revascularization (TLR) in the BMS group, which all occurred in patients with bifurcational lesions; whereas in the DES group no deaths occurred and only one patient with bifurcational lesion had TLR. Conclusions (1) PCI is feasible and relatively safe to treat unprotected left main coronary artery disease in elderly patients at medical centers with experienced professionals. (2) BMS and DES have similar immediate and long-term efficacy in the treatment of ostium and shaft lesions of the LMCA. (3) DES are strongly suggested in the therapy of distal bifurcation lesion of unprotected LMCA.

  11. Clinical Coronary In-Stent Restenosis Follow-Up after Treatment and Analyses of Clinical Outcomes

    Science.gov (United States)

    Marino, Barbara Campos Abreu; Nascimento, Guilherme Abreu; Rabelo, Walter; Marino, Marcos Antônio; Marino, Roberto Luiz; Ribeiro, Antonio Luiz Pinho

    2015-01-01

    Background Clinical in-stent restenosis (CISR) is the main limitation of coronary angioplasty with stent implantation. Objective Describe the clinical and angiographic characteristics of CISR and the outcomes over a minimum follow-up of 12 months after its diagnosis and treatment. Methods We analyzed in 110 consecutive patients with CISR the clinical presentation, angiographic characteristics, treatment and combined primary outcomes (cardiovascular death, nonfatal acute myocardial infarction [AMI]) and combined secondary (unstable angina with hospitalization, target vessel revascularization and target lesion revascularization) during a minimal follow-up of one year. Results Mean age was 61 ± 11 years (68.2% males). Clinical presentations included acute coronary syndrome (ACS) in 62.7% and proliferative ISR in 34.5%. CISR was treated with implantation of drug-eluting stents (DES) in 36.4%, Bare Metal Stent (BMS) in 23.6%, myocardial revascularization surgery in 18.2%, balloon angioplasty in 15.5% and clinical treatment in 6.4%. During a median follow-up of 19.7 months, the primary outcome occurred in 18 patients, including 6 (5.5%) deaths and 13 (11.8%) AMI events. Twenty-four patients presented a secondary outcome. Predictors of the primary outcome were CISR with DES (HR = 4.36 [1.44–12.85]; p = 0.009) and clinical treatment for CISR (HR = 10.66 [2.53–44.87]; p = 0.001). Treatment of CISR with BMS (HR = 4.08 [1.75–9.48]; p = 0.001) and clinical therapy (HR = 6.29 [1.35–29.38]; p = 0.019) emerged as predictors of a secondary outcome. Conclusion Patients with CISR present in most cases with ACS and with a high frequency of adverse events during a medium-term follow-up. PMID:25651344

  12. Factors Associated with the Use of Drug-Eluting Stents in Patients Presenting with Acute ST-Segment Elevation Myocardial Infarction

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    Jose F. Chavez

    2015-01-01

    Full Text Available Background. Drug-eluting stents (DES have proven clinical superiority to bare-metal stents (BMS for the treatment of patients with ST-segment elevation myocardial infarction (STEMI. Decision to implant BMS or DES is dependent on the patient’s ability to take dual antiplatelet therapy. This study investigated factors associated with DES placement in STEMI patients. Methods. Retrospective analysis was performed on 193 patients who presented with STEMI and were treated with percutaneous coronary intervention at an urban, tertiary care hospital. Independent factors associated with choice of stent type were determined using stepwise multivariate logistic regression. Odds ratio (OR was used to evaluate factors significantly associated with DES and BMS. Results. 128 received at least one DES, while 65 received BMS. BMS use was more likely in the setting of illicit drug or alcohol abuse ([OR] 0.15, 95% CI 0.05–0.48, p≤0.01, cardiogenic shock (OR 0.26, 95% CI 0.10–0.73, p=0.01, and larger stent diameter (OR 0.28, 95% CI 0.11–0.68, p≤0.01. Conclusions. In this analysis, BMS implantation was associated with illicit drug or alcohol abuse and presence of cardiogenic shock. This study did not confirm previous observations that non-White race, insurance, or income predicts BMS use.

  13. The treatment of complex airway diseases with inverted Y-shaped self-expandable metal stent%倒Y型气道支架置入治疗复合气道病变

    Institute of Scientific and Technical Information of China (English)

    李建明; 贾广志

    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 tracheo-bronchial tree was technically successful in all patients. After the operation, the symptom of dyspnea was immediatly relieved and the bucking following foodintake 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. (J Intervent Radiol, 2011 , 20 : 210-213)%目的 探讨倒Y型一体化气道金属支架置入在气管下段、气管隆突和双主支气管复合病变(狭窄和瘘)中的应用.方法 根据气道复合病变的特殊解剖结构,设计倒Y型一体化自膨胀式金属内支架.在X线监视下,12例气道复合病变患者置入倒Y型一体化自膨胀式金属内支架12枚.结果 所有患者置入倒Y型金属气道支架均一次成功,12例患者置入内支架后呼吸困难即刻明显缓解,进食呛咳消失.一般状况明显改善,生活质量提高.结论 气道倒Y型一体化金属内支架置入治疗气道复合病变疗效可靠.

  14. [Magnetic resonance compatibility research for coronary mental stents].

    Science.gov (United States)

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

    2015-01-01

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

  15. Sonda RF per al seguiment no-invasiu d'implants mèdics (stents)

    OpenAIRE

    De Cabrera Estanyol, Ferran

    2015-01-01

    Stents are medical devices that are implanted inside blood vessels to restore partial occlusions (stenosis). These devices (Fig. 1) are made of a frame of filaments (usually metallic) following a geometry that allows the frame to expand when a radial pressure is exerted. To implant them, stents are crimped around inflatable balloon catheters which are used to position the stent at the vessel occlusion. Once properly placed, the balloon is inflated and the stent is fixed to the vessel wall, re...

  16. Coronary artery bypass surgery or coronary stenting in diabetic patients: too soon to make a statement?

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, Alfredo E., E-mail: arodriguez@centroceci.com.ar

    2014-11-15

    Diabetic patients have been associated with poor procedural and long term outcome if they were treated either with percutaneous coronary interventions or coronary artery bypass surgery. Recently several randomized clinical trials (RCT) in this subset of patients have been published showing a greater incidence of major adverse cardiovascular events, death/myocardial infarction/stroke, if they were treated with first generation drug eluting stents (DES) which was not observed previously in the bare metal stent era. However, almost simultaneously with this data, several RCT demonstrated better safety profile with new generation DES including biocompatible polymers, biodegradable polymers and lately complete absorbable DES, all of them showed reduction in adverse cardiac events compared to 1st generation DES in patients with diabetes. In this editorial we review the old and new randomized data in diabetic patients and conclude that there are many unresolved issues to make a definitive statement regarding which is the best revascularization preference in diabetic patients and the measured final efficacy of PCI and CABG will not be reached until the arrival of RCT using next generation DES, including complete absorbable scaffolds. - Highlights: • Diabetic patients have been associated with poor procedural and long term outcome if they were treated either with percutaneous coronary interventions or coronary artery bypass surgery. Recently several randomized clinical trials (RCT) in this subset of patients have been published showing a greater incidence of major adverse cardiovascular events, death/myocardial infarction/stroke, if they were treated with first generation drug eluting stents (DES) which was not observed previously in the bare metal stent era. • In recent years, several RCT demonstrated better safety profile with new generation DES including biocompatible polymers, biodegradable polymers and lately complete absorbable DES, all of them showed reduction in

  17. Vascular Biocompatibility of a Triple Layered Self Expanding Stent-Graft in a Dog Mode

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Jae Ik; Won, Je Hwan; Jang, Eun Ho; Lee, Sung Yeong; Ko, Kwang Tae [Dept. of Radiology, Ajou University School of Medicine, Suwon (Korea, Republic of); Jin, Bo Hwan [Medical Science Research Center, Ajou University School of Medicine, Suwon (Korea, Republic of); Lee, June Woo [Dept. of Radiology, Busan National University College of Medicine, Busan (Korea, Republic of)

    2012-02-15

    To evaluate performance and biocompatibility of a newly designed self-expanding stent graft, which consisted of two nitinol stents and an intervening expanded polytetrafluoroethylene membrane in a dog artery model. Twelve stent grafts were placed in the aorta of 6 dogs (beagle, mean body weight 11 kg) for 4 weeks (n = 4) and 12 weeks (n = 8). Luminal diameters were measured for each segment (the proximal bare, the middle graft, the distal bare) by angiographies after implantation and follow up periods. Percent luminal stenosis based on angiographies, histomorphometric, histologic, and scanning electron microscopic analyses of each segments were performed. Blood flow through the stent grafts was good after implantation and during the follow up period, without thrombotic occlusion or stent graft migration. The mean percent luminal stenosis of the proximal bare, the middle grafted and the distal bare segments after 12 weeks were 13.5%, 3.9%, 9.6% retrospectively. The mean neointimal areas of the middle grafted segment were 4.39 mm{sup 2} (4 week) and 4.92 mm{sup 2} (12 week). Mature endothelialization was evident in over 70% of the area of the stented artery after 4 weeks and in over 90% after 12 weeks. The stent graft was well placed in the attempted area without migration. During the 12-week-follow up period, it showed a good patency without thrombotic occlusion or significant in-stent luminal stenosis. Endothelialization was rapid and nearly complete. Neointima was thin and smooth on the middle graft segment and thicker and irregular on the bare segments.

  18. Rare and fatal complication of Gianturco tracheobronchial stent.

    Science.gov (United States)

    Asopa, Sanjay; Moorjani, Narain; Saad, Rasheed A; Turner, Jonathan T; Amer, Khalid M

    2007-11-01

    Tracheobronchial stents are increasingly being used for the management of compromised large airways. Traditionally they have been used to palliate malignant conditions; however, they are now being used more frequently for nonmalignant conditions. The use of Gianturco self-expanding metal stent (William Cook, Bjaeverskov, Denmark) has been challenged for treatment of tracheobroncheomalacia, as fracture of the metal work could prove fatal. In this report we describe a case of fracture in the metal framework of a Gianturco stent resulting in recurrent pneumothoraces; heralding fatal haemoptysis as a result of perforation of the left subclavian artery.

  19. Percutaneous Transhepatic Biliary Metal Stent for Malignant Hilar Obstruction: Results and Predictive Factors for Efficacy in 159 Patients from a Single Center

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-06-15

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

  20. Impacto dos stents e do sirolimus por via oral na vasomotilidade coronariana dependente e independente do endotelio Impact of stenting and oral sirolimus on endothelium-dependent and independent coronary vasomotion

    Directory of Open Access Journals (Sweden)

    Rósley Weber Alvarenga Fernandes

    2012-04-01

    compared to bare metal stenting (BMS. OBJECTIVE: This study aims to assess the impact of BMS and the effect of oral sirolimus on endothelial function. METHODS: Forty-five patients were randomized into three groups: BMS + high-dose oral sirolimus (initial dose of 15 mg, followed by 6 mg/day for four weeks; BMS + low-dose sirolimus (6 mg followed by 2 mg daily for four weeks; and BMS without sirolimus. Changes in vasoconstriction or vasodilation in a 15 mm segment starting at the distal stent end in response to acetylcholine and nitroglycerin were assessed by quantitative angiography. RESULTS: The groups had similar angiographic characteristics. The percent variation in diameter in response to acetylcholine was similar in all groups at the two time points (p = 0.469. Four hours after stenting, the target segment presented an endothelial dysfunction that was maintained after eight months in all groups. In all groups, endothelium-independent vasomotion in response to nitroglycerin was similar at four hours and eight months, with increased target segment diameter after nitroglycerin infusion (p = 0.001. CONCLUSION: The endothelial dysfunction was similarly present at the 15 mm segment distal to the treated segment, at 4 hours and 8 months after stenting. Sirolimus administered orally during 4 weeks to prevent restenosis did not affect the status of endothelium-dependent and independent vasomotion.

  1. Modeling the transport of drugs eluted from stents: physical phenomena driving drug distribution in the arterial wall.

    Science.gov (United States)

    Bozsak, Franz; Chomaz, Jean-Marc; Barakat, Abdul I

    2014-04-01

    Despite recent data that suggest that the overall performance of drug-eluting stents (DES) is superior to that of bare-metal stents, the long-term safety and efficacy of DES remain controversial. The risk of late stent thrombosis associated with the use of DES has also motivated the development of a new and promising treatment option in recent years, namely drug-coated balloons (DCB). Contrary to DES where the drug of choice is typically sirolimus and its derivatives, DCB use paclitaxel since the use of sirolimus does not appear to lead to satisfactory results. Since both sirolimus and paclitaxel are highly lipophilic drugs with similar transport properties, the reason for the success of paclitaxel but not sirolimus in DCB remains unclear. Computational models of the transport of drugs eluted from DES or DCB within the arterial wall promise to enhance our understanding of the performance of these devices. The present study develops a computational model of the transport of the two drugs paclitaxel and sirolimus eluted from DES in the arterial wall. The model takes into account the multilayered structure of the arterial wall and incorporates a reversible binding model to describe drug interactions with the constituents of the arterial wall. The present results demonstrate that the transport of paclitaxel in the arterial wall is dominated by convection while the transport of sirolimus is dominated by the binding process. These marked differences suggest that drug release kinetics of DES should be tailored to the type of drug used.

  2. A Dual Expandable Stent for Treatment of Malignant Colorectal Obstruction: Long-Term Follow-Up Results

    Energy Technology Data Exchange (ETDEWEB)

    Son, Won Young; Kang, Hee; Jung, Gyoo Sik [Dept. of Radiology, Kosin University College of Medicine, Gospel Hospital, Busan (Korea, Republic of)

    2012-11-15

    To analyze the long-term results and to evaluate the efficacy of a dual expandable stent for the treatment of malignant colorectal strictures. Under the fluoroscopic guidance, stents were placed in 60 patients with malignant colorectal strictures. A dual stent consists of two stents, the outer stent was placed into the stricture which was followed by coaxial placement of the inner bare stent. Technical and clinical success rates, complications, patient survival and stent patency during the follow-up period were evaluated in this study. Stent placement was technically successful in 57 of 60 patients (95%). Of them, obstructive symptoms resolved within two days in 12/12 (100%) patients in the preoperative group and in 36/45 (80%) patients in the palliative group. Complications associated with this procedure were perforation (n = 5), migration (n = 3), and tumor overgrowth (n = 2). Each of the six patients in the preoperative group underwent conventional laparotomy and laparoscopic surgery, respectively. The mean interval between stent insertion and surgery was nine days. In the palliative group, the median survival was 159 days (mean; 235) and the median patency of stent was 116 days (mean; 185). 1-month, 3-month, 6-month, 12-month and 24-month stent patency were 75%, 60%, 27%, 13% and 7%, respectively. Insertion of a dual expandable nitinol stent into malignant colorectal obstruction is a safe and effective procedure for the palliative treatment of malignant colorectal obstruction. This procedure is also effective for preoperative decompression.

  3. A new stent with streamlined cross-section can suppress monocyte cell adhesion in the flow disturbance zones of the endovascular stent.

    Science.gov (United States)

    Chen, Zengsheng; Zhan, Fan; Ding, Jun; Zhang, Xiwen; Deng, Xiaoyan

    2016-01-01

    We proposed a new stent with streamlined cross-sectional wires, which is different from the clinical coronary stents with square or round cross-sections. We believe the new stent might have better hemodynamic performance than the clinical metal stents. To test the hypothesis, we designed an experimental study to compare the performance of the new stent with the clinical stents in terms of monocyte (U-937 cells) adhesion. The results showed that when compared with the clinical stents, the adhesion of U-937 cells were much less in the new stent. The results also showed that, when Reynolds number increased from 180 (the rest condition for the coronary arteries) to 360 (the strenuous exercise condition for the coronary arteries), the flow disturbance zones in the clinical stents became larger, while they became smaller with the new stent. The present experimental study therefore suggests that the optimization of the cross-sectional shape of stent wires ought to be taken into consideration in the design of endovascular stents.

  4. Fabrication and in vitro deployment of a laser-activated shape memory polymer vascular stent

    Directory of Open Access Journals (Sweden)

    Matthews Dennis L

    2007-11-01

    Full Text Available Abstract Background Vascular stents are small tubular scaffolds used in the treatment of arterial stenosis (narrowing of the vessel. Most vascular stents are metallic and are deployed either by balloon expansion or by self-expansion. A shape memory polymer (SMP stent may enhance flexibility, compliance, and drug elution compared to its current metallic counterparts. The purpose of this study was to describe the fabrication of a laser-activated SMP stent and demonstrate photothermal expansion of the stent in an in vitro artery model. Methods A novel SMP stent was fabricated from thermoplastic polyurethane. A solid SMP tube formed by dip coating a stainless steel pin was laser-etched to create the mesh pattern of the finished stent. The stent was crimped over a fiber-optic cylindrical light diffuser coupled to an infrared diode laser. Photothermal actuation of the stent was performed in a water-filled mock artery. Results At a physiological flow rate, the stent did not fully expand at the maximum laser power (8.6 W due to convective cooling. However, under zero flow, simulating the technique of endovascular flow occlusion, complete laser actuation was achieved in the mock artery at a laser power of ~8 W. Conclusion We have shown the design and fabrication of an SMP stent and a means of light delivery for photothermal actuation. Though further studies are required to optimize the device and assess thermal tissue damage, photothermal actuation of the SMP stent was demonstrated.

  5. Fabrication and In Vitro Deployment of a Laser-Activated Shape Memory Polymer Vascular Stent

    Energy Technology Data Exchange (ETDEWEB)

    Baer, G M; Small IV, W; Wilson, T S; Benett, W J; Matthews, D L; Hartman, J; Maitland, D J

    2007-04-25

    Vascular stents are small tubular scaffolds used in the treatment of arterial stenosis (narrowing of the vessel). Most vascular stents are metallic and are deployed either by balloon expansion or by self-expansion. A shape memory polymer (SMP) stent may enhance flexibility, compliance, and drug elution compared to its current metallic counterparts. The purpose of this study was to describe the fabrication of a laser-activated SMP stent and demonstrate photothermal expansion of the stent in an in vitro artery model. A novel SMP stent was fabricated from thermoplastic polyurethane. A solid SMP tube formed by dip coating a stainless steel pin was laser-etched to create the mesh pattern of the finished stent. The stent was crimped over a fiber-optic cylindrical light diffuser coupled to an infrared diode laser. Photothermal actuation of the stent was performed in a water-filled mock artery. At a physiological flow rate, the stent did not fully expand at the maximum laser power (8.6 W) due to convective cooling. However, under zero flow, simulating the technique of endovascular flow occlusion, complete laser actuation was achieved in the mock artery at a laser power of {approx}8 W. We have shown the design and fabrication of an SMP stent and a means of light delivery for photothermal actuation. Though further studies are required to optimize the device and assess thermal tissue damage, photothermal actuation of the SMP stent was demonstrated.

  6. Solving the Issue of Restenosis After Stenting of Intracranial Stenoses: Experience with Two Thin-Strut Drug-Eluting Stents (DES)—Taxus Element™ and Resolute Integrity™

    Energy Technology Data Exchange (ETDEWEB)

    Kurre, Wiebke, E-mail: wiebke.kurre@gmx.de; Aguilar-Pérez, Marta [Klinikum Stuttgart, Klinik für Diagnostische und Interventionelle Neuroradiologie (Germany); Fischer, Sebastian [Universitätsklinikum Knappschaftskrankenhaus Bochum GmbH, Institut für Diagnostische und Interventionelle Radiologie, Neuroradiologie und Nuklearmedizin (Germany); Arnold, Guy [Klinikverbund Südwest, Klinikum Sindelfingen, Klinik für Neurologie (Germany); Schmid, Elisabeth; Bäzner, Hansjörg [Klinikum Stuttgart, Klinik für Neurologie (Germany); Henkes, Hans [Klinikum Stuttgart, Klinik für Diagnostische und Interventionelle Neuroradiologie (Germany)

    2015-06-15

    PurposeThin-strut, flexible DES are suitable for intracranial stenting and may improve long-term vessel patency. The purpose of this study was to report our experience with two new-generation DES for the treatment of intracranial atherosclerotic disease.Patients and MethodsWe retrospectively reviewed all patients treated with Taxus Element™ or Resolute Integrity™ stent for an intracranial atherosclerotic stenosis between March 2011 and August 2013. Technical success was defined as the ability to deploy the device at the desired location and reduce the degree of stenosis below 50 %. All procedure-related strokes were recorded. Control angiography was scheduled after 6 weeks, 3, 6, and 12 months and yearly thereafter. A luminal narrowing ≥50 % was regarded as a restenosis. Stroke recurrence in the territory of the treated artery was reported.ResultsIn the defined period we treated 101 patients harboring 117 intracranial stenoses. The procedure was successful in 100 (85.5 %) lesions. Procedure-related strokes occurred in 10 (9.9 %) patients with a permanent morbidity in 3 (3.0 %). Follow-up angiography was available for 83 of 100 (83.0 %) successfully treated lesions with an average of 355 days (IQR 153–482 days). Three (3.6 %) asymptomatic restenoses were detected. All occurred after treatment with Resolute Integrity™, none after Taxus Element™ (p = 0.059). New strokes in the territory of the treated artery were encountered in 2 (2.6 %) occasions.ConclusionThin-strut DES improve long-term patency and reduce the risk of subsequent stroke. Differences between devices may exist. Feasibility is comparable to bare-metal balloon-mounted stents and procedure-related strokes occurred within the expected range.

  7. A review on biodegradable materials for cardiovascular stent application

    Science.gov (United States)

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

    2016-09-01

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

  8. Biocompatibility of coronary stent materials: effect of electrochemical polishing

    Energy Technology Data Exchange (ETDEWEB)

    Scheerder, I. de [University Hospital Leuven (Belgium). Dept. of Cardiology; Sohier, J.; Froyen, L.; Humbeeck, J. van [Louvain Univ. (Belgium). Dept. of Metallurgy and Materials Engineering; Verbeken, E. [University Hospital Leuven (Belgium). Dept. of Pathology

    2001-02-01

    Percutaneous Transluminal Coronary Revascularization (PTCR) is now a widely accepted treatment modality for atherosclerotic coronary artery disease. Current multicenter randomized trials comparing PTCR with the more invasive Coronary Artery Bypass Grafting could not show long-term significant survival differences. During the last two decades progress has been made to further optimize PTCR. The most logic approach to treat atherosclerotic coronary narrowings is to remove the atherosclerotic material using especially developed devices. Several trials, however, could not show a significant beneficial outcome after use of these devices compared to plain old balloon angioplasty. Another approach was to implant a coronary prothesis (stent), scaffolding the diseased coronary artery after PTCA. This approach resulted in a decreased restenosis rate at follow-up. The beneficial effects of stenting, however, was not found to be related to the inhibition of the neointimal cellular proliferation after vascular injury, but simply to be the mechanical result of overstretching of the treated vessel segment. The most important remaining clinical problem after stenting remains the neointimal hyperplasia within the stent, resulting in a significant stent narrowing in 13 to 30% of patients. Further efforts to improve the clinical results of coronary stenting should focus on the reduction of this neointimal hyperplasia. Neointimal hyperplasia after stent implantation results from (1) a healting response to the injury caused by the stent implantation and (2) a foreign body response to the stent itself. Factors that seem to influence the neointimal hyperplastic response are genetic, local disease related, stent delivery related and stent related factors. Biocompatibilisation of coronary stents by looking for more biocompatible metal alloys, optimized surface characteristics and optimized stent designs should result in a better late patency. Furthermore drug eluting and radioactive stents

  9. Auxetic coronary stent endoprosthesis

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  10. Efeitos a curto prazo de "stents" não recobertos e recobertos com politetrafluoroetileno em aorta de suínos: um modelo experimental Short-term effects of polytetrafluoroethylene covered and uncovered metallic "stents" in pig aorta: an experimental model

    Directory of Open Access Journals (Sweden)

    Marco Aurélio Grüdtner

    2004-04-01

    -expandable uncovered metallic stent. On group III animals (n=10 an auto-expandable stent covered with PTFE was inserted. After four weeks the animals were killed, the specimens were harvested and the intimal thickening was quantified by morphometric analysis. RESULTS: In the comparison among groups I, II and III referring to intimal, medial area and intimal index, it was not observed statistically significant variation. Differences were identified among groups referring to luminal proximal (p=0,036 and distal areas (p=0,044. Through multiple comparison tests for Kruskal-Wallis it was identified a difference between groups I and II. However, when these variables were controlled by weigh factor (luminal area/weigh relation, this difference was not observed anymore. CONCLUSION: In this short term study, the PTFE covering is not associated to further intimal thickening besides that promoted by the metallic mesh in large arteries and in high flow conditions.

  11. Study on the drug during coronary stent in animal%药物洗脱冠状动脉支架系统动物实验研究

    Institute of Scientific and Technical Information of China (English)

    张志刚; 王闻宇; 孙爱平

    2010-01-01

    Objective To explore the feasibility of clinical application of biodegradable polymer-coated drug-eluting stent. Methods Thirty each of the drug-eluting stent or bare-metal stents were implanted randomly into the anterior descending arteries, circumflex and right canine coronary arteries of thirty healthy pigs. The pathological examination was taken at 2 weeks to 6 months after coronary angiography to investigate the inflammation, thrombosis and endothelialization. Results Macroscopic observation of the stented arteries demonstrated complete incorporation of stent wires into the arterial wall and smooth vessel lumens. There were no significant differences existing between two kinds of the stents in terms of thrombosis, inflammation and endothelialization. The lumen loss in the biodegradable polymer-coated drug-eluting stent group is less than that in the bare-metal stent group. Conclusion The biodegradable polymer-coated drug-eluting stent is promising with good biocom-patibility, blood compatibility and phyaicochemical stability after being implanted into pig coronary arteries. The blood vessel transplanted with the drug-eluting stents maintains a high patency rate due to rapid endothelialization.%目的 通过观察在猪动脉中置入心畅可降解聚合物涂层药物洗脱冠状动脉支架(天津百畅公司开发)及对照组支架后的植入后管腔丢失、内皮化、炎症反应、损伤及血栓形成情况来评价国产可降解聚合物涂层药物洗脱支架临床应用的可行性.方法 将2种共60枚支架分别置入30头猪冠状动脉的前降支、回旋支以及右冠状动脉.支架植入后的2,5,12,25周,将不同数量的猪处死行组织形态学检查,观察炎症、血栓形成情况和内皮化评价.结果 支架置入术后的冠脉通畅,无明显狭窄;支架贴血管内壁良好,血管内腔表面光滑;2种支架均无血栓形成,心畅可降解聚合物涂层药物洗脱支架炎症反应及内皮化与对照组无明

  12. A numerical framework for the mechanical analysis of dual-layer stents in intracranial aneurysm treatment.

    Science.gov (United States)

    Alherz, Ali I; Tanweer, Omar; Flamini, Vittoria

    2016-08-16

    Dual-layer stents and multi-layer stents represent a new paradigm in endovascular interventions. Multi-layer stents match different stent designs in order to offer auxiliary functions. For example, dual-layer stents used in the endovascular treatment of intracranial aneurysms, like the FRED(TM) (MicroVention, CA) stent, combine a densely braided inner metallic mesh with a loosely braided outer mesh. The inner layer is designed to divert blood flow, whereas the outer one ensures microvessels branching out of the main artery remain patent. In this work, the implemented finite element (FE) analysis identifies the key aspects of dual-stent mechanics. In particular, dual-layer stents used in the treatment of intracranial aneurysms require the ability to conform to very narrow passages in their closed configuration, while at the same time they have to provide support and stability once deployed. This study developed a numerical framework for the analysis of dual-layer stents for endovascular intracranial aneurysm treatment. Our results were validated against analytical methods. For the designs considered, we observed that foreshortening was in average 37.5%±2.5%, and that doubling the number of wires in the outer stent increased bending moment by 23%, while halving the number of wires of the inner stent reduced von Mises stress by 2.3%. This framework can be extended to the design optimization of multi-layer stents used in other endovascular treatments.

  13. Colorectal stenting for colonic obstruction: The indications, complications, effectiveness and outcome-5-Year review

    Energy Technology Data Exchange (ETDEWEB)

    Athreya, S. [Department of Radiology, Gartnavel General Hospital, Great Western Road, Glasgow (United Kingdom)]. E-mail: harshavbs@yahoo.com; Moss, J. [Department of Radiology, Gartnavel General Hospital, Great Western Road, Glasgow (United Kingdom)]. E-mail: j.moss@clinmed.gla.ac.uk; Urquhart, G. [Department of Radiology, Southern General Hospital, Glasgow (United Kingdom); Edwards, R. [Department of Radiology, Gartnavel General Hospital, Great Western Road, Glasgow (United Kingdom); Downie, A. [Department of Radiology, Victoria Infirmary, Glasgow (United Kingdom); Poon, F.W. [Department of Radiology, Royal Infirmary, Glasgow (United Kingdom)

    2006-10-15

    Introduction: Currently self-expanding metallic stents are being used for palliation and acute decompression of colonic obstruction. The aim of this study is to review our experience of using these metallic stents over a 5-year period. Materials and methods: Case records of 102 patients who had colorectal stenting between 1998 and 2004 were reviewed retrospectively. The indications for colorectal stenting, efficacy of the procedure in relieving the obstruction, complications and clinical outcome were analysed. Results: Ninety-nine patients had malignant disease and in three patients a benign cause of obstruction was demonstrated. All procedures were performed during normal working hours. Stenting was technically successful in 87 patients (85%). A single stent was placed in 80 patients. Seven patients required two stents. Of the successful cases, 67 had stents placed by fluoroscopy alone and 20 by a combined fluoroscopy/endoscopy procedure. Four percent had early complications (within 30 days) which included four perforations. There were late complications (over 30 days) in 9% which included five stent migrations, two blocked stents and one colovesical fistula. Ninety percent (n = 76) of the successful patients needed no further radiological or surgical intervention later. Survival ranged from 14 days to 2 years. Conclusion: Colorectal stenting when technically successful is an effective procedure for both preoperative and palliative decompression of colonic obstruction.

  14. Clinical evidence-based study on new-generation drug-eluting stent:everolimus-eluting stents(Xience Ⅴ)%新一代药物洗脱支架依维莫司药物洗脱支架临床循证研究

    Institute of Scientific and Technical Information of China (English)

    高文俊; 刘文洁; 柯永胜

    2009-01-01

    Percutaneous coronary intervention (PCI) has been a mainstay in the management of coronary artery disease since its introduction in the late 1970s. Bare-metal stents and, more recently,first-generation drug-eluting stents ( DES) , such as sirolimus-eluting (Cypher) and paclitaxel-eluting stents ( Tax-us) , have further improved results of percutaneous coronary intervention by improving early results and reducing the risk of restenosis. There are currently debates on the safety of these first-generation DES, given the potential for late stent thrombosis which is a first-generation drug-eluting stent of the largest security issue, es- pecially after discontinuation of dual antiplatelet therapy. Next-generation DES such as everolimus-eluting stents (Xience V) holds the promise of superior anti-restenosis efficacy as well as long-term safety. This review makes a presentation of the evidence-based clinical research according to everolimus-eluting stents (Xience V).%经皮冠状动脉介入(percutaneous coronary intervention,PCI)自20世纪70年代末应用临床以来,已成为治疗冠心病主要手段之一.第一代药物洗脱支架(drug-eluting stent,DES)如雷帕霉素洗脱支架(Cypher)和紫杉醇洗脱支架(Taxus)的循证医学证据表明其与金属裸支架比较,能进一步改善PCI的早期疗效,并减少再狭窄的风险.第一代DES在停止双重抗血小板治疗后出现的潜在的支架晚期血栓形成,是第一代DES最大的安全性问题.新一代DES依维莫司药物涂层支架(Xience Ⅴ)具有优越的抗再狭窄疗效以及长期安全性.本文就依维莫司药物涂层支架(Xience Ⅴ)的临床循证研究作一介绍.

  15. Histopathological evaluation of thrombus in patients presenting with stent thrombosis. A multicenter European study: a report of the prevention of late stent thrombosis by an interdisciplinary global European effort consortium†

    Science.gov (United States)

    Riegger, Julia; Byrne, Robert A.; Joner, Michael; Chandraratne, Sue; Gershlick, Anthony H.; ten Berg, Jurrien M.; Adriaenssens, Tom; Guagliumi, Giulio; Godschalk, Thea C.; Neumann, Franz-Josef; Trenk, Dietmar; Feldman, Laurent J.; Steg, Philippe Gabriel; Desmet, Walter; Alfonso, Fernando; Goodall, Alison H.; Wojdyla, Roman; Dudek, Dariusz; Philippi, Vanessa; Opinaldo, Sheryl; Titova, Anna; Malik, Nikesh; Cotton, James; Jhagroe, Darshni A.; Heestermans, Antonius A.C.M.; Sinnaeve, Peter; Vermeersch, Paul; Valina, Christian; Schulz, Christian; Kastrati, Adnan; Massberg, Steffen

    2016-01-01

    Background Stent thrombosis (ST) is a rare but serious complication following percutaneous coronary intervention. Analysis of thrombus composition from patients undergoing catheter thrombectomy may provide important insights into the pathological processes leading to thrombus formation. We performed a large-scale multicentre study to evaluate thrombus specimens in patients with ST across Europe. Methods Patients presenting with ST and undergoing thrombus aspiration were eligible for inclusion. Thrombus collection was performed according to a standardized protocol and specimens were analysed histologically at a core laboratory. Serial tissue cross sections were stained with haematoxylin–eosin (H&E), Carstairs and Luna. Immunohistochemistry was performed to identify leukocyte subsets, prothrombotic neutrophil extracellular traps (NETs), erythrocytes, platelets, and fibrinogen. Results Overall 253 thrombus specimens were analysed; 79 (31.2%) from patients presenting with early ST, 174 (68.8%) from late ST; 79 (31.2%) were from bare metal stents, 166 (65.6%) from drug-eluting stents, 8 (3.2%) were from stents of unknown type. Thrombus specimens displayed heterogeneous morphology with platelet-rich thrombus and fibrin/fibrinogen fragments most abundant; mean platelet coverage was 57% of thrombus area. Leukocyte infiltrations were hallmarks of both early and late ST (early: 2260 ± 1550 per mm2 vs. late: 2485 ± 1778 per mm2; P = 0.44); neutrophils represented the most prominent subset (early: 1364 ± 923 per mm2 vs. late: 1428 ± 1023 per mm2; P = 0.81). Leukocyte counts were significantly higher compared with a control group of patients with thrombus aspiration in spontaneous myocardial infarction. Neutrophil extracellular traps were observed in 23% of samples. Eosinophils were present in all stent types, with higher numbers in patients with late ST in sirolimus-and everolimus-eluting stents. Conclusion In a large-scale study of histological thrombus analysis from

  16. 内镜金属支架姑息性治疗胆管远端恶性梗阻272例分析%272 cases of distal malignant biliary obstruction palliatively treated in endoscopic metal biliary stent

    Institute of Scientific and Technical Information of China (English)

    吴瑜; 秦鸣放; 王庆; 勾承月; 李宁

    2011-01-01

    [ Objective ] To explore the therapeutic effect and clinic value of distal malignant biliary obstruction in endoscopic metal biliary stent. [ Method ] The clinical data of 272 cases of distal malignant biliary obstruction unreseetable were retrospectively analyzed. The patients were treated in endoscopic metal biliary stent from December of 2000 to December of 2009. [ Result ] Endoscopic retrograde cholangio pancreatography were successfully performed in 258 cases (258/272, 94.8%). The levels of TBIL and DBIL were restored (73.3%) after stents were implanted two weeks later. Complications were cured including acute cholangititis in 13 patients (5.0%) and hyperamylascmia in 10 patients (3.9%). Follow-up observation was of 182 cases. Average survivng time was (24 ± 3.3) months (range: 3~37 months) after endoscopic metal biliary stent treatment. 1 year survival was 51.4% (94/182) and 2 year survival was 2.1% (40/182). [Conclusion] Metal stent implantation is safe and effective to relive obstruction for inoperable patients of malignant biliary obstruction with fewer invasive, fewer complication,better improvement of hepatic function and accord with physiology.%目的 探讨内镜金属支架对胆管远端恶性梗阻的治疗效果和临床应用价值.方法 回顾性分析该院2000年12月至~2009年12月内镜金属支架治疗272例无法手术根治性切除的胆管远端恶性梗阻患者的临床资料.结果 272例插管成功258例,失败14例,成功率为94.8%.术后2周胆红素降至正常189例(73.3%).术后并发急性胆管炎13例(5.0%),高淀粉酶血症10例(3.9%),均经保守治疗痊愈.随访182例,平均生存时间(24±3.3)个月(3~37个月),1年生存率为51.4%(94/182),2年生存率为22.1%(40/182).结论 对无法手术根治性切除的恶性胆管远端梗阻患者,内镜金属支架治疗可有效解除胆管梗阻,改善肝功能,同时具有创伤小、并发症少、符合生理等特点.该方法是安全、有效的.

  17. [Results of the upper digestive tract stenting with self-expanding stents].

    Science.gov (United States)

    Fedorov, A G; Davydova, S V; Klimov, A E; Lebedev, N V

    2013-01-01

    The work is based on the analysis of the palliative treatment of 66 patients with malignant upper digestive tract obstruction who underwent implantation of 75 self-expanding metallic stents in the period of 2003-2012 yy. Early postoperative complications developed in 10 (15.2%) cases. Procedure-related complications were observed in 8 (12.1%) patients, non-specific complications occurred in 2 (3.0%) patients. In-hospital lethality was 4.5% (3 patients). 51 patients were followed until death. Symptomatic relapse of obstruction was observed in 4 cases. Median survival was 97 days. Stenting with self-expanding metal stents was concluded to be an effective and safe method of palliation of malignant upper digestive tract stenosis.

  18. 射频深部热疗中金属支架对猪食管黏膜的损伤%Damage to pig esophageal mucosa caused by metal stent in radiofrequency hyperthermia

    Institute of Scientific and Technical Information of China (English)

    陈玉林; 吴敬波; 宿向东; 谭燕琼; 范娟; 文庆莲; 黄镇东

    2008-01-01

    BACKGROUND: Thermotherapy has achieved remarkable therapeutic effect on patients with esophageal cancer. However, there are still some problems which cannot be answered today, such as the damage of esophageal mucosa during deep thermotherapy when metal stent is placed in esophagus. OBJECTIVE: To study the metal stent-caused damages to esophageal mucosa of pigs in radiofrequency hyperthermia. DESIGN, TIME AND SETTING: Observational study which was performed in the Department of Tumor, Affiliated Hospital of Luzhou Medical College from October 2004 to January 2005. MATERIALS: 13 pigs weighing 35-40 kg were used in this study. Esophagus stent of memory alloy with membrane was provided by Zhiye Medical Apparatus Institute of Changzhou, China METHODS: Five points were located for measurement, i.e. the middle of the stent, the exit of the stent, 2 cm and 4 cm a distance from the exit and 4 cm from the entrance. Esophagus of 13 pigs was heated for 30 minutes by SR-1000 radiofrequency hyperthermia machine in frequency of 40.82 MHz, pole plate of 25 cm Ⅱ 25 cm and power of 500-700 W. MAIN OUTCOME MEASURES: The esophageal mucosa was observed with naked eyes. And optical microscopy was used to observe the changes of the esophageal mucosa. RESULTS: Because one pig died of anesthesia and there were troubles of thermal detector lines in 4 pigs, only 8 pigs were included in the final analysis. Level of damage of esophageal mucosa on five temperature checkpoints was observed from grade 0 to 1 in naked eyes, and the difference of damaged level between five checkpoints was not obvious in statistics (H=2.0, P=0.157). Level of the damage was observed from grade 0 to 2 in microscope, and the difference was not obvious in statistics too (H=2.734, P=0.255). CONCLUSION: Influence of the metal stent on esophageal mucosa can be neglected in radiofrequency hyperthermia, and metal stent does not cause obvious mechanical damage or thermal damage to esophageal mucosa of pigs. It is safe and

  19. Effect of force-induced mechanical stress at the coronary artery bifurcation stenting: Relation to in-stent restenosis

    Science.gov (United States)

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

    2014-05-01

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

  20. Therapeutic value of endoscopic metal pyloric stent implantation for gastric outlet obstruction%经内镜放置幽门金属支架对胃出口梗阻的治疗价值

    Institute of Scientific and Technical Information of China (English)

    朱静; 张杰; 陈婧; 郎海波; 于剑锋; 郝建宇

    2012-01-01

    目的 探讨经内镜放置幽门金属支架对胃出口梗阻的治疗价值.方法 对2008年1月至2012年1月因多种良恶性疾病引起胃出口梗阻而接受内镜下幽门金属支架植入术的21例患者的病例资料进行回顾性分析.结果 21例成功进行了幽门十二指肠支架置入术,14例24小时内症状明显缓解,1例于48小时后行CRE球囊扩张后缓解,总缓解率为71.4%.21例中有3例十二指肠壶腹部受累伴梗阻性黄疸的病例成功进行了双支架的置入治疗.3例出现术中出血,对症治疗后停止.1例良性狭窄病例使用覆膜支架发生移位,4例出现支架术后再堵塞,其中2例行二次支架置入.恶性肿瘤引起的狭窄术后生存时间平均为2.5个月.结论 对由于各种原因导致胃出口梗阻且无法手术或拒绝外科治疗的患者,幽门支架的置入可有效解除梗阻,改善患者生活质量.%Objective To evaluate the therapeutic value of endoscopic implantation of metal stent in gastric outlet obstruction. Methods Data of 21 patients who developed benign or malignant gastric outlet obstruction from January 2008 to January 2011 were retrospectively reviewed. Results Endoscopic metal pyloric stents were successfully placed in 21 patients. Symptoms were subsided in 14 patients. 1 patient subsided after CRE ballon in 48 hours. Response rate was 71.4%. 3 duodenal patients ampulla involvement with cases of obstructive jaundice successfully treated two-stent implantation. Bleeding occurred in 3 patients, 1 case of benign stenosis using stent occurred displacement , Obstruction occurred in 4 patients, and 2 of them received the second metal pyloric stent. The average survival time of obstruction patient with malignant was 2.5 months. Conclusion No chance of surgical treatment or refuse surgery patients because of some causes gastric outlet obstruction can effectively remove the obstruction and improve patients quality of life.

  1. Endovascular Gene Delivery from a Stent Platform: Gene- Eluting Stents.

    Science.gov (United States)

    Fishbein, Ilia; Chorny, Michael; Adamo, Richard F; Forbes, Scott P; Corrales, Ricardo A; Alferiev, Ivan S; Levy, Robert J

    A synergistic impact of research in the fields of post-angioplasty restenosis, drug-eluting stents and vascular gene therapy over the past 15 years has shaped the concept of gene-eluting stents. Gene-eluting stents hold promise of overcoming some biological and technical problems inherent to drug-eluting stent technology. As the field of gene-eluting stents matures it becomes evident that all three main design modules of a gene-eluting stent: a therapeutic transgene, a vector and a delivery system are equally important for accomplishing sustained inhibition of neointimal formation in arteries treated with gene delivery stents. This review summarizes prior work on stent-based gene delivery and discusses the main optimization strategies required to move the field of gene-eluting stents to clinical translation.

  2. Airport and superficial femoral artery obstruction due to a wandering coronary stent: the possibility of airport detection of modern implant metals.

    Science.gov (United States)

    Teijink, J A W; van Herwaarden, J A; van den Berg, J C; Overtoom, T C; Moll, F L

    2004-06-01

    In the treatment of coronary artery disease, peripheral loss of a coronary stent is an unusual complication. We present the case of a patient who suggested that his right leg claudication was caused by a slipped coronary stent 2 years previously. The patient was convinced about this unusual finding based on an airport security check. Examination proved him to be right. However, the ability to detect an object using eddy currents is dependent on the object's permeability and its conductivity. Ferrous (iron) content is not the critical factor. Modern implant materials and processing techniques result in implants that are difficult to magnetize i.e. their permeability is very low. In addition their conductivity is very low. This enables modern implants to escape detection at airports. For this reason the event at the airport, as described by our patient, is considered coincidental.

  3. Self-expanding Metallic Stent Placement for Colonic Stoma Stenosis:Case Report%自扩张金属支架置入治疗结肠造口狭窄1例

    Institute of Scientific and Technical Information of China (English)

    于俊秀; 赵传林; 张彦波; 成红刚

    2016-01-01

    [Summary] In October 2015, a patient presented colonic stoma stenosis after laparoscopic rectal surgery for cancer , which led to intestinal obstruction .After repeated finger dilation therapy which turned to be ineffective , a self-expandable metal stent was implanted in the colonic stoma .The colonic stoma stenosis and intestinal obstruction was relieved on the next day .The stent was removed 3 weeks later .After 3 months of follow-up, no occurrence of colonic stoma stenosis was observed .%2015年10月,1例腹腔镜直肠癌切除术后患者出现结肠造口狭窄导致肠梗阻,多次手指扩张无效后,经结肠造口置入记忆合金网状支架,狭窄及肠梗阻第2天解除,3周后去除支架,随访3个月未见狭窄复发。支架置入术应成为治疗结肠造口狭窄的首选方法。

  4. Trimming of a Migrated Biliary Nitinol Stent Using Argon Plasma

    Directory of Open Access Journals (Sweden)

    Hiroyuki Matsubayashi

    2009-07-01

    Full Text Available Metallic stent migration is a well-known complication which cannot always be managed by removal or repositioning, especially in case of uncovered stent. We report a patient who developed obstructive jaundice due to migration of an expandable metallic stent (EMS inserted in the lower bile duct. Trimming of the EMS using argon plasma was performed, with the power setting of 60 W and 2.0 l/min of argon flow. The distal part of the EMS was removed and mechanical cleaning using balloon catheter was performed for remnant EMS. Without additional stent insertion, jaundice was relieved in a few days. No complication was recognized during the procedure and no recurrence of jaundice in the rest of his life.

  5. Skirt followed by trouser stenting technique: True anatomical preservation of coronary Y-shaped bifurcation lesions while using "vanishing" bioresorbable scaffolds: A report of two cases.

    Science.gov (United States)

    Elabbassi, Wael; Al Nooryani, Arif

    2016-11-03

    We report on two cases in which Y-shaped coronary bifurcations were treated with the use of Bioresorbable scaffolds. The first case was of a 50-year-old man with NSTEMI. Coronary angiography showed stenosis involving a Y-shaped bifurcation of proximal to mid LAD and diagonal. The lesion was wired using two 0.14 BMW guide wires, followed by serial pre-dilatation of LAD and Diagonal branch. The stent into proximal LAD was deployed first as a skirt (3.5 × 12 BVS). Stent was post-dilated. A second 2.5 × 28 BVS was deployed into diagonal branch, protruding backwards; along with a 2.0 × 15 SC balloon continuing into the mid LAD. Both balloons where pulled back proximally and re-inflated. The technique was repeated in reversed order for stenting the mid LAD using the third BVS (3.0 × 18 BVS). Finally two NC balloons where used to post-dilate both legs of the newly-formed trouser. The result was checked by OCT. The second case was that of a 62-year-old man with chest pain and NSTEMI. He had a history of previous PCI to LCx using bare metal stent. Coronary angiogram showed severe in-stent restenosis in mid LCX, extending into two large obtuse marginal branches. After wiring both OMs, serial pre-dilatation was done with two NC 2.5 × 20 balloons, followed by initial stenting of mid LCx inside old stent, as the proximal segment of bifurcation, using a 3.5 × 12 BVS, followed by implanting a 2.5 × 28 BVS into OM2 and 2.5 × 18 into OM1. At 6 months a clinical follow up via telephone contact revealed no recurrence of chest pain in both cases and no further intervention required.

  6. A novel electrical potential sensing method for in vitro stent fracture monitoring and detection.

    Science.gov (United States)

    Park, Chan-Hee; Tijing, Leonard D; Yun, Yeoheung; Kim, Cheol Sang

    2011-01-01

    This article describes a preliminary investigation and prototype fabrication of a novel potential sensing method to continuously monitor vascular stent fractures. A potential measurement system consisting of Wheatstone bridge circuit and signal conditioning circuit was designed for the cardiovascular stent durability and fatigue test. Each end of a bare and polyurethane-covered Nitinol vascular stent was electrically connected to the potential measurement system and then immersed either in simulated body fluid (SBF) media or distilled water at 36.4 ± 1 °C. When the stent experienced fracture (i.e., a cut), its electrical potential decreased with an increase in electrical resistance. This method successfully measured fractures in the stent regardless of location. Furthermore, the number of cycles at the onset of stent fracture was accurately detected and continuously monitored using this technique. Thus, the present fracture detection method, which to our knowledge is the first ever report to use electrical potential measurement for stent durability test, gives a fast, real-time, accurate and efficient detection of fractures in stent during in vitro fatigue and durability test.

  7. 金属支架用于食管肿瘤局部热疗的温度场数值模拟%Numerical Simulation of Heat Transfer for Esophageal Cancer Hyperthermia with a Heatable Metal Stent

    Institute of Scientific and Technical Information of China (English)

    雷庆春; 乐恺; 张欣欣

    2011-01-01

    Based on the analysis of biological heat transfer process for the esophageal cancer local hyperthermia with metal stent and Pennes bio-heat transfer equation, the three-dimension heat transfer model has been established to calculate the transient temperature distribution using the finite element method. The simulation results were in good agreement with the experimental data from foreign reference. The maximum temperature difference is 0. 7℃. The effects of the heating temperature, blood perfusion rate, and thermal conductivity on temperature distributions have been analyzed, and effects of the key parameters of metal stent on the temperature distribution were discussed. The results showed that the temperatures of tissues as well as thermal penetration depths were rising with the increase of heating temperature, thermal conductivity and the decrease of blood perfusion rate. For instance, when the heating temperature is 48℃ and 50℃ , there will be 1℃ temperature difference in central heating tissue. The stent length and stent diameter influenced on the temperature distribution, however, effect of the stent mesh size could be neglected. The results provided theoretical foundation for clinical trials.%针对金属支架用于食管肿瘤的局部热疗进行生物传热分析,基于Pennes生物传热方程建立肿瘤组织三维传热模型,采用有限元法模拟计算肿瘤组织中的三维温度场,将数值模拟结果与实验数据比较,吻合较好,最大温度差值为0.7℃.讨论加热温度、血液灌注率和导热系数对温度分布的影响,以及金属支架各关键参数对组织温度的影响规律.结果表明,加热温度升高、血液灌注率降低及导热系数增加,都可提高肿瘤组织的温度,增大组织透热深度,如在加热温度分别为50及48°C时,加热中心组织温度将会相差1℃.支架的长度和直径对组织中的温度分布有较大影响,但支架网格大小对温度分布的影响不大.研

  8. Biomechanical Challenges to Polymeric Biodegradable Stents.

    Science.gov (United States)

    Soares, Joao S; Moore, James E

    2016-02-01

    Biodegradable implants have demonstrated clinical success in simple applications (e.g., absorbable sutures) and have shown great potential in many other areas of interventional medicine, such as localized drug delivery, engineered tissue scaffolding, and structural implants. For endovascular stenting and musculoskeletal applications, they can serve as temporary mechanical support that provides a smooth stress-transfer from the degradable implant to the healing tissue. However, for more complex device geometries, in vivo environments, and evolving load-bearing functions, such as required for vascular stents, there are considerable challenges associated with the use of biodegradable materials. A biodegradable stent must restore blood flow and provide support for a predictable appropriate period to facilitate artery healing, and subsequently, fail safely and be absorbed in a controllable manner. Biodegradable polymers are typically weaker than metals currently employed to construct stents, so it is difficult to ensure sufficient strength to keep the artery open and alleviate symptoms acutely while keeping other design parameters within clinically acceptable ranges. These design challenges are serious, given the general lack of understanding of biodegradable polymer behavior and evolution in intimal operating conditions. The modus operandi is mainly empirical and relies heavily on trial-and-error methodologies burdened by difficult, resource-expensive, and time-consuming experiments. We are striving for theoretical advancements systematizing the empirical knowledge into rational frameworks that could be cast into in silico tools for simulation and product development optimization. These challenges are evident when one considers that there are no biodegradable stents on the US market despite more than 30 years of development efforts (and currently only a couple with CE mark). This review summarizes previous efforts at implementing biodegradable stents, discusses the

  9. Renal Artery Stent Outcomes

    Science.gov (United States)

    Murphy, Timothy P.; Cooper, Christopher J.; Matsumoto, Alan H.; Cutlip, Donald E.; Pencina, Karol M.; Jamerson, Kenneth; Tuttle, Katherine R.; Shapiro, Joseph I.; D’Agostino, Ralph; Massaro, Joseph; Henrich, William; Dworkin, Lance D.

    2016-01-01

    BACKGROUND Multiple randomized clinical trials comparing renal artery stent placement plus medical therapy with medical therapy alone have not shown any benefit of stent placement. However, debate continues whether patients with extreme pressure gradients, stenosis severity, or baseline blood pressure benefit from stent revascularization. OBJECTIVES The study sought to test the hypothesis that pressure gradients, stenosis severity, and/or baseline blood pressure affects outcomes after renal artery stent placement. METHODS Using data from 947 patients with a history of hypertension or chronic kidney disease from the largest randomized trial of renal artery stent placement, the CORAL (Cardiovascular Outcomes in Renal Atherosclerotic Lesions) study, we performed exploratory analyses to determine if subsets of patients experienced better outcomes after stent placement than the overall cohort. We examined baseline stenosis severity, systolic blood pressure, and translesion pressure gradient (peak systolic and mean) and performed interaction tests and Cox proportional hazards analyses for the occurrence of the primary endpoint through all follow-up, to examine the effect of these variables on outcomes by treatment group. RESULTS There were no statistically significant differences in outcomes based on the examined variables nor were there any consistent nonsignificant trends. CONCLUSIONS Based on data from the CORAL randomized trial, there is no evidence of a significant treatment effect of the renal artery stent procedure compared with medical therapy alone based on stenosis severity, level of systolic blood pressure elevation, or according to the magnitude of the transstenotic pressure gradient. (Benefits of Medical Therapy Plus Stenting for Renal Atherosclerotic Lesions [CORAL]; NCT00081731) PMID:26653621

  10. Drug-eluting stents to prevent stent thrombosis and restenosis.

    Science.gov (United States)

    Im, Eui; Hong, Myeong-Ki

    2016-01-01

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

  11. Shrinking the Supply Chain for Implantable Coronary Stent Devices.

    Science.gov (United States)

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

    2016-02-01

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

  12. Implanted central venous catheter-related acute superior vena cava syndrome: management by metallic stent and endovascular repositioning of the catheter tip

    Energy Technology Data Exchange (ETDEWEB)

    Qanadli, S.D.; Mesurolle, B.; Sissakian, J.F.; Chagnon, S.; Lacombe, P. [Service de Radiologie, Hopital Ambroise Pare, 92 - Boulogne (France)

    2000-08-01

    We describe a case of a 49-year-old woman with stage-IIIB lung adenocarcinoma who experienced an acute superior vena cava syndrome related to an implanted central venous catheter without associated venous thrombosis. The catheter was surgically implanted for chemotherapy. Superior vena cava syndrome appeared after the procedure and was due to insertion of the catheter through a subclinical stenosis of the superior vena cava. Complete resolution of the patient's symptoms was obtained using stent placement and endovascular repositioning of the catheter tip. (orig.)

  13. Nanomaterial coatings applied on stent surfaces.

    Science.gov (United States)

    Bagheri, Mahsa; Mohammadi, Marzieh; Steele, Terry Wj; Ramezani, Mohammad

    2016-05-01

    The advent of percutaneous coronary intervention and intravascular stents has revolutionized the field of interventional cardiology. Nonetheless, in-stent restenosis, inflammation and late-stent thrombosis are the major obstacles with currently available stents. In order to enhance the hemocompatibility of stents, advances in the field of nanotechnology allow novel designs of nanoparticles and biomaterials toward localized drug/gene carriers or stent scaffolds. The current review focuses on promising polymers used in the fabrication of newer generations of stents with a short synopsis on atherosclerosis and current commercialized stents, nanotechnology's impact on stent development and recent advancements in stent biomaterials is discussed in context.

  14. Fully covered self-expanding metal stents in the management of difficult common bile duct stones Prótesis metálicas autoexpandibles totalmente recubiertas en el tratamiento de coledocolitiasis difíciles

    Directory of Open Access Journals (Sweden)

    Jesús García-Cano

    2013-01-01

    Full Text Available Background and objectives: plastic biliary stents are often used after an ERCP session without complete common bile duct stones (CBDS extraction. Sometimes, the volume of biliary drainage with these stents may be insufficient. We present our experience with the use of fully covered self-expanding metal stents (FCSEMS in the setting of incomplete CBDS extraction. Patients and methods: after an ERCP session with difficult CBDS not completely removed, biliary FCSEMS (Wallflex were inserted in some patients when it was deemed that biliary sphincterotomy and a single plastic stent would not provide an adequate drainage. Results: a retrospective study was performed. Biliary FCSEMS were inserted in 29 patients, mean age 81 years. CBDS could not be extracted through a biliary sphincterotomy due to its large size (n = 18 or because of the presence of inflammatory distal strictures (n = 11. The greatest biliary drainage with shortest ERCP time was considered mandatory due to clinical instability of patients and/or poor tolerance to conscious sedation administered by the endoscopist. Successful biliary drainage was obtained in all cases. FCSEMS were removed after a median of 199.5 days in 16 patients with a complete CBDS extraction in 15 (93.7%. FCSEMS were not removed in the remaining 13 patients due to their clinical condition, and a wait-and-see strategy was undertaken. Conclusions: in selected cases, utilization of removable FCSEMS can be a good option for a quick and adequate biliary drainage in the setting of difficult CBDS. Because of the higher cost of these stents its use needs to be individualized.Introducción y objetivos: las prótesis biliares plásticas suelen emplearse tras una sesión de CPRE sin extracción completa de coledocolitiasis. En ocasiones, el calibre de drenaje con estas prótesis puede ser insuficiente. Presentamos nuestra experiencia en la utilización de prótesis metálicas autoexpandibles totalmente recubiertas (PMATR en

  15. Matrix methods for bare resonator eigenvalue analysis.

    Science.gov (United States)

    Latham, W P; Dente, G C

    1980-05-15

    Bare resonator eigenvalues have traditionally been calculated using Fox and Li iterative techniques or the Prony method presented by Siegman and Miller. A theoretical framework for bare resonator eigenvalue analysis is presented. Several new methods are given and compared with the Prony method.

  16. Fire testing of bare uranium hexafluoride cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Pryor, W.A. [PAI Corp., Oak Ridge, TN (United States)

    1991-12-31

    In 1965, the Oak Ridge Gaseous Diffusion Plant (ORGDP), now the K-25 Site, conducted a series of tests in which bare cylinders of uranium hexafluoride (UF{sub 6}) were exposed to engulfing oil fires for the US Atomic Energy Commission (AEC), now the US Department of Energy (DOE). The tests are described and the results, conclusions, and observations are presented. Two each of the following types of cylinders were tested: 3.5-in.-diam {times} 7.5-in.-long cylinders of Monel (Harshaw), 5.0-in.-diam {times} x 30-in.-long cylinders of Monel, and 8-in.-diam {times} 48-in.-long cylinders of nickel. The cylinders were filled approximately to the standard UF{sub 6} fill limits of 5, 55, and 250 lb, respectively, with a U-235 content of 0.22%. The 5-in.- and 8-in.-diam cylinders were tested individually with and without their metal valve covers. For the 3.5-in.-diam Harshaw cylinders and the 5.0-in.-diam cylinder without a valve cover, the valves failed and UF{sub 6} was released. The remaining 6 cylinders ruptured explosively in time intervals ranging from about 8.5 to 11 min.

  17. Fire testing of bare uranium hexafluoride cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Pryor, W.A. [PAI Corp., Oak Rige, TN (United States)

    1991-12-31

    In 1965, the Oak Ridge Gaseous Diffusion Plant (ORGDP), now the K-25 Site, conducted a series of tests in which bare cylinders of uranium hexafluoride (UF{sub 6}) were exposed to engulfing oil fires for the US Atomic Energy Commission (AEC), now the US Department of Energy (DOE). The tests are described and the results, conclusions, and observations are presented. Two each of the following types of cylinders were tested: 3.5-in.-diam {times} 7.5-in.-long cylinders of Monel (Harshaw), 5.0-in.-diam {times} 30-in.-long cylinders of Monel, and 8-in.-diam {times} 48-in.-long cylinders of nickel. The cylinders were filled approximately to the standard UF{sub 6} fill limits of 5, 55, and 250 lb, respectively, with a U-235 content of 0.22%. The 5-in.- and 8-in.-diam cylinders were tested individually with and without their metal valve covers. For the 3.5-in.-diam Harshaw cylinders and the 5.0-in.-diam cylinder without a valve cover the valves failed and UF{sub 6} was released. The remaining cylinders ruptured explosively in time intervals ranging from about 8.5 to 11 min.

  18. Bare strange quark stars formation and emission

    CERN Document Server

    Xu, R X

    2002-01-01

    Recent achievements of bare strange stars are briefly reviewed. A nascent protostrange star should be bare because of strong mass ejection and high temperature after the supernova detonation flame, and a crust can also hardly form except for a super-Eddington accretion. The magnetosphere of a bare strange star is composed mainly of electron-positron pair plasma, where both inner and outer vacuum gaps work for radio as well as high energy nonthermal emission. A featureless thermal spectrum is expected since no ion is above the quark surface, whilst electron cyclotron lines could appear in some bare strange stars with suitable magnetic fields. Various astrophysical implications of bare strange stars are discussed.

  19. Potentially fatal haemobilia due to inappropriate use of an expanding biliary stent

    Institute of Scientific and Technical Information of China (English)

    Rakesh Rai; John Rose; Derek Manas

    2003-01-01

    AIM: To highlight the fatal complication caused by expanding biliary stents and the importance of avoiding use of expanding stent in potentially curable diseases.METHODS: Arteriobiliary fistula is an uncommon cause of haemobilia. We describe a case of right hepatic artery pseudoaneurysm causing arteriobiliary fistula and presenting as severe malena and cholangitis, in a patient with a mesh metal biliary stent. The patient had lymphoma causing bile duct obstruction.RESULTS: Gastroduodenoscopy failed to establish the exact source of bleeding and hepatic artery angiography and selective embolisation of the pseudo aneurysm successfully controlled the bleeding.CONCLUSION: Bleeding from the pseudo aneurysm of the hepatic artery can be fatal. Mesh metal stents in biliary tree can cause this complication as demonstrated in this case.So mesh metal stent insertion should be avoided in potentially benign or in curable conditions. Difficulty in diagnosis and management is discussed along with the review of the literature.

  20. Behaviour of implantable coronary stents during magnetic resonance imaging.

    Science.gov (United States)

    Friedrich, Matthias G; Strohm, Oliver; Kivelitz, Dietmar; Gross, Werner; Wagner, Anja; Schulz-Menger, Jeanette; Liu, Xiaomeng; Hamm, Bernd

    1999-01-01

    BACKGROUND: Magnetic resonance imaging (MRI) becomes more and more a routine diagnostic tool in clinical cardiology. In patients undergoing MRI, metallic implants may be harmful by motion or heating under certain circumstances. Many cardiac patients have implanted intracoronary stents. However, the safety of these metallic implants and especially their temperature behaviour during MRI has not been sufficiently tested. METHODS: This study investigated motion and temperature changes of 14 different stents for intracoronary application in two clinical scanners at field strengths of 1.0 and 1.5 T. At 1.5 T these studies were repeated after implantation of the stents into the coronary arteries of excised porcine hearts. Furthermore, the clinical status of 33 patients was assessed after a cardiac MR study and compared with a group of 33 patients matched for age, sex and risk factors for restenosis. RESULTS: No visible motion of the stents was observed. Furthermore, using a highly sensitive infrared camera any significant heating of the stents during MRI could be excluded. The rate of clinical events was not different in patients after MRI as compared with the control group. CONCLUSION: It is concluded that MRI is safe in patients with the currently available intracoronary stents.

  1. Heating of cardiovascular stents in intense radiofrequency magnetic fields.

    Science.gov (United States)

    Foster, K R; Goldberg, R; Bonsignore, C

    1999-01-01

    We consider the heating of a metal stent in an alternating magnetic field from an induction heating furnace. An approximate theoretical analysis is conducted to estimate the magnetic field strength needed to produce substantial temperature increases. Experiments of stent heating in industrial furnaces are reported, which confirm the model. The results show that magnetic fields inside inductance furnaces are capable of significantly heating stents. However, the fields fall off very quickly with distance and in most locations outside the heating coil, field levels are far too small to produce significant heating. The ANSI/IEEE C95.1-1992 limits for human exposure to alternating magnetic fields provide adequate protection against potential excessive heating of the stents.

  2. The expression of p16,p53 induced by metallic biliary stent in canine%犬胆管金属支架诱导p16、p53基因扩增的实验研究

    Institute of Scientific and Technical Information of China (English)

    毛晓楠; 卢再鸣; 郭启勇; 温锋; 梁宏元; 刘兆玉

    2009-01-01

    Objective To explore the value of the metallic biliary stents in inducing the expression of anti-oncogenes.Methods The biliary stents were implanted in the inferior segments of CBD after a percutaneous transhepatic puncture at cholecyst in 24 dogs.After a generally observing time of half a year,the median abdominal incisions were made on the dogs under general anesthesia and the bile duet wall covered by the stents(group Ⅰ) and uncovered(group Ⅱ) were cut respectively.The expression of p16、p53、p15、Bcl-2 and K-ras in bile duct wall were detected by RT-PCR,and the positive rates of these gene expression were calculated.The differences between the two groups were analyzed by chi-spuare test for the statistics.Results The animal models were successfully set in 20 of 24 dogs.The positive rates of p16,p53 gene expression were 80% (16/20),45% (9/20) in the bile duct wall covered by the stents and 15% (3/20),0% in the bile duet wall uncovered respectively,there were significant differences between the two groups(X~2=16.94,9.17 ,P<0.05).The positive rates of p15,Bcl-2 and K-ras gene expression were 60% (12/20),100% (20/20),0% in the bile duct wail covered by the stents and 70% (14/20),100% (20/20),0% in the bile duct wall uncovered,there were no significant differences between the two groups (P>0.05).Conclusion The enhancement of p16,p53 gene expression have some correlations with the implantation of metallic biliary stents.The biliary stenting is strongly recommended for the patients with malignant obstructive jaundice when no contraindications exist.%目的 探讨胆道金属支架在诱导抑癌基因扩增方面的价值.方法 健康成年实验犬24只,采用经皮经肝穿刺胆囊的方法于犬胆总管下段植入支架1枚,术后正常喂养平均半年,再次麻醉后活体开腹取支架覆盖段胆管壁与支架上段胆管壁组织,通过逆转录聚合酶链反应(RT-PCR)方法检测所取组织p16、p53、p15、Bcl-2及K-ras基因的表达

  3. Role of self expandable stents in management of colorectalcancers

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    Acute malignant colorectal obstruction is a complicationof colorectal cancer that can occur in 7%-29% of patients. Self-expanding metallic stent placement formalignant colorectal obstruction has gained popularity asa safe and effective procedure for relieving obstruction.This technique can be used in the palliation of malignantcolorectal obstruction, as a bridge to elective surgery forresectable colorectal cancers, palliation of extracolonicmalignant obstruction, and for nonmalignant etiologiessuch as anastomotic strictures, Crohn's disease, radiationtherapy, and diverticular diseases. Self-expandingmetallic stent has its own advantages and disadvantagesover the surgery in these indications. During the insertionof the self-expanding metallic stent, and in the followup,short term and long term morbidities should be keptin mind. The most important complications of the stentsare perforation, stent obstruction, stent migration, andbleeding. Additionally, given the high risk of perforation,if a patient is treated or being consideredfortreatmentwithantiangiogenic agents such as bevacizumab, it isnot recommended to use self-expanding metallic stentas a palliative treatment for obstruction. Therefore, thereis a need for careful clinical evaluation for each patientwho is a candidate for this procedure. The purpose ofthis review was to evaluate self-expanding metallic stentin the management of the obstruction of the colon dueto the colorectal and extracolonic obstruction.

  4. Impacted calculus within a urethral stent: A rare cause of urinary retention

    Directory of Open Access Journals (Sweden)

    Shanmugasundaram Rajaian

    2011-01-01

    Full Text Available An elderly male presented to the emergency department with acute urinary retention. He had poor flow of urine associated with serosanguinous discharge per urethra for 3 days duration. Earlier he underwent permanent metallic urethral stenting for post TURP bulbar urethral stricture. Plain X-ray of Pelvis showed an impacted calculus within the urethral stent in bulbar urethra. Urethrolitholapaxy was done with semirigid ureteroscope. Urethral stent was patent and well covered. Subsequently he had an uneventful recovery. We describe a unique case of acute urinary retention due to calculus impaction within a urethral stent.

  5. Percutaneous transhepatic recanalization of malignant hilarobstruction: A possible rescue for early failure of endoscopic y-stenting

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Hoon; Kim, Chang Won; Lee, Tae Hong; Kim, Dong Uk [Pusan National University School of Medicine, Pusan National University Hospital, Busan (Korea, Republic of); Jeon, Ung Bae; Kang, Dae Hwan [Pusan National University School of Medicine, Yangsan Pusan National University Hospital, Yangsan (Korea, Republic of)

    2013-11-15

    Endoscopic biliary stenting is well known as an optimal method of management of malignant hilar obstruction, but sometimes the result is not satisfactory, with early stent failure. Percutaneous transhepatic biliary drainage (PTBD) has a distinct advantage over endoscopic retrograde cholangiopancreatoscopy in that with ultrasound guidance one or more appropriate segments for drainage can be chosen. We evaluated the effectiveness of percutaneous transhepatic stenting as a rescue of early failure of endoscopic stenting. Ten patients (4 men, 6 women; age range, 52-78 years; mean age, 69 years) with inoperable biliary obstruction (2 patients with gall bladder cancer and hilar invasion, and 8 patients with Klatskin tumor) and with early endoscopic stent failure were included in our study. All of the patients underwent PTBD and percutaneous transhepatic biliary stenting. Metallic stents were placed in all patients for internal drainage. Percutaneous rescue stenting was successful in all the patients technically and clinically. Mean time for the development of biliary obstruction was 13.5 days after endoscopic stenting. The mean patency of the rescue stenting was 122 days. The mean survival time for percutaneous transhepatic rescue stenting was 226.3 days. In early failure of endoscopic biliary stenting, percutaneous transhepatic recanalization can be a possible solution.

  6. Strut thickness effect on restenosis of Multi-Link and Tri-Star stenting

    Institute of Scientific and Technical Information of China (English)

    Honin Kanaya

    2003-01-01

    @@ Background Increased thrombegenicity and smooth muscle cell proliferative response induced by the metal struts compromise the advantages of coronary stenting. Adnan Kastrati et al. reported in the ISAR-STEREO trial that a reduced strut thickness of coronary stent is associated with improved follow up angiographic and clincal results.

  7. Transradial artery Palmaz-Schatz coronary stent implantation: results of a single-center feasibility study.

    Science.gov (United States)

    Kiemeneij, F; Laarman, G J

    1995-07-01

    The purpose of this study was to evaluate the feasibility and safety of implantation of unsheathed Palmaz-Schatz coronary stents introduced via the radial artery. Anticoagulation after coronary stenting carries the risk of vascular complications if large-bore guiding catheters are introduced via the femoral artery. These complications have serious local sequelae and lead to suboptimal anticoagulation and prolonged hospitalization. By combining 6F guiding catheters and low-profile dilatation catheters mounted with Palmaz-Schatz stents, smaller vessels such as the radial artery can be selected as the entry site. It is hypothesized that with this technique major puncture site-related complications rarely occur because hemostasis is easily achieved and because no veins and nerves are near this artery. With the double blood supply to the hand, radial artery occlusion is well tolerated. In 100 consecutive patients, stent implantation was attempted for 122 lesions in 104 vessels. Immediately after stent implantation and final angiography, the introducer sheath was withdrawn and intense anticoagulation and mobilization initiated. The radial artery puncture site was studied by two-dimensional and Doppler ultrasound. Successful stent implantation via the radial artery was achieved in 96 patients. In 2 patients, arterial puncture failed but was followed by successful stenting via another entry site. In 1 patient, stent implantation was achieved with a stent delivery system via the femoral artery after a failed attempt to cross the lesion with a bare stent via the radial approach, complicated by groin bleeding requiring transfusions and vascular surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Novel oesophago-gastro-duodenal stenting for gastric leaks after laparoscopic sleeve gastrectomy.

    Science.gov (United States)

    Liu, Shirley Yuk-Wah; Wong, Simon Kin-Hung; Ng, Enders Kwok-Wai

    2015-01-01

    The management of gastric leak after laparoscopic sleeve gastrectomy (LSG) can be complex and challenging. Whilst operative interventions are mostly complicated and reserved for unstable or refractory cases, endoscopic self-expandable metal stenting (SEMS) is increasingly preferred as a safer treatment option. Yet, SEMS carries the problems of frequent stent migration and inconsistent healing as ordinary SEMS is designed mainly for stenotic disease. We hereby present two cases of early and chronic post-LSG leakage that were respectively failed to be treated by surgery and ordinary SEMS but were successfully managed by a dedicated extra-long oesophago-gastro-duodenal stent. In oesophago-gastro-duodenal stenting, the characteristics of extra-long stent length allow total gastric exclusion between the mid-oesophagus and the first part of duodenum to prevent stent migration and to equalise high pressure gradient within the gastric sleeve to promote fistula healing.

  9. Complications and the management of fully covered retrievable metal stent placement in benign tracheal stenosis%可回收全覆膜金属支架治疗良性气管狭窄的并发症及处理

    Institute of Scientific and Technical Information of China (English)

    王征宇; 王永利; 陈光利; 梁熙虹; 王振常; 马建中; 吴广忠; 张效平

    2012-01-01

    Objective To study complications and the management of the use of covered retrievable expandable metallic stents in the treatment of benign tracheal stenosis.Methods Fully covered retrievable metal stents were placed in 21 patients with benign tracheal stenosis.Stent-related complications and the management were reviewed and analysised.Results 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 (FEV1) 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].Conclusion Fully covered retrievable metallic stent may be a safe and effective in benign tracheal stenosis.Stent-related complications may be effectively managed.%目的 探讨可回收全覆膜金属支架治疗良性气管狭窄的并发症及处理方法.方法 可回收全覆膜金属支架治疗良性气管狭窄患者21例,其中男18例,女3例,年龄16~ 65岁,平均年龄(33±15)岁,回顾总结分

  10. Biological safety evaluation of 125I-filled carbon nanotubes covered with metallic esophageal stent%125I碳纳米管覆膜金属支架生物安全性的实验研究

    Institute of Scientific and Technical Information of China (English)

    董生; 袁正; 李文新; 吴胜伟

    2011-01-01

    Objective To evaluate the biological safety of 125I-filled carbon nanotubes covered with metallic esophageal stent with regard to the normal esophagus before clinical application.Methods 125I-filled carbon nanotubes covered with metallic esophageal stent was prepared.Eighteen of New Zealand rabbits were randomly divided into three groups with 6 rabbits in each group.Three groups of stents,non-radioactive,low radio-activity ( 3.7 - 5.6 MBq),and high activity ( 11.1 - 13.0 MBq ) were placed in the midpiece of esophagus of rabbits.Esophagus opacification and three-diamensions DSA were performed at 0.5 h,7,14 and 30 d after insertion of the stents,respectively.The rabbits were killed at 30d after insertion of the stents,and histologic examinations of the esophageal walls were performed.Results In non-radioactive and low activity groups,1 of 6 rabbits died of wound infection at 1 and 3 d after surgery due to pulmonary infection,respectively.All specimens were obtained from 16 rabbits.Microscopically,in all rabbits of low activity and high activity groups,there were membrana mucosa necrotic and swell and breakage of the muscle fiber in esophageal submucosa and muscularis,submucosal inflammation,which were more severe in high activity group.In low activity group,one esophagus ectal membrane was involved,however,esophageal perforation did not develop.In high activity group,3 of 6rabbits esophageal perforation had developed,in which one esophagus mediastinum fistula developed,without inflammation.In non-radioactive group,it was almost normal in mucosa layer,a small amount of inflammatory cells were found in submucosal layer,and part of muscle fibers was fractured and no pathological changes of necrosis was found.Conclusions Radioactive 125I carbon nanotubes covered metallic stent with low activity(3.7 -5.6 MBq) can be used as intraluminal palliative brachytherapy,which is safe and effective.%目的 探讨125I碳纳米管覆膜金属支架对兔正常

  11. The location of obstruction predicts stent occlusion in malignant gastric outlet obstruction

    Science.gov (United States)

    Grunwald, Douglas; Cohen, Jonah; Bartley, Anthony; Sheridan, Jennifer; Chuttani, Ram; Sawhney, Mandeep S.; Pleskow, Douglas K.; Berzin, Tyler M.; Mizrahi, Meir

    2016-01-01

    Background: Gastric outlet obstruction (GOO) can occur with locally invasive or metastatic cancer involving the upper gastrointestinal tract at the pylorus or the duodenum. Endoscopic management with self-expanding metal stents (SEMSs) is often the preferred palliative approach. Stent occlusion is a common reason for failure and reintervention. We set out to determine whether the location of the malignant obstruction is associated with the angulation of the stent and can predict stent occlusion. Methods: We performed a retrospective review of consecutive patients who underwent successful duodenal stenting with SEMS for malignant GOO between 2006 and 2015 at a large advanced endoscopy referral center. We determined the location of obstruction, the stent angle, and the rate of technical and clinical success of stent placement. We then identified cases of subsequent stent occlusion confirmed by endoscopic evaluation. Results: A total of 100 consecutive patients were included in the study; 91 of these patients had enough data to evaluate SEMS occlusion. A total of 21 patients (23%) developed stent occlusion with a median time of 39 days. The risk of occlusion sequentially increased as the obstruction occurred more distally from the antrum to the third or fourth portion of the duodenum (p = 0.006). This relationship was maintained after controlling for stent angle (p = 0.05). Conclusions: A distal location of malignant GOO was strongly predictive of stent occlusion, independent of stent angle. This may be due to longer and more complex distal obstructions, along with foreshortening of the stent during placement and tumor infiltration. If replicated, these results will have implications for endoscopic practice and future device development. PMID:27803736

  12. Long-term effects of forgotten biliary stents: a case series and literature review

    Science.gov (United States)

    Odabasi, Mehmet; Arslan, Cem; Akbulut, Sami; Abuoglu, Haci Hasan; Ozkan, Erkan; Yildiz, Mehmet Kamil; Eris, Cengiz; Gunay, Emre; Tekesin, Kemal; Muftuoglu, Tolga

    2014-01-01

    There are many studies about the biliary stents, however there is a little information about the long-term stayed forgotten biliary stents except a few case reports. We have reported the results of a number of cases with biliary stents that were forgotten or omitted by the patient and the endoscopist. During February 2010 to May 2013, five patients were referred to the general surgery clinic of Haydarpasa Numune Training and Research Hospital, Istanbul Turkey. Past history and medical documents submitted by the patient did not indicate a replacement of the biliary stent in 3 patients. Two patients knew that they had biliary stents. We also conducted a literature review via the PubMed and Google Scholar databases of English language studies published until March 2014 on forgotten biliary stent. There were 3 men and 2 women ranging in age from 22 to 68 years (mean age 41.6 years). Patients presented with pain in the upper abdomen, jaundice, fever, abnormal liver function tests or dilatation of the biliary tract alone or in combination. Patients’ demographic findings are presented in Table 1. A review of three cases reported in the English medical literature also discussed. The mean duration of the patency of the stent is about 12 months. The biliary stenting is performed either with plastic or metal stents, studies recommending their replacement after 3-6 months. Patients with long stayed forgotten biliary stents are inevitably treated with surgical intervention. We recommend for all endoscopic retrograde cholangiopancreatography units provide a stent registry system that the stents placed for various therapeutic procedures are not forgotten both by the patient as well as the physician. There should be a deadline for biliary stents in the registry system for each patient. PMID:25232385

  13. 全覆膜与非覆膜金属支架治疗胆道恶性梗阻随机对照研究%Covered versus uncovered self-expandable metal stents for malignant biliary obstruction: a randomized, controlled study

    Institute of Scientific and Technical Information of China (English)

    冀明; 王拥军; 李鹏; 吕富靖; 李巍; 张澍田

    2012-01-01

    目的 比较全覆膜金属支架与非覆膜金属支架治疗胆道恶性梗阻的有效性和安全性.方法 2010年10月至2012年8月无法手术根治性切除胆道恶性梗阻病例,随机分为两组,A组置入全覆膜金属支架,B组置入非覆膜金属支架,观察治疗效果及并发症情况.结果 共入组81例患者,其中A组41例,B组40例,两组均成功置入支架,达到有效引流目的.A组支架开放中位时间182.5 d,B组支架开放中位时间195.0 d,两组间支架开放时间差异无统计学意义(P=0.616).A组发生并发症3例(7.3%),B组发生4例(10%).结论 全覆膜金属支架与非覆膜金属支架治疗胆道恶性梗阻均安全有效,通畅时间相似.%Objective To compare therapeutic efficacy and safety of covered and uncovered self-expandable metal stents for malignant biliary obstruction.Methods From October 2010 to August 2012,patients with unresectable malignant biliary obstruction were recruited and divided into 2 groups to receive covered metal stents (group A) or uncovered metal stents (group B).Efficacy and complication of the procedure were compared.Results A total of 81 patients were recruited,with 41 in group A and 40 in group B.Stents were placed successfully in all patients.The median patency time of stent in group A was 182.5 d,which was not significantly different from that of group B (195.0 d,P =0.616).Complications occurred in 3 patients of group A (7.3%) and 4 of group B (10%).Conclusion Covered and uncovered metal stents are both safe and effective for treatment of malignant biliary obstruction with same patency time.

  14. 多聚紫杉醇洗脱支架与裸金属支架治疗复杂冠心病患者的比较随机对照试验%Comparison of a Polymer-Based Paclitaxel-Eluting Stent With a Bare Metal Stent in Patients With Complex Coronary Artery Disease A Randomized Controlled Trial

    Institute of Scientific and Technical Information of China (English)

    Gregg W. Stone; Jeffrey J. Popma; Joerg Koglin; Mary E. Russell; 倪永斌; 孙艺红; Stephen G. Ellis; Louis Cannon; J. Tift Mann; Joel D. Greenberg; Douglas Spriggs; Charles D O' Shaughnessy; Samuel DeMaio; Patrick Hall

    2006-01-01

    背景:与裸金属支架相比,药物洗脱支架可降低非复杂病变的再狭窄发生率.尚未在复杂狭窄病变中评价药物洗脱支架的应用情况.目的:在比既往试验更复杂的患者人群中研究多聚缓释紫杉醇洗脱支架的安全性和效果.设计、地点及参试者:于2003年2月至2004年3月在66家大学和社区医疗机构进行前瞻性、安慰剂对照、双盲、多中心试验.1 156例患者接受了单支冠状动脉狭窄(血管直径,2.25~4.0 mm;病变长度,10~46 mm)支架植入治疗,包括664例(57.4%)患有复杂或既往未曾研究的病变(需要2.25mm、4.0 mm和/或多个支架),并于9个月时进行临床和血管造影随访.干预:患者随机分配接受1个或多个裸金属支架(n=579)或者外观相同的紫杉醇洗脱支架(n=577).主要观测指标:9个月时因缺血而需要靶血管血运重建.结果:基线特征匹配良好.糖尿病患者占31%.平均(SD)参照血管直径为2.69(0.57)mm,参照病变长度为17.2(9.2)mm,B2/C型病变占78%.每个病变平均植入1.38(0.58)个支架(总平均长度[SD],28.4[13.1]mm);需要多个支架的病变占33%.使用直径2.25 mm和4.0 mm支架的病变分别为18%和17%.与裸金属支架相比,紫杉醇洗脱支架可使9个月靶病变血运重建率从15.7%降至8.6%(P<0.001),靶血管血运重建率从17.3%降至12.1%(P=0.02).心源性死亡或心肌梗死(裸金属支架5.5%,紫杉醇洗脱支架5.7%)和支架血栓形成发生率两者类似(两组均为0.7%).在整个研究队列,血管造影再狭窄从33.9%降至18.9%(P<0.001),包括采用2.25 mm支架(49.4%比31.2%;P=0.01)、4.0mm支架(14.4%比3.5%;P=0.02)和多个支架(57.8%比27.2%;P<0.001)的患者.结论:与裸金属支架相比,在有复杂病变的患者人群中植入紫杉醇洗脱支架可有效降低临床和血管造影再狭窄的发生率.

  15. Use of fully covered self-expanding metal stents for the management of benign biliary conditions Utilización de prótesis metálicas autoexpandibles totalmente recubiertas en procesos biliares benignos

    Directory of Open Access Journals (Sweden)

    J. García-Cano

    2010-09-01

    Full Text Available Background and aim: biliary self-expanding metal stents (SEMS have the advantage of being inserted undeployed with very small sizes and provide, when fully opened, large diameters for biliary drainage. However, their use in benign conditions has been very limited, mainly because of difficulty in their extraction. We present our initial experience with a fully covered SEMS (Wallflex for the management of benign problems of the bile duct. Patients and methods: in a prospective study, stents of 8 mm in diameter and 4, 6 or 8 cm long were inserted by means of ERCP. These SEMS were chosen when according to medical judgement it was thought that diameters greater than 10 French (3.3 mm were needed for proper biliary drainage. Stents were extracted also endoscopically, several months later when deemed clinically appropriate. Results: twenty biliary SEMS were inserted. Reasons for insertion were: large intrahepatic biliary fistula after hydatid cyst surgery (1, perforation of the papillary area following endoscopic sphincterotomy (2, coaxial insertion to achieve patency in obstructed uncovered stents inserted in benign conditions (3, benign strictures (7, multiple and large common bile duct stones that could not be extracted because of tapering and stricturing of the distal common bile duct (7. In all cases, successful biliary drainage was achieved and there were no complications from insertion. Stents were easily extracted after a mean time of 132 days (36-270 in place. Complete resolution of biliary problems was obtained in 14 patients (70%. Conclusions: in our initial experience, the fully covered Wallflex biliary stent was removed without any complication after being in place in the common bile duct for a mean time of over four months. Therefore, it could be used in the management of benign biliary conditions.Introducción y objetivo: las prótesis metálicas autoexpandibles biliares (PMAB tienen la ventaja de introducirse plegadas con calibres muy

  16. Endoscopic stenting-Where are we now and where can we go?

    Institute of Scientific and Technical Information of China (English)

    Mark Terence McLoughlin; Michael Francis Byrne

    2008-01-01

    Self expanding metal stents (SEMS) play an important role in the management of malignant obstructing lesions in the gastrointestinal tract.Traditionally,they have been used for palliation in malignant gastdc outlet and colonic obstruction and esophageal malignancy.The development of the polyflex stent,which is a removable self expanding plastic stent,allows temporary stent insertion for benign esophageal disease and possibly for patients undergoing neoadjuvant chemotherapy prior to esophagectomy.Potential complications of SEMS insertion include perforation,tumour overgrowth or ingrowth,and stent migration.Newer stents are being developed with the aim of increasing technical and clinical success rates,while reducing complication rates.Other areas of development include biodegradable stents for benign disease and radioactive or drug-eluting stents for malignant disease.It is hoped that,in the future,newer stents will improve our management of these difficult conditions and,possibly,provide prognostic as well as symptomatic benefit in the setting of malignant obstruction.

  17. Comparing coronary stent material performance on a common geometric platform through simulated bench testing.

    Science.gov (United States)

    Grogan, J A; Leen, S B; McHugh, P E

    2012-08-01

    Absorbable metallic stents (AMSs) are a newly emerging cardiovascular technology which has the potential to eliminate long-term patient health risks associated with conventional permanent stents. AMSs developed to date have consisted of magnesium alloys or iron, materials with inferior mechanical properties to those used in permanent stents, such as stainless steel and cobalt-chromium alloys. However, for AMSs to be feasible for widespread clinical use it is important that their performance is comparable to modern permanent stents. To date, the performances of magnesium, iron, and permanent stent materials have not been compared on a common stent platform for a range of stent performance metrics, such as flexibility, radial strength, and recoil. In this study, this comparison is made through simulated bench testing, based on finite-element modelling. The significance of this study is that it allows potential limitations in current AMS performance to be identified, which will aid in focusing future AMS design. This study also allows the identification of limitations in current AMS materials, thereby informing the on-going development of candidate biodegradable alloys. The results indicate that the AMSs studied here can match the recoil characteristics and radial strength of modern permanent stents; however, to achieve this, larger strut dimensions are required. It is also predicted that the AMSs studied are inferior to permanent stents in terms of maximum absolute curvature and longitudinal stiffness.

  18. Endovascular stent placement in the treatment of upper extremity central venous obstruction in hemodialysis patients

    Energy Technology Data Exchange (ETDEWEB)

    Aytekin, Cueneyt E-mail: cuneytaytekin@hotmail.com; Boyvat, Fatih; Yagmurdur, Mahmut Can; Moray, Goekhan; Haberal, Mehmet

    2004-01-01

    Objective: To evaluate the efficacy of stent placement for treating upper extremity central venous obstruction in chronic hemodialysis patients. Methods and Material: Between January 1999 and October 2001, we inserted metallic stents into the upper extremity central veins of 14 patients with shunt dysfunction and/or arm swelling. The indications for stent placement were stenosis or occlusion of the central vein in the upper extremity used for dialysis. Six of the individuals were diagnosed with subclavian vein stenosis, and 5 with brachiocephalic vein stenosis. Of the remaining 3 patients, 2 had subclavian vein occlusion, and 1 had left brachiocephalic vein occlusion. Results: All the stent placement procedures were technically successful, and there were no major complications. Follow-up ranged from 2 weeks to 29 months. The 1-, 3-, 6- and 12-month primary stent patency rates were 92.8, 85.7, 50 and 14.3%, respectively. Repeat interventions, including percutaneous transluminal angioplasty and additional stent placement, were required in 9 patients. The 3-, 6-, 12-month, and 2-year assisted primary stent patency rates were 100, 88.8, 55.5 and 33.3%, respectively. Conclusion: Endovascular stent placement is an effective alternative to surgery in patients with shunt dysfunction due to obstruction of an upper extremity central vein. Repeated interventions are usually required to prolong stent patency.

  19. Neoatherosclerosis:Coronary stents seal atherosclerotic lesions but result in making a new problem of atherosclerosis

    Institute of Scientific and Technical Information of China (English)

    Hidenori; Komiyama; Masamichi; Takano; Noritake; Hata; Yoshihiko; Seino; Wataru; Shimizu; Kyoichi; Mizuno

    2015-01-01

    Chronic inflammation of the native vessel wall with infiltration of lipid-laden foamy macrophages through impaired endothelium results in atherosclerosis. Percutaneous coronary intervention, including metallic stent implantation, is now widely utilized for the treatment of atherosclerotic lesions of the coronary artery. Baremetal stents and the subsequently developed drugeluting stents seal the atherosclerosis and resolve lumen stenosis or obstruction of the epicardial coronary artery and myocardial ischemia. After stent implantation, neointima proliferates within the stented segment. Chronic inflammation caused by a foreign body reaction to the implanted stent and subsequent neovascularization, which is characterized by the continuous recruitment of macrophages into the vessel, result in the transformation of the usual neointima into an atheromatous neointima. Neointima with an atherosclerotic appearance, such as that caused by thin-cap fibroatheromas, is now recognized as neoatherosclerosis, which can sometimes cause in-stent restenosis and acute thrombotic occlusion originating from the stent segment following disruption of the atheroma. Neoatherosclerosis is emerging as a new coronary stent-associated problem that has not yet been resolved. In this review article, we will discuss possible mechanisms, clinical challenges, and the future outlook of neoatherosclerosis.

  20. The virtual histology intravascular ultrasound appearance of newly placed drug-eluting stents.

    Science.gov (United States)

    Kim, Sang-Wook; Mintz, Gary S; Hong, Young-Joon; Pakala, Rajbabu; Park, Kyung-Sook; Pichard, Augusto D; Satler, Lowell F; Kent, Kenneth M; Suddath, William O; Waksman, Ron; Weissman, Neil J

    2008-11-01

    Intravascular ultrasound (IVUS) is used before and after intervention and at follow-up to assess the quality of the acute result as well as the long-term effects of stent implantation. Virtual histology (VH) IVUS classifies tissue into fibrous and fibrofatty plaque, dense calcium, and necrotic core. Although most interventional procedures include stent implantation, VH IVUS classification of stent metal has not been validated. In this study, the VH IVUS appearance of acutely implanted stents was assessed in 27 patients (30 lesions). Most stent struts (80%) appeared white (misclassified as "calcium") surrounded by red (misclassified as "necrotic core"); 2% appeared just white, and 17% were not detectable (compared with grayscale IVUS because of the software-imposed gray medial stripe). The rate of "white surrounded by red" was similar over the lengths of the stents; however, undetectable struts were mostly at the distal edges (31%). Quantitatively, including the struts within the regions of interest increased the amount of "calcium" from 0.23 +/- 0.35 to 1.07 +/- 0.66 mm(2) (p stents have an appearance that can be misclassified by VH IVUS as "calcium with or without necrotic core." It is important not to overinterpret VH IVUS studies of chronically implanted stents when this appearance is observed at follow-up. A separate classification for stent struts is necessary to avoid these misconceptions and misclassifications.

  1. Effect of force-induced mechanical stress at the coronary artery bifurcation stenting: Relation to in-stent restenosis

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-05-28

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

  2. 覆膜与非覆膜胆道金属支架治疗恶性胆道梗阻的临床观察%Clinical observation of the treatment for malignant biliary obstruction with plastic film coated and non coated metal stents

    Institute of Scientific and Technical Information of China (English)

    梁凯伦; 孙大勇

    2015-01-01

    Objective To compare the clinical results of coated and non coated metallic biliary stents in patients with malignant biliary obstruction. Methods One hundred and twenty six patients with malignant bil-iary obstruction were treated with coated stents (59 cases) and non coated stents (67 cases) under endoscopy. The intubation success rate, therapeutic efficacy, survival time, stent patency time and complications rate were analyzed and compared. Results The intubation success rates were 100%in both two groups. The overall drainage rates、pancreatitis rates and cholecystitis rates in coated and non coated groups were 96.6%vs 94.0%(P>0.05), 13.6%vs 1.5%(P0.05). The median stent patency time was 368 days in the coated group, and 190 days in the non coated group(P0.05)、13.6%vs 1.5%(P<0.05)、11.9%vs 1.5%(P<0.05)。覆膜组和无膜组的中位生存时间分别为389 d和372 d(P<0.05),中位支架通畅时间分别为368 d和190 d(P<0.05)。结论胆道金属支架可解除中下段胆总管恶性梗阻,延长患者生存时间。覆膜金属支架通畅时间明显优于非覆膜金属支架,术后胰腺炎和胆囊炎发生率均明显高于非覆膜金属支架。

  3. 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.

  4. Study on therapeutic significance of endoscopic self-expandable metal stents implantation in treatment of right-side colonic obstruction ;due to colonic cancer%结肠自膨胀金属支架治疗右半结肠癌性梗阻的疗效研究

    Institute of Scientific and Technical Information of China (English)

    周艳华; 李鹏; 冀明; 张澍田

    2016-01-01

    Objective To explore the therapeutic significance of endoscopic self-expandable metal stent implantation in treatment of right-side colonic obstruction caused by colonic cancer. Methods The clinical data of 17 patients with right-side colonic obstruction due to co-lonic cancer underwent stent implantation during January 2010 to April 2016 were retrospectively analyzed. Results Self -expandable metal stents were successfully implanted in 16 patients,and the symptoms of colonic obstruction had effectively been alleviated. The technical successful rate was 94. 1%(16/17),and the clinical successful rate was 100%(16/16). Colonic stent implantation in 3 cases(18. 75%)had been per-formed as a bridge to elective surgery in 3-15 days later,the other 13 cases(81. 25%)had been placed colonic stents for palliative treatment. There was no complications of colonic perforation,bleeding or stent migration occurred,but the reccurrence of colonic obstruction had been hap-pened in 3 cases(23. 1%)within 3 to 6 months after stent placement. There was no death within 3 months except one died of respiratory failure caused by tuberculosis in 9 days after the stent implantation. Conclusion The endoscopic implantation of self-expandable metal stent in treat-ment of right-side colonic obstruction due to colonic cancer is effective and safe. .%目的:探讨结肠自膨胀金属支架置入术对右半结肠癌性梗阻的治疗价值。方法对2010年1月至2016年4月因右半结肠癌肠梗阻行结肠金属支架置入术的17例病例进行回顾性分析。结果16例患者成功置入结肠支架,术后肠梗阻有效缓解,结肠支架术的技术成功率为94.1%,技术成功者的临床成功率为100%;其中3例(18.75%)于支架后3~15天行手术治疗,13例(81.25%)行结肠支架作为姑息治疗。所有患者术中及术后均未出现结肠穿孔、出血、支架移位的并发症,3例(23.1%)于支架治疗后3~6个月再发肠梗阻。随访9

  5. Feasibility of application of anti-reflux metallic stent for malignant biliary obstruction%抗反流金属支架用于胆道恶性梗阻的可行性研究

    Institute of Scientific and Technical Information of China (English)

    王田田; 胡冰; 潘亚敏; 时之梅; 王书智; 陆蕊; 黄慧; 王淑萍

    2010-01-01

    目的 评价抗反流金属支架用于非肝门部胆道恶性梗阻的安全性和有效性.方法 对符合标准的2007年8月至2009年4月诊断为胆总管下段或中段恶性梗阻的患者采用抗反流金属支架进行治疗,记录操作成功率,随访观察早期并发症、支架通畅期和生存期.结果 共有23例无法切除的非肝门部胆道恶性梗阻的患者被纳入研究,均一次性成功置入抗反流金属支架,操作难度与普通自膨式金属支架(SEMS)大致相当,无操作相关并发症.22例患者完成随访,其中20例患者血清总胆红素水平在术后1个月内降至正常水平.有6例患者在随访期内发生支架失效,其中肿瘤组织长入支架腔内1例、超出支架端部2例、支架移位3例;其余患者至随访终点或死亡均未出现胆道症状.抗反流金属支架的中位通畅期为14个月,第3、6和12个月的支架通畅率分别为95.1%、74.2%和55.9%;患者的生存期为1~14个月,平均7.9个月,在术后第3、6和12个月的生存率分别为91.0%、81.3%和17.2%.结论 应用抗反流金属支架治疗低位胆道恶性梗阻在技术上是可行的,并且是安全和有效的.%Objective To evaluate the safety and efficacy of a newly designed anti-reflux metallic stent (ARMS) for malignant extra-hepatic biliary obstruction. Methods A total of 23 patients with unresectable biliary malignancy in the middle or lower part of common bile duct underwent endoscopic retrograde cholangiopancreatography (ERCP) and ARMs placement. The success rate, early complications, stent patency and patients' survival were recorded. Results The ARMSs were successfully placed in all patients and no procedure-related complication was recorded. The average operation time was similar to that of self-expanding metallic stents (SEMs). In 22 patients completing the follow-up, the total serum bilirubin dropped to normal within one month in 20. ARMs dysfunction occurred in 6, including tumor in

  6. Angioplasty and stent - heart - discharge

    Science.gov (United States)

    Drug-eluting stents - discharge; PCI - discharge; Percutaneous coronary intervention - discharge; Balloon angioplasty - discharge; Coronary angioplasty - discharge; Coronary artery angioplasty - discharge; Cardiac ...

  7. Sirolimus-eluting cobalt-chromium stents: two-year clinical results from first-in-man study on the Firebird 2TM stent

    Institute of Scientific and Technical Information of China (English)

    Xu Bo; LI Jian-ping; CHEN Ji-lin; HUO Yong; GAO Run-lin; SHEN Wei-feng; ZHANG Qi; YANG Yue-jin; QIAO Shu-bin; ZHANG Rui-yan; ZHANG Jian-sheng; HU Jian; QIN Xue-wen; HONG Tao

    2008-01-01

    Background Drug-eluting stents(DES)have been shown to significantly reduce clinical events and angiographic restenosis in the treatment of coronary artery disease(CAD).This study was conducted to assess the long-term efficacy and safety of the polymer-based sirolimus-eluting cobalt-chromium Firebird 2TM stents in the treatment of patients with CAD.Methods This first-in-man study using the Firebird 2TM stent is a prospective,historically-controlled multicenter clinical study,which enrolled 67 patients with CAD who were treated with the sirolimus-eluting cobalt-chromium stent(Firebird 2TM,Microport Shanghai,Firebird 2 group),compared to another 49 patients treated with a bare cobalt alloy stent(Driver,Medtronic,control group).Continued 2-year clinical follow-up was performed after getting the initial 6-month angiographic and 1-year clinical follow-up.The incidence of major adverse cardiac events(MACE)including cardiac death,reinfarction and target lesion revascularization(TLR)and stent thrombosis were compared between the two groups.Results All patients in the Firebird 2 group(100.0%)and 48 patients in the control group(98.O%)completed the 2-year clinical follow-up.At the 1-year follow-up the use of the Firebird 2 stent was highly effective,resulting in a significant 94% decrease of TLR (26.5%in the control group and 1.5%in the Firebird 2 group,P<0.0001).A significant difference in TLR was maintained at 2-year follow-up,Firebird 2 group 1.5%and the control group 31.3%(P<0.0001).Between 1-and 2-year post-stenting.no more TLR occurred in the Firebird 2 group compared with two cases in the control group (P>0.05).There was a 1.5%incidence of MACE at 1-and 2-year follow-up in the Firebird 2 group,compared with 26.5% and 33.3%in the control group,respectively(all P<0.0001).The cumulative 1-and 2-year MACE free survival rates were 98.5%in the Firebird 2 group vs 73.5%and 66.7% in the control group (log rank P<0.0001).No case of stent thrombosis occurred during 2

  8. Membrana-covered Esophageal Self-expanding Metallic Stent for Malignant Esophageal Stricture and Tracheoesophageal Fistula%自膨式食管金属加膜支架治疗恶性食管狭窄和气管食管瘘

    Institute of Scientific and Technical Information of China (English)

    徐怀阳; 钟竑; 陆善伟; 赵华

    2011-01-01

    目的:探讨自膨式食管金属加膜支架治疗恶性食管狭窄和气管食管瘘的疗效和并发症.方法:2004年1月至2009年6月对63例恶性食管狭窄和气管食管瘘患者实施食管支架置入,男45例,女28例;年龄45~81岁,平均69.3岁.支架为MTN型形状记忆钛镍合金食管加膜支架(南京微创医学科技有限公司生产),支架植入均在DSA监视下操作完成.结果:63例均一次性放置成功,即刻口服造影通过顺利剂.结论:自膨式食管金属加膜支架是治疗恶性食管狭窄和气管食管瘘的有效方法.%Objective: To explore the effect and complication of membrana-covered esophageal self-expanding metallic stent in the treatment of malignant esophageal stricture and tracheoesophageal fistula.Methods: From January 2004 to June 2009, 63 patients(45 males and 28 females), aged from 45 to 81 years old with an average age of 69.3, suffering from malignant esophageal stricture or tracheoesophageal fistula were treated by esophageal stent deployment under DSA monitoring.The esophageal stent was a kind of MTN typed shape memory Titanium stent covered with membrane (Made in Nanjing minimally invasive medicial Technology Co.,Ltd).Results: Stent implantation was successful in all the 63 patients during their first deployment.Immediately, oral contrast material could be swallowed through the esophagus smoothly.Concultion: Membrana-covered esophageal self-expanding metallic stent implantation is an effective and safe method for the treatment of malignant esophageal stricture and tracheoesophageal fistula.

  9. Nasal packing and stenting

    Directory of Open Access Journals (Sweden)

    Weber, Rainer K.

    2009-01-01

    Full Text Available Nasal packs are indispensable in ENT practice. This study reviews current indications, effectiveness and risks of nasal packs and stents. In endoscopic surgery, nasal packs should always have smooth surfaces to minimize mucosal damage, improve wound healing and increase patient comfort. Functional endoscopic endonasal sinus surgery allows the use of modern nasal packs, since pressure is no longer required. So called hemostatic/resorbable materials are a first step in this direction. However, they may lead to adhesions and foreign body reactions in mucosal membranes. Simple occlusion is an effective method for creating a moist milieu for improved wound healing and avoiding dryness. Stenting of the frontal sinus is recommended if surgery fails to produce a wide, physiologically shaped drainage path that is sufficiently covered by intact tissue.

  10. Carotid artery stenting: which stent for which lesion?

    Science.gov (United States)

    Bosiers, Marc; Deloose, Koen; Verbist, Jürgen; Peeters, Patrick

    2005-01-01

    The different geometries and working principles of carotid stents (nitinol or cobalt chromium, open- or closed-cell configuration) provide each product with unique functional properties. The individual characteristics of each device may make it an attractive choice in one circumstance but render it less desirable in other situations. In approximately 75% of all procedures, all types of stents will achieve similar outcomes, making adequate device selection unnecessary. For the remaining quarter, careful preoperative screening is mandatory. In addition to eventual access issues, the choice of the optimal carotid stent depends mainly on arterial anatomy and lesion morphology. When treating a tortuous anatomy, stents with a flexible and comformable open-cell configuration are preferred. In arteries with a significant mismatch between common carotid artery and internal carotid artery diameter, cobalt chromium (Elgiloy) or tapered nitinol stents are selected. Lesions with suspected high emboligenicity are best covered with stents with a closed-cell configuration, whereas highly calcified lesions need treatment with nitinol stents. Thorough knowledge of the characteristics, advantages and disadvantages, and working principles of the different available stents is mandatory to optimally select the materials to be used for patients eligible for carotid revascularization.

  11. Hemodynamics in Idealized Stented Coronary Arteries: Important Stent Design Considerations.

    Science.gov (United States)

    Beier, Susann; Ormiston, John; Webster, Mark; Cater, John; Norris, Stuart; Medrano-Gracia, Pau; Young, Alistair; Cowan, Brett

    2016-02-01

    Stent induced hemodynamic changes in the coronary arteries are associated with higher risk of adverse clinical outcome. The purpose of this study was to evaluate the impact of stent design on wall shear stress (WSS), time average WSS, and WSS gradient (WSSG), in idealized stent geometries using computational fluid dynamics. Strut spacing, thickness, luminal protrusion, and malapposition were systematically investigated and a comparison made between two commercially available stents (Omega and Biomatrix). Narrower strut spacing led to larger areas of adverse low WSS and high WSSG but these effects were mitigated when strut size was reduced, particularly for WSSG. Local hemodynamics worsened with luminal protrusion of the stent and with stent malapposition, adverse high WSS and WSSG were identified around peak flow and throughout the cardiac cycle respectively. For the Biomatrix stent, the adverse effect of thicker struts was mitigated by greater strut spacing, radial cell offset and flow-aligned struts. In conclusion, adverse hemodynamic effects of specific design features (such as strut size and narrow spacing) can be mitigated when combined with other hemodynamically beneficial design features but increased luminal protrusion can worsen the stent's hemodynamic profile significantly.

  12. Intervenção coronária percutânea utilizando Full Metal Jacket com stents farmacológicos: eventos cardíacos adversos maiores em um ano

    Directory of Open Access Journals (Sweden)

    Rita Calé

    2013-08-01

    Full Text Available FUNDAMENTO: O benefício clínico de intervenção coronária percutânea (ICP para lesões coronárias longas é incerto; além disso, foram levantadas dúvidas questões sobre a sua segurança. OBJETIVO: Avaliar os preditores de eventos cardíacos adversos maiores (ECAM associados à ICP utilizando Full Metal Jacket (FMJ, definido como a sobreposição de stents farmacológicos (SF medindo >60 mm de comprimento, para lesões muito longas. MÉTODOS: Foram incluídos 136 pacientes consecutivos com lesões coronárias longas, requerendo FMJ em nosso cadastro de centro único. O desfecho primário incluiu a ocorrência combinada de todas as causas de morte, infarto do miocárdio (IM e revascularização do vaso alvo (RVA. Variáveis demográficas, clínicas, angiográficas e de procedimento foram avaliadas por meio de análise de regressão de Cox para determinar os preditores independentes de desfecho. RESULTADOS: O comprimento médio do stent por lesão foi de 73,2 ± 12,3 mm e o diâmetro médio do vaso de referência foi de 2,9 ± 0,6 mm. O sucesso angiográfico foi de 96,3%. A ausência de ECAM foi de 94,9% em 30 dias e 85,3% em um ano. No acompanhamento de um ano, a taxa de mortalidade por todas as causas foi de 3,7% (1,5% por mortes cardíacas, a taxa de IM foi de 3,7%, e a incidência de trombose de stent (TS definitiva ou provável foi de 2,9%. O gênero feminino [risco relativo (RR, 4,40; intervalo de confiança de 95% (IC, 1,81-10,66, p = 0,001 e ICP de artéria coronária não direita (RR, 3,49; p = 0,006; IC 95%, 1,42-8,59 foram preditores independentes de ECAM em um ano. A ausência de eventos adversos em um ano foi maior em pacientes com angina estável submetidos à ICP (RR, 0,33; IC 95% 0,13-0,80, p = 0,014. CONCLUSÕES: A ICP utilizando FMJ com SF para lesões muito longas foi eficaz, mas associada a uma alta taxa de TS em acompanhamento de um ano. No entanto, a taxa de mortalidade cardíaca, IM não relacionado a procedimento, e

  13. Percutaneous Creation of Bare Intervascular Tunnels for Salvage of Thrombosed Hemodialysis Fistulas Without Recanalizable Outflow

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Matt Chiung-Yu, E-mail: jjychen@gmail.com [Yuan’s General Hospital, Department of Interventional Radiology (China); Wang, Yen-Chi [E-Da Hospital, Department of Radiology (China); Weng, Mei-Jui [Kaohsiung Veterans General Hospital, Department of Radiology (China)

    2015-08-15

    PurposeThis study aimed to retrospectively assess the efficacy of a bare intervascular tunnel for salvage of a thrombosed hemodialysis fistula. We examined the clinical outcomes and provided follow-up images of the bare intervascular tunnel.Materials and MethodsEight thrombosed fistulas lacked available recanalizable outflow veins were included in this study. These fistulas were salvaged by re-directing access site flow to a new outflow vein through a percutaneously created intervascular tunnel without stent graft placement. The post-intervention primary and secondary access patency rates were calculated using the Kaplan–Meier method.ResultsThe procedural and clinical success rates were 100 %. Post-intervention primary and secondary access patency at 300 days were 18.7 ± 15.8 and 87.5 ± 11.7 %, respectively. The mean follow-up period was 218.7 days (range 10–368 days). One patient died of acute myocardial infarction 10 days after the procedure. No other major complications were observed. Minor complications, such as swelling, ecchymosis, and pain around the tunnel, occurred in all of the patients.ConclusionsPercutaneous creation of a bare intervascular tunnel is a treatment option for thrombosed hemodialysis fistulas without recanalizable outflow in selected patients.

  14. Erosion of esophageal stent into left main bronchus causing airway compromise

    Science.gov (United States)

    Aneeshkumar, S; Sundararajan, L; Santosham, Rajan; Palaniappan, Rajkumar; Dhus, Ubal

    2017-01-01

    Covered or uncovered self-expanding metal stents are currently used for the palliative treatment of neoplastic esophageal strictures or compressions and esophageal leaks or fistulas due to malignancies. Erosion of esophageal stents into the respiratory tract is a rare complication and that too has been reported mostly as an early complication within few days or weeks. Here, we present the case of a 31-year-old female, who presented with a late complication of an esophageal stent eroding into the left main bronchus causing respiratory distress. She was stented for a benign corrosive esophageal stricture following caustic soda ingestion 3 years ago. She underwent a thoracotomy and closure of esophagobronchial fistula along with laparoscopic esophagectomy and gastric pull through. Postoperatively, patient developed an anastomotic leak which was corrected by placing a temporary stent. PMID:28144066

  15. Successful Endobronchial stenting for bronchial compression from a massive thoracic aortic aneurysm

    Directory of Open Access Journals (Sweden)

    David Comer

    2010-06-01

    Full Text Available A case of bronchial occlusion caused by a thoracic aortic aneurysm and the relief of this obstruction by the implantation of expandable metallic stents is described. Stent deployment provided an immediate improvement in lung ventilation and chest radiograph appearances. Stent insertion was uncomplicated, but weaning from mechanical ventilation was unsuccessful and the patient died from a ventilator-associated pneumonia, unrelated to the procedure. Endobronchial stenting should be considered as a non-invasive therapy for the treatment of bronchial obstruction, with respiratory compromise, caused by a thoracic aortic aneurysm when vascular surgery is not an option. The medium to long term survival of this patient group is poor. This can be attributed to complications related to the stent and also to the poor performance status of these patients.

  16. Heparin-Coated Coronary Stents.

    Science.gov (United States)

    van Der Giessen WJ; van Beusekom HM; Larsson; Serruys

    1999-09-01

    The development of the heparin-coated (HC)-stent should be viewed against the backdrop of the early unfavorable results with noncoated stents in the pre-intravascular ultrasound and pre-ticlopidine era. Notwithstanding, results of pilot and randomized trials show a surprisingly low incidence of (sub)acute stent thrombosis under challenging circumstances, such as acute coronary syndromes. Considering the quite low incidence of early complications with noncoated second-generation stents, it may require large trials to prove the clinical efficacy of the heparin- coating against noncoated devices. However, even if the "added value" of the heparin-coating will never be clinically proven, it has helped to enhance the penetration of stent therapy in interventional cardiology. Unlike the situation in 1992, very few cardiologists will now disagree with the statement that stents contribute to the state-of-the-art treatment of patients with angina pectoris or acute myocardial infarction. A preliminary comparison of available trials also suggests that the heparin-coated Palmaz-Schatz stent (Cordis Corp., Waterloo, Belgium) is as effective as the noncoated stent plus abciximab treatment.

  17. Development of a New Hanging-Type Esophageal Stent for Preventing Migration: A Preliminary Study in an Animal Model of Esophagotracheal Fistula

    Energy Technology Data Exchange (ETDEWEB)

    Endo, Masayuki, E-mail: masay010@yahoo.co.jp; Kaminou, Toshio, E-mail: kaminout@med.tottori-u.ac.jp; Ohuchi, Yasufumi, E-mail: oyasu@med.tottori-u.ac.jp [Tottori University, Department of Radiology, Faculty of Medicine (Japan); Sugiura, Kimihiko, E-mail: kimihikosugiura@gmail.com [Yonago Medical Center, Department of Radiology (Japan); Yata, Shinsaku, E-mail: yata-s@med.tottori-u.ac.jp; Adachi, Akira, E-mail: july1st@med.tottori-u.ac.jp; Kawai, Tsuyoshi, E-mail: prgr-xxio@kuc.biglobe.ne.jp; Takasugi, Syohei, E-mail: stakasugi@med.tottori-u.ac.jp; Yamamoto, Shuichi, E-mail: yamamotoshu@med.tottori-u.ac.jp; Matsumoto, Kensuke, E-mail: matsumoto-k@v103.vaio.ne.jp [Tottori University, Department of Radiology, Faculty of Medicine (Japan); Hashimoto, Masayuki, E-mail: hashimotom@pref.tottori.jp [Tottori Prefectural Kosei Hospital, Department of Radiology (Japan); Ihaya, Takashi, E-mail: iahaya@orange.ocn.ne.jp [Sanin Rosai Hospital, Department of Radiology (Japan); Ogawa, Toshihide, E-mail: ogawa@med.tottori-u.ac.jp [Tottori University, Department of Radiology, Faculty of Medicine (Japan)

    2012-10-15

    Purpose: Covered, self-expandable metallic stents (SEMS) have been enthusiastically adopted for the treatment of esophagotracheal fistula, but problems with stent migration have yet to be resolved. To overcome this problem, we have developed a new hanging-type esophageal stent designed to prevent migration, and we conducted an animal study to assess the efficacy of our method. Methods: A total of six female pigs were used in this study. The main characteristic of our stent was the presence of a string tied to the proximal edge of the stent for fixation under the skin of the neck. The first experiment was performed to confirm technical feasibility in three pigs with esophagotracheal fistula. The second experiment was performed to evaluate stent migration and esophagotracheal fistula in three pigs. Results: Creation of the esophagotracheal fistula and stent placement were technically successful in all pigs. In the first experiment, esophagotracheal fistula was sealed by stent placement. In the second experiment, no stent migration was seen 11 or 12 days after stent placement. Gross findings showed no fistulas on the esophageal or tracheal wall. Conclusions: Our new hanging-type esophageal stent seems to offer a feasible method for preventing stent migration.

  18. A fully-covered stent (Alimaxx-E) for the palliation of malignant dysphagia: a prospective follow-up study

    NARCIS (Netherlands)

    M.J. Uitdehaag; J.E. van Hooft; E.M.L. Verschuur; A. Repici; E.W. Steyerberg; P. Fockens; E.J. Kuipers; P.D. Siersema

    2009-01-01

    Background: The majority of the Currently available metal stents are partially covered to reduce migration risk. However, one of the remaining issues is tissue ingrowth through the uncovered stent parts. Objective: To determine efficacy, recurrent dysphagia, and complications of a fully covered sten

  19. Follow-up after stent insertion in the tracheobronchial tree: role of helical computed tomography in comparison with fiberoptic bronchoscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ferretti, G.R.; Kocier, M.; Calaque, O.; Coulomb, M. [Service Central de Radiologie et Imagerie Medicale, INSERM EMI 9924, CHU, BP 217, 38043, Grenoble Cedex 9 (France); Arbib, F.; Pison, C. [Departement de Medecine Aigue Specialisee (DMAS), CHU Grenoble, CHU, BP 217, 38043, Grenoble Cedex 9 (France); Righini, C. [Service d' Oto Rhino Laryngologie, CHU Grenoble, BP 217, 38043, Grenoble Cedex 9 (France)

    2003-05-01

    The aim of thi