scholarly journals In Vitro Behavior and Surface Morphology of Modified 316L Stainless Steel Stents

2008 ◽  
Vol 14 (S3) ◽  
pp. 35-36 ◽  
Author(s):  
J. Nunes ◽  
A.P. Piedade ◽  
C.B. Duarte ◽  
M.T. Vieira

When compared with conventional bare metal stents, such as 316L stainless steel, the introduction of drug-eluting stents can promote reduction in the incidence of in-stent restenosis. However, the chemical discrepancy between the metallic stent and the polymeric material that acts as the reservoir for the drug is responsible for some problems during the cardiovascular surgery. Besides the research work aiming at the development of new bulk alloys for stent production, focus as been also directed to the surface modification of these devices. However, the use of functional graded coatings (FGC), i.e., coatings with a gradient of chemical composition between the substrate and the outmost layer, has never been reported in devices for cardiovascular surgery.

2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Akintunde M Akinjero ◽  
Oluwole Adegbala ◽  
Tomi Akinyemiju

Background: In-stent restenosis accounts for major morbidity and mortality among patients treated with Bare-Metal Stents (BMS). Early efforts to treat BMS in-stent restenosis with plain balloon angioplasty and first generation drug eluting stents (DES) have been ineffective, leaving drug-eluting balloon (DEB) and second generation DES, such as everolimus eluting stents (EES), as the only remaining options. For BMS in-stent restenosis, studies performed so far have yielded conflicting results, while prior meta-analyses have been influenced by inclusion of observational studies. This is the first meta-analysis to compare EES versus DEB using results from only randomized controlled trials (RCTs). Methods: A systematic search of PUBMED and EMBASE databases was conducted from first available date to August, 2016 for RCTs comparing DEB with EES. Two reviewers evaluated studies for eligibility and extracted data with binary restenosis rate as the main endpoint. We identified 901 unique citations. Odds ratios were pooled using random-effects modeling. Funnel plots were used to assess publication bias. Heterogeneity was assessed using I 2 statistic. All analysis were performed using Review Manager (RevMan) version 5.3 (Cochrane Collaboration, 2014). Results: Three RCTs met study eligibility criteria, with 684 patients and a mean follow-up of 9.5 months. There were 184 and 185 patients in the EES and DEB arms respectively. In pooled analyses, EES was not superior to DEB in binary restenosis rates (pooled odds ratio: 0.76; 95% confidence interval: 0.25-2.32; P=0.14). Heterogeneity was minimal (I 2 = 49%), and the funnel plot did not suggest publication bias. Conclusion: In patients with BMS in-stent restenosis, there were no significant differences in binary restenosis rates between EES and DEB. Our results can enhance physician decision-making regarding choice of revascularization tool in this patient population.


Author(s):  
Jaya Chandrasekhar ◽  
Adriano Caixeta ◽  
Philippe Généreux ◽  
George Dangas ◽  
Roxana Mehran

Since the inception of percutaneous coronary intervention, restenosis has been considered a significant problem. Although drug-eluting stents (DES) have reduced rates of in-stent restenosis (ISR) compared with bare metal stents across all lesion subsets, ISR has not been abolished. DES efficacy has been limited by suboptimal polymer biocompatibility, efficacy of pharmacological agents, in vivo pharmacokinetic properties, and local drug resistance and toxicity. While the first two DES to be manufactured (sirolimus- and paclitaxel-eluting stents) have the longest clinical follow-up, extensive data are now also available on zotarolimus- and everolimus-eluting stents. The uptake of biolimus-eluting stents has recently increased in clinical practice. Although the low frequency of DES ISR makes it difficult to investigate this condition fully, many studies have examined the mechanism, incidence, predictors, and optimal treatment of DES restenosis. This review discusses the data relevant to DES restenosis and the perspective on the current treatment of this condition.


2019 ◽  
Vol 9 (17) ◽  
pp. 3527 ◽  
Author(s):  
Alexandre Hideo-Kajita ◽  
Samuel Wopperer ◽  
Vinícius Bocchino Seleme ◽  
Marcelo Harada Ribeiro ◽  
Carlos M. Campos

In the treatment of atherosclerotic disease patients, the adoption of second-generation drug-eluting stents (DES) in percutaneous coronary intervention reduced the occurrence of in-stent restenosis (ISR) and acute stent thrombosis (ST) when compared to bare metal stents and 1st generation DES. However, the permanent encaging of the vessel wall by any of the metallic stents perpetuates the inflammation process and prevents vasomotion in the treated segment. Aiming to overcome this issue, the bioresorbable scaffold (BRS) concept was developed by providing transient vascular radial support to the target segment during the necessary time to heal and disappearing after a period of time. Close to 20 years since BRS technology was first reported, the interventional cardiology field saw the rise and fall of several BRS devices. Although iron-based BRS is an emerging technology, currently, magnesium-alloy resorbable scaffolds devices are supported with the most robust data. This manuscript aims to review the concept of magnesium-based BRS devices, as well as their bioresorption mechanisms and the status of this technology, and the clinical outcomes of patients treated with magnesium BRS and to review the available evidence on iron-based BRS technology.


Author(s):  
Saami K. Yazdani ◽  
Qi Cheng ◽  
Debashis Dutta ◽  
Frank D. Kolodgie ◽  
Renu Virmani

Drug-eluting stents (DES) have significantly improved restenosis rates as compared to bare metal stents (BMS), however, an increased risk in late stent thrombosis (LST) has been observed due to delayed healing and incomplete endothelialization. These adverse events have been associated to the high level of anti-proliferative drugs eluted from 1st generation DES, as well as non-erodible polymers that remain intact. The purpose of this study was to fist determine optimal surface modification in vitro and to then assess trends in endothelial coverage and recovery of the modified non-polymeric DES in a rabbit iliac stent model.


2016 ◽  
Vol 4 ◽  
pp. 55-61
Author(s):  
Krzysztof Milewski ◽  
Anna Turek ◽  
Agata Krauze ◽  
Paweł Gąsior ◽  
Aleksandra Błachut ◽  
...  

New generation, drug-eluting stents used in the treatment of coronary and peripheral atherosclerotic disease (CPAD) significantly reduced restenosis and revascularization rates as well as frequency of thrombosis as compared to bare metal stents and first-generation drug eluting stents. However, despite fast development of this technology several reports have been published recently that describe cases of late and very late stent thrombosis, restenosis and neoatheroslerosis within arterial segments with previously implanted stents. For this reason many research are being conducted with the aim to design alternative methods for intra-arterial drugs delivery in order to reduce restenosis and revascularization rates, yet eliminating adverse effects mentioned above. One of possibilities is lipophilic and antiproliferative drug coated balloon technology, which offers high drug concentration in arterial tissue and restenotic effect in selected clinical situations despite the short balloon inflation time. A particularly interesting option is intra-arterial delivery of drugs with different mechanisms of action, regardless of their lipophilicity by loading them into biodegradable nanospheres. In this paper, currently used systems for local drug delivery have been described including their limitations and opportunities. In addition, we provided a brief description of the project sponsored by Polpharma Scientific Foundation, which aimed to evaluate potentials of local delivery of biodegradable nanospheres loaded with everolimus, which could be used to reduce restenosis rate after stent implantation.


2009 ◽  
Vol 103 (4) ◽  
pp. 491-495 ◽  
Author(s):  
Daniel H. Steinberg ◽  
Michael A. Gaglia ◽  
Tina L. Pinto Slottow ◽  
Probal Roy ◽  
Laurent Bonello ◽  
...  

2017 ◽  
Vol 23 (2) ◽  
pp. 180-185 ◽  
Author(s):  
Jun Young Chang ◽  
Hyun Park ◽  
Oki Kwon ◽  
Moon-Ku Han

We have performed stenting in 11 patients with symptomatic vertebral arterial orifice stenosis refractory to medical treatment or impairment in anterior circulation. Three of the 11 patients experienced asymptomatic severe in-stent restenosis or occlusion. Bare metal stents were used in those three patients, two of whom received revascularization therapy. Development of sufficient cervical collateral channels reconstituting the distal vertebral artery was the common feature in patients with asymptomatic in-stent restenosis. In selecting appropriate stents, consideration of mechanical strength and drug-eluting properties of a stent according to characteristics of the target vessel is important to reduce the risk of in-stent restenosis. Any decision to perform revascularization should be based on the presence of abundant cervical collaterals as well as clinical symptoms of vertebrobasilar ischemia.


2010 ◽  
Vol 5 (1) ◽  
pp. 23 ◽  
Author(s):  
Kamal Chitkara ◽  
Anthony Gershlick ◽  
◽  

Drug-eluting stents (DES) have demonstrated their superiority over bare-metal stents (BMS) with respect to in-stent restenosis and the need for repeat revascularisation. BMS and first-generation DES, such as sirolimus-eluting (Cypher®) and paclitaxel-eluting stents (Taxus®), have further improved the results of percutaneous coronary intervention (PCI) by improving early results and reducing the risk of restenosis. However, there is currently a debate as to the safety of these first-generation DES given the potential for late stent thrombosis, especially after discontinuation of dual-antiplatelet therapy. Second-generation DES, such as zotarolimus-eluting (Endeavor®) and everolimus-eluting stents (Xience V®), have recently become available in the US and Europe. The available data already suggest the superiority of the Xience V stent in comparison with the Taxus stent in terms of prevention of restenosis, without significant untoward events. Nonetheless, the number of patients studied and the follow-up duration are still too limited to enable definitive conclusions. This systematic review aims to provide a concise and critical appraisal of the available data to compare first- and second-generation stents.


Sign in / Sign up

Export Citation Format

Share Document