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The effectiveness of cardiovascular stenting procedure depends on the crimping and expansion characteristics of a stent, influenced by its design parameters. In this study, CoCr stents are fabricated, crimped on a tri-folded balloon, and expanded using manual inflation device. Similarly, in the finite element model, a tri-folded balloon is used to expand the stent. The length and diameter are measured to evaluate the radial strength, recoil, foreshortening, and dogboning. The simulation and experimental results match satisfactorily. The validated FE model can be used with confidence to optimize future stent designs, thus reducing the number of testing and product development time.

Objectives We present a first-in-man clinical use of a new hybrid design stent in stenosed large vessels. Its unique C and S polylinks prevent foreshortening without compromising its strength. Its thin profile permits use of smaller introducer sheaths. Background Stent angioplasty is widely employed in large vessel and conduit stenosis. These procedures are associated with difficulties due to large stent profiles, stent fractures, foreshortening and recoil. Cobalt chromium stents have high tensile strengths compared to stainless steel stents. Methods A retrospective analysis of feasibility and safety of a new Cobalt chromium stent in large vessels namely aorta, pulmonary arteries and outflow conduits was done from two institutions. Demographic patient details, procedural results, complications and medium term follow-up were analyzed. Stent recoil, foreshortening, fractures were assessed. Results Twenty patients including three with aortic coarctations, seven with stenosed conduits and 10 with pulmonary artery stenosis underwent stent angioplasty using 23 stents. Three stents were deployed to expand further a previously implanted stent. Procedure was successful in all patients, lumen increased by 150-300%, gradients reduced in all patients. There was no stent recoil, foreshortening or fractures. There were no complications. At a follow up of 3-27 months, there were no stent related complications and the gradients remained stable. Conclusions The new Zephyr stent was useful in a wide variety of stenotic lesions involving large vessels including those that were previously stented. Lack of stent recoil and foreshortening seems to be an advantage for this new stent that needs validation in larger multicenter studies.

Aims The natural course of post-procedural incomplete strut apposition (ISA) after the implantation of bioresorbable scaffolds (BVS) remains unknown. The purpose of the present study was to evaluate the fate of post-procedural ISA after everolimus-eluting Absorb BVS in comparison with the second-generation everolimus-eluting cobalt chromium stent (CoCr-EES). Methods and results Fate of post-procedural ISA was evaluated by serial optical coherence tomography (OCT) in the ABSORB Japan randomized trial [OCT-1 subgroup: 110 paired lesions of post-procedure and 2-year follow-up (BVS 73 lesions vs. CoCr-EES 37 lesions)] with respect to ISA distance. Post-procedure ISA struts were categorized into either 'resolved' or 'persistent' by matched OCT imaging at 2-year follow-up. Post-procedure % malapposed strut and ISA area were smaller in BVS than in CoCr-EES (% malapposed strut: 4.8 +/- 6.9% vs. 9.9 +/- 9.8%, P = 0.002; ISA area 0.10 +/- 0.18 mm(2) vs. 0.23 +/- 0.26 mm(2), P = 0.003). At 2-year follow-up, the difference diminished, and majority of the ISA struts spontaneously resolved in both arms (% malapposed strut: 0.10 +/- 0.46% vs. 0.24 +/- 0.65%, P = 0.183). Receiver operating characteristic curve analysis (BVS 661 struts vs. CoCr-EES 807 struts) demonstrated that the best cut-off value of endoluminal ISA distance post-procedure for predicting persistent-ISA at 2-year follow-up was 396 mu m for BVS (sensitivity 0.875; specificity 0.851) and 359 mu m for CoCr-EES (sensitivity 0.778; specificity 0.881). Conclusion BVS as compared with CoCr-EES allows larger ISA distance at post-procedure, although we should make every effort to minimize post-procedure ISA. The reported cut-off value of OCT-estimated ISA distance at post-stenting for predicting persistent-ISA would be helpful to optimize PCI with BVS and CoCr-EES

Purpose: The aim of this trial was to assess the feasibility and safety of endothelial progenitor cells capture (EPC) stent in the treatment of acute ST-elevation myocardial infarction (STEMI) when compared with cobalt-chromium stents (CoCr). Methods: Between July 2006 and May 2008, 100 patients with single vessel disease undergoing primary PCI for STEMI were randomly assigned to receive either EPC stent (N = 50) or CoCr stent (N = 50). High-pressure stent implantation was carried out in both groups. Dual antiplatelet treatment was administered for 30 days in both groups. All patients underwent 6-month clinical, angiographic, and IVUS follow-up. Results: The rate of major adverse cardiovascular events (MACEs) at 30 days was comparable in both groups. At 6-month follow-up, the rates of MACEs and TLR in the EPC stent group when compared with CoCr stent were 24% vs.10%; P = 0.06 and 14% vs. 4%; P = 0.08, respectively. There were three cases (6%) of stent thrombosis (ST) in the EPC stent group versus none in CoCr group. Conclusion: The use of EPC capture stents in the setting of STEMI is feasible and safe in terms of 30-days outcome. However, at the 6-month follow-up, we found a trend of higher rates of MACE and TLR in the EPC stent capture group compared to CoCr stents. The study does not support the use of EPC capture stents with short duration dual antiplatelet therapy in patients with STEMI. Future randomized studies with large sample sizes would be necessary to demonstrate the safety of such approach. © 2010 Wiley-Liss, Inc.

Stent expansion remains one of important predictors of restenosis and subacute thrombosis, even in use of drug-eluting stent. In addition, the bioresorbable vascular scaffold requires sufficient lesion preparation for their appropriate apposition. The aim of this study was to clarify the impact of

Introduction: Rapamycin and its analogs are now being coated on different stent platforms, using different polymer matrices to prevent restenosis by impairing vascular smooth muscle cell proliferation and neointimal formation. Methods: We evaluated the feasibility and compared the efficacy of biostable polymeric everolimus and sirolimus (CYPHER®, Cordis) eluting stents in a porcine coronary model. Cobalt chromium balloon expandable stents (ML VISION®, Guidant) were coated with a polymer containing everolimus (190 μg/cm2). Twelve pigs underwent placement of 36 oversized sirolimus (n = 12), everolimus (n = 12), and bare metal (cobalt chromium, n = 12) stents in the coronary arteries. Results: At day 28, vessel injury scores were low (

Background: Second generation bare metal stents made of cobalt chromium alloy are superior to first generation stain less steel stents. The thin struts are shown to reduce clinical and angiographic adverse outcomes. Objective: To study the long term clinical and angiographic outcomes in patients who underwent coronary angioplasty with an indigenously made cobalt chromium bare metal stents with thin strut Cobal+C™ (Relisys). Methods: A total of 268 consecutive patients who underwent coronary angioplasty with Cobal+C stents were studied retrospectively. Clinical follow up was done after a minimum period of nine months through telephonic interview and angiographic follow up was done in 80 patients chosen randomly. The end points analyzed included major adverse cardiac events (MACE) at nine months and the rate of binary restenosis at follow up angiogram done between 9 and 15 months post angioplasty. Results: Thirty four percent were diabetic and 33% had acute myocardial infarction. Females constituted 17%. Mean stent diameter was 2.88 ± 0.28 and mean stent length 18.8 ± 4.2. MACE at nine months was 4.5% with TLR 0.3%. The rate of binary restenosis was 21%. Patients with longer stent lengths and non-compliance with medications had significantly higher rates of binary restenosis. Conclusions: The use of Relisys Cobal+C stents was associated with good long term clinical and angiographic outcomes as evidenced by low incidence of MACE and binary restenosis rates for a bare metal stent.

Prolonged dual antiplatelet therapy (DAPT) after coronary stent implantation is associated with higher risk for bleeding. Second-generation drug-eluting stents (G2-DES), cobalt-chromium everolimus-eluting stent (CoCr-EES) in particular, are reported to have lower risk for stent thrombosis (ST)

Background Dedicated IVUS analyses of the second CObalt chromium STent with Antiproliferative for Restenosis (COSTAR II) trial have not been documented. We aim to compare IVUS findings between CoStar paclitaxel-eluting stent (PES) and Taxus PES in patients enrolled in the COSTAR II trial. We also attempted to examine the possible regional impact of multiple stenting. Methods and materials Among the 1700 patients enrolled, 238 were assigned to an IVUS cohort including 168 patients treated by provisional multiple stenting. At 9 months, qualitative and quantitative IVUS observations including incomplete stent apposition (ISA) and neointimal proliferation (neointimal obstruction: neointimal volume/stent volume ×100) were compared between CoStar and Taxus PESs. Results In qualitative analysis, late-acquired ISA was observed in 1 patient treated by Taxus PES. Impaired strut continuity suggestive of stent fracture was observed in 2 out of 33 patients treated by multiple CoStar, and 4 out of 21 patients treated by multiple Taxus ( P =.14). No such findings were found in single-stented patients in either stent subset. Quantitative analysis showed greater neointimal obstruction in CoStar (19.7%±13.4%, n =52) than in Taxus (10.7%±9.9%, n =38), whereas no significant difference in neointimal obstruction was found between single and multiple stenting in either CoStar or Taxus PES. Conclusions The CoStar PES exhibits greater neointimal proliferation compared with Taxus PES at 9 months but with similar qualitative outcomes including late-acquired ISA. IVUS findings suggestive of stent fracture were found only in multiple-stenting cases irrespective of the stent used.

Aim To report clinical follow-up at 6 months after implantation of the ultra-thin strut cobalt chromium SolarFlex 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 sites in Europe were enrolled in the SOLSTICE (SolarFlex Stent in Routine Clinical Practice) registry. Follow-up at 6 months was 100 %. Diabetes was present in 29 % of the patients, 30 % presented with acute myocardial infarction and 17 % had unstable angina. Of the patients, 27 % had previously undergone PCI or coronary artery bypass surgery. Lesion complexity was high (50 % B2 + C type lesions). Device success was achieved in 99.7 % of cases and the major adverse cardiac event (MACE) rate was 5.8 % at 6 months of follow-up. Target lesion revascularisation (TLR) was 5.0 % at 6 months. Conclusions The SOLSTICE registry showed that in a complex real-world setting the SolarFlex bare metal stent, with ultra-thin struts and customised scaffolding, provided low clinical MACE and TLR rates. These results provide support for the use of the latest generation bare metal stent in contemporary European practice.

The effect of current generation cobalt–chromium stents on neointimal proliferation has not been fully elucidated. IVUS images of 137 patients treated with a single thin-strut cobalt–chromium stent (Driver: DRI, n =74) or stainless steel stent (Multilink plus: ML, n =63) were selected. Although % neointima volume (neointimal volume divided by stent volume) were comparable, DRI showed significantly smaller maximum %cross-sectional narrowing (%CSN: neointimal area divided by stent area) ( P =0.006) with significantly less %CSN>60 (percent stent length with %CSN>60%) than ML ( P =0.04). In conclusion, the amount of neointimal hyperplasia after DRI implantation was comparable to that after ML. However, current generation cobalt–chromium DRI may show less and shorter severe narrowing than the stainless steel ML.

The management of renal artery stenosis (RAS) remains controversial. While some evidence suggests that treatment with stent placement is beneficial, randomized trials have failed to demonstrate a significant benefit. Ongoing clinical trials should help to better define the role for stenting of RAS while avoiding limitations seen with earlier trials. When it comes to stenting for RAS, several stents have been used; however, many stents which have been used previously and which are still being used are biliary stents that are used "off-label." These stents have typically come onto the market through the 510(k) pathway. To date, a total of five stents have been approved by the United States Food and Drug Administration for use in the renal arteries. Of the five stents that have received approval, the Bridge™ Extra Support (Medtronic Cardio- Vascular, Santa Rosa, CA) and the Palmaz(®) (Cordis Corporation, Bridgewater, NJ) stents are no longer available. Currently, the Express(®) SD (Boston Scientific, Natick, MA), Formula™ (Cook Medical, Bloomington, IN), and Herculink Elite(®) (Abbott Vascular, Santa Clara, CA) stents are Food and Drug Administration approved and available for use. The Herculink Elite is the most recently approved of the renal stents, having received approval in late 2011. The Herculink Elite stent is the only cobalt chromium stent approved for use in the renal arteries. Although trial data are limited and direct comparisons among renal stents is not possible, the Herculink Elite stent has demonstrated good performance. Additionally, the design of the Herculink Elite offers some advantages that may translate into improved outcomes.

Figure 1: Critical stenosis with massive calcifications of the proximal and mid-right coronary artery in angiography (A). Angiogram after initial balloon angioplasty in the mid-right coronary artery (after an unsuccessful attempt to place a stent) and stent implantation in the proximal RCA (Multilink Vision 3.5 mm/12 mm, 24 atm) (B). Three months later coronary angiography revealed a giant aneurysm (31 × 23 mm) in the proximal segment of the RCA (C). There was also a complete transverse fracture of the stent (arrows) with displacement of the two fragments (D, arrowheads showing calcifications), which was confirmed by computed tomography (E and F, arrowheads showing an aneurysm). Intraoperatively, a large, round aneurysm (arrowhead) was found located close to the RCA orifice (G).