nitinol and Coronary-Restenosis

Device technology in interventional cardiology is continuously evolving. Self-expandable (SE) coronary artery stents were the first device to be implanted within a human coronary artery. However, because of their initial limitations, balloon-expandable (BE) stents were predominantly developed and used in the last 30 years. Unfortunately, in challenging anatomical settings such as bifurcation lesions, large, ectatic or aneurysmal vessels, tapered vessels or vasoconstricted arteries, outcomes with BE stents are not always optimal. The Stentys (Stentys SA, Paris, France) SE nitinol stents were initially developed for the treatment of coronary bifurcation lesions. The understanding of the underlying mechanism involved in incomplete stent apposition and subsequent stent thrombosis led to the introduction of self-apposing stents in the treatment of acute coronary syndrome in order to overcome the limitations of drug-eluting stents in presence of high thrombus burden. In this regard, Stentys allows a progressive stent expansion which could reduce the rates of incomplete stent apposition by conforming to vascular remodeling. Enhancing the advantages of this technology by adding the release of an antiproliferative drug to prevent restenosis is even more attractive and potentially effective. Recently, the results of the new Stentys sirolimus-eluting stent have been reported. This article provides an overview of the pathobiological rational, device characteristics and results of the new Stentys self-expandable sirolimus-eluting stent.

Topics: Acute Coronary Syndrome; Alloys; Coronary Restenosis; Coronary Vessels; Drug-Eluting Stents; Humans; Percutaneous Coronary Intervention; Prosthesis Design; Sirolimus

The number of peripheral procedures is increasing at a rapid pace and in a variety of vessels. This review will discuss current findings in carotid intervention and drug-eluting stents in superficial femoral arteries (SFA).

Topics: Alloys; Carotid Artery Diseases; Coronary Restenosis; Drug-Eluting Stents; Endarterectomy, Carotid; Femoral Artery; Humans; Immunosuppressive Agents; Risk Factors; Sirolimus; Stents; Vascular Patency

The aim of this study was to evaluate the Sparrow sirolimus-eluting stent (Sparrow-SES) against the Sparrow bare-metal stent (Sparrow-BMS) and conventional balloon-expandable bare-metal stent (BMS: Driver/Micro-Driver stent, Medtronic Vascular, Santa Rosa, CA).. The Sparrow stent (Biosensors International, Singapore) consists of a guide wire-based, self-expandable, ultra-thin nitinol stent. The performance of this device with sirolimus in a fully biodegradable polymer has not been determined.. A total of 74 patients were included in this intravascular ultrasound (IVUS) sub-study of the CARE II trial, which was a prospective, randomized, multicenter trial in the treatment of single de novo native coronary artery lesions in vessels ranging from 2.0 mm to 2.75 mm in diameter (Sparrow-SES: n = 31, Sparrow-BMS: n = 22, BMS: n = 21).. Stent volume index (VI) was significantly increased 8-month later in Sparrow-SES and Sparrow-BMS, but not in BMS (4.0 ± 1.0 to 4.6 ± 1.0 mm(3) /mm, p<0.0001, 4.0 ± 0.6 to 4.4 ± 0.8 mm(3) /mm, p<0.05, and 5.2 ± 1.0 to 5.1 ± 0.9 mm(3) /mm, p=0.421, respectively). % neointimal obstruction in Sparrow-SES was significantly smaller than those in Sparrow-BMS and BMS at follow-up (17.6 ± 9.4 vs. 36.2 ± 13.8 and 39.9 ± 11.1%, p<0.001). Sparrow-SES showed a mean 15% stent expansion and good suppression of neointimal proliferation, resulting in a significantly lower percentage of change in lumen VI during follow-up period (Sparrow-SES: -6.2 ± 16.2%, Sparrow-BMS: -30.4 ± 11.6%, BMS: -40.4 ± 10.0%, p<0.001).. The self-expanding Sparrow-SES demonstrated chronic stent expansion, good suppression of neointimal proliferation and resulted in a more preserved lumen in stented small vessels compared with the Sparrow-BMS and conventional balloon expandable BMS.

Topics: Aged; Alloys; Angioplasty, Balloon, Coronary; Cardiovascular Agents; Cell Proliferation; Coronary Artery Disease; Coronary Restenosis; Coronary Vessels; Drug-Eluting Stents; Female; Humans; Male; Middle Aged; Neointima; Predictive Value of Tests; Prospective Studies; Prosthesis Design; Sirolimus; Stents; Time Factors; Treatment Outcome; Ultrasonography, Interventional

Primary percutaneous coronary intervention (PCI) has considerably improved clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI) when compared with thrombolytic therapy. Prognosis after primary PCI might be further improved by decreasing stent-related complications such as stent thrombosis. The STENTYS self-apposing stent has been shown to be superior compared with balloon-expandable stents with regard to stent apposition. The current prospective randomized trial was designed to evaluate whether the superior stent apposition of the STENTYS stent results in clinical outcomes that are at least noninferior to a conventional balloon-expandable stent.. The APPOSITION V is a prospective, multicenter, international, single-blinded, randomized controlled trial in STEMI patients. Randomization will be performed in a 2:1 ratio between the self-apposing nitinol bare-metal STENTYS stent and the balloon-expandable bare-metal MULTI-LINK. The primary end point is defined as target vessel failure, which is a composite of cardiac death, target vessel-related recurrent myocardial infarction, or clinically driven target vessel revascularization, at 1-year follow-up. Baseline intravascular ultrasound and optical coherence tomography (OCT) substudies will be performed in 212 and 60 subjects, respectively, and a repeat angiography at 12 to 13 months will be performed in 105 subjects, including intravascular ultrasound and OCT (in the 60 OCT patients). This study is registered on ClinicalTrials.gov with number NCT01732341.. APPOSITION V will be the first randomized trial powered on clinical end points that directly compares the STENTYS self-apposing stent with a conventional balloon-expandable stent in patients presenting with STEMI undergoing primary PCI.

Topics: Alloys; Angioplasty, Balloon, Coronary; Coronary Angiography; Coronary Restenosis; Humans; Myocardial Infarction; Percutaneous Coronary Intervention; Prosthesis Design; Prosthesis Failure; Recurrence; Single-Blind Method; Stents; Tomography, Optical Coherence; Treatment Outcome; Ultrasonography, Interventional

Earlier generation self-expanding stents (SExS) showed high restenosis rates and long-term stent over-expansion. A novel SExS with reduced outward expansive force has been developed to overcome these limitations. This first-in-human study aimed to evaluate the safety and feasibility of the low pressure self-expanding nitinol-based vProtect™ luminal shield (LS) in the treatment of intermediate coronary lesions.. A total of 29 patients with clinical evidence of myocardial ischaemia and intermediate de novo coronary lesions were included. The LS was deployed after low-pressure balloon pre-dilatation. Acute procedural and device success was achieved in all patients. Angiographic follow-up at nine months showed an in-stent lumen loss of 0.50±0.30 mm and a binary restenosis rate of 10.3%. There were no cases of late LS over-expansion or acute/late malapposition as evaluated by intravascular ultrasound (IVUS). The cumulative major adverse cardiac events (MACE) rate at nine months was 10.3%, consisting of three target lesion revascularisations, with no cases of death, myocardial infarction or stent thrombosis.. Implantation of the LS in non-complex coronary lesions of intermediate severity was feasible, safe, and resulted in low rates of late loss and restenosis. IVUS analysis at nine months showed favourable mechanical properties of the LS without evidence of late device over-expansion.

Topics: Aged; Alloys; Angioplasty, Balloon, Coronary; Colombia; Coronary Angiography; Coronary Artery Disease; Coronary Restenosis; Feasibility Studies; Female; Humans; Male; Middle Aged; Prospective Studies; Prosthesis Design; Severity of Illness Index; Stents; Time Factors; Treatment Outcome; Ultrasonography, Interventional

To assess the efficacy of the AXXESS stent on the treatment of left main coronary artery (LMCA) bifurcation lesions using IVUS.. The treatment of LMCA bifurcation lesions remains challenging even with the use of drug-eluting stents. The AXXESS system is a biolimus A9-eluting self-expanding stent, dedicated to the treatment of bifurcation lesions.. Data were obtained from the AXXENT trial, a prospective, single-arm, multicenter study designed to evaluate the efficacy of the AXXESS stent on the treatment of LMCA bifurcation lesions. IVUS was available in 26 cases at 6-months follow-up. Volumetric and cross-sectional analyses within the AXXESS stent, and cross-sectional analyses at the ostia of left anterior descending (LAD) and left circumflex coronary arteries (LCX) were performed.. Within the AXXESS stent, percent neointimal volume obstruction was (3.0 +/- 4.1)% with a minimal lumen area of 10.3 +/- 2.6 mm(2). AXXESS stent volume showed an 12.4% increase at follow-up compared with postprocedure (P = 0.04). Lumen area was significantly smaller in the LCX ostium compared with the LAD ostium at follow-up (3.6 +/- 1.3 mm(2) vs. 5.5 +/- 2.0 mm(2), P = 0.0112). There was greater neointimal formation in the LCX ostium compared with the LAD ostium (1.37 +/- 1.20 mm(2) vs. 0.30 +/- 0.36 mm(2), P = 0.0003).. The AXXESS stent in the LMCA showed enlargement through 6-months follow-up and significant neointimal suppression. Greater neointimal formation and relatively inadequate stent expansion may contribute to luminal narrowing in the LCX ostium.

Topics: Aged; Alloys; Angioplasty, Balloon, Coronary; Cardiovascular Agents; Cell Proliferation; Coronary Angiography; Coronary Restenosis; Coronary Stenosis; Coronary Vessels; Drug-Eluting Stents; Europe; Female; Humans; Male; Middle Aged; Prospective Studies; Prosthesis Design; Sirolimus; Stents; Time Factors; Treatment Outcome; Tunica Intima; Ultrasonography, Interventional; United States

Topics: Aged; Alloys; Coronary Restenosis; Female; Humans; Stents

This paper reports a novel shape memory alloy (SMA) nitinol type active stent for non-invasive restenosis treatment, which operates using a radiofrequency (RF) electro-thermo-mechanical actuation technique for wireless revascularization. The developed stent is equipped with a capacitive pressure sensor for in-artery blood pressure measurement and can provide multiple expansion to restore the blood pressure flow. The device design, working principle, fabrication, and characterization of the nitinol active stent are reported in this work. The wireless monitoring feature is achieved via peak shifting in the reflection coefficient of the S

Topics: Alloys; Coronary Restenosis; Coronary Vessels; Humans; Stents; Treatment Outcome

Bare-metal stents are used to treat arterial stenotic lesions. Morbidity and mortality are less important compared with other techniques. Drug-eluting balloons are often used to treat stent stenosis. We reported the case of a bare-metal stent infection after drug-eluting balloon and a review on the subject.. Two weeks after percutaneous transluminal angioplasty with paclitaxel-eluting balloon and a bare-metal stent, our patient presented an infection of the stent. Diagnosis was based on the clinical presentation, positron emission tomography findings and isolation of Propionibacterium granulosum in repeated blood cultures. Adapted antibiotic therapy was given for three months with removal of the surgical bare-stent. Antibiotic therapy was interrupted after a second positron emission tomography. A literature search (PubMed and Cochrane) was performed on the subject.. We found 49 cases of peripheral bare-metal stent infection including our patient. This is a rare but serious complication with a high morbidity (25% amputation rate) and mortality (30%). It seems to be underestimated. Treatment is based on surgical ablation of the bare-metal stent and intravenous antibiotics. The role of the paclitaxel-eluting balloon is not clearly established but some authors believe that it can produce a local immunosuppression.. We report the first case of bare-metal stent infection after paclitaxel-eluting balloon. This complication is rare and difficult to diagnose. Manifestations are often limited to skin signs. Functional and vital prognosis is poor.

Topics: Aged, 80 and over; Alloys; Amoxicillin; Angioplasty, Balloon, Coronary; Anti-Bacterial Agents; Arteriosclerosis Obliterans; Bacteremia; Coronary Disease; Coronary Restenosis; Device Removal; Equipment Contamination; Female; Femoral Artery; Gentamicins; Gram-Positive Bacterial Infections; Humans; Immunosuppressive Agents; Paclitaxel; Penicillanic Acid; Piperacillin; Piperacillin, Tazobactam Drug Combination; Popliteal Artery; Propionibacterium; Prosthesis-Related Infections; Stents; Tomography, Emission-Computed, Single-Photon

In this study, we describe the synthesis of an upright nanotubular coating with discrete, exposed nanotubes on top of superelastic Nitinol via anodization and characterization of the surface elemental composition and nickel release rates. We demonstrate, for the first time, that this coating could improve re-endothelialization by increasing the cell spreading and migration of primary human aortic endothelial cells on Nitinol. We also show the potential for reducing neointimal hyperplasia by decreasing the proliferation and expression of collagen I and MMP-2 in primary human aortic smooth muscle cells (HASMC). Furthermore, we did not observe the nanotubular surface to induce inflammation through ICAM-1 expression in HASMC as compared to the flat control. This coating could be used to improve Nitinol stents by reducing restenosis rates and, given the extensive use of Nitinol in other implantable devices, act as a generalized coating strategy for other medical devices.

Topics: Alloys; Aorta; Biocompatible Materials; Cell Movement; Cell Proliferation; Collagen Type I; Coronary Restenosis; Endothelial Cells; Endothelium, Vascular; Flow Cytometry; Humans; Inflammation; Intercellular Adhesion Molecule-1; Matrix Metalloproteinase 2; Microscopy, Electron, Scanning; Microscopy, Fluorescence; Myocytes, Smooth Muscle; Nanotechnology; Nanotubes; Stents; Surface Properties

Despite the considerable progress made in the stent development in the last decades, cardiovascular diseases remain the main cause of death in western countries. Beside the benefits offered by the development of different drug-eluting stents, the coronary revascularization bears also the life-threatening risks of in-stent thrombosis and restenosis. Research on new therapeutic strategies is impaired by the lack of appropriate methods to study stent implantation and restenosis processes. Here, we describe a rapid and accessible procedure of stent implantation in mouse carotid artery, which offers the possibility to study in a convenient way the molecular mechanisms of vessel remodeling and the effects of different drug coatings.

Topics: Alloys; Animals; Carotid Arteries; Coronary Restenosis; Disease Models, Animal; Drug-Eluting Stents; Male; Mice; Mice, Inbred C57BL; Plaque, Atherosclerotic; Stents

Topics: Alloys; Angina, Stable; Angioplasty; Coronary Restenosis; Humans; Male; Middle Aged; Prosthesis Failure; Stents; Ultrasonography, Interventional

The purpose of this prospective registry was to evaluate the safety and efficacy, at 1 year, of the use of drug-eluting balloons (DEB) for the treatment of superficial femoral artery (SFA) in-stent restenosis (ISR).. The use of the self-expanding nitinol stent has improved the patency rate of SFA after percutaneous transluminal angioplasty (PTA). As the population with SFA stenting continues to increase, occurrence of ISR has become a serious problem. The use of DEB has showed promising results in reducing restenosis recurrence in coronary stents.. From December 2009 to December 2010, 39 consecutive patients underwent PTA of SFA-ISR in our institution. All patients underwent conventional SFA PTA and final post-dilation with paclitaxel-eluting balloons (IN.PACT, Medtronic, Minneapolis, Minnesota). Patients were evaluated up to 12 months.. Technical and procedural success was achieved in every patient. No in-hospital major adverse cardiac and cerebrovascular events occurred. At 1 year, 1 patient died due to heart failure. Primary endpoint, primary patency rate at 12 months, was obtained in 92.1% (35 patients). At 1 year, patients were asymptomatic for claudication, and duplex assessment demonstrated lack of recurrent restenosis (100% rate of Secondary patency). The presence of an occlusive restenosis at the time of treatment was not associated with an increased restenosis rate, when compared with non-occlusive restenosis, at 1 year.. The data suggest that adjunctive use of DEB for the treatment of SFA-ISR represents a potentially safe and effective therapeutic strategy. These data should be considered hypothesis-generating to design a randomized trial.

Topics: Aged; Alloys; Angioplasty; Coronary Restenosis; Drug-Eluting Stents; Female; Femoral Artery; Humans; Male; Middle Aged; Prospective Studies; Registries; Stents; Treatment Outcome; Vascular Diseases; Vascular Patency

In the setting of ST-elevation myocardial infarction (STEMI), epicardial vasoconstriction and thrombus load may lead to stent undersizing and malapposition after primary percutaneous coronary intervention (PPCI), which can both be responsible for stent thrombosis or restenosis. Aggressive stent deployment can, on the other hand, cause distal embolisation and the no-reflow phenomenon. The purpose of our study was to evaluate the safety and feasibility of a novel self-expanding stent by assessing the clinical, angiographic and intravascular outcomes after stent deployment at three days and at six months follow-up.. This prospective, multicentre, non-randomised study enrolled 25 STEMI patients undergoing PPCI; a nitinol, self-expanding, coronary stent (STENTYS® stent; STENTYS, Paris, France) was used in all patients. Angiography and intravascular ultrasound (IVUS) or optical coherence tomography (OCT) were performed immediately after stent deployment, after three days and at six months. Primary safety endpoints were mortality, reinfarction, stent thrombosis and stroke at discharge and at six months. The primary feasibility endpoints were technical, device and procedural success, and stent apposition at three days and six months. Secondary endpoints included distal embolisation, binary restenosis, ischaemia-driven target lesion revascularisation (TLR) and late lumen loss (LLL). There were no adverse events at discharge or at six months. Technical, device and procedural success were 100%, 96% and 96%, respectively. IVUS showed a significant vasodilatation distal to the culprit lesion at three-day follow-up (+19%), with a concordant expansion of the implanted stent (+18%), p≤0.001 for both values. One case of distal embolisation was reported. There were no cases of late stent malapposition at six months. In-stent and in-segment LLL were 0.71±0.71 mm and 0.58±0.61 mm. Binary restenosis was 25%, ischaemia-driven TLR was 12%.. This study shows that the use of the STENTYS® self-expanding stent is safe and feasible in STEMI patients. Three days after the procedure, the stent expanded to the same extent as the epicardial vasodilatation and appeared completely apposed to the vessel wall. This could be of benefit in preventing stent thrombosis in the setting of STEMI.

Topics: Adult; Aged; Alloys; Angioplasty, Balloon, Coronary; Coronary Angiography; Coronary Restenosis; Embolism; Europe; Feasibility Studies; Female; Humans; Male; Middle Aged; Myocardial Infarction; Prospective Studies; Prosthesis Design; Recurrence; Stents; Thrombosis; Time Factors; Tomography, Optical Coherence; Treatment Outcome; Ultrasonography, Interventional

Topics: Alloys; Angioplasty, Balloon, Coronary; Cardiovascular Agents; Coronary Restenosis; Coronary Stenosis; Drug-Eluting Stents; Humans; Prosthesis Design; Sirolimus; Stents; Treatment Outcome; Ultrasonography, Interventional

The stenting of aorto-ostial lesions in the native coronary circulation, renal arteries, and saphenous vein grafts is technically challenging.. We report the first in the world use of the Ostial Protrade mark, a novel nitinol-based device, utilized in conjunction with standard stenting techniques to assist in the precise placement of stents for the treatment of aorto-ostial lesions.. The Ostial Pro, is a relatively simple nitinol device that is positioned within the guiding catheter. It has distal, self-expanding legs that are advanced just distal to the tip of the guiding catheter after the ostial lesion has been crossed with the coronary guidewire and stent delivery system. The expanded nitinol legs prevent the entry of the guiding catheter into the target vessel, mark the plane of the aortic wall, and align the tip of the guide with the aorto-ostial plane. We report the successful and precise placement of stents in the aorto-ostial location in two patients with; (1) a saphenous vein graft ostial lesion and (2) a right coronary ostial lesion, using the new Ostial Pro stent positioning device. Excellent stent positioning, relative to the aorto-ostial plane, was confirmed by angiography and long axis intravascular ultrasound in both cases.. (1) The Ostial Pro is a new, commercially available (FDA cleared), nitinol device that is simple to use and appears effective in allowing the precise placement of stent(s) at the aorto-ostial location. (2) This approach may provide a simple and effective means to assure accurate stent placement in these difficult to treat lesions.

Topics: Aged; Alloys; Angioplasty, Balloon, Coronary; Cardiac Catheterization; Coronary Artery Bypass; Coronary Restenosis; Coronary Stenosis; Drug-Eluting Stents; Equipment Design; Equipment Safety; Follow-Up Studies; Graft Occlusion, Vascular; Humans; Male; Middle Aged; Radiography; Risk Assessment; Sensitivity and Specificity; Treatment Outcome

To compare aortic intimal thickening of normal and hyperhomocysteinemic pigs (induced with a methionine-rich diet) following placement of a self-expanding nitinol stent.. Eighteen Macau pigs were used. They were older than eight weeks in age and had an average weight of 30 kg. Pigs were randomly divided into two groups. The first, Group C (control), was fed a regular diet, and the second group, Group M, was fed a methionine-rich diet for 30 days to induce hyperhomocysteinemia. The self-expandable nitinol stents were 25mm in length and 8 mm in diameter after expansion. Blood samples were collected to measure total cholesterol, triglycerides, HDL and homocysteine concentrations. All animals were subjected to angiography. Thirty days after the procedure, the animals were sacrificed, and the abdominal aorta was removed for histological and digital morphometry analysis.. Under microscopic evaluation, the intima was significantly thicker in Group C than in Group M. When groups were compared by digital morphometric analysis, intimal thickening of the vessel wall was higher in Group C than in Group M. There was no significant change in total cholesterol, triglycerides or HDL concentrations in either group. In group C the levels of plasma homocysteine ranged from 14,40 to 16,73 micromol/l; in Group M, plasma homocysteine levels ranged from 17.47 to 59.80 micromol/l after 30 days of a methionine-rich diet.. Compared to normal pigs, less intimal hyperplasia was observed in the abdominal aortas of hyperhomocysteinemic pigs thirty days after the insertion of a self-expandable nitinol stent.

Topics: Alloys; Animals; Aorta; Aorta, Abdominal; Atherosclerosis; Biocompatible Materials; Cholesterol, HDL; Coronary Restenosis; Diet, Atherogenic; Disease Models, Animal; Hyperhomocysteinemia; Hyperplasia; Random Allocation; Stents; Swine; Triglycerides; Tunica Intima

To test the feasibility of self-expanding drug-coated nitinol stents for prevention of restenosis in an animal model. Stent implantation in the carotid artery (CA) has been shown to be feasible for treatment of CA stenosis. Even though the restenosis rate in CA is reported to be lower than in the coronary and peripheral arteries, problems may arise with increasing numbers of treated patients and lengthier follow-up.. After predilatation with 8-mm balloons, 8 Goettinger minipigs were randomly selected to receive a sirolimus-eluting self-expanding nitinol stent (7 mm/80 mm) as well as the same stent without sirolimus/polymer coating in the right or left CA. Aspirin was given starting 3 days before the intervention and administered for an additional 4 weeks. Clopidogrel was administered for 10 days.. After 6 weeks, 2 subacute occlusions were observed in both groups. In the remaining vessels, the neointima was significantly reduced by sirolimus/polymer-coated stents (5.9+/-2.5 versus 0.7+/-1.0 mm2).. Sirolimus self-expanding nitinol stents may be an effective tool in reducing neointimal formation in CA.

Topics: Alloys; Angioplasty, Balloon, Coronary; Animals; Anti-Inflammatory Agents, Non-Steroidal; Aspirin; Atherosclerosis; Carotid Arteries; Clopidogrel; Coronary Angiography; Coronary Restenosis; Disease Models, Animal; Male; Polymers; Sirolimus; Stents; Swine; Ticlopidine; Time Factors; Ultrasonics

To evaluate a self-expanding rhenium 188 (188Re) radiochemically labeled radioactive stent in sheep.. A self-expanding nitinol stent (30 mm in length, 8 mm in diameter) coated with a functionalized polymer layer was radiolabeled with 188Re. Fifty prostheses, 25 of which were radioactive (mean radioactivity, 20 MBq +/- 3.8 [SD]) and 25 of which were nonradioactive, were implanted into the external iliac arteries of 25 sheep. Stent patency was assessed with angiography. Neointimal formation was assessed with intravascular ultrasonography and histologic examination 1 month (in all sheep) and 3 months (in 12 sheep) after implantation. The results were analyzed by using repeated-measures analysis of variance with two repeated factors and paired t tests for comparison at each measuring point.. All stents were placed successfully. Data in one animal had to be excluded from the study. After 3 months, a mean neointimal area reduction of 70 mm2 +/- 55 (SD) was observed inside the radioactive stents, and a mean lumen reduction of 126 mm2 +/- 39 was observed inside the nonradioactive control stents (P =.022). An edge effect was observed in the radioactive stents in that they showed an amount of neointimal formation at the edges that was similar to that seen in control stents. This neointimal formation accounted for the maximum lumen loss in the vascular segment with the stent.. As compared with a nonradioactive stent, a beta particle-emitting stent, through endovascular irradiation, significantly inhibits neointimal formation inside the stent but not at the stent edges.

Topics: Alloys; Animals; Coronary Restenosis; Disease Models, Animal; Follow-Up Studies; Prosthesis Implantation; Radioisotopes; Rhenium; Sheep; Stents; Tunica Intima