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Neointimal Proliferation (neointimal + proliferation)
Selected AbstractsDES Design: Theoretical Advantages and Disadvantages of Stent Strut Materials, Design, Thickness, and Surface CharacteristicsJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 2009F.A.C.C., F.A.H.A., F.S.C.A.I., STEVEN R. BAILEY M.D. Endovascular stents have historically been manufactured using metals and metal composites. While metallic implants in nonvascular locations have been biologically well tolerated, endovascular implants have been plagued by neointimal proliferation resulting in recurrent stenosis. Using prior in vitro and in vivo outcomes, novel research projects are under way to improve vascular implants. This review summarizes prior investigations of metal stents, analyzes new biopolymeric systems, and examines emerging technologies and manufacturing processes for surface modifications as well as bioabsorbable stent materials. Limitations of these new materials and manufacturing processes will be discussed along with potential new biologic applications. [source] Understanding and Preventing the Edge EffectJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 1 2003EDOUARD CHENEAU M.D. Edge stenosis, combining neointimal proliferation and negative remodeling, remains a serious limitation of vascular brachytherapy. This review comprehensively presents terminology, definitions, mechanisms, and treatment strategies to better understand the complexities of edge narrowing. The major contributors to this phenomenon are known; understanding the practical solutions will enable us to further minimize the problem of the edge effect. (J Interven Cardiol 2003;16:1,7) [source] Diffuse In-Stent RestenosisJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 6 2001HANS STÖRGER M.D. Stent restenosis, especially the diffuse pattern, has developed into a significant clinical and economical problem. It has been estimated that up to 250,000 patients developed in-stent restenosis in 2,000 alone, two thirds of them can be expected to have diffuse in-stent restenosis, which is difficult to treat because of high recurrence rates. None of the conventionally available interventional treatment modalities provides optimal long-term results. Intravascular radiation therapy is currently the only effective percutaneous therapy, for combating in-stent restenosis. Late thrombotic complications have largely been eliminated by extended antiplatelet regimens. Geographical miss, a major reason for recurrence of in-stent restenosis after brachytherapy, can be reduced by an improved radiation technique. The first preliminary data on drug-eluting stents, showing only minimal neointimal proliferation at 6-month postimplantation, could represent a major breakthrough in the quest to solve restenosis. [source] Macrophage Depletion Suppresses Cardiac Allograft Vasculopathy in MiceAMERICAN JOURNAL OF TRANSPLANTATION, Issue 12 2007W. H. Kitchens Cardiac allograft vasculopathy (CAV) is a major source of late posttransplant mortality. Although numerous cell types are implicated in the pathogenesis of CAV, it is unclear which cells actually induce the vascular damage that results in intimal proliferation. Because macrophages are abundant in CAV lesions and are capable of producing growth factors implicated in neointimal proliferation, they are leading end-effector candidates. Macrophages were depleted in a murine heterotopic cardiac transplant system known to develop fulminant CAV lesions. C57BL/6 hearts were transplanted into (C57BL/6 × BALB/c)F1 recipients, which then received anti-macrophage therapy with intraperitoneal carrageenan or i.v. gadolinium. Intraperitoneal carrageenan treatment depleted macrophages by 30,80% with minimal effects upon T, B or NK cells as confirmed by flow cytometry and NK cytotoxicity assays. Carrageenan treatment led to a 70% reduction in the development of CAV, as compared to mock-treated controls (p = 0.01), which correlated with the degree of macrophage depletion. Inhibition of macrophage phagocytosis alone with gadolinium failed to prevent CAV. Macrophages may represent the end-effector cells in a final common pathway towards CAV independent of T-cell or B-cell alloreactivity and exert their injurious effects through mechanisms related to cytokine/growth factor production rather than phagocytosis. [source] Feasibility and efficacy of stent redilatation in aortic coarctation,CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 4 2008Keyhan S. Zanjani MD Abstract Objectives: We evaluated the efficacy and safety of stent redilation in patients with aortic coarctation (COA). Methods and Results: In our retrospective study of 28 stent redilation procedures on 22 patients, the interval between implantation and redilation ranged from 2.5 month to 11 years (median 18 months). Ten patients had native COAs, one had repaired interrupted aortic arch. The remaining patients had residual COAs after surgery. Stent redilation was successful in 26 procedures. Pressure gradients decreased from a mean of 26 ± 13.8 mm Hg to 7.9 ± 6.52 mm Hg (P < 0.001). The mean diameter of the stents increased from 9.19 ± 3.29 mm to 12.1 ± 3.68 mm (P < 0.001). In a patient with Williams-Beuren syndrome, massive neointimal proliferation made stent redilation impossible. One other patient developed aortic aneurysm after redilation and was operated after 3 years. Conclusions: Stent redilation for aortic COA is a safe and successful procedure. © 2008 Wiley-Liss, Inc. [source] Use of Taxus polymer-coated paclitaxel-eluting stents for treatment of in-stent restenosis in real world patients: Results of clinical and angiographic follow-up at six months in a single-center registryCATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 3 2006Victor Y. Lim MRCP Abstract Objective:To evaluate the safety and efficacy of Taxus paclitaxel-eluting stents in a real world group of unselected patients with coronary in-stent restenosis (ISR) lesions. Methods: This is a prospective single-center registry of a consecutive series of 94 patients with 104 ISR lesions, without previous brachytherapy, over a period of 1 year. Quantitative coronary angiographic analyses were performed at baseline and at 6-month angiographic follow-up. Clinical follow-up were obtained at 6 months. Results:Pre-intervention mean reference vessel diameter was 2.62 ± 0.50 mm and mean lesion length was 13.95 ± 6.78 mm. Baseline ISR patterns were mostly either Type I focal (32.7%) or Type II diffuse intrastent (48.1%). At 6-month angiographic follow-up, the in-stent and in-segment binary restenosis was 3.8% (4/105) and 7.6% (8/105) respectively, and the in-stent and in-segment late loss was 0.30 ± 0.50 mm and 0.57 ± 0.54 mm, respectively. Seven of these eight restenosed lesions had a diffuse or proliferative ISR pattern prior to intervention. Lesions that restenosed had longer mean stent length per lesion (37.3 mm vs. 22.5 mm in nonrestenosed group; P = 0.001) and more likely to have had a pattern of total occlusion pre-intervention (25.0% vs. 3.1% in nonrestenosed group; P = 0.046). At 6-month clinical follow-up, the MACE rate was 8.5% and target lesion revascularization rate was 7.4%. There was no death but subacute stent thrombosis occurred in 1 patient (1.1%) at 3 days after intervention. Conclusions: Paclitaxel-eluting Taxus stent for the treatment of ISR effectively suppresses recurrent neointimal proliferation, and was safe and efficacious at 6-month follow-up. © 2006 Wiley-Liss, Inc. [source] "Head-to-head comparison between sirolimus-eluting and paclitaxel-eluting stents in patients with complex coronary artery disease: An intravascular ultrasound study"CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 6 2006FSCAI, Pavel, ervinka MD Abstract Background: The aim of this study was to assess neointimal hyperplasia following sirolimus-eluting (SES) and paclitaxel-eluting stents (PES) implantation in a patients with complex coronary disease. Method: Between January to December 2004, 70 patients were enrolled in this study (SES = 37; PES = 33. The primary objective was to assess the efficacy of SES and PES on neointimal proliferation inhibition in patients with complex coronary lesions by volumetric 3D intravascular ultrasound (IVUS) assessment at six-month follow-up. Results: Baseline clinical, demographic or angiographic characteristics were well balanced in both groups. All procedures as well as hospitalisation were uneventful. The percentage of B2/C lesions in our study was >90% in both groups. The IVUS-assessed in-stent mean neointimal hyperplasia volume was significantly lower in lesions treated with SES compared to PES (4.1 ± 11 mm3 vs. 17.4 ± 23 mm3, p < 0.002) at 6 month follow-up. No difference in both MACE (3.0 versus 6.0%, p = NS) and restenosis (5.4 versus 9.1%, p = NS) were found. The in-segment late loss at six month was 0.26 mm in the SES and 0.48 mm in the PES group (p = NS). Conclusions: The present study showed reduced neointimal proliferation after sirolimuseluting as compared to paclitaxel-eluting stents in patients with complex coronary artery disease. Both SES and PES were associated with low rate of angiographic restenosis or major adverse cardiovascular events. © 2006 Wiley-Liss, Inc. [source] | ||||||||||