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Endovascular Stents (endovascular + stent)
Terms modified by Endovascular Stents 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] Bronchial compression due to stent placement in pulmonary artery in a child with congenital heart diseasePEDIATRIC ANESTHESIA, Issue 12 2005MÓNICA NÚÑEZ MD Summary Congenital heart disease, such as transposition of the great vessels (TGV), requires surgical procedures which can lead to important complications. We report on a case of bronchial obstruction following placement of a pulmonary artery stent in a 4-year-old boy who had undergone a Rastelli procedure to correct TGV, ventricular septal defect and pulmonary stenosis. There are many complications that can arise as a consequence of intravascular stents in heart surgery, as well as many causes of bronchial compression. However we have not found any report which describes bronchial compression as a direct consequence of endovascular stent. [source] Endovascular stent implantation for treatment of peripheral artery diseaseEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 3 2007M. Schillinger Endovascular stent implantation is a rapidly emerging technology for treatment of arterial obstructions in the entire circulation. During recent years, several randomized studies evaluated the effects of stenting in lower limb arteries. We herein provide an overview on data of trials in the iliac and femoropopliteal vessel area discussing the benefits and limitations of endovascular stents. In the iliac arteries, midterm and long-term data from one randomized trial including analysis on patency, clinical outcomes, cost-effectiveness and quality of life indicate that balloon angioplasty with selective stenting remains the therapy of choice for endovascular revascularization. In the femoropopliteal arteries, balloon-expanding stents were not superior to balloon angioplasty for treatment of short lesions, and self-expanding nitinol stents also failed to show a beneficial effect in short lesions below 5 cm. However, including longer lesions, one randomized trial indicated a beneficial effect of nitinol stents in lesions with a median length around 10,12 cm. Further studies and longer follow-up intervals are needed to confirm these data. Meanwhile, balloon angioplasty with optional stenting also remains the recommended endovascular approach for the femoropopliteal segment. [source] Anisotropic Behavior of Radiopaque NiTiPt Hypotube for Biomedical ApplicationsADVANCED ENGINEERING MATERIALS, Issue 11 2009Zhicheng Lin This paper presents the first characterization of anisotropic stress,strain behavior in micron-sized specimens cut directly from hypotubes, the starting material for the manufacture of endovascular stents and other biomedical devices, of a new radiopaque alloy NiTiPt. Experimental results show that NiTiPt hypotube has very different anisotropic characteristics when compared to its NiTi counterpart including higher tensile strength and strain, higher stress,strain nonlinearity, smaller hysteresis loop, and sharper tails during loading,unloading. [source] The mechanisms of coronary restenosis: insights from experimental modelsINTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 2 2000Gordon A.A. Ferns Since its introduction into clinical practice, more than 20 years ago, percutaneous transluminal coronary angioplasty (PTCA) has proven to be an effective, minimally invasive alternative to coronary artery bypass grafting (CABG). During this time there have been great improvements in the design of balloon catheters, operative procedures and adjuvant drug therapy, and this has resulted in low rates of primary failure and short-term complications. However, the potential benefits of angioplasty are diminished by the high rate of recurrent disease. Up to 40% of patients undergoing angioplasty develop clinically significant restenosis within a year of the procedure. Although the deployment of endovascular stents at the time of angioplasty improves the short-term outcome, ,in-stent' stenosis remains an enduring problem. In order to gain an insight into the mechanisms of restenosis, several experimental models of angioplasty have been developed. These have been used together with the tools provided by recent advances in molecular biology and catheter design to investigate restenosis in detail. It is now possible to deliver highly specific molecular antagonists, such as antisense gene sequences, to the site of injury. The knowledge provided by these studies may ultimately lead to novel forms of intervention. The present review is a synopsis of our current understanding of the pathological mechanisms of restenosis. [source] A fracture-mechanics-based approach to fracture control in biomedical devices manufactured from superelastic Nitinol tubeJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2008S. W. Robertson Abstract Several key fracture-mechanics parameters associated with the onset of subcritical and critical cracking, specifically the fracture toughness, crack-resistance curve, and fatigue threshold, have recently been reported for the superelastic alloy Nitinol, in the product form of the thin-walled tube that is used to manufacture several biomedical devices, most notably endovascular stents. In this study, we use these critical parameters to construct simple decision criteria for assessing the quantitative effect of crack-like defects in such Nitinol devices with respect to their resistance to failure by deformation or fracture. The criteria are based on the (equivalent) crack-initiation fracture toughness and fatigue threshold stress-intensity range, together with the general yield strength and fatigue endurance strength, and are used to construct a basis for design against single-event (overload) failures as well as for time-/cycle-delayed failures associated with fatigue. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2008 [source] Catheter-directed therapy for DVT after pancreas transplantationCLINICAL TRANSPLANTATION, Issue 6 2007Harish D Mahanty Abstract:, Introduction:, Iliac vein deep venous thrombosis (DVT) ipsilateral to the pancreas transplant can lead to severe leg edema and compromise graft function. Treatment modalities for iliac vein DVT in the pancreas transplant recipient are limited. Methods:, Medical records of patients receiving pancreas transplants at a single center from November 1989 to July 2003 were reviewed retrospectively, identifying patients with iliac vein DVT. There were 287 pancreas transplants performed during this time. Pancreas transplantation in all recipients was performed in the right iliac fossa with the arterial supply consisting of a donor iliac artery Y interposition graft. Systemic venous drainage was to the iliac vein. Exocrine drainage was enteric or to the bladder. Results:, Four (1.4%) cases of iliac DVT were identified. All patients manifested lower extremity edema ipsilateral to the pancreas transplant. DVT was detected by ultrasound on days 4, 5, 13, and 60 post-transplant. In all cases, the iliac vein caudad to the pancreatic venous anastomosis was noted to be stenotic. Management involved balloon dilatation and endovascular stent placement in one patient, thrombolysis with tissue plasma antigen (t-PA) followed by stent placement in one patient, and percutaneous mechanical thrombectomy in two patients. All patients had improvement in leg edema and two patients continue to have good pancreatic allograft function. Conclusions:, Iliac DVT is a rare complication of pancreas transplantation that usually develops in an area of stenosis caudad to the pancreatic venous anastomosis. Catheter-based treatment modalities with use of endovascular stents for treatment of underlying stenoses can serve as an adjunct in treating these complications. [source] | |||||||||||||