Ansel Gary M, Lumsden Alan B
MidOhio Cardiology and Vascular Consultants, Midwest Cardiology Research Foundation, Riverside Methodist Hospital, Columbus, Ohio 43214, USA.
J Endovasc Ther. 2009 Apr;16(2 Suppl 2):II82-97. doi: 10.1583/08-2654.1.
Despite technical advances in balloon design and technique, there has been little improvement of primary patency rates after balloon-based endovascular interventions for all but focal femoropopliteal lesions. Improving on stainless steel models, nitinol stents have been associated with favorable short- and midterm primary patency rates; studies with longer-term follow-up will be required to learn whether restenosis is ongoing, with continued loss of primary patency. Studies in recent years have shown varying incidences of mechanical fatigue leading to nitinol stent fracture. Covered stents are designed to prevent the tissue infiltration and intimal hyperplasia that can lead to bare metal in-stent restenosis. Several clinical studies, mainly single-center registries, have demonstrated a general effectiveness of the Hemobahn/Viabahn polytetrafluoroethylene-covered stent-grafts, approved for femoral arterial occlusive disease, and have helped to distinguish indications for use and to delineate possible failure modes. A multicenter randomized trial, which has completed enrollment, will compare the Viabahn with self-expanding bare nitinol stents. The primary use of drug-eluting stents (DES) has become routine clinical practice for coronary artery disease. The 2-phase multicenter randomized double-blind SIROCCO trials have been completed, with results published through 24 months. Follow-up demonstrated the feasibility and safety of deploying sirolimus-eluting stents in the femoropopliteal segment but failed to show superior efficacy for DES versus bare nitinol stents. However, the restenosis rates with bare metal stents were unexpectedly low. A paclitaxel-eluting stent without a polymer coating is currently being evaluated in the recently enrolled Zilver PTX randomized trial and international registry. A polymer-based everolimus-eluting stent is being evaluated for femoropopliteal use in the nonrandomized European STRIDES trial. Balloons coated with paclitaxel have recently been evaluated for simple femoropopliteal disease with encouraging results through 2 years of follow-up. The bioabsorbable stent concept emerged in response to the potential issues with metal stents, but to date no investigational device has successfully overcome issues such as relatively low radial force and variable degradation rates.
尽管球囊设计和技术取得了技术进步，但除局灶性股腘病变外，基于球囊的血管内介入治疗后的初始通畅率几乎没有提高。在不锈钢模型的基础上，镍钛诺支架的短期和中期初始通畅率良好；需要进行长期随访研究，以了解再狭窄是否持续存在，初始通畅率是否会持续下降。近年来的研究表明，机械疲劳导致镍钛诺支架断裂的发生率各不相同。覆膜支架旨在防止可导致裸金属支架内再狭窄的组织浸润和内膜增生。几项临床研究，主要是单中心登记研究，已证明用于股动脉闭塞性疾病的Hemobahn/Viabahn聚四氟乙烯覆膜支架移植物具有总体有效性，并有助于明确使用指征和描述可能的失败模式。一项已完成入组的多中心随机试验将比较Viabahn与自膨式裸镍钛诺支架。药物洗脱支架（DES）在冠状动脉疾病中的主要应用已成为常规临床实践。两阶段多中心随机双盲SIROCCO试验已经完成，结果已公布至24个月。随访证明了在股腘段植入西罗莫司洗脱支架的可行性和安全性，但未能显示DES相对于裸镍钛诺支架具有更高的疗效。然而，裸金属支架的再狭窄率出人意料地低。一种无聚合物涂层的紫杉醇洗脱支架目前正在最近入组的Zilver PTX随机试验和国际登记研究中进行评估。一种基于聚合物的依维莫司洗脱支架正在非随机的欧洲STRIDES试验中评估其在股腘段的应用。最近对涂有紫杉醇的球囊用于单纯股腘疾病进行了评估，随访2年结果令人鼓舞。生物可吸收支架的概念是为应对金属支架的潜在问题而出现的，但迄今为止，没有研究装置成功克服诸如径向力相对较低和降解速率可变等问题。
