原标题：生物可吸收聚合物DES代表了支架平台的演变
注：drug-eluting stents (DES)即药物洗脱支架。
TCT 2014大会上一场聚焦于未来金属DES的讲座所传递的信息显示，各式更新换代的药物洗脱支架（DES）之间存在着较小的早期差异性。而相对的，生物可吸收和永久性聚合物装置之间的差异则仅在长期结果中显现。
Juan F. Granada博士（纽约奥兰治堡 CRF Skirball创新中心执行总监及首席创新官）对耐久性和生物可吸收聚合物涂层DES的技术及治疗结果的细微差异进行了讨论。
据Granada博士解释，在早期治愈阶段，由于聚合载体及抗增殖药物的表现，不同装置间促凝性的极小差异或许会体现在不同的DES技术上。早期时段过后，支架表面生物适应性和促凝性则在长期临床结果中扮演者重要角色。
尽管永久性聚合物DES提供了较低的支架内再狭窄和支架内血栓发生率，但其临床结果仍有改善空间。例如，高风险的复杂病变患者易存在更有侵略性的血栓形成环境，因此会使用到辅助装置及支架重叠技术。这一亚组患者的支架内血栓发生率较高，且需要延长双联抗血小板治疗以确保患者安全。
在试验性装置中，相较于耐久性聚合物，置于管腔内的生物可吸收聚合物展现出的血管壁炎症和促凝性程度更低。但是，大型随机对照临床试验或许还需要进一步证明这一技术方法的临床优越性。
依照聚合物药物吸收时间，Granada博士指出，首个6至9个月内，生物可吸收和永久聚合物在治愈净效上或具可比性。一旦药物脱离支架，聚合物进入退化阶段，金属与聚合物表面之间在治愈时间上就出现差异。相较平面金属表面，凹槽表面内皮细胞迁移速度为其2倍还多。
“对每一款生物可吸收DES的概念进行归类是十分困难的，无论是对正在研发中还是已在临床应用中的生物可吸收DES。原因之一是因为每项技术都有不同的支架平台，不同药物或聚合物类型，所有这些差异则构成了对血管的整体效力，” Granada博士最后还谈到。
（以上编译内容来自微信公众号：医心），以下为英文原文：
Bioabsorbable Polymer DES Represent Evolution to Stenting Platform
Few early differences exist among the various iterations of drug-eluting stents (DES). Instead, disparities between bioresorbable and permanent polymer devices only emerge over the long term, according to a lecture focusing on the future of metallic DES held Monday at TCT 2014.
granadaJuan F. Granada, MD, Executive Director and Chief Innovation Officer of the CRF Skirball Center for Innovation, Orangeburg, N.Y., discussed the technological and therapeutic nuances of durable vs. bioabsorbable polymer DES.
“In the early phases of healing and due to the presence of polymeric carriers and antiproliferative drugs, minimal differences in device thrombogenicity may be seen between different DES technologies,” Granada explained. “Beyond this early phase, stent surface biocompatibility and thrombogenicity plays an important role in long-term clinical outcomes.”
Although permanent polymer DES provide low rates of restenosis and stent thrombosis, he said, there remains room for improvement in clinical outcomes. For example, high-risk patients with complex lesions tend to have more aggressive thrombogenic milieu, therefore ancillary devices and overlapping stents are used. Rates of stent thrombosis in this subset remain high, and prolonged dual antiplatelet therapy should be maintained to ensure safety.
“In the experimental setting, abluminally placed bioabsorbable polymers display lower degrees of vessel wall inflammation and thrombogenicity when compared with durable polymers,” he said. “However, large randomized controlled clinical trials may be required to prove the clinical superiority of this technological approach.”
Depending upon the polymer-drug absorption time, Granada said the net effect on healing may be comparable between bioabsorbable and durable polymers within the first 6 to 9 months. Once the drug is out of the stent and the polymer is in the process of degrading, there are differences in healing times between metallic and polymeric surfaces. Migration speed of endothelial cells is more than twofold with grooved surfaces vs. flat metal surfaces.
“It is very difficult to group all of the concepts of every single bioresorbable DES either under development or in the clinical arena,” he said. “One of the reasons is because every technology has a different stent platform, different drug or polymer type, and all of these differences contribute to the overall efficacy of the vessel.”
From：TCTMD