Machi Paolo, Jourdan Franck, Ambard Dominique, Reynaud Cedric, Lobotesis Kyriakos, Sanchez Mathieu, Bonafé Alain, Costalat Vincent
Centre Hospitalier Universitaire Gui de Chauliac, Montpellier, France.
Department of Mechanical Engineering, University of Montpellier, France.
J Neurointerv Surg. 2017 Mar;9(3):257-263. doi: 10.1136/neurintsurg-2015-012213. Epub 2016 Mar 25.
Five randomized controlled trials recently appeared in the literature demonstrating that early mechanical thrombectomy in patients with acute ischemic stroke is significantly related to an improved outcome. Stent retrievers are accepted as the most effective devices for intracranial thrombectomy.
To analyze the mechanical properties of stent retrievers, their behavior during retrieval, and interaction with different clots and to identify device features that might correlate with the effectiveness of thrombus removal.
All stent retrievers available in France up to June 2015 were evaluated by mechanical and functional tests aimed at investigating the variation of their radial force and their behavior during retrieval. Devices were also tested during in vitro thrombectomies using white and red experimental thrombi produced with human blood. Functional tests and in vitro thrombectomies were conducted using a rigid 3D printed vascular model.
Mechanical tests showed a variation in radial force during retrieval for each stent. A constant radial force during retrieval was related to continuous cohesion over the vessel wall and a higher rate of clot removal efficacy. All stent retrievers failed when interacting with white large thrombi (diameter ≥6 mm).
None of the tested devices were effective in removing white clots of large diameter (≥6 mm). Constant radial force during retrieval allows constant cohesion to the vessel wall and pressure over the clot; such features allow for a higher rate of clot removal.
最近有五项随机对照试验发表于文献中，表明急性缺血性中风患者早期进行机械取栓与改善预后显著相关。支架取栓器被认为是颅内取栓最有效的器械。
分析支架取栓器的机械性能、取栓过程中的行为以及与不同血栓的相互作用，并确定可能与血栓清除效果相关的器械特征。
对截至2015年6月法国市场上所有可用的支架取栓器进行机械和功能测试，旨在研究其径向力变化及其取栓过程中的行为。还使用人血制成的白色和红色实验性血栓在体外取栓过程中对器械进行测试。功能测试和体外取栓使用刚性3D打印血管模型进行。
机械测试显示每个支架在取栓过程中径向力存在变化。取栓过程中恒定的径向力与血管壁上的持续附着以及更高的血栓清除率相关。所有支架取栓器在与白色大血栓（直径≥6 mm）相互作用时均失败。
所测试的器械均无法有效清除大直径（≥6 mm）的白色血栓。取栓过程中恒定的径向力可使器械与血管壁保持恒定附着并对血栓施加压力；这些特征可实现更高的血栓清除率。
