Interventions in bifurcation lesions often requires aggressive overexpansion of stent diameter in the setting of long tapering vessel segment. Overhanging struts in front of the side branch (SB) ostium are thought to act as a focal point for thrombi formation and consequently possible stent thrombosis. This study aimed to evaluate the overexpansion capabilities and thrombogenicity at the SB ostia after implantation of four latest generation drug-eluting stents (DES) in an in-vitro bifurcation model. Four clinically available modern DES were utilized: one bifurcation dedicated DES (Bioss LIM C) and three conventional DES (Ultimaster, Xience Sierra, Biomime). All devices were implanted in bifurcation models with proximal optimization ensuring expansion before perfusing with porcine blood. Optical coherence tomography (OCT), immunofluorescence (IF) and scanning electron microscope analysis were done to determine thrombogenicity and polymer coating integrity at the over-expanded part of the stents. Computational fluid dynamics (CFD) was performed to study the flow disruption. OCT (p = 0.113) and IF analysis (p = 0.007) demonstrated lowest thrombus area at SB ostia in bifurcation dedicated DES with favorable biomechanical properties compared to conventional DES. The bifurcated DES also resulted in reduced area of high shear rate and maximum shear rate in the CFD analysis. This study demonstrated numerical differences in terms of mechanical properties and acute thrombogenicity at SB ostia between tested devices.

分叉病变的干预通常要求在血管逐渐变细的情况下支架直径过度扩张。侧支（SB）口前的悬垂支柱被认为是形成血栓并因此可能引起支架血栓的焦点。这项研究旨在评估在体外分叉模型中植入四个最新一代药物洗脱支架（DES）后，SB口的过度扩张能力和血栓形成性。利用了四种临床上可用的现代DES：一种分叉专用DES（Bioss LIM C）和三种常规DES（Ultimaster，Xience Sierra和Biomime）。所有设备均植入分叉模型中，并进行了近端优化，以确保在灌注猪血之前进行扩展。光学相干断层扫描（OCT），进行了免疫荧光（IF）和扫描电子显微镜分析，以确定支架过度膨胀部分的血栓形成性和聚合物涂层的完整性。进行了计算流体动力学（CFD）以研究流动中断。十月（p  = 0.113）和IF分析（p  = 0.007）证明，与传统DES相比，分叉专用DES中SB口处的血栓面积最低。在CFD分析中，分叉的DES还导致高剪切速率和最大剪切速率的面积减小。这项研究表明，在受测装置之间，机械性能和SB口处急性血栓形成的数值差异。