Nguyen Duy T, Smith Alexander F, Jiménez Juan M
Department of Mechanical and Industrial Engineering, University of Massachusetts Amherst, Amherst, MA 01003, USA.
Department of Biomedical Engineering, University of Massachusetts Amherst, Amherst, MA 01003, USA.
J R Soc Interface. 2021 Aug;18(181):20210023. doi: 10.1098/rsif.2021.0023. Epub 2021 Aug 18.
Stent thrombosis (ST) carries a high risk of myocardial infarction and death. Lack of endothelial coverage is an important prognostic indicator of ST after stenting. While stent strut thickness is a critical factor in ST, a mechanistic understanding of its effect is limited and the role of haemodynamics is unclear. Endothelialization was tested using a wound-healing assay and five different stent strut models ranging in height between 50 and 150 µm for circular arc (CA) and rectangular (RT) geometries and a control without struts. Under static conditions, all stent strut surfaces were completely endothelialized. Reversing pulsatile disturbed flow caused full endothelialization, except for the stent strut surfaces of the 100 and 150 µm RT geometries, while fully antegrade pulsatile undisturbed flow with a higher mean wall shear stress caused only the control and the 50 µm CA geometries to be fully endothelialized. Modest streamlining and decrease in height of the stent struts improved endothelial coverage of the peri-strut and stent strut surfaces in a haemodynamics dependent manner. This study highlights the impact of the stent strut height (thickness) and geometry (shape) on the local haemodynamics, modulating reendothelialization after stenting, an important factor in reducing the risk of stent thrombosis.
支架内血栓形成（ST）具有较高的心肌梗死和死亡风险。缺乏内皮覆盖是支架置入术后ST的一个重要预后指标。虽然支架支柱厚度是ST的一个关键因素，但其作用的机制理解有限，且血流动力学的作用尚不清楚。使用伤口愈合试验和五种不同的支架支柱模型进行内皮化测试，这些模型的高度在50至150μm之间，包括圆弧形（CA）和矩形（RT）几何形状，以及一个无支柱的对照。在静态条件下，所有支架支柱表面均完全内皮化。逆转脉动性紊乱血流导致完全内皮化，但100和150μm RT几何形状的支架支柱表面除外，而具有较高平均壁面剪应力的完全顺行脉动性无扰动血流仅导致对照和50μm CA几何形状完全内皮化。适度的流线型设计和支架支柱高度的降低以血流动力学依赖的方式改善了支柱周围和支架支柱表面的内皮覆盖。本研究强调了支架支柱高度（厚度）和几何形状（形状）对局部血流动力学的影响，调节支架置入术后的再内皮化，这是降低支架内血栓形成风险的一个重要因素。
