经皮支架植入过程对左冠状动脉的血流动力学影响

HEMODYNAMIC CHANGES OF THE LEFT CORONARY ARTERY DURING PERCUTANEOUS CORONARY INTERVENTION

经皮冠状动脉介入治疗(percutaneous coronary intervention,PCI)是检查和治疗冠心病的常用手段,冠状动脉支架植入过程中可能引发急性血栓的发生。本文通过血流动力学计算探究PCI支架植入手术过程对急性血栓形成的影响。根据真实的冠状动脉计算机断层扫描影像进行建模,在脉动生理血流条件下模拟该手术过程中导丝介入的5个阶段,获得各项血流动力学参数。计算结果表明,导丝介入过程会导致冠状动脉内各项血流动力学参数发生改变,即冠状动脉内血流出现偏心现象,时均壁面剪切力升高,振荡剪切指数下降,粒子相对停留时间降低,横向壁面剪切应力小幅上升,使得血管的内皮细胞暴露在高壁面剪切力的环境下。虽然较短的相对粒子停留时间、较小的振荡剪切指数对急性血栓的形成具有阻碍作用,但高时均壁面剪切力与血流偏心对急性血栓形成的诱导作用可能更加明显。

Percutaneous coronary intervention(PCI)is widely adopted to check and cure coronary heart disease.However,acute thrombus may occur during surgery.This study aims to numerically find out the underlying mechanism of the acute thrombus during surgery in terms of hemodynamics.Patient-specific 3D models of the coronary arteries(CA)were reconstructed based on the computed tomography scan images.And the hemodynamic parameters in the five stages of PCI guided operation were obtained under pulsatile physiological flow conditions.The results show that the intervention process resulted in changes of hemodynamics in the CAs,such as the eccentric blood flow in the CA,the increased time-averaged wall shear stress(Tawss)and the decreased oscillatory shear index(OSI).Also,the decrease in relative resistance time(RRT)for a particle and the slightly increase in transverse WSS(Transwss)were also observed,which indicates that the vascular endothelial cells are exposed to high WSS.The predispose to the thrombus formation due to the exposure to high Tawss and the eccentricity of blood flow may overweight the inhibition e?ect of low RRT and OSI.