基于病例研究冠状动脉扭曲对血流动力学的影响

Effect of Coronary Artery Tortuosity on Coronary Hemodynamics Based on Case Study

目的探讨扭曲冠状动脉血流动力学的改变,从而阐明扭曲对冠状动脉血流灌注和壁面切应力（wall shear stress,WSS）的影响。方法选取冠状动脉左前降支（left anterior descending,LAD）扭曲和无扭曲两例个体病例,在Mimics软件中重建出LAD扭曲和无扭曲血管模型,并将模型导入ANSYS Fluent软件中进行血流动力学模拟计算,比较两种不同LAD模型的血流动力学情况。结果扭曲的冠状动脉在最大曲率大于1 mm^-1的弯曲处WSS下降较为明显,这种情况可能导致下游供血不足;弯曲外侧具有较低WSS（0～26 Pa）,而弯曲内侧WSS相对较高（〉100 Pa）;无扭曲和扭曲血管WSS均值分别为10.79、36.12 Pa,相比于无扭曲血管,扭曲血管整体WSS增高。结论扭曲冠状动脉整体WSS增高,从而可能延缓冠状动脉粥样硬化的进展。

Objective To investigate the hemodynamic changes in a tortuous coronary to elucidate the effects of tortuosity on coronary perfusion and wall shear stress（ WSS）. Methods A single tortuous and non-tortuous patient-specific left anterior descending（ LAD） coronary artery cases were selected. Two LAD models with and without coronary tortuosity were reconstructed in Mimics software and then transferred to the ANSYS Fluent software for performing computational fluid dynamics（ CFD） simulation. The hemodynamic characteristics of both the LAD models were compared. Results The vessel WSS of the tortuous coronary artery clearly decreased in the bend section where the maximum curvature was larger than 1 mm^-1. Such a scenario could led to an inadequate blood supply in the downstream vessels. A low WSS（ 0-26 Pa） acted on the outer wall of the bend,whereas the inner wall of the bend had a high WSS（ 〉100 Pa）. The mean WSS of the non-tortuous and tortuous models was 10. 79 Pa and 36. 12 Pa,respectively. The overall WSS of the tortuous model was larger compared with that of the non-tortuous model. Conclusions Coronary tortuosity increased the overall WSS,which could delay the progress of coronary atherosclerosis.