主动脉瓣狭窄对升主动脉瘤流场特征的影响

Effects of Aortic Valve Stenosis on the Flow Field Characteristics of Ascending Aortic Aneurysm

【目的】基于计算流体力学技术,及血流动力学指标评价主动脉瓣狭窄对升主动脉瘤流场特征的影响。【方法】回顾性分析2017年1月至2021年12月中山大学孙逸仙纪念医院63名升主动脉扩张或升主动脉瘤的入院患者,根据瓣口面积分为主动脉瓣狭窄组及非狭窄组,对两组患者进行倾向性匹配分析后,比较两组的血流动力学指标(如:压力、剪切应变率(SSR)、壁面剪切力(WSS)、时间均化剪切应变率(TASSR)和时间均化壁面剪切力(TAWSS));并根据中心线划分升主动脉为6块具有独特空间特征的区域,比较两组6块区域之间血流动力学指标的差异。【结果】主动脉瓣狭窄组升主动脉的SSR(191.70[117.22~248.78]s^(-1))和WSS(2.87[1.88~4.00]Pa)与非狭窄组的SSR(93.23[68.59~145.35]s^(-1))和WSS(1.20[1.04~2.18]Pa)相比,差异具有统计学意义(SSR:Z=2.167,P=0.030;WSS:Z=2.233,P=0.026),且差异主要表现在升主动脉近端及小弯侧(P<0.05)。而压力、TASSR或TAWSS的差异无统计学意义。【结论】主动脉瓣狭窄改变了升主动脉扩张或升主动脉瘤的血流动力学,增大了正切于血管的力(如:SSR、WSS),而对垂直于血管的力(如:压力)无明显的影响。

【Objection】To evaluate the effects of aortic valve stenosis on the flow field characteristics of ascending aor⁃tic aneurysm by computational fluid dynamics and hemodynamic indexes.【Methods】A total of 63 patients aged 18 or over with ascending aortic dilation or aneurysm were retrospectively recruited from Sun Yat-sen Memorial Hospital of Sun Yat sen University and assigned to aortic valve stenosis(AS)or none aortic valve stenosis(NAS)group.Propensity score matching analysis and ascending aortic division based on centerline were performed to compare the hemodynamic indexes[pressure,shear stress rate(SSR),wall shear stress(WSS),time average shear stress rate(TASSR),time average wall shear stress(TAWSS)].【Results】There were significant differences in SSR(191.70[117.22~248.78]s^(-1)vs.93.23[68.59~145.35]s^(-1),Z=2.167,P=0.030)and WSS(2.87[1.88~4.00]Pa vs.1.20[1.04~2.18]Pa,Z=2.233,P=0.026)between AS group and NAS group.The differences were mainly found in the proximal and lesser curvature of as⁃cending aorta(P<0.05).There was no statistical significance in pressure,TASSR or TAWSS.【Conclusions】Aortic valve stenosis alters the hemodynamics in ascending aortic dilation or aneurysms,which increases tangential component force(e.g.SSR,WSS)but has no significant effects on perpendicular component force(e.g.pressure).