Stanford A型主动脉夹层的个体化血流数值模拟

Individualized Numerical Simulation of Blood Flow in Stanford Type A Aortic Dissection

目的研究Stanford A型主动脉夹层的血流动力学变化。方法收集4名Stanford A型主动脉夹层患者和2名健康志愿者的主动脉计算机断层扫描血管造影(computed tomography angiography,CTA)图像,建立主动脉三维模型并进行网格划分,使用流体仿真软件对模型进行数值模拟。结果健康志愿者主动脉内血流近似层流。夹层真腔的血流近似层流,位于破口附近的真腔和被假腔压迫的真腔会在局部形成湍流。真腔的壁面压力高于假腔。心脏收缩期,假腔的壁面压力峰值位于夹层第一个破口处,被假腔压迫的真腔和假腔破口处出现较高的壁面剪切力且破口处出现了应力集中。相比于单一破口的夹层,有2个破口的夹层其破口周围的壁面剪切力更低。结论个体化计算流体力学分析可以为主动脉夹层的个性化诊疗提供参考。

Objective To investigate the hemodynamic changes after the occurrence of Stanford type A aortic dissection.Methods Computed tomography angiography(CTA) images of the aorta were collected from 4 Stanford A type aortic dissection patients and 2 healthy volunteers,and the three-dimensional models of the aorta were established and meshed.The above models were numerically simulated by fluid simulation software.Results The blood flow in the aorta of healthy volunteers was approximately laminar.The blood flow field in the true lumen was approximately laminar.Turbulence not only occurred near the intimal tear of the true lumen,but also near the area where the false lumen compressed the true lumen.The wall pressure of the true lumen was higher than that of the false lumen.During the systolic phase,the peak wall pressure of the false lumen was located at the primary entry tear of the dissection,the high wall shear stress appeared around the true lumen compressed by false lumen and the tear of false lumen.Moreover,stress concentration occurred at the intimal tear.Compared to aortic dissection with a single tear,aortic dissection with two tears exhibited lower wall shear stress around the intimal tear.Conclusion Individualized computational fluid dynamics analysis can provide reference for personalized diagnosis and treatment of aortic dissection.