不同血压环境下椎动脉粥样硬化仿真研究

Simulation Study of Vertebral Atherosclerosis under Different Blood Pressure

针对椎动脉粥样硬化后脑组织缺血现象,探讨血管狭窄及血压变化下的血流动力学响应,根据剪切应力及流速对动脉易损部位进行预测.基于CTA影像数据,利用逆向方法构建了椎动脉单侧狭窄模型,开展椎动脉壁面与血流双向流固耦合仿真,观察血流矢量速度与血管壁面剪切应力变化.通过与临床椎动脉狭窄术前术后流速对比,验证了椎–基底动脉有限元模型有效性.结果显示,随血压级别升高,基底动脉顶端产生动脉瘤区域局部发生壁面剪切应力下降现象,狭窄侧椎动脉流速下降,健康侧椎动脉流速提升,基底动脉整体流速上升,加剧血液对动脉瘤冲击作用.研究结果为进一步开展对椎–基底动脉粥样硬化模型的血流动力学的响应机理研究奠定基础,为椎–基底动脉血管扩张手术提供理论依据.

In view of the phenomenon of cerebral tissue ischemia after vertebral atherosclerosis,hemodynamic response under the condition of vascular stenosis and blood pressure changes was investigated.Based on the CTA image data,a unilateral vertebral artery stenosis model was constructed by using the reverse method,and the simulation of two-way fluid-solid coupling between vertebral artery wall and blood flow was carried out to observe the changes of blood flow vectorvelocity and vascular wall shear stress.The effectiveness of the vertebra-basilar finite element model was verified by comparing it with the flow velocity before and after clinical vertebral artery stenosis operation.The results showed that with the increase of blood pressure,the wall shear stress in the area with aneurysm at the top of the basilar artery decreasedlocally,the flow velocity of the vertebral artery on the narrow side decreased,the flow velocity of the vertebral artery on the healthy side increased,and the overall flow velocity of the basilar artery increased,exacerbating the impact of blood on the aneurysm.The results lay a foundation for further studies on the hemodynamic response mechanism of the vertebrobasilaratherosclerosis model and provide a theoretical basis for the operation of vertebrobasilar artery vasodilation.