椎基底动脉延长扩张症的计算流体力学分析

目的：基于计算流体力学（computational fluid dynamics，CFD）技术对椎基底动脉延长扩张症（vertebrobasilar dolichoectasia，VBD）进行血流动力学分析。方法:使用Mimics软件读取1例VBD患者颅内动脉影像的DICOM（digital imaging and communications in medicine）数据，进行三维实体重建，应用Ansys软件对实体模型进行流体力学分析，模拟VBD患者椎基底动脉的血流动力学变化过程，并描述流线、管壁切应力和管壁压力情况。结果: 双侧椎动脉汇合为基底动脉后血流仍表现为分层流动，在基底动脉迂曲部出现绕壁血流。椎基底动脉汇合部及基底动脉下段的局部低壁面切应力和高壁面压力区域相吻合。推测VBD的生长初始部位可能位于椎基底动脉汇合部及基底动脉下段，低壁面切应力导致的血管壁退化及相应区域存在的高壁面压力可能与VBD的发生、发展有关。结论:CFD数值仿真可能为进一步研究血流动力学在VBD发生、发展中的作用提供理论基础。

Analysis of vertebrobasilar dolichoectasia based on computational fluid dynamics

Objective:To anslysis the hemodynamic states of vertebrobasilar dolichoectasia based on computational fluid dynamics technique.Methods:The original DICOM format image data from a patient with vertebrobasilar dolichoectasia (VBD), were imported by the Mimics software directly,and the 3D Objects were constructed.The simulation of model was made with Ansys software, the hemodynamic pa-rameters such as streamlines, wall shear stress( WSS) and wall pressure were described.Results:There was stable laminar flow in proximal basilar artery and was no blood flow mixed by bilateral vertebral arter-y.However, Spiral flows were appeared in distal tortuous basilar artery.The low WSS regions in the ver-tebra-basilar junction section and inferior segment of basilar artery were coincide with the high wall pres-sure regions.It could be speculated the initial growth regions might be located in the vertebra-basilar junction section and inferior segment of basilar artery.Local regions with low WSS and high wall pressure might be associated with the occurrence and development of VBD.Conclusion: CFD numerical simula-tion maybe can provide a theoretical basis for the role of hemodynamic factors in occurrence and develop-ment of VBD.