不同连接筋结构的支架治疗椎动脉狭窄的血流动力学数值模拟

Hemodynamic simulation of vertebral artery stenosis treated by stents with different links

目的研究具有不同连接筋结构的支架治疗椎动脉狭窄后的血流动力学效果,以期为支架的设计以及介入治疗提供更加科学的指导。方法采用Pro/Engineer建立带有狭窄的椎动脉模型和3种不同连接筋的支架模型(根据连接筋形状分别称为L-支架、V-支架和S-支架);在模拟这些支架在狭窄椎动脉中扩张后的结果的基础上分别建立3种支架治疗椎动脉狭窄后的流场有限元模型。利用有限元分析软件ANSYS-CFX对3个模型进行血流动力学数值模拟。结果与V型和S型连接筋相比,L型连接筋造成了较小的低壁面切应力分布面积及较少的血流停滞区。结论 L型连接筋具有较好的血流动力学效果,潜在地降低了支架内再狭窄发生的可能性,从而为支架选择、支架设计和手术规划等提供科学依据。

Objective To investigate the hemodynamic effect of stents with different types of links on treating ver- tebral artery stenosis, and provide scientific guidelines for the design of stent structure and the clinical procedure of stent intervention. Methods Models of vertebral artery with stenosis and three kinds of stents with different types of links （they were named as L-stent, V-stent and S-stent, respectively, according to the shape of links） were constructed by using Pro/Engineering. Based on the simulation results of the expansion of these stents in the stenotic vertebral artery, three finite element models of the stented vertebral artery were established for fluid flow analysis. Hemodynamic simulation was performed for the three models using ANSYS-CFX. Results Com- pared with V-link and S-link stent, L-link stent caused smaller area of low wall shear stress distribuUons and smal- ler blood stagnation area. Conclusions With better hemodynamic effect, L-stent can potentially reduce the pos- sibility of in-stent restenosis and provide scientific references for the choice of stent, the design of stent structure and surgical planning of stent intervention.