单纯支架治疗梭形动脉瘤的计算机仿真及血流动力研究

Computer simulation and hemodynamic analysis for sole stent treatment of fusiform aneurysm

目的血流导向是治疗颅内梭形或宽颈动脉瘤的重要概念。本研究拟通过计算机仿真技术,探讨单纯多支架治疗梭形动脉瘤的血流导向作用。方法选用病例特异性的椎动脉梭形动脉瘤CFD模型。使用快速虚拟支架植入法植入1～3枚Enterprise支架。使用ICEMCFD软件进行网格化处理,ANSYS软件进行血流动力学分析,比较不同数量支架植入后的各项血流动力学参数的变化。结果虚拟支架植入后支架位置良好、贴壁满意。虚拟植入1～3枚支架后,梭形动脉瘤壁的平均瘤壁面切应力(WSS)分别下降了10%、20.4%和28.3%;经过瘤体最大截面的血流量分别下降了9.6%、21%和32.6%;相对滞留时间延长至支架植入前的1.45倍、2.07倍和2.79倍;动脉瘤壁平均压力变化不大。结论单纯支架治疗颅内梭形动脉瘤具有血流导向作用,随着支架数量增加,上述作用明显增强。快速虚拟支架植入法仿真度高、操作时间短,是适用于临床的虚拟支架植入技术。

Objective Flow diversion is quite an important concept in treating intracranial aneurysms. This study aimed to evaluate the flow diversion effects of stent only treatment for intracranial fusiform aneurysms. Methods Patient-specific computational fluid dynamics （CFD） model for vertebral artery fusiform aneurysm was reconstructed from three dimention rotation angiography. One to three Enterprise stents were virtually implanted to reconstruct the parent artery. Subsequent hemodynamic analysis was performed with ANSYS. Hemodynamic parameters were compared when different number of stents was implanted. Results Stents were virtually deployed with perfect position and configuration. After the implantation of t to 3 stents, aneurysmal wall shear stress （WSS） was reduced by t0%, 20.4%, and 28.3%. The flow volume crossing the biggest transversal surface was reduced by 9.6%, 21%, and 32.6%. The aneurysmal relative residence time was increased to 145%, 207% , and 279%. The change of average pressure on the aneurysm wall is insignificant. Conclusion Stent only treatment is effective to divert the blood flow, and the effect was enhanced by additional stent deployment. Fast virtual stenting technique is efficacious and convenient to simulate the procedure of endovascular stenting.