颅内破裂动脉瘤的血流动力学特征:基于流固耦合技术的计算流体力学模拟分析

目的 探讨颅内破裂动脉瘤破裂点和瘤囊处血流动力学特征。方法 选择2018年1月至2019年6月收治的颅内破裂动脉瘤21例,根据术前CTA、DSA数据三维重建动脉瘤模型,采用ANSYS软件计算动脉瘤破裂点和瘤囊处血流动力相关参数[壁剪切应力（WSS）、切应力震荡指数（OSI）]。结果 动脉瘤破裂点WSS[（0.215±0.047）Pa]明显低于瘤囊WSS[（0.464±0.148）Pa;P<0.001]。动脉瘤破裂点OSI[（0.035±0.024）]与瘤囊OSI[（0.030±0.016）]无统计学差异（P>0.05）。在一个心动周期中,随着血流动力学的变化,动脉瘤形态出现规律的变化,载瘤动脉及动脉瘤的形态变化存在明显差异,即动脉瘤两侧壁的形态变化相对较小,动脉瘤破裂点处形态变化明显。结论 颅内动脉瘤破裂点较动脉瘤囊WSS更低而形态变化更大,颅内动脉瘤破裂与WSS呈负相关,而与形态变化呈正相关。

Hemodynamic characteristics of rupture point and aneurysm sac of ruptured intracranial aneurysms: computational fluid dynamics simulation and analysis based on fluid-structure coupling technology

Objective To explore the hemodynamic characteristics of the rupture point and aneurysm sac of the ruptured intracranial aneurysms. Methods The three-dimensional aneurysmal models were reconstructed using three-dimensional reconstruction technique using the preoperative CTA and DSA data obtained from 21 patients with ruptured intracrainel aneurysm who were admitted to our hospital from January 2018 to June 2019. The hemodynamic parameters including wall shear stress (WSS) and shear stress oscillation index (OSI), blood flow velocity and shape were calculated by computational fluid dynamic simulation using ANSYS software. Results The mean WSS [(0.215±0.047) Pa] of the rupture point was significantly lower than taht [(0.464±0.148) Pa] of the aneurysm sac (P<0.001). There was no statistical differcnce in OSI between the rupture point and the aneurysm sac [(0.035±0.024) vs. (0.030±0.016); P>0.05]. In a cardiac cycle, the shape of the aneurysm changed regularly with the change of hemodynamics. There were obvious differences in the morphological changes of the parent arteries and the aneurysms. The morphological changes at the rupture point were more obvious than the aneurysm sac. Conclusions The WSS of rupture point in intracranial aneurysm is lower than that of the aneurysm sac, but the morphological changes are more obvious. The rupture of intracranial aneurysm is negatively correlated with the WSS, but is positively correlated with the morphological changes.