出口边界条件对脑前交通动脉瘤内血流特征的影响

The influence of outflow boundary conditions on blood flow patterns in an AcoA aneurysm

脑前交通动脉是动脉瘤高发且易破裂的区域,其所处的多血管交汇位置使瘤内流场易受周边血流环境的影响。该文以理想化的动脉瘤模型为研究对象,采用CFD方法开展数值实验,考察了模型出口边界条件对瘤内血流参数的影响。结果表明,瘤内流场的结构特征、壁面剪切力等均随模型子管间流量分配比的改变而变化,同时,各参数的受影响程度与所处位置有关。虽然单一模型分析限制了该文研究结论的统计学意义,但研究结果明确了瘤内流场对边界条件的敏感性,提示在脑前交通动脉瘤的血流分析和风险评估中充分考虑脑动脉网络结构及系统血流环境的必要性。

Anterior communicating artery（ACo A） is among the cerebral arteries most susceptible to aneurysm development and rupture, its special location（at the junction of multiple arteries） makes blood flows in an ACo A aneurysm prone to the influence of the surrounding hemodynamic conditions. In this study, numerical experiments were performed on an idealized ACo A aneurysm model to investigate the sensitivity of intra-aneurysm blood flows to boundary conditions. Obtained results showed that varying the flow division between the daughter vessels led to significant changes in intra-aneurysm flow patterns and wall shear stress distribution, with the degree of changes varying with the site relative to the aneurysm. Although a single-model-based analysis compromised the statistical significance of the results, our study clearly demonstrated the sensitivity of intra-aneurysm flows to boundary conditions, implying that it would be necessary to fully take into account the anatomy of the cerebral artery network and systemic hemodynamics when studying blood flows in or assessing the risk of an ACo A aneurysm.