Toshiba Stroke Research Center and Department of Mechanical and Aerospace Engineering, State University of New York, Buffalo, New York 14214, USA.
Neurosurgery. 2013 Sep;73(3):497-505. doi: 10.1227/NEU.0000000000000016.
Intracranial aneurysms (IAs) occur more frequently at certain bifurcations than at others. Hemodynamic stress, which promotes aneurysm formation in animal models, also differs among bifurcations, depending on flow and vessel geometry.
To determine whether locations that are more likely to develop IAs experience different hemodynamic stresses that might contribute to higher IA susceptibility.
We characterized the hemodynamic microenvironment at 10 sites in or around the circle of Willis where IAs commonly occur and examined statistical relationships between hemodynamic factors and the tendency for a site to form IAs. The tendency for each site to develop IAs was quantified on the basis of the site distribution from systematic literature analysis of 19 reports including 26418 aneurysms. Hemodynamic parameters for these sites were derived from image-based computational fluid dynamics of 114 cerebral bifurcations from 31 individuals. Wall shear stress and its spatial gradient were calculated in the impact zone surrounding the bifurcation apex. Linear and exponential regression analyses evaluated correlations between the tendency for IA formation and the typical hemodynamics of a site.
IA susceptibility significantly correlated with the magnitudes of wall shear stress and positive wall shear stress gradient within the hemodynamic impact zone calculated for each site.
IAs occur more frequently at cerebral bifurcations that typically experience higher hemodynamic shear stress and stronger flow acceleration, conditions previously shown to promote aneurysm initiation in animals.
颅内动脉瘤（IAs）在某些分叉处比在其他分叉处更常见。在动物模型中促进动脉瘤形成的血流动力学应力也因分叉处的流量和血管几何形状而异。
确定是否更有可能发生 IAs 的位置会经历不同的血流动力学应激，这可能有助于提高 IAs 的易感性。
我们在 Willis 环内或周围的 10 个位置表征了常见发生 IAs 的部位的血流动力学微环境，并检查了血流动力学因素与部位发生 IAs 的倾向之间的统计关系。根据 19 项报告（包括 26418 个动脉瘤）的系统文献分析中各部位的分布，定量评估了各部位发生 IAs 的倾向。这些部位的血流动力学参数是从 31 个人的 114 个大脑分叉的基于图像的计算流体动力学中得出的。在分叉顶点周围的冲击区域计算壁面剪切应力及其空间梯度。线性和指数回归分析评估了 IA 形成倾向与部位典型血流动力学之间的相关性。
IA 易感性与为每个部位计算的血流动力学冲击区域内的壁面剪切应力和正壁面剪切应力梯度的大小显著相关。
在通常经历更高血流切应力和更强流动加速的大脑分叉处，更容易发生 IAs，这是先前在动物中促进动脉瘤起始的条件。
