Aneurysm growth occurs at region of low wall shear stress: patient-specific correlation of hemodynamics and growth in a longitudinal study.
Aneurysm growth occurs at region of low wall shear stress: patient-specific correlation of hemodynamics and growth in a longitudinal study.
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DOI：
10.1161/strokeaha.108.521617
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发表时间：
2008-11
期刊：
影响因子：
8.3
通讯作者：
Saloner D
中科院分区：
文献类型：
--
作者：
Boussel L;Rayz V;McCulloch C;Martin A;Acevedo-Bolton G;Lawton M;Higashida R;Smith WS;Young WL;Saloner D
颅内动脉瘤疾病的发展与作用于血管壁的血流动力学力有关。据报道，低壁剪切应力（WSS）对内皮细胞的正常生理有负面影响，可能是动脉壁局部重塑和动脉瘤生长和破裂的重要因素。使用在两个不同时间点（两个时间点之间平均16.4±7.4个月）获得的MR血管造影数据构建7个患者特异性颅内动脉瘤模型。采用数值模拟的方法对基线几何形状的流动进行了模拟，计算了WSS的分布。由两个时间点构建的管腔几何形状是人工共同注册的，并且壁的径向位移是逐像素计算的。这种位移与动脉瘤的局部生长相对应，并与该位置心脏周期的时间平均壁剪切应力（WSSTA）进行比较。为了进行统计分析，如果径向位移大于MR像素分辨率（0.3 mm）的一半，则认为径向位移显著。位移小于和大于0.3 mm区域的平均WSSTA值分别为2.55 +/−3.6和0.76 +/−1.5 Pa （p<0.001）。线性相关分析显示WSSTA与地表位移之间存在显著关系（p<0.001）。这些结果表明，动脉瘤生长可能发生在血管壁内皮层暴露于异常低壁剪切应力的区域。
Evolution of intracranial aneurysmal disease is known to be related to hemodynamic forces acting on the vessel wall. Low Wall Shear Stress (WSS) has been reported to have a negative effect on endothelial cells normal physiology and may be an important contributor to local remodeling of the arterial wall and to aneurysm growth and rupture. Seven patient-specific models of intracranial aneurysms were constructed using MR angiography data acquired at two different time points (mean 16.4 +/− 7.4 months between the two time points). Numerical simulations of the flow in the base-line geometries were performed to compute WSS distributions. The lumenal geometries constructed from the two time points were manually co-registered and the radial displacement of the wall was calculated on a pixel-by-pixel basis. This displacement, corresponding to the local growth of the aneurysm, was compared to the time-averaged wall shear stress (WSSTA) through the cardiac cycle at that location. For statistical analysis, radial displacement was considered to be significant if it was larger than half of the MR pixel resolution (0.3 mm). Mean WSSTA values obtained for the areas with a displacement smaller and greater than 0.3 mm were 2.55 +/− 3.6 and 0.76 +/− 1.5 Pa respectively (p<0.001). A linear correlation analysis demonstrated a significant relationship between WSSTA and surface displacement (p<0.001). These results indicate that aneurysm growth is likely to occur in regions where the endothelial layer lining the vessel wall is exposed to abnormally low wall shear stress.