The influence of boundary conditions on wall shear stress distribution in patients specific coronary trees
The influence of boundary conditions on wall shear stress distribution in patients specific coronary trees
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DOI：
10.1016/j.jbiomech.2011.01.036
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发表时间：
2011-04-07
影响因子：
2.4
通讯作者：
Gijsen, Frank J. H.
中科院分区：
文献类型：
--
作者：
van der Giessen, Alina G.;Groen, Harald C.;Gijsen, Frank J. H.
患者特定的冠状动脉几何数据可以可靠地获得多层计算机断层扫描（MSCT）成像。MSCT不能提供血流动力学变量，必须估计通过侧分支的流出量。两种不同的模型，以确定流动通过侧分支对壁剪切应力（WSS）分布在患者特定的几何评估的影响。默里定律预测通过侧分支的流量比例与侧分支直径的三次方成正比。经验模型是基于Doriot等人（2000）在血管造影正常的冠状动脉中进行的流量测量。基于这些测量结果的拟合表明，通过侧分支的流量比可以用2.27的幂来最好地描述。实验数据表明，默里定律低估了通过侧分支的流量。我们应用这两种模型对6棵冠状动脉树的WSS分布进行了研究。在稳定流动条件下，两种模型的侧枝平均WSS差异显著：Murray定律的平均WSS高出8%，相对差值在-5%到+27%之间。这些差异随流量的不同而变化。在分岔附近，WSS的差异更为明显：应用经验模型时，低WSS区域的大小明显更大（13%），范围从-12%到+68%。根据默里定律预测流出量低估了通过侧分支的流量。特别是在动脉粥样硬化斑块优先发展的侧支附近，差异是显著的，Murray定律的应用低估了低WSS区域的大小。(C) 2011 Elsevier Ltd.版权所有。
Patient specific geometrical data on human coronary arteries can be reliably obtained multislice computer tomography (MSCT) imaging. MSCT cannot provide hemodynamic variables, and the outflow through the side branches must be estimated. The impact of two different models to determine flow through the side branches on the wall shear stress (WSS) distribution in patient specific geometries is evaluated.Murray's law predicts that the flow ratio through the side branches scales with the ratio of the diameter of the side branches to the third power. The empirical model is based on flow measurements performed by Doriot et al. (2000) in angiographically normal coronary arteries. The fit based on these measurements showed that the flow ratio through the side branches can best be described with a power of 2.27. The experimental data imply that Murray's law underestimates the flow through the side branches.We applied the two models to study the WSS distribution in 6 coronary artery trees. Under steady flow conditions, the average WSS between the side branches differed significantly for the two models: the average WSS was 8% higher for Murray's law and the relative difference ranged from -5% to +27%. These differences scale with the difference in flow rate. Near the bifurcations, the differences in WSS were more pronounced: the size of the low WSS regions was significantly larger when applying the empirical model (13%), ranging from -12% to +68%.Predicting outflow based on Murray's law underestimates the flow through the side branches. Especially near side branches, the regions where atherosclerotic plaques preferentially develop, the differences are significant and application of Murray's law underestimates the size of the low WSS region. (C) 2011 Elsevier Ltd. All rights reserved.