A numerical parametric study of the mechanical action of pulsatile blood flow onto axisymmetric stenosed arteries
A numerical parametric study of the mechanical action of pulsatile blood flow onto axisymmetric stenosed arteries
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DOI：
10.1016/j.medengphy.2012.02.010
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发表时间：
2012-12-01
影响因子：
2.2
通讯作者：
Delache, Alexandre
中科院分区：
文献类型：
--
作者：
Belzacq, Tristan;Avril, Stephane;Delache, Alexandre
在本文中，开发了一个流体-结构相互作用模型，质疑的机械作用的血液到动脉粥样硬化斑块的长度和狭窄的严重程度的影响。一个轴对称模型被认为是。假设流体是牛顿流体。斑块被建模为由动脉壁、脂质核心和纤维帽组成的异质超弹性各向异性固体。规定了实际脉动血流的瞬时速度和压力条件。模拟是使用COMSOL商业有限元软件包中的任意拉格朗日欧拉格式实现的。结果揭示了根据狭窄的长度（表示为L）和严重性（表示为S）的不同类型的行为。大斑块（L > 10 mm）在血压的作用下大多变形，而短斑块（L < 10 mm）似乎受到剪应力的显著影响。剪应力倾向于通过挤压使斑块变形，这种效应被称为“挤压效应”。它对斑块的机械响应有重要影响。对于半径严重度S = 45%相同的两个斑块，短斑块（L = 5 mm）的纤维帽中的最大应力比较大斑块（L = 10 mm）的纤维帽中的最大应力大50%，并且最大壁切应力增加了100%。如果这些结果得到实验研究的证实，这些结果可能为理解短斑块的脆弱性提供一些新的视角。(C)2012年IPEM。由爱思唯尔有限公司出版。保留所有权利。
In the present paper, a fluid-structure interaction model is developed, questioning how the mechanical action of the blood onto an atheromatous plaque is affected by the length and the severity of the stenosis. An axisymmetric model is considered. The fluid is assumed Newtonian. The plaque is modelled as a heterogeneous hyperelastic anisotropic solid composed of the arterial wall, the lipid core and the fibrous cap. Transient velocity and pressure conditions of actual pulsatile blood flow are prescribed. The simulation is achieved using the Arbitrary Lagrangian Eulerian scheme in the COMSOL commercial Finite Element package. The results reveal different types of behavior in function of the length (denoted L) and severity (denoted S) of the stenosis. Whereas large plaques (L > 10 mm) are mostly deformed under the action of the blood pressure, it appears that shorter plaques (L < 10 mm) are significantly affected by the shear stresses. The shear stresses tend to deform the plaque by pinching it. This effect is called: "the pinching effect". It has an essential influence on the mechanical response of the plaque. For two plaques having the same radius severity S = 45%, the maximum stress in the fibrous cap is 50% larger for the short plaque (L = 5 mm) than for a larger plaque (L = 10 mm), and the maximum wall shear stress is increased by 100%. Provided that they are confirmed by experimental investigations, these results may offer some new perspectives for understanding the vulnerability of short plaques. (C) 2012 IPEM. Published by Elsevier Ltd. All rights reserved.