Department of Mathematics, University of Houston, 4800 Calhoun Rd, Houston, TX 77204, USA.
Math Biosci Eng. 2013 Apr;10(2):295-318. doi: 10.3934/mbe.2013.10.295.
Recent in vivo studies, utilizing ultrasound contour and speckle tracking methods, have identified significant longitudinal displacements of the intima-media complex, and viscoelastic arterial wall properties over a cardiac cycle. Existing computational models that use thin structure approximations of arterial walls have so far been limited to models that capture only radial wall displacements. The purpose of this work is to present a simple fluid-struture interaction (FSI) model and a stable, partitioned numerical scheme, which capture both longitudinal and radial displacements, as well as viscoelastic arterial wall properties. To test the computational model, longitudinal displacement of the common carotid artery and of the stenosed coronary arteries were compared with experimental data found in literature, showing excellent agreement. We found that, unlike radial displacement, longitudinal displacement in stenotic lesions is highly dependent on the stenotic geometry. We also showed that longitudinal displacement in atherosclerotic arteries is smaller than in healthy arteries, which is in line with the recent in vivo measurements that associate plaque burden with reduced total longitudinal wall displacement. This work presents a first step in understanding the role of longitudinal displacement in physiology and pathophysiology of arterial wall mechanics using computer simulations.
最近的体内研究利用超声轮廓和斑点跟踪方法，确定了中膜复合层在心动周期内的显著纵向位移和粘弹性动脉壁特性。现有的使用动脉壁薄结构近似的计算模型迄今为止仅限于仅捕获径向壁位移的模型。本工作的目的是提出一种简单的流固相互作用（FSI）模型和一种稳定的、分区的数值方案，该方案可捕获纵向和径向位移以及粘弹性动脉壁特性。为了测试计算模型，我们将颈总动脉和狭窄冠状动脉的纵向位移与文献中的实验数据进行了比较，结果显示出极好的一致性。我们发现，与径向位移不同，狭窄病变中的纵向位移高度依赖于狭窄的几何形状。我们还表明，动脉粥样硬化动脉中的纵向位移小于健康动脉中的纵向位移，这与最近的体内测量结果一致，这些结果将斑块负担与总纵向壁位移减少相关联。这项工作代表了使用计算机模拟理解动脉壁力学中纵向位移在生理学和病理生理学中作用的第一步。
