Department of Energy Sciences, Lund Institute of Technology, P.O. Box 118, SE-221 00 Lund, Sweden.
Med Eng Phys. 2010 Mar;32(2):189-202. doi: 10.1016/j.medengphy.2009.11.008. Epub 2010 Jan 19.
The exact role of fluid mechanics in the patho-physiological process of atherosclerosis has been a research topic over many years, yet without clear conclusive result. One has observed that morphological manifestations of the disease are found at some well-defined locations: certain vessel bifurcations and in curvatures. The flow in these regions is characterized by unsteadiness and often separation. Currently there are no complete theories that can explain the process since the different components in the process are not fully understood. Here we carry out detailed computations of the unsteady flow in an arterial segment typical to location of early appearance of arterial lesions. We study the wall shear stress (WSS) field variations near a junction with the purpose of identifying fluid-mechanical parameters that can be related to sites of atherosclerosis. The results show that regions associated with atherosclerosis experience highly elevated temporal- and spatial-derivatives of the WSS, also at less commonly known locations. Thus, large derivatives in time and space do not seem unique for the most common areas of atherosclerosis. Differences in WSS character between these locations are identified as differences in the time period of back flow as well as differences in the magnitude of the WSS derivatives. The data is presented in a way that facilitates understanding of the variations in WSS.
多年来，流体力学在动脉粥样硬化病理生理过程中的确切作用一直是研究课题，但没有明确的结论。人们已经观察到，这种疾病的形态表现出现在一些明确的位置：某些血管分叉处和弯曲处。这些区域的流动具有非稳定性，并且经常发生分离。目前还没有完整的理论可以解释这个过程，因为过程中的不同组成部分还没有被完全理解。在这里，我们对动脉病变早期出现部位的典型动脉段中的非定常流进行了详细的计算。我们研究了与交界处附近的壁面剪切应力 (WSS) 场变化，目的是确定可以与动脉粥样硬化部位相关的流体力参数。结果表明，与动脉粥样硬化相关的区域经历了高度升高的 WSS 时间和空间导数，即使在不太常见的位置也是如此。因此，时间和空间上的大导数似乎不是动脉粥样硬化最常见区域的独特特征。这些位置之间的 WSS 特征差异被确定为回流时间的差异以及 WSS 导数的幅度的差异。数据以一种便于理解 WSS 变化的方式呈现。
