Three-dimensional distribution of wall shear stress and its gradient in red cell-resolved computational modeling of blood flow in in vivo-like microvascular networks
Three-dimensional distribution of wall shear stress and its gradient in red cell-resolved computational modeling of blood flow in in vivo-like microvascular networks
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DOI：
10.14814/phy2.14067
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发表时间：
2019-05-01
影响因子：
2.5
通讯作者：
Bagchi, Prosenjit
中科院分区：
文献类型：
--
作者：
Balogh, Peter;Bagchi, Prosenjit
使用高保真，三维计算模型的微血管网络中的血流，我们提供了完整的三维分布的壁切应力（WSS），其梯度（WSSG），并量化的影响，红细胞（RBC）WSS和WSSG。在模型中精确地解决了单个RBC的变形和流动动力学，同时考虑了由多个分叉、会聚和曲折血管组成的生理上真实的微血管网络。预测整个网络中WSS和WSSG的强烈异质性，最高WSS发生在毛细血管前分叉和毛细血管中。WSS和WSSG的3D变化显示出由于网络形态和RBC的影响而发生。与不存在RBC时相比，RBC使WSS增加多达三倍，并且在小静脉中观察到最高的增加。WSSG也显著增加，并且在RBC存在的情况下，在更广泛的区域中出现高WSSG。在大多数血管中，在RBC存在下观察到WSSG的周向分量大于轴向分量，而当不考虑RBC时观察到相反的趋势。这些结果强调了红细胞对WSS和WSSG的重要作用，这不能通过广泛使用的网络血流的1D模型来预测。此外，由本模型预测的WSS和WSSG的亚内皮尺度变化在微血管系统中的内皮细胞功能方面具有影响。
Using a high-fidelity, 3D computational model of blood flow in microvascular networks, we provide the full 3D distribution of wall shear stress (WSS), and its gradient (WSSG), and quantify the influence of red blood cells (RBCs) on WSS and WSSG. The deformation and flow dynamics of the individual RBCs are accurately resolved in the model, while physiologically realistic microvascular networks comprised of multiple bifurcations, convergences, and tortuous vessels are considered. A strong heterogeneity in WSS and WSSG is predicted across the networks, with the highest WSS occurring in precapillary bifurcations and capillary vessels. 3D variations of WSS and WSSG are shown to occur due to both network morphology and the influence of RBCs. The RBCs increase the WSS by as much as three times compared to that when no RBCs are present, and the highest increase is observed in venules. WSSG also increases significantly, and high WSSGs occur over wider regions in the presence of RBCs. In most vessels, the circumferential component of WSSG is observed to be greater than the axial component in the presence of RBCs, while the opposite trend is observed when RBCs are not considered. These results underscore the important role of RBCs on WSS and WSSG that cannot be predicted by widely used 1D models of network blood flow. Furthermore, the subendothelium-scale variations of WSS and WSSG predicted by the present model have implications in terms of endothelial cell functions in the microvasculature.