Three-dimensional macro-scale assessment of regional and temporal wall shear stress characteristics on aortic valve leaflets
Three-dimensional macro-scale assessment of regional and temporal wall shear stress characteristics on aortic valve leaflets
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DOI：
10.1080/10255842.2015.1052419
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发表时间：
2016-04-25
影响因子：
1.6
通讯作者：
Sucosky, P.
中科院分区：
文献类型：
--
作者：
Cao, K.;Bukac, M.;Sucosky, P.
主动脉瓣（AV）实现左心室和主动脉之间的单向血液流动。尽管血流动力学应力已被证明可以调节瓣膜生物学，但AV小叶所经历的原生壁剪切应力（WSS）仍在很大程度上未知。本研究的目的是利用流固耦合模型对宏观尺度的小叶WSS环境进行量化计算。采用任意拉格朗日-欧拉方法来预测受生理跨瓣压力影响的三维房室几何结构中的瓣流和小叶动力学。用时间剪切强度（TSM）、振荡剪切指数（OSI）和时间剪切梯度（TSG）量化局部WSS特征。在小叶上预测的优势径向WSS在脑室上表现出高振幅和单向性(TSM>7.50dyn/cm(2), OSI325.54dyn/cm(2)s)，而在纤维上表现出低振幅和双向性（tssm0.38, TSG0.25）。本研究为小叶血流相互作用在瓣膜功能中的作用提供了新的见解，并为评估房颤疾病的血流动力学理论提供了关键的血流动力学应力数据。
The aortic valve (AV) achieves unidirectional blood flow between the left ventricle and the aorta. Although hemodynamic stresses have been shown to regulate valvular biology, the native wall shear stress (WSS) experienced by AV leaflets remains largely unknown. The objective of this study was to quantify computationally the macro-scale leaflet WSS environment using fluid-structure interaction modeling. An arbitrary Lagrangian-Eulerian approach was implemented to predict valvular flow and leaflet dynamics in a three-dimensional AV geometry subjected to physiologic transvalvular pressure. Local WSS characteristics were quantified in terms of temporal shear magnitude (TSM), oscillatory shear index (OSI) and temporal shear gradient (TSG). The dominant radial WSS predicted on the leaflets exhibited high amplitude and unidirectionality on the ventricularis (TSM>7.50dyn/cm(2), OSI325.54dyn/cm(2)s) but low amplitude and bidirectionality on the fibrosa (TSM0.38, TSG0.25). This study provides new insights into the role played by leaflet-blood flow interactions in valvular function and critical hemodynamic stress data for the assessment of the hemodynamic theory of AV disease.