Decorato Iolanda, Kharboutly Zaher, Vassallo Tommaso, Penrose Justin, Legallais Cécile, Salsac Anne-Virginie
Biomechanics and Bioengineering Laboratory (UMR CNRS 7338), Université de Technologie de Compiègne, 60203 Compiègne, France.
Int J Numer Method Biomed Eng. 2014 Feb;30(2):143-59. doi: 10.1002/cnm.2595. Epub 2013 Nov 5.
The objective of the study is to investigate numerically the fluid-structure interactions (FSI) in a patient-specific arteriovenous fistula (AVF) and analyze the degree of complexity that such a numerical simulation requires to provide clinically relevant information. The reference FSI simulation takes into account the non-Newtonian behavior of blood, as well as the variation in mechanical properties of the vascular walls along the AVF. We have explored whether less comprehensive versions of the simulation could still provide relevant results. The non-Newtonian blood model is necessary to predict the hemodynamics in the AVF because of the predominance of low shear rates in the vein. An uncoupled fluid simulation provides informative qualitative maps of the hemodynamic conditions in the AVF; quantitatively, the hemodynamic parameters are accurate within 20% maximum. Conversely, an uncoupled structural simulation with non-uniform wall properties along the vasculature provides the accurate distribution of internal wall stresses, but only at one instant of time within the cardiac cycle. The FSI simulation advantageously provides the time-evolution of both the hemodynamic and structural stresses. However, the higher computational cost renders a clinical use still difficult in routine.
本研究的目的是对特定患者的动静脉内瘘（AVF）中的流固相互作用（FSI）进行数值研究，并分析这种数值模拟为提供临床相关信息所需的复杂程度。参考FSI模拟考虑了血液的非牛顿行为以及沿AVF血管壁力学性能的变化。我们探讨了模拟的简化版本是否仍能提供相关结果。由于静脉中低剪切率占主导，非牛顿血液模型对于预测AVF中的血流动力学是必要的。非耦合流体模拟提供了AVF中血流动力学状况的定性信息图；在定量方面，血流动力学参数的最大误差在20%以内。相反，沿血管系统具有非均匀壁特性的非耦合结构模拟提供了内壁应力的准确分布，但仅在心动周期内的某一时刻。FSI模拟有利地提供了血流动力学和结构应力的时间演变。然而，较高的计算成本使得在常规临床应用中仍然困难。
