Wei Zhenglun, Singh-Gryzbon Shelly, Trusty Phillip M, Huddleston Connor, Zhang Yingnan, Fogel Mark A, Veneziani Alessandro, Yoganathan Ajit P
Wallace H. Coulter School of Biomedical Engineering, Georgia Institute of Technology, 313 Ferst Drive NW, Atlanta, GA, 30332, USA.
School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, USA.
Ann Biomed Eng. 2020 Aug;48(8):2204-2217. doi: 10.1007/s10439-020-02527-8. Epub 2020 May 5.
The Fontan procedure is a common palliative surgery for congenital single ventricle patients. In silico and in vitro patient-specific modeling approaches are widely utilized to investigate potential improvements of Fontan hemodynamics that are related to long-term complications. However, there is a lack of consensus regarding the use of non-Newtonian rheology, warranting a systematic investigation. This study conducted in silico patient-specific modeling for twelve Fontan patients, using a Newtonian and a non-Newtonian model for each patient. Differences were quantified by examining clinically relevant metrics: indexed power loss (iPL), indexed viscous dissipation rate (iVDR), hepatic flow distribution (HFD), and regions of low wall shear stress (A). Four sets of "non-Newtonian importance factors" were calculated to explore their effectiveness in identifying the non-Newtonian effect. No statistical differences were observed in iPL, iVDR, and HFD between the two models at the population-level, but large inter-patient variations exist. Significant differences were detected regarding A, and its correlations with non-Newtonian importance factors were discussed. Additionally, simulations using the non-Newtonian model were computationally faster than those using the Newtonian model. These findings distinguish good importance factors for identifying non-Newtonian rheology and encourage the use of a non-Newtonian model to assess Fontan hemodynamics.
Fontan手术是先天性单心室患者常见的姑息性手术。计算机模拟和体外患者特异性建模方法被广泛用于研究与长期并发症相关的Fontan血流动力学的潜在改善。然而，关于非牛顿流变学的使用缺乏共识，需要进行系统研究。本研究对12例Fontan患者进行了计算机模拟患者特异性建模，对每位患者使用牛顿模型和非牛顿模型。通过检查临床相关指标来量化差异：指数功率损失（iPL）、指数粘性耗散率（iVDR）、肝血流分布（HFD）和低壁面切应力区域（A）。计算了四组“非牛顿重要性因子”以探索其在识别非牛顿效应方面的有效性。在群体水平上，两个模型在iPL、iVDR和HFD方面未观察到统计学差异，但患者间存在较大差异。在A方面检测到显著差异，并讨论了其与非牛顿重要性因子的相关性。此外，使用非牛顿模型的模拟在计算上比使用牛顿模型的模拟更快。这些发现区分了识别非牛顿流变学的良好重要性因子，并鼓励使用非牛顿模型来评估Fontan血流动力学。
