Uncertainty quantification of simulated biomechanical stimuli in coronary artery bypass grafts
Uncertainty quantification of simulated biomechanical stimuli in coronary artery bypass grafts
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DOI：
10.1016/j.cma.2018.10.024
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发表时间：
2019-03-01
影响因子：
7.2
通讯作者：
Marsden, Alison L.
中科院分区：
文献类型：
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作者：
Tran, Justin S.;Schiavazzi, Daniele E.;Marsden, Alison L.
在美国，每年有超过 400,000 名患者接受冠状动脉旁路移植手术 (CABG)。然而，与动脉移植相比，CABG 期间植入的隐静脉移植物 (SVG) 的通畅性较差，术后 10 年内失败率高达 40%。已知机械刺激的差异会导致适应不良，并与内皮损伤和血栓形成相关。由于这些量很难在体内测量，多尺度冠状动脉模型提供了一种量化它们的方法，同时考虑了复杂的冠状动脉生理学。然而，先前的研究主要集中于确定性评估，而没有报告由于不确定性而导致的模型参数的变化。本研究旨在评估壁剪切应力和壁应变多尺度预测的置信度，同时考虑外周血流动力学和材料特性的不确定性。边界条件分布是通过同化不确定的临床数据来计算的，而血管壁刚度的空间变化是通过随机场的近似来获得的。我们开发了一种随机子建模方法，以减轻重复多尺度模型评估的计算负担，以专注于旁路移植。这会将感兴趣的数量两级分解为子模型贡献和完整模型/子模型差异。我们使用先前提出的多分辨率方法在前向不确定性传播的背景下利用这两个级别。时间和空间平均壁剪应力可以很好地估计，其变异系数为
Coronary artery bypass graft surgery (CABG) is performed on more than 400,000 patients annually in the U.S. However, saphenous vein grafts (SVGs) implanted during CABG exhibit poor patency compared to arterial grafts, with failure rates up to 40% within 10 years after surgery. Differences in mechanical stimuli are known to play a role in driving maladaptation and have been correlated with endothelial damage and thrombus formation. As these quantities are difficult to measure in vivo, multi-scale coronary models offer a way to quantify them, while accounting for complex coronary physiology. However, prior studies have primarily focused on deterministic evaluations, without reporting variability in the model parameters due to uncertainty. This study aims to assess confidence in multi-scale predictions of wall shear stress and wall strain while accounting for uncertainty in peripheral hemodynamics and material properties. Boundary condition distributions are computed by assimilating uncertain clinical data, while spatial variations of vessel wall stiffness are obtained through approximation by a random field. We developed a stochastic submodeling approach to mitigate the computational burden of repeated multi-scale model evaluations to focus exclusively on the bypass grafts. This produces a two-level decomposition of quantities of interest into submodel contributions and full model/submodel discrepancies. We leverage these two levels in the context of forward uncertainty propagation using a previously proposed multi-resolution approach. The time- and space-averaged wall shear stress is well estimated with a coefficient of variation of