Numerical simulation of aneurysmal haemodynamics with calibrated porous-medium models of flow-diverting stents
Numerical simulation of aneurysmal haemodynamics with calibrated porous-medium models of flow-diverting stents
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DOI：
10.1016/j.jbiomech.2018.08.026
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发表时间：
2018-10-26
影响因子：
2.4
通讯作者：
Qian, Yi
中科院分区：
文献类型：
--
作者：
Li, Yujie;Zhang, Mingzi;Qian, Yi
将血流导向（FD）支架建模为多孔介质（PM）显著提高了颅内动脉瘤治疗研究中计算流体动力学（CFD）模拟的效率。然而，到目前为止，用于模拟的PM模型的参数很少被校准以匹配所表示的FD结构。因此，我们试图评估具有代表性的各种市售支架的PM参数，从而表征市场上不同FD器械的血流导向行为。我们为使用PED、Silk+、FRED和双PED支架的治疗生成了完全解析的几何形状。然后，我们根据CFD模拟相应推导出每种支架设计的校准PM参数-渗透率（k）和惯性阻力因子（C-2），以确保校准PM模型与其代表的FD支架具有相同的流动阻力。分别在两个动脉瘤中部署每个校准的PM模型，我们研究了这些支架配置的血流导向效应，这项工作首次报告了PM模型的几组参数，这对于解决当前的知识差距和纠正PM模型模拟中的错误至关重要，从而为未来使用PM模型的研究设置正确的建模协议。流动阻力参数受到市售支架的孔隙率和有效厚度的强烈影响，因此在PM模型中得到了解释。使用PM支架模型进行的流动模拟显示了不同支架设计之间的稳态质量流率（MFR）和能量损失（EL）的差异。本研究通过使用校准的PM模型改进了FD模拟的实用性，提供了一种具有改进的模拟效率和准确性的个性化方法。(C)2018爱思唯尔有限公司版权所有
Modelling flow-diverting (FD) stents as porous media (PM) markedly improves the efficiency of computational fluid dynamics (CFD) simulations in the study of intracranial aneurysm treatment. Nonetheless, the parameters of PM models adopted for simulations up until now were rarely calibrated to match the represented FD structure. We therefore sought to evaluate the PM parameters for a representative variety of commercially available stents, so characterising the flow-diversion behaviours of different FD devices on the market.We generated fully-resolved geometries for treatments using PED, Silk+, FRED, and dual PED stents. We then correspondingly derived the calibrated PM parameters-permeability (k) and inertial resistance factor (C-2)-for each stent design from CFD simulations, to ensure the calibrated PM model has identical flow resistance to the FD stent it represents. With each of the calibrated PM models respectively deployed in two aneurysms, we studied the flow-diversion effects of these stent configurations.This work for the first time reported several sets of parameters for PM models, which is vital to address the current knowledge gap and rectify the errors in PM model simulations, thereby setting right the modelling protocol for future studies using PM models. The flow resistance parameters were strongly affected by porosity and effective thickness of the commercial stents, and thus accounted for in the PM models. Flow simulations using the PM stent models revealed differences in aneurysmal mass flowrate (MFR) and energy loss (EL) between various stent designs.This study improves the practicability of FD simulation by using calibrated PM models, providing an individualised method with improved simulation efficiency and accuracy. (C) 2018 Elsevier Ltd. All rights reserved.