Centre Internacional de Mètodes Numèrics en Enginyeria, Biomedical Engineering Department, Technical University of Catalonia, C/Gran Capità, s/n, 08034 Barcelona, Spain.
Comput Math Methods Med. 2013;2013:472564. doi: 10.1155/2013/472564. Epub 2013 Jun 24.
The objective of this study is to find a correlation between the abdominal aortic aneurysm (AAA) geometric parameters, wall stress shear (WSS), abdominal flow patterns, intraluminal thrombus (ILT), and AAA arterial wall rupture using computational fluid dynamics (CFD). Real AAA 3D models were created by three-dimensional (3D) reconstruction of in vivo acquired computed tomography (CT) images from 5 patients. Based on 3D AAA models, high quality volume meshes were created using an optimal tetrahedral aspect ratio for the whole domain. In order to quantify the WSS and the recirculation inside the AAA, a 3D CFD using finite elements analysis was used. The CFD computation was performed assuming that the arterial wall is rigid and the blood is considered a homogeneous Newtonian fluid with a density of 1050 kg/m(3) and a kinematic viscosity of 4 × 10(-3) Pa·s. Parallelization procedures were used in order to increase the performance of the CFD calculations. A relation between AAA geometric parameters (asymmetry index ( β ), saccular index ( γ ), deformation diameter ratio ( χ ), and tortuosity index ( ε )) and hemodynamic loads was observed, and it could be used as a potential predictor of AAA arterial wall rupture and potential ILT formation.
本研究旨在利用计算流体动力学（CFD）寻找腹主动脉瘤（AAA）的几何参数、壁面切应力剪切（WSS）、腹部流动模式、腔内血栓（ILT）和 AAA 动脉壁破裂之间的相关性。通过对 5 名患者体内获得的计算机断层扫描（CT）图像进行三维（3D）重建，创建了真实的 AAA 3D 模型。基于 3D AAA 模型，使用整个域的最佳四面体纵横比创建了高质量的体积网格。为了量化 WSS 和 AAA 内的再循环，使用有限元分析进行了 3D CFD。假设动脉壁是刚性的，血液被认为是密度为 1050kg/m(3)、运动粘度为 4×10(-3)Pa·s 的均质牛顿流体，对 CFD 计算进行了。为了提高 CFD 计算的性能，使用了并行化程序。观察到 AAA 几何参数（不对称指数（β）、囊状指数（γ）、变形直径比（χ）和迂曲指数（ε））与血流动力学负荷之间的关系，可作为 AAA 动脉壁破裂和潜在 ILT 形成的潜在预测因子。
