Fluid-solid interaction simulation of flow and stress pattern in thoracoabdominal aneurysms: A patient-specific study
Fluid-solid interaction simulation of flow and stress pattern in thoracoabdominal aneurysms: A patient-specific study
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DOI：
10.1016/j.jfluidstructs.2007.08.005
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发表时间：
2008-02-01
影响因子：
3.6
通讯作者：
Xu, X. Y.
中科院分区：
文献类型：
--
作者：
Borghi, A.;Wood, N. B.;Xu, X. Y.
胸腹动脉瘤（TA）是一种涉及胸降主动脉下部主动脉直径扩大的病理学，其危险因素包括主动脉夹层、主动脉炎或结缔组织疾病。患病主动脉壁上的异常血流模式和血流动力学应力被认为在这种病理学的发展中发挥着重要作用，并且内壁应力已被证明作为破裂的预测因素比腹主动脉瘤的最大直径更可靠；但对于涉及胸主动脉的动脉瘤，这一假设尚未得到验证。在本研究中，使用磁共振成像 (MRI) 技术对三名具有不同最大直径的 TA 的患者进行了扫描。根据从患者获得的体内 MRI 数据重建动脉瘤的真实模型，并应用受试者特定的血流条件作为边界条件。壁和血栓被建模为超弹性材料，其特性源自文献。还模拟了正常的降主动脉，以提供用于比较的数据。使用 ADINA 8.2 进行全耦合流固相互作用 (FSI) 模拟以及固体静态模拟。结果表明，壁应力分布及其大小很大程度上取决于动脉瘤的 3D 形状和血栓的分布。所有 TA 模型中的最大壁应力均高于正常主动脉，并且最大壁应力值与最大动脉瘤直径没有直接关系。 FSI 和固体静态模拟结果之间的比较显示最大壁应力没有显着差异，这支持了先前的研究，即 FSI 模拟对于壁应力预测不是必需的。 (c) 2007 Elsevier Ltd. 保留所有权利。
Thoracoabdominal aneurysm (TA) is a pathology that involves the enlargement of the aortic diameter in the inferior descending thoracic aorta and has risk factors including aortic dissection, aortitis or connective tissue disorders. Abnormal flow patterns and haemodynamic stress on the diseased aortic wall are thought to play an important role in the development of this pathology and the internal wall stress has proved to be more reliable as a predictor of rupture than the maximum diameter for abdominal aortic aneurysms; but this assumption has not been validated yet for aneurysms involving the thoracic aorta. In the present study, three patients with TAs of different maximum diameters were scanned using magnetic resonance imaging (MRI) techniques. Realistic models of the aneurysms were reconstructed from the in vivo MRI data acquired from the patients, and subject-specific flow conditions were applied as boundary conditions. The wall and thrombus were modelled as hyperelastic materials and their properties were derived from the literature. A normal descending aorta was also simulated to provide data for comparison. Fully coupled fluid-solid interaction (FSI) simulations as well as solid static simulations were performed using ADINA 8.2. The results show that the wall stress distribution and its magnitude are strongly dependent on the 3-D shape of the aneurysm and the distribution of thrombus. Maximum wall stresses in all TA models are higher than in the normal aorta, and values of maximum wall stress are not directly related to the maximum aneurysm diameter. Comparisons between the FSI and solid static simulation results showed no significant difference in maximum wall stress, supporting those previous studies which found that FSI simulations were not necessary for wall stress prediction. (c) 2007 Elsevier Ltd. All rights reserved.