Laboratoire Central de Traitement des Images, Research Center, Hôpital Notre-Dame, Centre Hospitalier de l'Université de Montréal-CRCHUM, Montréal, QC H2L 4M1, Canada.
Comput Math Methods Med. 2012;2012:820389. doi: 10.1155/2012/820389. Epub 2012 Sep 6.
The purpose of this paper is to present the basic principles and relevant advances in the computational modeling of abdominal aortic aneurysms and endovascular aneurysm repair, providing the community with up-to-date state of the art in terms of numerical analysis and biomechanics. Frameworks describing the mechanical behavior of the aortic wall already exist. However, intraluminal thrombus nonhomogeneous structure and porosity still need to be well characterized. Also, although the morphology and mechanical properties of calcifications have been investigated, their effects on wall stresses remain controversial. Computational fluid dynamics usually assumes a rigid artery wall, whereas fluid-structure interaction accounts for artery compliance but is still challenging since arteries and blood have similar densities. We discuss alternatives to fluid-structure interaction based on dynamic medical images that address patient-specific hemodynamics and geometries. We describe initial stresses, elastic boundary conditions, and statistical strength for rupture risk assessment. Special emphasis is accorded to workflow development, from the conversion of medical images into finite element models, to the simulation of catheter-aorta interactions and stent-graft deployment. Our purpose is also to elaborate the key ingredients leading to virtual stenting and endovascular repair planning that could improve the procedure and stent-grafts.
本文旨在介绍腹主动脉瘤和血管内动脉瘤修复的计算建模的基本原理和相关进展,为社区提供数值分析和生物力学方面的最新技术水平。描述主动脉壁力学行为的框架已经存在。然而,腔内血栓的非均匀结构和孔隙率仍需要很好地描述。此外,尽管已经研究了钙化的形态和力学特性,但它们对壁应力的影响仍存在争议。计算流体动力学通常假设动脉壁是刚性的,而流体-结构相互作用则考虑了动脉的顺应性,但由于动脉和血液的密度相似,这仍然具有挑战性。我们讨论了基于动态医学图像的替代流体-结构相互作用方法,这些方法可以解决患者特定的血液动力学和几何形状问题。我们描述了初始应力、弹性边界条件和用于破裂风险评估的统计强度。特别强调了从医学图像转换为有限元模型的工作流程开发,以及导管-动脉相互作用和支架-移植物部署的模拟。我们的目的还在于详细阐述导致虚拟支架和血管内修复规划的关键因素,这些因素可以改进手术和支架-移植物。