Jozsef Nagy, Julia Maier, Veronika Miron, Wolfgang Fenz, Zoltan Major, Andreas Gruber, Matthias Gmeiner
Abstract: The treatment of patients with cerebral aneurysms poses multiple challenges to physicians from rupture to treatment risk assessment and their consequences to the patient’s health. Risk estimation support is highly required to make the optimum decisions for individual patients. The aim of this study is to develop the workflow of a simulation method for the analysis of hemodynamics and structural mechanics of cerebral aneurysms as well as its possible clinical implementation. Medical imaging data was taken and converted into CAD data (STL format) to use as geometric input for simulations. Fluid-Structure Interaction (FSI) simulations are utilized in the inflow vessel, the outflow vessels as well as a typical aneurysm. Aitken’s underrelaxation method is used to ensure convergence between hemodynamics and structural mechanics. The influence of linear and non-linear elastic material properties of the vessel wall as well as the influence of wall thickness reduction in the aneurysm sac are investigated. In this work, two major hemodynamic (wall shear stress and oscillatory shear index) and two structural mechanic quantities (wall displacement and Mises stress) are evaluated and compared between the different models. The linear elastic material model tends to overestimate displacements at high strain rates. The reduction of wall thickness in the aneurysm region shows an increase in wall stresses. In both cases hemodynamic phenomena are not changed, however a tendency of aneurysm growth can be identified. The model is implemented as part of a graphical user interface. With this, it is possible for medical personnel without simulation background to run sophisticated Fluid-Structure interaction simulations with ease and in future to make optimized decisions for patient treatment.
Keywords: Cerebral aneurysm, Hemodynamics, Structural mechanics, Fluid-structure interaction, Visualization.
Date Published: October 3, 2023 DOI: 10.11159/jbeb.2023.003
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