Evaluating Abdominal Aortic Aneurysm Stress Distribution: Effect of Asymmetry

An abdominal aortic aneurysm (AAA) is a gradual enlargement of the aorta that can threaten the patient’s life if it ruptures. Several factors are effective in reducing the chance of aneurysm rupture. One of the important factors is the geometric characteristics of the aneurysm; its relationship with the risk of rupture helps in making decisions about the treatment and monitoring the treatment process. Geometrical parameters have an effect on wall stress, which is the cause of aneurysm rupture. In this study, a three-dimensional fluid-solid interaction model of two abdominal aortic aneurysm geometries was evaluated using ADINA. Wall stress distribution in symmetric and asymmetric geometries (eccentricity) has been investigated. Uniform thickness and an isotropic linear elastic material were considered for the wall. In the asymmetric aneurysm, the central line of the aneurysm was shifted. The results showed that in the asymmetry geometry, the magnitude of Von Mises stress and the maximum displacement increased by 5% and 19%, respectively. Also, the place of maximum stress was transferred from the anterior wall to the posterior wall.