A multiphysics simulation of a healthy and a diseased abdominal aorta

Abdominal Aortic Aneurysm is a potentially life-threatening disease if not treated adequately. Its pathogenesis is complex and multifactorial and is still not fully understood. Many biochemical and biomechanical mechanisms have been identified as playing a role in the formation of aneurysms but it is as yet unclear what triggers the process. We investigated the role of the relevant biomechanical factors, in particular the wall shear stress and the intramural wall stress by simulating fluid structure interaction between the blood flow and the deforming arterial wall in a healthy abdominal aortic bifurcation, the preferred location of the disease. We then extended this study by introducing a hypothetical weakening of the aortic wall. Intramural wall stress was considerably higher and wall shear stress considerably lower in this configuration, supporting the hypothesis that biomechanical aneurysmal growth factors are self-sustaining.