Comparative Study of Aortic Wall Stress According to Geometric Parameters in Abdominal Aortic Aneurysms

In abdominal aortic aneurysm (AAA), the rupture of the aortic tissue is directly related to wall stress. Thus, the investigation of maximum wall stress is a necessary procedure to predict the aortic rupture in AAA. In this study, computational simulations were performed to investigate the correlation between peak wall stress (PWS) and AAA geometry. The Holzapfel model and various orientations of the collagen fibers and thicknesses of the layers of the aorta were employed in the simulation. The material constants used in the Holzapfel model were estimated from the examination and analysis of the biaxial tensile test results of the normal abdominal aorta and AAA. The aneurysm diameter, height, neck angle, and iliac angle were selected as geometric factors affecting the AAA rupture. In addition, a simulation scenario was conceived and created based on the measurement results using the computed tomography data of patients with AAA. Accordingly, the correlation between the PWS and AAA geometry was estimated.

Automated summary

This study investigated the correlation between peak wall stress (PWS) and abdominal aortic aneurysm (AAA) geometry through computational simulations, using the Holzapfel model and varying orientations of collagen fibers and thicknesses of aortic layers. Material constants were estimated from biaxial tensile test results of normal abdominal aorta and AAA. Geometric factors such as aneurysm diameter, height, neck angle, and iliac angle were identified as factors affecting AAA rupture, with a simulation scenario created based on computed tomography data of AAA patients to estimate the correlation between PWS and AAA geometry.