Geometry Dependent Computational Study of Patient Specific Abdominal Aortic Aneurysm

Abstract

Computational approach for analyzing and modeling haemodynamic phenomena in an abdominal aortic aneurysm (AAA) is becoming more prevalent in today’s medical industry and scientific community. AAA is a local dilatation of an aorta in abdominal region. Due to this degenerative disorder the capacity of aorta to withstand the mechanical forces decreases resulting into rupture at any time. There is a great demand in understanding the physiological cause, determining the factors which influence growth causing rupture and thus the treatment of AAA. There is no general consensus to determine the actual cause of aneurysm rupture in treated or untreated patients. However, vascular wall stress analysis and maximum diameter are considered two influential factors leading to rupture risk in field of computational study. Therefore it is of utmost importance to understand the behavior of blood flow in the aneurysmal aorta. The work presented here is the preliminary approach towards constructing a realistic patient specific model for fluid simulations. The approach concentrates on how the geometrical differences in vascular structure can lead to pathological differences in results which could ultimately change the wall stress dynamics. The fluid simulation of blood flow results show us how flow patterns and wall shear differ when considering different degree of complexity of AAA model, for example the aortic arc and thoracic aorta in the computational domain. And the study also shows the necessity of implementing noise filters on raw medical data to give us accurate segmented vascular structures. The results show significant differences in behavior of the flow patterns in geometrical models with varying complexity.