Flow dynamics in anatomical models of abdominal aortic aneurysms: computational analysis of pulsatile flow.

Abstract

Blood flow in human arteries is dominated by time-dependent transport phenomena. In particular, in the abdominal segment of the aorta under a patient's average resting conditions, blood exhibits laminar flow patterns that are influenced by secondary flows induced by adjacent branches and in irregular vessel geometries. The flow dynamics becomes more complex when there is a pathological condition that causes changes in the normal structural composition of the vessel wall, for example, in the presence of an aneurysm. An aneurysm is an irreversible dilation of a blood vessel accompanied by weakening of the vessel wall. This work examines the importance of hemodynamics in the characterization of pulsatile blood flow patterns in individual Abdominal Aortic Aneurysm (AAA) models. These patient-specific computational models have been developed for the numerical simulation of the momentum transport equations utilizing the Finite Element Method (FEM) for the spatial and temporal discretization. We characterize pulsatile flow dynamics in AAAs for average resting conditions by means of identifying regions of disturbed flow and quantifying the disturbance by evaluating wall pressure and wall shear stresses at the aneurysm wall.