Hemodynamics Assessments of Ascending Thoracic Aortic Aneurysm – the Influence of Hematocrit with Fluid-Structure Interaction Analysis

Abstract

Aortic aneurysm is one of the cardiovascular diseaseswith localized abnormal growth of a blood vessel with a risk of rupture or dissect. The precise pathological pathway for disease progression in aneurysm formation is not completely understood. In the current study, ascending thoracic aortic aneurysms are investigated using fully coupled fluid-structure interaction
method with the focus to investigate the importance of changes in hematocrit under normotension and hypertension. Blood was modelled as incompressible flow within laminar regime
with the use of the Quemada model to account for the effect of hematocrits. The anisotropic hyperelastic properties of the aortic wall were considered. Given the change in the degree
of shear thinning from the non-Newtonian behavior of blood due to the change in hematocrit, the simulated result could provide valuable information in clinical practice. Indeed, our results suggested that with the increase in hematocrit, the shear stress distribution as well as the maximum shear stress magnitude along the arterial wall would increase significantly. The arterial wall stress distributions, however, remained unchanged with respect to the changes in hematocrit.