Computational Fluid Dynamics and Numeric Analysis of Aortic Wall Shear Stress Alterations Induced by Fatty Streaks

Abstract

Atherosclerosis, a disease of the large arteries, is the primary cause of heart disease and stroke. It often begins with the formation of fatty streaks (FS). The FS consists of subendothelial accumulations of cholesterol-engorged macrophages, called ‘foam cells’. For this to happen, there needs to be a significant change in the permeability of the endothelial layer. Considering the established influence of mechanical stresses on endothelial properties, shear stress can increase the permeability of the endothelial layer. This study employs a hybrid approach, combining computational fluid dynamics (CFD) simulation with numerical analysis, on a simplified model of the aorta to Investigate Endothelial Shear Stress (ESS) changes in the FS. Our findings reveal that the presence of FS leads to quantitative changes in ESS. Further numerical analysis in MATLAB 9.14 suggests a pattern that metaphorically resembles a dam, potentially trapping ‘foam cells’. In an additional aspect of this study, our findings suggest that an increase in blood flow could potentially counteract the permeability increase, thus acting as a preventative measure against atherosclerosis progression. These results underscore the importance of early intervention strategies to mitigate atherosclerosis progression.