Numerical modeling of varying hemodynamic features with changing internal carotid artery bifurcation angles and degrees of stenosis

Abstract

Atherosclerosis is a disease clinically categorized as a silent killer as its symptoms only become pronounced after the buildup has extensively progressed. Therefore, early detection, prediction and treatment become of great priority. The focus of this study is to develop a deeper understanding of plaque formation and the role of key structural variations, specifically the bifurcation angle and degree of stenosis, on its progression in a numerical carotid artery model. A two-way coupled Fluid–Solid Interaction (FSI) numerical approach has been implemented, with the consideration of isotropic elasticity for the artery wall. Geometrically induced hemodynamic flow variations were monitored by tracking changes in hemodynamic indicators, such as the wall shear stress (WSS) and vortex structures. The numerical results demonstrate general trends of the bifurcation angle amplifying recirculation zones, reducing WSS at the sinus far walls, and inhibiting wall deformations about the apex. Meanwhile, progressive stenosis is shown to induce new vortices, increase and decrease WSS at the outer walls and the inner walls respectively, and promote larger deformations. These hemodynamic flow and structural variations hint at increased risk of further plaque buildup with the increase of bifurcation angle at lower degrees of stenosis, while an increased risk of plaque rupture was associated with higher degrees of stenosis.