Investigation of wall shear stress related factors in realistic carotid bifurcation geometries and different flow conditions

Cardiovascular diseases are one of the major causes of death in the world; atherosclerosis being one aspect. Carotid bifurcation is one of the sites that are vulnerable to this disease. Wall Shear Stress (WSS) is known to be responsible for the process of atherogenesis. In this study, we have simulated the blood flow for Newtonian and non-Newtonian, steady and unsteady, flow conditions in three idealistic and five realistic geometries. A risk factor has been presented based on the results of wall shear stress and, then, a relation was found between geometrical features and the wall shear stress risk factor. Our main conclusions are: 1) The non-Newtonian behavior of blood elevates the value of wall shear stress, however, the wall shear stress pattern is similar, 2) The bifurcation angle is not the main cause of atherosclerosis and cannot be considered a predictor for atherosclerosis disease, and 3) The ratio of sinus diameter to the internal carotid artery diameter is more important than other geometrical factors, and the WSS pattern is influenced by this factor. © Sharif University of Technology, October 2010