Numerical analysis of unsteady blood flow model of fluid-solid interaction in carotid artery / 介入放射学杂志

ABSTRACT

Objective To study the distribution of hemodynamics in carotid artery under the fluid-solid interaction at the typical point of time during a single cardiac cycle, and to explore the mechanism of the formation and development of carotid atherosclerotic plaque. Methods Numerical analysis the blood flow characteristics within a cardiac cycle in carotid artery was analyzed by using computational method of fluid dynamics. Based on the hemodynamic parameters, the influences of the cardiac systole and diastole on the blood flow distribution were analyzed. Results The distribution of blood flow in the carotid artery within a typical cardiac cycle was obtained. Compared with the findings in cardiac diastole, a larger area of blood stasis at the entrance of external carotid artery was observed. In this area, the flow velocity, the wall pressure and the wall shear stress were all lower, while the arterial wall deformation and von Mises equivalent stress were larger. Conclusion Under fluid-solid interaction, the low blood flow in carotid artery causes blood reflux, resulting in the deposition of lipid, fiber and other large molecular materials. The low wall pressure produced“negative pressure” effect, thus the normal blood flow is changed, the flow velocity becomes slow, and the blood supply of the brain becomes insufficient. The low wall shear stress destroys the blood flow near the wall, causing the increase of platelet activity and intimal hyperplasia. The larger arterial wall deformation variable and von Mises equivalent stress can cause stress concentration and increase vascular rupture risk.