Study on the radial sectional velocity distribution and wall shear stress associated with carotid artery stenosis

Abstract

Atherosclerosis is an important cause of cardiovascular disease. The wall shear stress (WSS) is one of the key factors of plaque formation and dislodgement. Currently, WSS estimation is based on the measurement of the blood velocity gradient. However, due to the lack of flow field measurements in carotid stenosis vessels, the two distribution forms (parabolic and non-parabolic) commonly considered in numerical simulations could cause WSS estimates to differ by more than 40%, which could seriously affect the accuracy of mechanical analysis. This study applied three-dimensional (3D) printing technology to create an experimental model of real-structure carotid arteries. Microparticle image velocimetry was adopted to comprehensively measure blood velocity field data at the stenosis location, providing experimental validation of numerical simulation (Fluent; finite volume method) results. Then, the flow field was simulated at a normal human heart rate (45–120 beats per minute). The radial sectional velocity exhibited a plateau-like distribution with a similar velocity in the central region (more than 65% of the total channel width). This study provides an accurate understanding of the WSS at the carotid stenosis location and proposes a reliable method for the study of flow fields under various blood flow conditions.