Hemodynamics of Asymmetrically Stenotic Vertebral Arteries Based on Fluid-solid Coupling

Stenosis in the vertebral artery, often associated with atherosclerosis, presents complexities regarding the relationship between internal resistance, shear stress and the geometric characteristics of stenosis lesions. This study aims to elucidate these relationships through computational simulations utilizing medical imaging data of human vertebral arteries. Various models representing different stenotic configurations were constructed, allowing for comprehensive analysis via Computational Fluid Dynamics (CFD) and Fluid-Structure Interaction (FSI) methods. Hemodynamic parameters such as blood flow velocity, time-averaged wall shear stress (TWASS), oscillation shear index (OSI), relative retention time (RRT), and solid mechanics indicators including total deformation and vascular Von-Mises stress were evaluated. Our findings revealed that different lesion modes had different impacts on the blood flow field in the vertebral artery. Upon comparing the mathematical model with CFD and FSI results, it was found that an augmented stenosis rate led to the creation of a watershed environment within the blood vessel, thereby expediting the onset of atherosclerosis. In cases where the vertebral artery experienced complete narrowing due to a consistent stenosis rate, there was a substantial rise in blood flow velocity. Neglecting timely intervention to alter the blood flow environment heightened the peril of triggering vascular dissection or even puncturing the blood vessel wall directly.