Effects of sand therapy on hemodynamics in the femoral artery bifurcation at different degrees of stenosis / 中国组织工程研究

ABSTRACT

BACKGROUND: Sand therapy has been shown to exhibit a positive effect on reducing femoral atherosclerosis and inhibiting thrombosis. OBJECTIVE: To investigate the effects of sand therapy on hemodynamic parameters of different stenosis models of femoral bifurcation through comparing the hemodynamic parameters and wall shear stress in four stenosis models before and after sand therapy. METHODS: The study protocol was performed in strict accordance with the relevant ethical requirements of School of Mechanical Engineering of Xinjiang University. Each participant provided written informed consent. Medical software Mimics10.01, reverse engineering software Geomagic Studio 2012 and three-dimensional CAD software UG8.5 were used to separate and optimize the CT data of a subject’s lower extremities and the geometric model of the femoral artery bifurcation was obtained. According to the classification criteria of vascular stenosis caused by femoral atherosclerotic plaque in the lower extremity, the degree of plaque stenosis on the side wall of the femoral bifurcation tube was set as 0% (normal), 15% (normal), 30% (mild) and 50% (moderate). Computational fluid dynamics method was used for numerical simulation. The Laminar flow model was selected for blood flow before sand therapy, and the standard turbulence model κ-ε was selected for blood flow after sand therapy. Blood flow velocity and wall shear stress were analyzed before and after sand therapy. RESULTS AND CONCLUSION: The maximum blood flow velocity after sand therapy was 0.35-0.45 m/s higher than that before sand therapy. After sand therapy, the wall shear stress at the stenosis was increased by 5-11 Pa compared with that before sand therapy, and the wall shear stress at 50% vascular stenosis rate model reached 41 Pa. These results suggest that the trend of atherosclerotic plaque enlargement is decreased after sand therapy, but patients with 50% (moderate) vascular stenosis have the risk of plaque rupture.