Numerical study of hemodynamic factors in computational fluid dynamic modeling of intracranial artery atherosclerotic stenosis

Abstract

Objective To study the role of risk factors associated with hemodynamics in patients with intracranial artery stenosis. Methods Eighteen patients with local stenosis of middle cerebral artery were recruited in this study retrospectively. According to patients' clinical symptoms and magnetic resonance imaging findings, they were divided into the symptomatic group (n=13) and the asymptomatic group (n=5). Wall shear stress (WSS), oscillatory shear index (OSI), velocity and pressure of the stenotic artery wall were compared between the two groups after reconstructing 3-dimentional model of hemodynamics.Then related risk factors of hemodynamics were analyzed in symptomatic intracranial atherosclerotic stenosis. Results There were no statistically significant differences between the two groups in the parameters such as age, sex, degree of artery stenosis, mean arterial pressure and some medical histories of hypertension and diabetes. The results showed obvious changes of hemodynamics in local artery stenosis. The WSS(78.69(68.15, 117.65) Pa vs 39.34(22.76, 60.54) Pa, U=4, P=0.003), pressure of the stenotic artery wall (1 815.14(1 242.44, 4 398.84) Pa vs 735.55(361.17, 1 528.78) Pa, U=7, P=0.010)and velocity of the local stenosis(3.87(2.58, 4.52) m/s vs 2.31(1.38, 3.12) m/s, U=12, P=0.046)in the symptomatic group were much higher than those in the asymptomatic group; however, there were no significant differences between the two groups in OSI. Conclusions Hemodynamic features do exist in local intracranial atherosclerotic stenosis. The WSS, wall pressure and velocity of the local stenosis may be vital risk factors associated with symptomatic intracranial atherosclerotic stenosis. Key words: Hemodynamics; Intracranial arteriosclerosis; Cerebral angiography; Blood flow velocity; Retrospective studies