Numerical Study of Pulsatile Flow in 3-Dimensional Sinuous Basilar Aneurysms

Abstract

The morphology of basilar aneurysms is a crucial factor which has great influence on the hemodynamics and hence the growth, thrombosis, and rupture of aneurysms. No one has ever studied the hemodynamics in the sinuous basilar aneurysms (SBAs) by means of numerical simulation. The objectives of the work are twofold: one is to simulate the 3-dimensional physiologically pulsatile blood flow in the SBAs; the other is to analyze and examine the hemodynamics in the two aneurysms, and assess the possibilities of rupture for these aneurysms. Geometrically idealized 3-dimensional fusiform SBAs model generated from a S-shaped artery was constructed via CAD software, and numerical simulation of pulsatile flow in this model was performed using finite element method. The distributions and alternations of flow patterns, pressure-drops and wall shear stresses over a cardiac cycle in the SBAs were collected, and the hemodynamic data in the two aneurysms were compared. The proximal aneurysm has higher pressure than the distal one, and the proximal aneurysm is subject to stronger flow strike than the distal one during the deceleration phase. The wall shear stresses in the proximal aneurysm oscillate more violently than those in the distal one, and the secondary flow vortices in the distal aneurysm are more obvious than those in the proximal one which indicates that the distal aneurysm is prone to thrombus development compared with the proximal one. These hemodynamic phenomena suggest that the proximal aneurysm in the SBAs has more dangerous tendency to aneurysmal growth and rupture.