A comparative study on computational fluid dynamic, fluid-structure interaction and static structural analyses of cerebral aneurysm

Computational Fluid Dynamics (CFD) and Fluid-Structure Interaction (FSI) are increasingly used to predict the hemodynamic and structural behaviors of cerebral aneurysms (CAs) whilst a less-pursued method is the static structural analysis (SSA) using the finite element method. In this paper, hemodynamic parameters including the flow velocity and wall shear stress predicted by CFD and FSI are compared whilst structural parameters including the wall displacement and wall stress predicted by SSA and FSI are compared for four patient-specific CA models under different systolic/diastolic pressures. The predicted distribution patterns of the same parameters for the same CA model under different pressures are similar. However, the percentage differences of the maximum hemodynamic parameters increase with increasing pressure. Conversely, the percentage differences of the maximum structural parameters decrease from a few to less than 1.5% when the systolic/diastolic pressure changes from 120/80 to 180/110 mmHg. The ratio of the computation times for CFD, SSA and FSI is typically 75:1:165. If the maximum wall stress under either ongoing or temporary hypertension is the most critical factor for immediate rupture and, thus, clinical treatment of CAs, SSA can provide a low cost and efficient predictions close to those of FSI for assessing the rupture risk.