Impact of Modeling Assumptions on Hemodynamic Stresses in Predicting Cerebral Aneurysm Rupture Status

Approximately 3% of the population is estimated to have cerebral aneurysms, which are the leading cause of subarachnoid haemorrhage. Convincing evidences suggest that wall shear stresses (WSS) play a role in vessel remodeling and in the development of vascular diseases. SinceWSS cannot be directly measured, researchers have resorted to using medical images available in routine clinical practice to simulate computational fluid dynamics (CFD) and investigate patient-specific vascular conditions. They retrospectively analyse the correlation between WSS and disease outcomes to find potential clinical tools for future use. However, most of these models are based on assumptions that introduce variability and error. In this work we investigated the effects of a non-Newtonian viscosity model and inflow uncertainty on the prediction of commonly computed hemodynamic metrics. Our results show a substantial influence of the non-Newtonian model and blood flow rate on CFD outcomes, highlighting the need of incorporating non-Newtonian rheology and patient-specific blood flow measurements in CFD simulations.