The Influence of inlet boundary conditions upon hemodynamic analysis of human cerebral aneurysms with computational fluid dynamics technique

We previously suggested that arise in wall shear stress (WSS) plays a central role in cerebral aneurysm formation due to asymmetric shape of the circle of Willis. Several models have recently been reported details of hemodynamics in human aneurysms with computational fluid dynamics analyses, carried out in most cases using assumed flow rates as inlet boundary conditions. However, measured values derived from physiological data of individual patients may have to be used since a shift in hemodynamic stress is caused by disturbed hemodynamics in the circle of Willis. Thus, we examined the influence of inlet boundary conditions between theoretically assumed and actually measured values on hemodynamics in human aneurysms of the anterior communicating artery where bilateral anterior cerebral arteries (ACA) converge. There is a significant difference in flow rates between assumed and measured values. Locations of high WSS, high gradient oscillatory number, and enhanced flow disturbance inside aneurysms are observed more frequently using measured values, caused by a difference in flow rates between bilateral ACA. The results illustrate that measured flow rates should be used as inlet boundary conditions.