Comparison of hemodynamic parameters that can predict an aneurysmal rupture: 20 patient-specific models experiment

Hemodynamic analysis of cerebral aneurysms is widely performed to understand the mechanism of aneurysmal rupture. Computational fluid dynamics (CFD) studies have suggested that several hemodynamic parameters are associated with such ruptures. However, a number of factors remain to be addressed to correlate these parameters with aneurysmal ruptures, especially under analytical conditions. Specifically, CFD analysis is often performed with rigid wall models due to computational cost limitations. Here, to evaluate the effects of the deformation of the aneurysmal wall, experimental flow measurement with elastic models under pulsating conditions was conducted using three-dimensional particle image velocimetry (3D PIV). By analyzing 20 patient-specific, elastic, silicone aneurysm models, the hemodynamic parameters of ruptured and unruptured aneurysms were statistically compared to identify the variables that can effectively predict an aneurysmal rupture. Our analyses yielded three parameters (average wall shear stress ratio, in-phase deviation ratio, and pressure difference) which could effectively predict an aneurysmal rupture. These results suggested that measurement of wall shear stress (WSS) at both the aneurysm dome and parent artery is important and that pressure difference can also be a potential indicator of aneurysmal rupture.