Patient-specific flow analysis of brain aneurysms at a single location: comparison of hemodynamic characteristics in small aneurysms.

The purpose of this study is to examine and compare the hemodynamic characteristics of small aneurysms at the same anatomical location. Six internal carotid artery-ophthalmic artery aneurysms smaller than 10 mm were selected. Image-based computational fluid dynamics (CFD) techniques were used to simulate aneurysm hemodynamics. Flow velocity and wall shear stress (WSS) were also quantitatively compared, both in absolute value and relative value using the parent artery as a baseline. We found that flow properties were similar in ruptured and unruptured small aneurysms. However, the WSS was lower at the aneurysm site in unruptured aneurysms and higher in ruptured aneurysms (P < 0.05). Hemodynamic analyses at a single location with similar size enabled us to directly compare the hemodynamics and clinical presentation of brain aneurysms. The results suggest that the WSS in an aneurysm sac can be an important hemodynamic parameter related to the mechanism of brain aneurysm growth and rupture.