Hemodynamic effects of stenting on wide-necked intracranial aneurysms.

BACKGROUND: Stent placement has been widely used to assist coiling in cerebral aneurysm treatments. The present study aimed to investigate the hemodynamic effects of stenting on wide-necked intracranial aneurysms. METHODS: Three idealized plexiglass aneurismal models with different geometries before and after stenting were created, and their three-dimensional computational models were constructed. Flow dynamics in stented and unstented aneurismal models were studied using in vitro flow visualization and computational fluid dynamics (CFD) simulations. In addition, effects of stenting on flow dynamics in a patient-specific aneurysm model were also analyzed by CFD. RESULTS: The results of flow visualization were consistent with those obtained with CFD simulations. Stent deployment reduced vortex inside the aneurysm and its impact on the aneurysm sac, and decreased wall shear stress on the sac. Different aneurysm geometries dictated fundamentally different hemodynamic patterns and outcomes of stenting. CONCLUSIONS: Stenting across the neck of aneurysms improves local blood flow profiles. This may facilitate thrombus formation in aneurysms and decrease the chance of recanalization.

[Three-dimensional numerical simulation and hemodynamic analysis of intracranial longitypical aneurysms].

OBJECTIVE: To establish a model of three-dimensional numerical simulation of intracranial longitypical aneurism and analyze the hemodynamic features thereof. METHODS: Ten patients with intracranial longitypical aneurism underwent surgical treatment. Intracranial vascular ultrasonography was conducted before operation. Intra-operatively three-dimensional angiography of the aneurysm was conducted and multifunctional physiological monitor was used to record the dynamic pressure and pressure wave form of the main branch parent artery. Matlab, Ansys, and Fluent software were used to simulate the blood flow of the longitypical aneurysms. RESULTS: The hemodynamic parameter levels were the highest at the inflow tract, followed by those at the outflow tract, and were the lowest at the top of aneurysm, for example, the blood flow velocity was (1.07+/-0.23) m/s, the dynamic pressure was (574+/-186) Pa, and the wall shear stress was (7.7+/-2.0) Pa at the inflow tract, all significantly higher than those at the top [(0.15+/-0.07) m/s, (37+/-13) Pa, and (0.40+/-0.13) Pa respectively, all P<0.05]. No eddy or just simple eddy occurred in the aneurysm. CONCLUSION: The dynamic pressure, velocity, and wall shear stress are the lowest at the top of longitypical aneurysm which may contribute to the rupture of aneurysm.