Hemodynamic Alterations for Various Stent Configurations in Idealized Wide-neck Basilar Tip Aneurysm

Abstract

Stent-assisted coiling technology is widely used in the treatment of intracranial aneurysms. However, differences among various stent configurations have not been fully characterized. This study investigates the hemodynamic effects for various stent configurations. Computational fluid dynamics simulations were performed on an idealized wide-neck basilar tip aneurysm model, which was constructed from digital subtraction angiography images with a virtual stenting technique. The orifice of the aneurysm was tilted toward the left posterior cerebral artery (PCA). The right half-Y configuration caused only a small change in the overall intra-aneurysmal flow pattern compared with the pattern produced without a stent. Percentage of hemodynamic changes were all compared to the untreated aneurysm. The values of wall shear stress (WSS) and flow velocity showed reductions of 16.36 and 3.22 %, respectively. Although the Y configuration showed relatively obvious decreases of 56.27 and 33.55 % in WSS and flow velocity, respetively, the left half-Y configuration, which is usually deployed as the first stent clinically, produced a more obvious flow reduction than those of the right half-Y and Y configurations. Consistent decreases in the velocity and WSS were observed. WSS and flow velocity showed reductions of 58.39 and 41.76 %, respectively. The cross-bar configuration showed the highest WSS and flow velocity reductions (58.42 and 46.49 %, respectively). The right half-Y configuration had relative more impacts on the WSS of the right PCoA than the left half-Y configuration. For the Y and cross-bar configurations, the WSS of the right PCA obviously decreased. The overall pressure change was less than 1 % for the various configurations, with the Y configuration having the highest pressure increase (0.728 %). Simulation results demonstrate obvious differences among the various stent configurations in a wide-neck basilar tip aneurysm.