Hemodynamic Changes Caused by Multiple Stenting in Vertebral Artery Fusiform Aneurysms: A Patient-Specific Computational Fluid Dynamics Study

LV, N.; CAO, W.; LARRABIDE, I.; KARMONIK, C.; ZHU, D.; LIU, J.; HUANG, Q.; FANG, Y.

AMERICAN JOURNAL OF NEURORADIOLOGY

AMER SOC NEURORADIOLOGY

Año: 2017

0195-6108

BACKGROUND AND PURPOSE: The multiple stent placement technique has largely improved the long-term outcomes of intracranialfusiform aneurysms, but the hemodynamic mechanisms remain unclear. In this study, we analyzed the hemodynamic changes caused bydifferent stent-placement strategies in patient-specific models using the computational fluid dynamics technique, aiming to provideevidence for clinical decision-making.MATERIALS AND METHODS: Ten vertebral artery fusiform aneurysms were included, and their patient-specific computational fluiddynamics models were reconstructed. A fast virtual stent placement technique was used to simulate sequential multiple stent placements(from a single stent to triple stents) in the vertebral artery fusiform aneurysm models. Hemodynamic parameters, including wall shearstress, pressure, oscillatory shear index, relative residence time, and flow pattern, were calculated and compared among groups withdifferent numbers of stents.RESULTS: Virtual stents were deployed in all 10 cases successfully, consistent with the real stent configuration. Wall shear stress decreasedprogressively by 7.2%, 20.6%, and 25.8% as the number of stents increased. Meanwhile, relative residence time and pressure increased onaverage by 11.3%, 15.4%, and 45.0% and by 15.7%, 21.5%, and 28.2%. The oscillatory shear index showed no stable variation trend. Flowpatterns improved by weakening the intensity of the vortices and displacing the vortex center from the aneurysmal wall.CONCLUSIONS: Stent placement modifies hemodynamic patterns in vertebral artery fusiform aneurysms, which might favor thrombosisformation in the aneurysmal sac. This effect is amplified with the number of stents deployed. However, a potential risk of rupture or recanaliza-tion exists and should be considered when planning to use the multiple stent placement technique in vertebral artery fusiform aneurysms.