Fluid Mechanics Characterization of a Native vs Stented Giant Intracranial Aneurysm

摘要

Endovascular intervention of large intracranial aneurysms in the elderly is a complex form of treatment due to the associated co-morbidities and peri-procedural complications that may occur. We present a case of a 69-year old patient with a giant 32 mm fusiform basilar artery aneurysm that resulted in significant disability from brainstem compression. The cerebrovasculature was reconstructed from CT angiographic images by means of semi-automated 3D segmentation techniques. The resulting native geometry was used to generate a finite element mesh and a subsequent computational fluid dynamics (CFD) analysis was performed. Pre-endovascular planning resulted in a sequence of two overlapping NeuroForm-2 stents (Neuroform Microdelivery Stent System, Boston Scientific, Natick, MA) deployed into the basilar artery and communicating with the right vertebral artery. We performed modeling of such stents and incorporated them into the finite element mesh to study the fluid mechanics environment within the aneurysm and the basilar artery after stent placement. Pre- and post-repair scenarios were analyzed by means of assessment of intra-aneurysmal flow patterns and wall shear stress distributions. The numerical modeling technique provides a tool to evaluate the efficacy of this treatment within the context of reducing the intra-aneurysmal flow rate and diverting blood flow in the basilar artery.