Qualifying the Risk of Developing Secondary Aneurysms due to Arterial Wall Shear Stresses Caused by the Presence of a Primary Aneurysm

Intracranial aneurysms are localized dilations of blood vessels located primarily around the Circle of Willis, an important network of arteries at the base of the brain. Aneurysms are at constant risk of hemorrhage; however, the dangers of treatment and the risk of recurrence often null the efficacy of preventative surgery. Although the mechanisms behind the formation of individual cerebral aneurysms have been extensively modeled as the consequence of local hemodynamic conditions, these simulations have concentrated on a single aneurysm. Using OpenFOAM, an open source fluid dynamics toolkit, we model how changes in the hemodynamics of the Circle of Willis caused by the presence of a primary aneurysm can facilitate the formation of a secondary aneurysm. Additionally, we constructed a 3-D mesh from MRI data that we used as the boundary condition for our equations. We hope to propose an ordering of arterial bifurcations, qualifying the risk of developing a secondary aneurysm given a primary aneurysm at a particular bifurcation. We intend that our results, coupled with the increased risk of rupture in the presence of multiple intracranial aneurysms, will give surgeons another tool to weigh the risks of preventative treatment.