Assessing the Effectiveness of WEB Devices to Occlude Bifurcation Intracranial Aneurysms: A CFD Analysis

Abstract

Intracranial aneurysms are abnormalities formed in the cerebral arteries characterized by outpouching regions of their walls. The danger with these lesions occurs if they rupture, which causes an intracranial haemorrhage and possibly leads to the death of the patient, presenting a mortality rate as high as 50 %. The rupture event is hard to predict and surgical treatments also pose risks to patients. Hence, due to a better outcome for the patient and low risk of post¿surgical complications, the procedure known as embolization has become the most common option among neurosurgeons. In this procedure, the aneurysm is filled with coils, to stop blood flowing into the aneurysm and, subsequently, a stent is placed inside the artery to prevent the migration of coils. More recently, devices deployed directly into the aneurysm sac, such as the so¿called WEB, have been used. Despite their success, post¿treatment follow¿up is important to avoid aneurysmal recurrence, especially those related to blood flow in the treated region. Numerical simulations of flow within aneurysms have been widely used to study them due to the connection between hemodynamics and their initiation, growth and rupture, in addition to the effects of different treatments on the evolution of the disease. In this context, this project aims to compare the blocking effect of stents and WEB on blood flow in a model of a bifurcation aneurysm using CFD. Boundary conditions close to patient¿specific ones will be used and the geometries will be created in CAD software. The blood will be modeled as a Newtonian fluid and the Navier¿Stokes equations governing the flow will be solved numerically with the Finite Volume Method implemented in OpenFOAM. The results may help in improving these devices used in aneurysmtreatment and understanding the hemodynamics of treated aneurysms. (AU)