Investigation of the response of the vascular wall to hemodynamic changes in different hematocrit levels in intracranial aneurysms with CFD

The intracranial aneurysm is a cerebrovascular disease observed as an abnormal dilatation in the arterial vessel wall. The incidence of subarachnoid hemorrhage (SAH) due to rupture of intracranial aneurysms is 6.67 / 100.000 annually. Accordingly, almost 500,000 people die each year due to aneurysm-related SAH. Evaluation of the relationship between hemodynamic factors and rupture of aneurysms which are effective in the mechanism of intracranial aneurysms and determining the effective and correct methods to be used during aneurysm treatment are of great importance. For this purpose, intravascular hemodynamic changes have been investigated by using computational fluid dynamics (CFD). The aim of this study is to investigate the effects of different hematocrit (Hct) levels of 20%, 40%, 60% on hemodynamic forces in the parent artery and aneurysm. In this study, computed tomography angiography (CTA) images of patients with intracranial aneurysm applied to the Department of Neurosurgery in Gaziantep University Faculty of Medicine were used.3-dimensional (3D) vessel models created by using HOROS v 3.0.1 (https://horosproject.org/) software, then transferred into the ANSYS® FLUENT program for CFD analyzes. Blood, accepted as a non-Newtonian fluid and the vessel outer wall considered as rigid. Pulsatile flow is provided in the vessels. The pressure obtained from this pulsatile flow was applied to the inlet and outlets. As a result of this study; turbulence flow observed in the aneurysm sac and increased when the Hct value increased. However, low wall shear stress (WSS) areas are observed in the aneurysm dome, while the mean WSS in the artery increases approximately 3 times when the Hct was 3 times higher. Thanks to the CFD method, the relationship between hemodynamic factors and rupture-induced effects can be readily examined in a non-invasive manner and it's hoped that in the future it will help doctors to determine the most effective treatment method for the patients. Key words: Intracranial aneurysm, Computational fluid dynamics, Pulsatile flow, Hemodynamics, Subarachnoid Hemorrhage