Role of wall shear hemodynamic characteristics in determining cerebral aneurysms severity: A stroke-related study

Tangential and orthogonal forces within arterial walls are essential hemodynamic factors that enhance the understanding of rupture mechanisms in cerebral aneurysms (CAs). Assessing the rupture risk in patients with unruptured cerebral aneurysms poses considerable challenges, given the critical influence of hemodynamics on the development of cerebral aneurysms. This study compares the hemodynamic characteristics of aneurysms, focusing on normal and tangential wall forces, across patients with differing aspect ratios of saccular and fusiform aneurysms and varying rupture risks. Numerical simulations utilized a patient-specific model of a cerebral aneurysm situated at the internal carotid artery. The vascular geometry was reconstructed using real patient medical imaging data. This research examines the severity of fusiform and saccular aneurysms through the analysis of tangential and normal wall forces under uniform boundary conditions. The results indicate that fusiform aneurysms exhibiting higher aspect ratios demonstrate a reduced susceptibility to rupture in comparison to saccular aneurysms with lower aspect ratios. The findings indicate that saccular aneurysms display lower tangential wall forces and higher normal wall forces relative to fusiform aneurysms. The study reveals for the same AR (e.g. 2:1), saccular 20% more vulnerable to rupture than the fusiform one. These hemodynamic metrics serve as important biomarkers for evaluating aneurysm stability and the risk of rupture. The results emphasize the significance of wall shear stress (WSS)-related metrics in assessing aneurysm morphology and rupture risk, underscoring their relevance for the prevention and clinical management of cerebrovascular diseases.