Association between intracranial artery stenosis and aneurysm rupture risk: Proximal stenosis as a potential protective factor

ObjectiveParent artery and hemodynamics are related to intracranial aneurysms (IAs) rupture. Although proximal parent artery stenosis (PPAS) can both change parent artery configuration and hemodynamics, correlation between PPAS and IAs rupture has not been clearly clarified in large sample size. This study aims to explore the correlation between PPAS and IAs rupture in a large Chinese cohort.MethodsA retrospective cross-sectional study was conducted. Imaging and clinical data were collected from consecutive patients with IAs diagnosed by CTA between January 2013 and December 2022. Two neuroradiologists independently assessed the characteristics of the IAs. To minimize the effect of confounding variables, propensity score matching (PSM) was applied.ResultsAfter PSM, no significant differences were found between groups for interference factors. However, IAs in the PPAS group had a significantly lower proportion of ruptures compared to the non-PPAS group (p = 0.031). Additionally, unruptured aneurysms had a significantly higher prevalence of PPAS compared to ruptured aneurysms (p = 0.011). There was no significant difference in rupture rates between non-PPAS IAs with other intracranial artery stenosis (IAS) and those without IAS (p = 0.596). And ruptured non-PPAS IAs showed a significantly higher incidence of IAS compared to unruptured non-PPAS IAs (p = 0.010).ConclusionNon-PPAS may be associated with a higher risk of aneurysm rupture. In contrast, PPAS may be associated with unruptured aneurysm.