Ruptured intracranial aneurysm with spontaneous occlusion of internal carotid artery: clinical characteristics, prognostic risk factors, and survival analysis.

Background: Ruptured intracranial aneurysm (RIA) combined with internal carotid artery occlusion (ICAO) is a rare and serious vascular condition. We aimed to describe the clinical characteristics and outcomes of these patients.

Methods: We retrospectively analyzed cases of RIA with concurrent spontaneous ICAO from the Chinese Multicenter Aneurysm Database (CMAD). Logistic regression analysis was used to identify independent risk factors associated with patient prognosis. Cox proportional hazards model was performed to determine predictors of cumulative mortality.

Results: We analyzed 52 cases of RIA with ICAO, including 41 unilateral and 11 bilateral cases. Among unilateral ICAO cases, aneurysms were ipsilateral in 8, contralateral in 16, and midline in 17. Treatment included coiling (31 cases), clipping (6 cases), and conservative management (15 cases). Prognosis was favorable in 26 cases and unfavorable in 17, including 12 deaths. Logistic regression identified Hunt-Hess grade IV-V, conservative treatment, and symptomatic cerebral infarction as independent risk factors for unfavorable outcome. Cox proportional hazards model found Hunt-Hess grade IV-V to be a predictor of mortality during the 2-year follow-up.

Conclusion: Hunt-Hess grade, treatment, and in-hospital cerebral infarction independently predict unfavorable outcome, with grades IV-V linked to early death. ICAO may increase the risk of aneurysm rupture, highlighting the importance of aneurysm location and its related hemodynamic mechanisms in clinical management.