Long-term Outcomes After Intraprocedural Aneurysm Rupture During Coil Embolization of Unruptured Intracranial Aneurysms

The long-term outcomes of patients with intraprocedural aneurysm rupture (IPR) during endovascular coiling of unruptured intracranial aneurysms (UIAs) remain unclear. We investigated the long-term outcomes and predictors of neurological outcomes in patients who sustained IPR during coil embolization of UIAs.We retrospectively analyzed the medical record of 312 untreated UIAs in 284 patients who underwent endovascular coiling between April 2013 and July 2018.The mean follow-up period for the entire cohort was 25.6 months. Twelve patients (3.8%) experienced IPR. The mean aneurysm size in the IPR cohort was significantly smaller than that in the no-IPR cohort (P = 0.045). The IPR cohort had a higher percentage of earlier subarachnoid hemorrhage from another aneurysm (P = 0.019), anterior communicating artery (AComA) aneurysm (P0.001), and basilar artery (BA) aneurysm (P = 0.022) than the no-IPR cohort. Neurologic deterioration was observed in 3 patients. The morbidity and mortality rates of the IPR cohort were 25% and 8.3%, respectively. Patients with IPR during coil embolization for AComA aneurysm did not develop neurological deterioration. Two of the 3 patients (66.7%) with a BA aneurysm had neurological deterioration. The proportion of patients with an mRS score of 0-2 at the last follow-up did not differ between the 2 cohorts (P = 0.608).The proportion of functionally independent patients did not differ between patients with and without IPR. Patients with BA aneurysms who developed an IPR tended to exhibit more unfavorable clinical courses than patients with AcomA aneurysms.