Understanding complication rates in elective endovascular aneurysm repair for consideration of same-day discharge

OBJECTIVE: Elective repair of unruptured intracranial aneurysms (UIA) is performed to prevent potentially catastrophic rupture. There exists potential for outpatient elective endovascular aneurysm repair given low risk for complications. However, concern remains for development of delayed post-operative complications, which has led to overnight observation being common practice. We aim to determine this practice's necessity by identifying rate and timing of delayed complications and associated factors. METHODS: All patients undergoing elective endovascular UIA treatment between 2014 and 2024 were included. Demographic and clinical data, including primary aneurysm location and size, complications, anticoagulant/antiplatelet (AC/AP) use, and discharge destination was collected. RESULTS: Of 151 patients, 4 experienced intra-operative complications and 9 (5.9%) experienced post-operative complications. The average time to post-operative complication was 4.67 hours. MCA aneurysms were found to be an independent risk factor for peri-procedural complication (OR = 9.65, 95% CI: 1.15-80.7, p = 0.03). Conversely, no peri-procedural complications were seen when treating posterior circulation aneurysms. Although a significant proportion of peri-procedural complications were associated with bleeding, the rate of peri-procedural complications was not significantly higher in those on AC/AP. All but two peri-procedural complications resolved by discharge, with one resolving upon follow-up. The rate of permanent deficit from peri-procedural complications was 0.66%. CONCLUSION: Elective repair of UIA carries a low post-operative complication rate (5.9%) and a very low permanent complication rate (0.66%) in this study. The incidence of delayed complication is low, however, it does occur at a mean time of nearly 5 hours and up to 24 hours requiring additional hospital-based services for diagnosis and management. Based on these findings, we advocate for continued practice of overnight observation.