RT Journal Article SR Electronic T1 O-072 Optimal timing of microsurgical treatment for ruptured arteriovenous malformations: a systematic review and meta-analysis JF Journal of NeuroInterventional Surgery JO J NeuroIntervent Surg FD BMJ Publishing Group Ltd. SP A54 OP A54 DO 10.1136/jnis-2024-SNIS.72 VO 16 IS Suppl 1 A1 Orscelik, A A1 Musmar, B A1 Matsukawa, H A1 Ismail, M A1 Elawady, S A1 Assad, S A1 Cunningham, C A1 Sowlat, M A1 Kasem, R A1 Spiotta, A YR 2024 UL http://jnis.bmj.com/content/16/Suppl_1/A54.abstract AB Introduction Ruptured brain arteriovenous malformations (bAVMs) present complex challenges in neurosurgical management, with timing of microsurgical treatment (MST) being a subject of ongoing debate. This study aims to evaluate the impact of MST timing on clinical outcomes in patients with ruptured bAVMs.Methods We conducted a systematic review and meta-analysis following PRISMA guidelines. A comprehensive search of PubMed, Embase, Scopus, and Web of Science databases identified relevant studies. The timing was defined as the duration from the rupture of bAVM to the MST. The patients were divided into four different groups based on MST timing: <48 hours, <1 week, <2 weeks, and <1 month. The primary outcome included favorable outcome defined as a modified Rankin Scale (mRS) score of 0-2 or a Glasgow Outcome Scale (GOS) score of 4-5 in the last clinical follow-up. Secondary outcomes were periprocedural mortality and complete excision.Results Fifteen studies comprising 1026 patients were included in the meta-analysis. MST time >48 hours group had a significantly higher favorable outcome rate (odds ratio [OR]:9.71, 95% confidence interval [Cl]:3.09-30.57, p<0.01) and a lower mortality rate (OR:0.15, 95% Cl:0.02-0.88, p=0.04) compared to MST timing ≤48 hours group. (Figure 1) After excluding patients who underwent MST with preoperative EVT, MST time >48 hours were associated with a significantly higher favorable outcome rate (OR:9.39, 95% CI: 2.53–34.89, p<0.01). (Figure 2) There were no significant differences in terms of favorable outcomes, mortality, and complete excision when comparing MST times of ≤1 week versus >1 week, ≤2 weeks versus >2 weeks, and ≤1 month versus >1 month.Abstract O-072 Figure 1 Abstract O-072 Figure 2 Conclusions Our findings suggest that delaying MST beyond 48 hours with and without preoperative EVT may improve favorable outcomes and reduce mortality rates in patients with ruptured bAVMs.Disclosures A. Orscelik: None. B. Musmar: None. H. Matsukawa: None. M. Ismail: None. S. Elawady: None. S. Assad: None. C. Cunningham: None. M. Sowlat: None. R. Kasem: None. A. Spiotta: None.