Introduction Substantial evidence of the benefit of early embolization of ruptured brain arteriovenous malformations (rBAVM) regarding rebleeding is lacking.

Aim of Study to determine whether patients with a rBAVM benefit from an early embolization.

Methods rBAVMs treated first by embolization between March 2002 and May 2022 were included. Embolization was defined early (group 1) when performed within 10 days post bleeding. If done later, embolization was considered delayed (group 2). Demographic and rBAVM data were compared. High-risk bleeding components and reasons for deferring embolization were noted. Primary endpoint was rebleeding. Secondary endpoints were good functional outcome (FO, modified Rankin Scale mRS ≤ 2) and angiographic occlusion rate. Predictors of rebleeding and FO were determined by multivariate analysis.

Results 105 patients were recruited (N=34 in group 1 and N=71 in group 2). No rebleeding was noted before, during or after the first embolization session in the early embolization group. Late embolization depended on missed diagnosis on angiography and referral pattern. Eleven patients (10.5%) suffered a rebleeding, of whom N=3 before embolization (group 2), N=5 peri-embolization (N=2 at the 2^nd embolization session in group 1) and N=3 spontaneously more than 30 days post-embolization. More high-risk components were embolized in group 1 (19/34; 55.9% versus 17/71; 23.9%; P=0.011). Rebleeding rates, FO at last FU (90.9%; 74.3%) and occlusion rates (80.8%; 88.5%) did not differ between the groups. Glasgow coma scale ≤8 predicted re-bleeding, rebleeding poor FO.

Conclusion Early embolization did prevent rebleeding but did not reduce the rebleeding risk linked to following embolizations. Rebleeding predicted final FO.

Disclosure of Interest no.