Management of high-grade brain arteriovenous malformations: the current state of knowledge

We read with great interest the retrospective cohort study by Li et al.¹ that evaluated the long-term outcomes of patients with Spetzler-Martin grade IV–V brain arteriovenous malformation (bAVM) managed at a single high-volume center. Eighty-two patients with high-grade ruptured or unruptured bAVMs who received follow-up for a mean of approximately 5 years were studied to compare functional outcome, obliteration rate, seizure control, and risk of hemorrhage between those who received conservative management and those who underwent intervention (microsurgery, embolization, or hybrid surgery). This is one of the largest single-center series dedicated to high-grade bAVM. It showed that intervention had an advantage for avoidance of long-term severe disability (modified Rankin Scale score > 3) in comparison with observation (1.7% vs 18.2%). Intervention also demonstrated better seizure control and protection from subsequent hemorrhage, with hybrid surgery resulting in less intraoperative blood loss than microsurgery.