BACKGROUND: Brain arteriovenous malformations (AVMs) pose a significant treatment challenge, with options including microsurgical resection, endovascular embolization, radiosurgery, or combinations thereof. We present our experience with a curative strategy combining complete endovascular treatment followed by microsurgical resection under the same anesthesia session, without relying on a hybrid operating room. METHODS: We reviewed consecutive patients with AVM who underwent endovascular treatment and microsurgical resection in a single anesthesia session (COMBI-AVM protocol) from December 2017 to July 2022. Primary endpoints were angiographic AVM obliteration status and modified Rankin Scale score at last follow-up. AVMs were graded by the Spetzler-Martin (SM) system, comparing low-grade (SM I, SM II, SM III with nidus <
3 cm) and high-grade (SM III with nidus ≥3 cm, SM IV, SM V) AVMs. RESULTS: Of 46 patients with AVM, 34 had low-grade (73.9%) and 12 had high-grade (26.1%) AVMs. The protocol feasibility was 100%. Median anesthesia time was 8.7 hours (interquartile range, 7.6-10.6). Complete AVM removal was achieved in 45 patients (97.8%), with no recurrences at late (>
6 months) follow-up in any of the 32 patients (71.1%) with available follow-up data. Good clinical outcomes (modified Rankin Scale score ≤2) were seen in 91.3% of patients. Disabling treatment-related complications occurred in 4 patients (8.6%), including 1 death (2.2%). CONCLUSIONS: Combining maximal endovascular embolization and complete surgical resection in a single session in patients with AVM yielded a high cure rate and low morbidity, especially for low-grade lesions. This technique may make it possible to treat high-grade AVMs previously considered ineligible for surgery and reduce periprocedural morbidity.