Minimal target embolization of high-risk component in brain arteriovenous malformation combined with stereotactic radiosurgery: a proof-of-concept study

BACKGROUND: Brain arteriovenous malformations (AVMs) with high-risk angioarchitecture features are associated with the risk of hemorrhage. This study evaluated the safety and effectiveness of a combined approach involving targeted embolization of high-risk components and stereotactic radiosurgery (SRS). METHODS: This single-center retrospective study included 17 consecutive patients with 17 AVMs with high-risk components who underwent targeted embolization and SRS. Technical success, procedural complications, obliteration rates, and hemorrhage during the latency period were assessed. RESULTS: Of the total, 15 (88%) patients had a history of AVM rupture. Target embolization using liquid embolic material was successful in 16 (94%) patients, with minimal embolization of the nidus (median, 2.8%). Complications related to embolization occurred in three (17.6%) patients, with only one (5.9%) experiencing a minor persistent deficit. Among the 14 patients with >1 year follow-up (median 60 months), complete AVM obliteration was confirmed in 9 (64%) patients, and the cumulative obliteration rates at 3, 5, and 7 years after SRS were 35%, 54%, and 85%, respectively. Target embolization was unsuccessful in one patient (5.9%), who experienced hemorrhage during the latency period. One bleeding event occurred during the latency period (1/17, 5.9%). CONCLUSIONS: MTE combined with SRS may represent a feasible strategy for morphologically high-risk brain AVMs, with the potential to reduce latency-period hemorrhage without clearly compromising nidus obliteration. However, given the small cohort and lack of a control group, the observed reduction in hemorrhage risk should be interpreted cautiously. These findings support the value of this approach as a proof-of-concept, but further prospective studies with larger cohorts are needed to confirm its clinical benefit.