Chris S Aboujudom, Simon Levinson, Spyridon Karadimas
In patients with low-grade, surgically favorable AVMs, microsurgical resection was associated with near-complete AVM obliteration and with rates of disability, stroke, and death below ARUBA benchmarks; findings do not extend to unselected or higher-grade lesions. These findings are hypothesis-generating and warrant confirmation in prospective trials such as TOBAS.
UNLABELLED: No prior meta-analysis has isolated microsurgical resection as the primary intervention and directly compared pooled outcomes against conservative management using post-ARUBA evidence.
OBJECTIVE: To compare stroke, death, and functional disability following microsurgical resection versus conservative management in patients with unruptured brain arteriovenous malformations (AVMs).
METHODS: A PROSPERO-registered systematic review and meta-analysis (CRD420261354328) searched six databases from January 2014 through March 2026. Fourteen studies met inclusion criteria across two analytic tracks. Track A was a pairwise meta-analysis of hazard ratios for stroke or death comparing microsurgical resection against concurrent conservative management arms (k = 3), and Track B was single-arm proportion pooling benchmarked against the ARUBA conservative arm (k = 5-9 by outcome). REML estimation with Hartung-Knapp adjustment was applied throughout.
RESULTS: Functional disability (modified Rankin Scale ≥2) occurred in 9.6% of microsurgical resection patients (95% CI 6.3-14.2%; I2 = 0%; k = 5, three countries) versus 15.1% in the ARUBA conservative arm. Angiographic obliteration was achieved in 97.7% (95% CI 95.5-98.8%; k = 9). Track A demonstrated a 61% reduction in stroke or death hazard favoring microsurgical resection (HR 0.39, 95% CI 0.10-1.44; p = 0.090; I2 = 0%; k = 3), consistent across sensitivity analyses (HR range 0.35-0.36). The pooled stroke or death rate was 3.7% (95% CI 1.0-12.7%; k = 8) versus the ARUBA benchmark of 10.1%.
CONCLUSIONS: In patients with low-grade, surgically favorable AVMs, microsurgical resection was associated with near-complete AVM obliteration and with rates of disability, stroke, and death below ARUBA benchmarks; findings do not extend to unselected or higher-grade lesions. These findings are hypothesis-generating and warrant confirmation in prospective trials such as TOBAS.