Stereotactic Radio Surgery, Embolization and Conservative Management for Cerebral Arteriovenous Malformation: A New Zealand Experience of Long-Term Outcomes.

[OBJECTIVE] Cerebral arteriovenous malformations (AVMs) can be treated by microsurgery, stereotactic radiosurgery (SRS) as a stand-alone procedure, or combining embolization and conservative management. This single-center, retrospective review explored the outcomes of patients treated with SRS alone, embolization before SRS (ESRS), or conservative management for cerebral AVMs.

[METHODS] Demographic details, Spetzler-Martin grade, SRS dose, obliteration, time to obliteration, imaging modality, rebleed, disease-specific mortality, and post-SRS complications were collected. Chi-square tests of independence and 1-way analysis of variance/Kruskal-Wallis tests were performed.

[RESULTS] Two-hundred and thirty-nine patients were treated with SRS alone, 37 were treated with ESRS, and 83 were conservatively managed. Obliteration rates were 78% (SRS alone) and 70% (ESRS). Rebleed rates were comparable among SRS alone (4%), ESRS (0%), and conservative management (8%). Disease-specific mortality rates were significantly lower for SRS alone (1%) and ESRS (0%) compared with conservative management (6%, X [2, n = 358] = 7.50, P = 0.024). Post-SRS complications occurred with SRS alone only and included radiation necrosis (n = 5), cavernous malformations (n = 2), and stroke (n = 1). Obliteration, rebleed, and disease-specific mortality rates were comparable among pediatric (<18 years), nonelderly (18-59 years), and elderly (≥60 years) age groups.

[CONCLUSIONS] Findings suggest that SRS and ESRS are safe and effective treatments for cerebral AVM (when quantified by obliteration, rebleed, and disease-specific mortality rates). With multinational, prospective, randomized controlled trials with long follow-up periods, the effectiveness and safety of SRS and ESRS compared with conservative management for AVM will be further clarified.