Effectiveness and outcomes of endovascular embolization on arteriovenous malformations with aneurysms: a nationwide multicenter prospective registry study.

Objective: This study aims to evaluate the long-term outcomes of cerebral arteriovenous malformations (AVMs) with associated aneurysms in patients who underwent exclusive endovascular embolization.

Methods: Patients with aneurysmal AVMs were identified from China's nationwide MATCH registry. Propensity score matching balanced baseline differences between embolization and conservative management groups. The primary outcome was long-term hemorrhagic stroke or death; secondary outcomes included obliteration rate and neurological status. Subgroup and sensitivity analyses using various designs assessed the robustness of the results.

Results: In the MATCH study, 230 patients with AVMs and associated aneurysms received embolization or conservative treatment. After screening, 83 patients received conservative management and 108 underwent embolization; 64 matched pairs were analyzed after propensity score matching. The embolization group had a mean follow-up of 6.88 years, with a post-procedure rupture risk of 2.75% per patient-year and a complete obliteration rate of 21.88%. Embolization was associated with a lower rate of hemorrhagic stroke or death (absolute risk reduction -3.50% per patient-year; HR 0.50) and a higher obliteration rate compared with conservative management. Neurological outcomes were similar between the two groups. Stratified analysis showed that curative and targeted embolization significantly reduced hemorrhagic stroke whereas palliative embolization did not. Subgroup and sensitivity analyses confirmed these trends, although the statistical power varied.

Conclusion: This study suggests that embolization may reduce the risk of long-term hemorrhagic stroke or death in patients with aneurysmal AVMs. Curative and targeted approaches showed protective effects while palliative embolization had limited benefits.