Long-Term Outcomes of Embolization Plus Stereotactic Radiosurgery in Brain AVMs

Background To compare the long‐term outcomes of stereotactic radiosurgery (SRS) with or without prior embolization in SRS‐indicational brain arteriovenous malformations (AVMs) (volume ≤ 10 ml). Methods Patients were recruited from a nationwide multicenter prospective collaboration registry (the MATCH study) between August 2011 and August 2021, and categorized into the combined embolization and SRS (E+SRS) and the SRS alone cohorts. We performed propensity score‐matched survival analysis to compare the long‐term risk of non‐fatal hemorrhagic stroke and death (the primary outcomes). The long‐term obliteration rate, favorable neurological outcomes, seizure, worsened mRS score, radiation‐induced changes (RIC) and embolization complications were also evaluated (the secondary outcomes). Hazard ratios (HRs) were calculated using Cox proportional hazards models. Results After study exclusions and propensity score matching, 486 patients (243 pairs) were included. The median (interquartile range) follow‐up duration for the primary outcomes was 5.7 (3.1‐8.2) years. Overall, the E+SRS cohort and SRS alone cohort were similar in preventing long‐term non‐fatal hemorrhagic stroke and death (0.68 vs 0.45 per 100 patient‐years; HR, 1.46 [95% CI, 0.56‐3.84]), as well as in facilitating AVM obliteration (10.02 vs 9.48 per 100 patient‐years; HR, 1.10 [95%CI, 0.87‐1.38]). However, the E+SRS strategy was significantly inferior to the SRS alone strategy in terms of neurological deterioration (worsened mRS: 16.0% vs 9.1%; HR, 2.00 [95%CI, 1.18‐3.38]). Conclusions In this observational prospective cohort study, the combined strategy of E+SRS does not show substantial advantages over the SRS alone strategy. The findings do not support the pre‐SRS embolization for AVMs with a volume ≤ 10 ml. image image