Comparison of Single-Session, Neoadjuvant, and Adjuvant Embolization Gamma Knife Radiosurgery for Arteriovenous Malformation

Neurosurgery 92:986–997, 2023

The purpose of intracranial arteriovenous malformations (AVMs) treatment is to prevent bleeding or subsequent hemorrhage with complete obliteration. For large, difficult-to-treat AVMs, multimodal approaches including surgery, endovascular embolization, and gamma knife radiosurgery (GKRS) are frequently used.

OBJECTIVE: To analyze the outcomes of AVMs treated with single-session, neoadjuvant, and adjuvant embolization GKRS.

METHODS: We retrospectively reviewed a database of 453 patients with AVMs who underwent GKRS between January 2007 and December 2017 at our facility. The obliteration rate, incidence of latent period bleeding, cyst formation, and radiation-induced changes were compared among the 3 groups, neoadjuvant-embolized, adjuvant-embolized, nonembolized group. In addition, the variables predicting AVM obliteration and complications were investigated.

RESULTS: A total of 228 patients were enrolled in this study. The neoadjuvant-embolized, adjuvant-embolized, and nonembolized groups comprised 29 (12.7%), 19 (8.3%), and 180 (78.9%) patients, respectively. Significant differences were detected among the 3 groups in the history of previous hemorrhage and the presence of aneurysms (P < .0001). Multivariate Cox regression analyses revealed a significant inverse correlation between neoadjuvant embolization and obliteration occurring 36 months after GKRS (hazard ratio, 0.326; P = .006).

CONCLUSION: GKRS with either neoadjuvant or adjuvant embolization is a beneficial approach for the treatment of AVMs with highly complex angioarchitectures that are at risk for hemorrhage during the latency period. Embolization before GKRS may be a negative predictive factor for late-stage obliteration (>36 months). To confirm our conclusions, further studies involving a larger number of patients and continuous follow-up are necessary.