1082. Embolization in High-Grade Arteriovenous Malformations

Authors: Jason Anthony Liew; Wuyang Yang, MD, MS; Risheng Xu, MD, PhD; Yuxi Chen; James Feghali; Justin Caplan; Rafael Tamargo; Judy Huang (Baltimore, MD)

Introduction: The effectiveness of embolization for intervention of high-grade arteriovenous malformations(AVMs) has yet to be demonstrated. It is unclear whether embolization of these lesions may be associated with adverse events or functional outcome at last follow-up. We aim to elucidate the functional outcome and rates of hemorrhage in patients receiving only endovascular intervention of their high-grade AVMs when compared to untreated patients. Methods: We retrospectively reviewed all Spetzler-Martin grade IV and V AVM patients seen at our institution from 1990-2017. Patients were divided into two groups, those who received embolization only and those who were conservatively managed. The primary outcome was mRS improvement at last follow-up. Secondary outcomes included obliteration and hemorrhage rates as well as mRS and clinical features at last follow-up. Results: A total of 54 patients were included, 16.7%(n=9) of these patients underwent embolization only for their AVM, typically as a salvage strategy. The mean age of embolized patients was 33.4 years compared with 37.6 years in the untreated group(p=0.535). 11.1%(n=1) of the patients in the embolized group presented with a ruptured AVM as opposed to 24.4%(n=11) in the untreated group. Improvement in mRS at last follow-up was slightly more prevalent in treated patients (50%(n=6) vs. 22.5%(n=9), though the difference was not significant (p=0.065). None of the embolized patients experienced hemorrhage during follow-up compared with 7 patients(15.6%) from the untreated group(p=0.586). The follow-up duration for treated patients was 7.71 years compared with 8.95 for untreated patients (p=0.741). Conclusion: Treatment of high-grade AVMs with embolization is controversial and the functional outcome of patients following embolization are not well defined. Our data suggests that embolization is not associated with worse functional outcomes. As expected, no patients in our study achieved obliteration, and therefore embolization does not preclude them from future hemorrhage .