Effects of Preoperative Embolization on Spetzler–Martin Grade I and II Arteriovenous Malformations: A Propensity-Adjusted Analysis
Joshua S. Catapano, Visish M. Srinivasan, Kavelin Rumalla, Stefan W. Koester, Anna R. Kimata, Kevin L. Ma, Mohamed A. Labib, Jacob F. Baranoski, Tyler S. Cole, Caleb Rutledge, Andrew F. Ducruet, Felipe C. Albuquerque, Robert F. Spetzler, Michael T. Lawton
Abstract
BACKGROUND: Cerebral arteriovenous malformations (AVMs) with low Spetzler-Martin grades (I and II) are associated with good neurological outcomes after microsurgical resection; however, the use of preoperative embolization for these lesions is controversial. OBJECTIVE: To compare the neurological outcomes of preoperative embolization with no embolization in patients with low-grade AVMs. METHODS: Patients with a Spetzler-Martin grade I or II AVM who underwent microsurgical resection during January 1, 1997, through December 31, 2019, were analyzed. Patients undergoing preoperative embolization were compared with patients not undergoing embolization. A propensity score was constructed from baseline characteristics and used to match intervention (embolization) and control (nonembolization) groups in a 1:1 ratio. The primary outcome was poor neurological status on last follow-up examination, defined as a modified Rankin Scale score >2 and a modified Rankin Scale score worse at follow-up than at the preoperative examination. RESULTS: Of the 603 patients analyzed, 310 (51.4%) underwent preoperative embolization and 293 (48.6%) did not. Patients in the embolization cohort compared with those in the nonembolization cohort had a higher percentage of Spetzler-Martin grade II AVMs (71.6% vs 52.6%, P < .001) and a lower percentage of hemorrhage (41% vs 55%, P = .001). After propensity score matching, no differences were found between paired cohorts (each N = 203) for baseline characteristics with a significant reduction in absolute standardized mean differences. No significant differences were found in primary outcomes between treatment groups in the matched or unmatched cohorts. CONCLUSION: Preoperative embolization of low-grade Spetzler-Martin AVMs is not associated with improved neurological outcomes after microsurgical resection.