Microsurgical resection of brain arteriovenous malformations in the elderly: Outcomes analysis and risk stratification

Abstract

Objective: Few outcomes studies have been published on microsurgical resection of arteriovenous malformations (AVMs) in elderly patients, and most are limited by a small sample size and the heterogeneous application of treatment modalities. This study aimed to determine whether functional outcomes at last follow-up (LFU) in patients 60 years or older differed when stratified by age. Methods: Patients 60 years or older (n = 104) who had undergone microsurgical AVM resection (total, n = 72; 60.65 years, n = 35; and > 65 years, n = 37) or observation (n = 32) were identified from a prospective database. Age, sex, Spetzler-Martin (SM) grade, supplemented SM grade, clinical presentation, AVM location, AVM-associated aneurysms, and functional outcome measured using the modified Rankin Scale (mRS score 0.2 [favorable] vs mRS score > 2 [unfavorable]) at LFU were analyzed. Results: AVM patients undergoing microsurgical resection were younger, had lower AVM grades, and were more likely to present with rupture. Overall outcome in the surgical group was favorable in 71% of the patients and was statistically significantly better in patients 60.65 years old (p = 0.039). In patients older than 65 years, outcome was dependent on SM grade and level of preexisting functional dependence. Patients with supplemented SM grades of greater than 6 points had favorable outcomes that were age dependent (p = 0.029). This difference was not observed in patients with lower supplemented SM grades or in those with low or high preoperative SM grades (SM grade ≤ 2 and grade ≥ 4, respectively). Conclusions: This study demonstrates that favorable outcomes can be achieved with microsurgical resection of AVMs in elderly patients, with careful patient selection. Outcomes in more elderly patients (> 65 years of age) are more dependent on preoperative SM and supplemented SM grading than those in younger cohorts.