Microsurgery for cerebral arteriovenous malformations: postoperative outcomes and predictors of complications in 264 cases

A total of 264 patients with cerebral arteriovenous malformation were treated with microsurgical resection between 1994 and 2010 at the Jefferson Hospital for Neuroscience. Initial hemorrhage, clinical presentation, Spetzler-Martin AVM grading system (SM), treatment modalities, clinical outcomes, and obliteration rates were reviewed.
Univariate analysis and multivariate analysis were used to determine predictors of operative complications.
Of the 264 patients treated with microsurgery, 120 (45%) patients initially presented with hemorrhage. There were 27 SM Grade I lesions (10.2%), 101 Grade II lesions (38.3%), 96 Grade III lesions (36.4%), 31 Grade IV lesions (11.7%), and 9 Grade V lesions (3.4%). Among these patients, 102 (38.6%) had undergone prior endovascular embolization. In all patients, resection resulted in complete obliteration of the AVM. Complications occurred in 19 (7.2%) patients and resulted in permanent neurological deficits in 5 (1.9%). In multivariate analysis, predictors of complications were increasing AVM size (OR 3.2, 95% CI 1.5-6.6; p = 0.001), increasing number of embolizations (OR 1.6, 95% CI 1.1-2.2; p = 0.01), and unruptured cerebral arteriovenous malformation (OR 2.7, 95% CI 1-7.2; p = 0.05).
Microsurgical resection of AVMs is highly efficient and can be undertaken with low rates of morbidity at high-volume neurovascular centers. Unruptured and larger AVMs were associated with higher complication rates ¹⁾.