Objective: Radiosurgery is commonly performed for patients with small to medium-sized arteriovenous malformations (AVMs). However, few articles present overall outcomes after one or more radiosurgical procedures, and few data are available for periods longer than 5 years after AVM radiosurgery.
Methods: Between 1990 and 1997, 144 patients underwent AVM radiosurgery and had angiographic follow-up. Of these patients, 112 (78%) had Spetzler-Martin Grade III or greater AVMs; 37 (26%) were located in the basal ganglia, thalamus, or brainstem. Twenty-six patients (18%) underwent repeat radiosurgery. The mean follow-up of 15 patients who died as a result of AVM bleeding or underwent AVM resection after the initial radiosurgery was 22 months (range, 3-47 mo); the mean follow-up of the remaining 129 patients was 86 months (range, 23-169 mo).
Results: Excellent (obliteration without deficit, n = 96) or good (obliteration with minor deficit, n = 9) outcomes were achieved in 73% of patients after one or more radiosurgical procedures. Twenty patients (14%) sustained major deficits (n = 15; five had obliteration) or died (n = 5) after radiosurgery. Sixteen patients (11%) had unchanged neurological examinations but persistent arteriovenous shunting. Five patients (4%) required surgery (cystoperitoneal shunting, n = 1; AVM resection, n = 4) at a median of 65 months after radiosurgery because of symptomatic cyst formation or persistent edema. The radiosurgery AVM score correlated with both excellent (R(2) = -0.93, P = 0.003) and excellent or good (R(2) = -0.92, P = 0.004) outcomes.
Conclusion: The majority of AVM patients are protected from the risk of future hemorrhage and continue their normal daily activities after radiosurgery. Late complications requiring treatment are rare but can occur many years after patients are considered cured of their AVMs. Overall outcomes after AVM radiosurgery seem to be predicted accurately by the described method.