PATIENT OUTCOMES AFTER STEREOTAXIC RADIOSURGERY FOR OPERABLE ARTERIOVENOUS-MALFORMATIONS

To define the outcomes after stereotactic radiosurgery performed for s maller volume arteriovenous malformations (AVMs) that are potentially suitable for surgical removal, we retrospectively reviewed our 4-year experience in 65 patients who declined microsurgery. AII 65 patients h ad Spetzler-Martin Grade I or II AVMs and a minimum follow-up of 24 mo nths (median, 29 mo). Symptomatic improvement after radiosurgery occur red in 52% of patients with seizures and in 63% of patients with heada ches. The annual risk of AVM hemorrhage during the latency interval af ter radiosurgery was 3.7%. Five patients (7.7%) had a subsequent hemor rhage (all within 8 mo of radiosurgery); two died, and three recovered (one after hematoma evacuation and two with conservative management). Forty-seven patients (72%) returned to their previous employment stat us or activity level within 1 week of radiosurgery (92% within 1 yr). No patient suffered radiation-related complications. Twenty-seven (84% ) of 32 patients evaluated by postradiosurgical angiography had comple te AVM obliteration. Radiosurgery is an effective and less invasive ma nagement strategy for Grade I or II AVM patients who are either medica lly unsuitable for or unwilling to undergo surgical removal. The risk of AVM hemorrhage during the latency interval until obliteration occur s appears to be no different than the natural history of untreated AVM s. These results (including hemorrhage prevention and symptom ameliora tion) indicate that the conservative management of small AVMs can rare ly be justified.