Embolization of cerebral arteriovenous malformations .2. Aspects of complications and late outcome

OBJECTIVE: From 1987 through 1993, we performed embolizations on 150 patients with cerebral arteriovenous malformations (AVMs) at Sahlgrenska University Hospital. The patients ranged in age from 5 to 70 years (35.5 +/- 14.8 yr, mean +/- standard deviation) and were selected by neurosurgeons in Scandinavia. We analyzed the risk of complications and late outcome to have a better basis for the decision to perform embolization. METHODS: The follow-up was a personal clinical examination of all surviving patients by a neurologist. Files for all patients were also studied. RESULTS: In 34 patients, the AVMs were eliminated by embolization alone (20 patients) or by supplementary surgery (14 patients). In 66 patients, the AVMs were embolized to a size suitable for supplementary stereotactic radiation. The clinical course was stable for those 100 patients. Another group of 50 patients who had undergone embolization was only partially treated, and as a group, those patients had less favorable outcomes. The manifestations or symptoms leading to diagnosis were in concordance with other studies. Headache and epilepsy showed a positive response to treatment in patients whose AVMs had been eliminated as well as in those who received only partial treatment. A history of cerebral bleeding did not influence the prognosis of recurrent bleeding. Conversely, AVMs with feeder or nidus aneurysms were related to an increased risk of bleeding. If there was a history of bleeding in a patient with large, partially treated AVMs, the prognosis for survival was diminished. CONCLUSION: The indication for treatment increases with the occurrence of AVMs with associated aneurysms. For patients with large AVMs, a history of bleeding justifies a more aggressive approach to treatment. The reduced risk of complications during the last years of the study also increases the indication for embolization.