Arteriovenous Anomalies of the Brain

lesions. Although arteriovenous anomalies of the brain are frequently reviewed, there continue to be divergent opinions concerning the indications for operation. The nidus of the controversy seems to be the scanty information that is published concerning the risk of death or disability from the unoperated lesion. Previous studies in which the results of surgical treatment were compared with the fate of patients who did not undergo surgery have been from centers that are surgically oriented toward these vascular malformations; Olivecrona and Ladenheim reported that more than 60 per cent underwent surgery, 2 Patterson and McKissock cited 48 per cent, 3 and, in his cumulative study, Pool reported that 46 per cent of the patients were operated on. 4 Any study of patients rejected for surgery must involve statistical bias, for the surgeon selects the patient who has the best chance for useful survival, and those who are denied surgery often have a poorer prognosis. For only ~ patients in the present series (~3 per cent) was surgery recommended. In 5 of these, a need to evacuate an intracerebral hematoma prompted surgery. Another 5 patients underwent surgery elsewhere after conservative management had been recommended. With relatively fewer patients having definitive surgery, a more accurate appraisal of the risks of harboring an intracranial alteriovenous anomaly can be ascertained.