[Long-term results of cerebral arteriovenous malformations--surgical and conservative treatment]

During the past 20 years, we have treated 187 cases with cerebral arteriovenous malformations (AVMs). These 134 patients were treated surgically and the remaining 53 patients were managed non-surgically. The purpose of this study is to clarify the surgical indications of AVMs, based on a comparison of the long-term follow-up results between the surgical and nonsurgical groups. Consequently, good results were obtained in the surgical group: the operative mortality was 7.5% and the morbidity was 12.7%. The long-term follow-up results were as follows: Of the 124 followed cases in the surgical group, there were 16 cases with improvement of neurological deficits (13%) and 3 cases with neurological aggravation (2%). Of the 47 followed cases in the nonsurgical group, there were 5 cases with improvement of neurological deficits (11%) and 6 cases with neurological aggravation (13%). As for the incidence of AVM hemorrhage, there were 8 cases with hemorrhage in the nonsurgical group including 4 cases (3 rebleeding cases) which were fatal (11%), in contrast to one case (subtotal resection) in the surgical group. On follow-up angiography, the size of AVMs were unchanged in the majority of cases in the nonsurgical group, with the exception of 2 cases in which there were slight regressions. In the surgical group, on the other hand, enlargement in 2 cases and spontaneous regression in 3 of residual AVM occurred following incomplete resection. Particularly in 2 cases involving unresectable AVMs, a newly formed aneurysm was discovered in the follow-up angiography, emphasizing the fact that serious follow-up angiography is required in cases of untreated AVMs.