Cerebrovascular bypass surgery for the treatment of Moyamoya disease: unsatisfactory outcome in the patients presenting with intracranial hemorrhage.

While the efficacy of cerebrovascular bypass surgery for Moyamoya disease with ischemic events has been substantiated, the surgical indication for the patients presenting with intracranial hemorrhage is as yet undetermined. In an effort to prevent rebleeding from rupture of Moyamoya vessels, seven patients with intracranial hemorrhage underwent indirect bypass surgery. During the follow-up period between 2 and 11 years (mean 4.9 years), one patient suffered rebleeding 5 years after bypass surgery. Follow-up cerebral angiography failed to show revascularization and reduction of moyamoya vessels in all but one of seven patients. Thus, the author's experience suggests that bypass surgery for Moyamoya disease with hemorrhage is angiographically far less successful compared to that with ischemia. A review of the series including patients with angiographically successful revascularization and reduction of Moyamoya vessels failed to demonstrate the definitive effectiveness in eliminating the risk of further intracranial hemorrhage.