Effect of Direct Bypass on the Prevention of Hemorrhage in Patients with the Hemorrhagic Type of Moyamoya Disease / 대한뇌혈관외과학회지

ABSTRACT

OBJECTIVE: The authors evaluated the effect of direct bypass (superficial temporal artery-middle cerebral artery bypass) in the prevention of rebleeding episodes in patients suffering from hemorrhagic moyamoya disease by comparing this method with indirect bypass. METHODS: Fifteen patients who had hemorrhagic moyamoya without aneurysm comprised the study group. The mean age of patients was 44.4 years and follow up period ranged from 0.8 to 7.1 years (mean; 3.61 years). Revascularization surgery was performed in 21 sides in 15 patients. Direct bypass was performed in 17 sides and indirect bypass in the other 4 sides. RESULTS: During the follow-up period after the revascularization surgery, three sides (14.3%) of the 21 sides presented with rebleeding episode, one of 17 sides (mean follow-up periods; 2.94 years) treated with direct method and 2 of 4 sides (mean follow-up periods; 6.45 years) treated with indirect method. Kaplan-Meier analysis of rebleedingfree survival showed quite different between direct and indirect method but statistically insignificant (p=0.0541). CONCLUSION: Direct bypass may reduce the risk of hemorrhage more effectively than indirect bypass. However, direct bypass cannot always prevent rebleeding.