Surgical therapy for adult moyamoya disease: Can surgical revascularization prevent the recurrence of intracerebral hemorrhage?

Background and Purpose: It is well recognized that revascularization surgery using direct and/or indirect bypass provides effective surgical management for pediatric moyamoya disease. However, surgical treatment of the adult hemorrhagic type remains controversial. In this study, the effect of surgery for adult moyamoya disease was investigated. Methods: We analyzed 35 patients with adult moyamoya disease (patient age, over 20 years), 24 patients with initial onset of intracerebral hemorrhage, and 11 patients with initial onset of cerebral ischemia who underwent both direct bypass surgery of the superficial temporal artery to the middle cerebral artery anastomosis and indirect revascularization of encephalo-duro-arteriomyo-synangiosis. Results: Of 24 patients with hemorrhagic-type disease, 3 showed rebleeding; of 11 patients with the ischemic type, 2 showed intracerebral hemorrhage after surgery. Overall, 5 of 35 patients (14.3%) had hemorrhage after revascularization surgery (mean follow-up period, 6.4 years). Postoperative angiography revealed that direct anastomosis is effective whereas indirect revascularization is not always effective for adult moyamoya disease. Moyamoya vessels, which are supposed to be responsible for hemorrhage, decreased in 25% of patients. Conclusions: Revascularization surgery cannot always prevent rebleeding. However, a decrease in moyamoya vessels was induced by surgery, which may reduce the risk of hemorrhage more effectively than conservative treatment. In cases of adult moyamoya disease, direct bypass is particularly important, since the indirect revascularization is not as useful in adult cases as in pediatric cases.