ABSTRACT
OBJECTIVE: The authors evaluated the effects of direct revascularization (superficial temporal artery-middle cerebral artery bypass) in the prevention of further stroke, including recurrent ischemic event or bleeding in patients with ischemic type of adult moyamoya disease by clinical, pathophysiological and angiographical studies. MATERIALS AND METHODS: Twenty four patients who had ischemic symptoms in adult moyamoya disease were investigated. The mean age of the patients was 40.8 years. The follow up period ranged from 6 months to 8 years. In 24 patients who were surgically treated, thirty one sides (both sides in 7 patients) were performed to superficial temporal artery-middle cerebral artery anastomosis and dura splitting. RESULT: Average follow up period was 4.12 years. Perioperative and postoperative course was uneventful in 16 patients. 2 patients had new ischemic attack probably due to intracerebral steal phenomenon during operation, 6 patients had neurologic symptoms due to change of hemodynamic flow pattern after successful EC-IC bypass that included temporary neurologic deficit in 4, postbypass occlusion of the preoperative stenosis of anterior cerebral artery in one and focal seizure in one. Long term follow up results of 24 patients were showing major deficit in one and minor deficit in two. All patients experienced no further ischemic or hemorrhagic events during follow up period. In postoperative angiogram, drastic diminution of basal moyamoya vessels, which are supposed to be responsible for hemorrhage, was observed in 15 of 18 patients(83%) who were capable of postoperative 3-6 months follow up angiogram. CONCLUSION: In case of adult moyamoya disease, direct bypass surgery is particularly important on the prevention of recurrent ischemic or hemorrhagic events. And a decrease in basal moyamoya vessels was induced significantly by direct bypass surgery, which may reduce the expected risk of hemorrhage effectively. But direct bypass in moyamoya disease had operative morbidity in high frequence. So, moyamoya disease patients who undergo direct revascularization should be monitored carefully during the perioperative and postoperative period.