Direct Bypass of STA-MCA Anastomosis Prevents Future Stroke in Patients with the Hemorrhagic Type of Moyamoya Disease

The prevention of future stroke is an important issue in hemorrhagic type moyamoya disease. However, the surgical treatment of moyamoya disease in adult hemorrhagic type is still controversial. We undertook the present study to analyze the effect of direct surgery of STA-MCA anastomosis on the prevention of future stroke in patients with the hemorrhagic type of moyamoya disease. We analyzed 30 patients with adult moyamoya disease whose mean age was 44 years old. The follow-up period was from 0.8 to 15.1 years after initial onset of intracerebral hemorrhage. Direct bypass surgery was performed on 10 patients and recurrence of hemorrhage was observed in 1 patient (10%) 9.3 years after first onset of hemorrhage. Indirect surgery was done on 6 patients, and 3 patients had future strokes (50%). Of the remaining 14 patients treated conservatively, stroke recurred in 8 patients (57%) during follow-up (average 2.71 years). The rate of future strokes and stroke-free time in the patients treated with direct bypass surgery was significantly lower (P<0.05) than that of patients managed conservatively or with indirect bypass surgery. In conclusion, in case of adult hemorrhagic type of moyamoya disease, direct bypass of STA-MCA anastomosis effectively prevents rebleeding and ischemic events.