The pre-, intra-, and postoperative hemodynamics were examined by a bidirectional ultrasonic Doppler flowmeter with sound-spectrograph in 12 patients of moyamoya disease undergoing 14 STA-MCA anastomoses, 2 encephalo-myo-synangioses and/or 2 omentum transplantation. In the preoperative transcutaneous flow measurement, flow pattern of bilateral STAs was the internal carotid type in 8 cases. In the three of them, apparent transdural anastomoses by way of STA were revealed by preoperative angiography. In the intraoperative direct flow measurement before anastomosis, flow was easily detected in the cortical branches of the MCA in 8 of 12 STA-MCA anastomoses. The prominent flow changes in the cortical branches of MCA with on-off clipping of the STA, namely the flow increase in distal to and the decrease or reverse of flow in proximal to anastomosis, were detected in 4 of 10. Postoperative bypass function evaluated according to the results of transcutaneous Doppler flowmetry of STA was good in 9 of 14 STA-MCA anastomoses. The results of intraoperative studies were not in agreement with those of intraoperative studies in 4. Bypass function in patients of moyamoya disease was relatively poor and labile in comparison with those in patients with the other cerebrovascular occlusive disorders.
