Ultrasonic Doppler assessment of hemodynamics in superficial temporal artery--middle cerebral artery anastomosis.

The pre-, intra-, and postoperative hemodynamics were examined by a newly developed ultrasonic Doppler flowmeter in 20 patients undergoing 24 STA-MCA anastomoses. During the operations, no reverse flow was detected in the cortical branch of the middle cerebral artery. After anastomosis, prominent flow changes in direction and in volume were evident in the cortical branches and the flow pattern of the STA changed from an external carotid type preoperatively to an internal carotid type in well functioning bypasses. The results of postoperative studies were not always in good agreement with those of intraoperative studies and bypass function was relatively not good and labile in patients with only stenotic lesions and in those with "moyamoya disease".