[Ultrasonic Doppler assessment of hemodynamics in extra-intracranial arterial anastomosis in children with Moyamoya disease].

Recently the extra-intracranial (EC/IC) arterial bypass operation has been introduced in the treatment of Moyamoya disease and excellent postoperative outcomes have been reported. To assess the cerebral hemodynamic changes after the bypass surgery, ultrasonic Doppler flowmetry was performed in 10 children with Moyamoya disease. Their surgical treatments included superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis or encephalo-duro-arterio-synangiosis. The flow velocity and pattern of the major cerebral arteries and STAs, the donor artery of the bypass, were studied both before and after the operation. The results of Doppler flowmetry were compared with clinical symptoms and angiographical findings. Though the Doppler sonography of the major cerebral arteries showed little change, the flow velocity of the STAs revealed a pronounced and rapid increase after the bypass surgery. The flow pattern of the STAs, which was of the external carotid type preoperatively, changed to the internal carotid type postoperatively. These ultrasonic Doppler findings were thought to be due to a decrease in the peripheral vascular resistance, and suggested a good patency of the bypass arteries. These results of the Doppler flowmetry were in good agreement with clinical and EEG improvement and the findings of the postoperative cerebral angiography. It is suggested that ultrasonic Doppler flowmetry is a noninvasive and reliable method of assessing the function of the EC/IC bypass in children with Moyamoya disease.