Ultrasonic Doppler assessment of hemodynamics in gradual carotid ligation.

Hemodynamic changes were examined with an ultrasonic Doppler flowmeter and with a sound-spectrograph in 5 patients with internal carotid giant aneurysms or with recurrent laryngeal cancer undergoing gradual carotid occlusion. The ultrasonic Doppler technique was useful for preoperative assessment of intracranial cross-filling and as a practical guide for the graded reduction of blood flow in the carotid artery. The degree of flow increase in the contralateral carotid artery when the ipsilateral carotid artery was totally occluded was greater in postoperative gradual occlusion than in intraoperative rapid occlusion. In one patient with bilateral internal carotid artery giant aneurysms, whose left internal carotid artery had already been ligated at its origin, gradual occlusion of the right internal carotid artery was performed after the bilateral superficial temporal artery-middle cerebral artery (STA-MCA) anastomoses. Flow in the donor artery of the right STA-MCA anastomosis developed with increasing occlusion of the right internal carotid artery.