Carotid flow, intrasinusal pressure, and collateral flow during carotid occlusion.

IRIUCHIJIMA, JURO, AND HIROYUKI KOIKE. Carotid flow, intrasinusal pressure, and collateral flow during carotid occlusion. Am. J. Physiol. 218(3) : 876-879. 1970.-Bilateral common carotid flow and systemic as well as intrasinusal pressure were observed in anesthetized dogs. Unilateral common carotid occlusion induced about a 30y0 increase in contralateral common carotid flow, mainly due to collateral flow to the occluded side. Based on certain assumptions, collateral flow and collateral flow resistance were approximately calculated. During common carotid occlusion the decrease in intrasinusal pulse pressure was much greater than that in mean pressure. Stimulation of the cervical sympathetics decreased ipsilateral carotid flow but not contralateral flow. However, during occlusion of the ipsilateral common carotid artery, contralateral carotid flow was decreased by sympathetic stimulation. These findings indicate a unilateral sympathetic innervation as well as unilateral flow distribution despite abundant, vascular communications across the midline. Sympathetic stimulation considerably restored the intrasinusal pressure which had been decreased by carotid occlusion, indicating that the site of sympathctic innervation was mostly peripheral to the communicating vessels.