Local anaesthesia in carotid surgery. A prospective study of 111 endarterectomies in 100 patients.

A prospective study was carried out on 100 patients consecutively undergoing carotid endarterectomy in local anaesthesia, in order to evaluate the usefulness of clinical signs in awake patients for monitoring of cerebral function and to determine the need for internal shunt in carotid surgery. The indications for operations were transient ischemic attacks in 67 patients and major or minor stroke in 24 (16 with persistent neurologic deficit). In nine asymptomatic patients the endarterectomy was prophylactic, following detection of bruit and angiographic stenosis. Bilateral stenosis was present in 47 patients, including 13 with total occlusion of the contralateral vessel, and 60 patients had significant vertebral artery stenosis. The carotid artery was first tentatively occluded and, if this was well tolerated for 5 min, endarterectomy was done without an internal shunt. Neurologic deficit signs during the trial occlusion necessitated such shunt in 16 patients with pressure in the internal carotid stump ranging from 0 to 40 (mean 22.4) mmHg. On the other hand, 11 additional patients with stump pressure less than 35 mmHg tolerated the trial occlusion well, underwent carotid endarterectomy without internal shunt and had no deficit symptoms during or after operation. One patient died postoperatively. Hemiparesis appeared in two more patients, but resolved completely in one and gave only minor sequelae in the other. These complications were related to the preoperative condition (stroke) and the postoperative residual pressure gradient. It is concluded that trial occlusion of the carotid artery and observation of the awake patient provide reliable information on the need for an internal shunt during carotid endarterectomy.