AWAKE PATIENT MONITORING TO DETERMINE THE NEED FOR SHUNTING DURING CAROTID ENDARTERECTOMY

Background. The indications for shunt placement to prevent cerebral is ischemia during carotid endarterectomy have been controversial. Some investigators have recommended empiric shunting for patients presumed to be at higher risk for cerebral ischemia with a recent/stroke or sev ere stenosis or occlusion of the contralateral internal carotid artery . Methods. Carotid endarterectomy was performed in 81 cases with cervi cal block anesthetic, monitoring the awake patient for the development of cerebral ischemia (unresponsiveness or paralysis) during carotid c lamping. The need for shunting (based on awake response) was compared in patients with the arbitrarily defined empiric indications for shunt ing (n = 29) versus those who did not have such clinical or anatomic f indings (n = 52). Results. Cerebral ischemia requiring shunting was ob served in five (17.2%) of 29 cases with the defined indications for em piric shunting. This was not different than the need for shunting in t he control group where cerebral ischemia was seen in eight (15.4%) of 52 cases. No intraoperative neurologic events occurred in any case, bu t one (1.2%) patient suffered a postoperative transient ischemia attac k and another (1.2%) had a postoperative stroke. Conclusions. Empiric clinical or anatomic indications for shunting were not reliable predic tors of cerebral ischemia that developed during carotid clamping in th is study. Awake patient monitoring during carotid endarterectomy with regional anesthetic allowed prompt, accurate identification of patient s with cerebral ischemia who would clearly benefit from placement of a shunt.