Neurologic changes during carotid endarterectomy under cervical block predict a high risk of postoperative stroke

This study was undertaken to confirm a previous report that patients having neurologic changes with carotid artery clamping were at greater risk of developing permanent postoperative neurologic complications after carotid endarterectomy. Superficial and deep cervical plexus blocks were performed in 389 patients undergoing carotid endarterectomy. The patients were premedicated and sedated to a level that allowed awake neurologic assessment. Intraoperative neurologic changes were recorded and all patients were examined postoperatively by an independent anesthesiologist to record postoperative neurologic outcome. Trial carotid artery cross clamping resulted in 24% of patients having neurologic changes that usually responded to declamping and shunt insertion. Postoperative permanent neurologic complications occurred in 2.6% of patients, but were more common in patients who had neurologic changes associated with carotid artery cross clamping (6.6% compared to 1.1%, P < 0.01). Thrombosis of the carotid artery was the most common finding in patients who underwent reexploration of the carotid artery after developing postoperative neurologic changes. This study confirms that patients undergoing carotid endarterectomy under cervical plexus block who have intraoperative neurologic changes have a sixfold increase in the chance of developing a postoperative stroke. This high-risk group may benefit from antithrombotic therapies to improve their outcome.