Background: 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.
Methods: 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.
Results: 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.
Conclusions: 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.