Brain Oxygen Supply Parameters in the Risk Assessment of Cerebral Complications During Carotid Endarterectomy

Objective To determine whether preoperative regional cerebral oxygen saturation (rSO₂) and the decrease in rSO₂ during carotid clamping were predictive of the risk for neurologic complications in carotid endarterectomy and to determine the cutoff values of the studied parameters. Design Cohort, prospective, nonrandomized trial. Setting Research Institute of Circulation Pathology, Novosibirsk, Russia. Participants The study comprised 466 adults who underwent carotid endarterectomy since 2012. Interventions None. Measurements and Main Results Patient characteristics, postoperative complications, and brain oxygen supply during carotid endarterectomy were analyzed. The primary endpoints were the perioperative and early postoperative neurologic complications. Ischemic stroke was diagnosed in 1.5% of patients, and cognitive disorders were reported in 2.6% of patients. Preoperative rSO₂ of 50% was the cutoff value for the prediction of stroke outcome after carotid endarterectomy, with a sensitivity of 90.7% and specificity of 66.7%. A 20% decrease in rSO₂ during temporary carotid clamping was the cutoff value for the prediction of stroke, with a sensitivity of 86.0% and specificity of 57.1%, and for the prediction of cognitive disorders, with a sensitivity of 88.1% and specificity of 58.3%. Preoperative rSO₂ less than 50% and a decrease in rSO₂ of at least 20% during temporary carotid artery clamping caused a significant increase in the hospitalization period. Conclusions A 20% or more decrease in rSO₂ during temporary internal carotid artery clamping during carotid endarterectomy caused a 10-fold increased risk of ischemic stroke and an 8-fold increased risk of cognitive disorders, whereas preoperative rSO₂ less than 50% resulted in a 6-fold increased risk of ischemic stroke in the perioperative and early postoperative periods of carotid endarterectomy.