Regional Cerebral Oxygen Saturation Monitoring during Carotid Endarterectomy

Abstract

Introduction: Carotid endarterectomy carries a risk of perioperative stroke from cross-clamp ischemia. This review examines whether near-infrared spectroscopy-guided regional cerebral oxygen saturation monitoring reduces postoperative neurologic complications.

Methods: Literature review of randomized trials and prospective cohort studies comparing near-infrared spectroscopy monitoring (with protocolized intervention for desaturation) versus conventional monitoring (awake neurological examination or electroencephalography) during carotid endarterectomy under general anesthesia. Primary outcome was new postoperative ipsilateral ischemic stroke. Secondary outcome was cognitive decline at three months.

Results: Six studies (1,203 patients) were included. Near-infrared spectroscopy-guided management reduced stroke risk from 7.2% to 3.0% (relative risk 0.42). Cognitive decline at three months occurred in 18% of conventional monitoring patients versus 11% of near-infrared spectroscopy patients. Interventions triggered by desaturation included increasing mean arterial pressure, placing a shunt, or raising inspired oxygen fraction.

Discussion: Regional cerebral oxygen saturation reflects the balance between oxygen delivery and consumption. Desaturation events often precede electroencephalographic changes, allowing earlier intervention. However, no standardized desaturation threshold exists across studies (ranging from 15% to 25% decrease from baseline). False positives occur with extracranial contamination.

Conclusions: Near-infrared spectroscopy monitoring reduces perioperative stroke and cognitive decline after carotid endarterectomy, likely by prompting timely interventions for cerebral desaturation. Standardized thresholds and response algorithms are recommended.