(Open access funding provided by Semmelweis University)
There are controversial data about the effect of carotid endarterectomy regarding
postoperative cognitive function. Our aim was to analyze the effect of cerebral tissue
saturation monitored by near-infrared spectroscopy (NIRS) on cognitive function. Perioperative
data of 103 asymptomatic patients undergoing elective carotid surgery under general
anesthesia were analyzed. Preoperatively and 3 months after the operation, MMSE (Mini
Mental State Examination) and MoCA (Montreal Cognitive Assessment) tests were conducted.
For cerebral monitoring, NIRS was used, and the lowest rSO2 value and the degree of
desaturation were calculated. Cognitive changes were defined as one standard deviation
change from the preoperative test scores, defined as postoperative neurocognitive
decline (PNCD) and cognitive improvement (POCI). PNCD was found in 37 patients (35.92%),
and POCI was found in 18 patients (17.47%). Female gender, patients with diabetes,
and the degree of desaturation were independently associated with PNCD. The degree
of desaturation during the cross-clamp period negatively correlated with the change
in the MoCA scores (R = - 0.707, p = 0.001). The 15.5% desaturation ratio had 86.5%
sensitivity and 78.8% specificity for discrimination. For POCI, a desaturation of
less than 12.65% had 72.2% sensitivity and 67.1% specificity. POCI was associated
with lower preoperative MOCA scores and a lower degree of desaturation. We found a
significant relation between the change of postoperative cognitive function proven
by the MoCA test and cerebral tissue saturation during the clamping period in patients
undergoing carotid endarterectomy.
