The Effect of Transoral Endoscopic Thyroidectomy Vestibular Approach on Regional Cerebral Oxygen Saturation: A Prospective Observational Study.

Abstract

Decreased regional cerebral oxygen saturation (rSO2) is associated with neurological events. We aimed to investigate the effects of carbon dioxide (CO2) insufflation applied to the neck during transoral endoscopic thyroidectomy vestibular approach (TOETVA) surgery on the rSO2. Patients scheduled for TOETVA and open thyroidectomy (OT) were enrolled between October 2019 and November 2020. Alongside hemodynamic parameters, the rSO2 values of the patients were recorded at 5 different times. These were; before anesthesia induction (T0), 10 minutes after anesthesia induction (T1), 5 minutes after the patient was placed in the operation position (T2), 10 minutes after the CO2 insufflation in the TOETVA group, 10 minutes after the platysma incision in the OT group (T3), 10 minutes after the CO2 desufflation in the TOETVA group, 10 minutes after platysma closure in the OT group (T4), at the end of the surgery (T5). A total of 40 patients, 20 in each group, were included in the study. The surgery duration was 113±26.9 minutes in the OT group, while it was 274.1±78.1 minutes in the TOETVA group (P=0.000). The EtCO2 values during the T3 time interval; group OT 31±2.2, group TOETVA 33.9±2.1 (P=0.000). The rSO2 values of the patients were similar, except for the T3 time interval. While the right rSO2 value we obtained during the T3 time interval in the TOETVA and OT groups were 66.9±9.1 and 73.9±7.8 (P=0.013), the left rSO2 value in the TOETVA and OT groups were 66.3±9.9 and 74.8±6.8 (P=0.003), respectively. As long as the patients stay within the limits of normocapnia, the CO2 insufflation applied during TOETVA surgery has no negative effects on rSO2.