Endoscopic thyroidectomy is frequently used for cosmetic reasons, such as reducing cervical scarring. Subcutaneous gas insufflation with CO₂ is needed to maintain the surgical space, and optimal surgical techniques and careful attention are required when conducting this procedure due to the limited space available for the endoscopic instruments. We report here a case of a tracheal laceration with a tear in the cuff of a reinforced tube, which was detected by an abrupt increase in end-tidal CO₂ to 90 mmHg. Reintubation was achieved using a tube exchanger and the patient was effectively ventilated without complications.