Incidence and risk factors of intubation-related vocal cord paralysis after unilateral thyroidectomy

Vocal cord paralysis (VCP) is a recognized complication of endotracheal intubation, but its true incidence may be underestimated because many asymptomatic cases remain undetected. Previous studies have focused primarily on VCP affecting the surgical side after unilateral thyroidectomy, whereas the non-surgical side has received less attention. The present study determines the incidence and risk factors of intubation-induced VCP on the non-surgical side in patients undergoing hemithyroidectomy.

This retrospective cohort included 339 patients who underwent hemithyroidectomy at a single institution between 2010 and 2018. All patients underwent routine pre- and postoperative laryngeal examinations using flexible endoscopy. The incidence of intubation-induced VCP on the non-surgical side was 2.4% (8/339). Patients who developed VCP had significantly lower body weight and body mass index than those without VCP, suggesting that underweight individuals may be more vulnerable. Most cases were transient, resolving within two months of surgery. No significant associations were identified between age, duration of surgery, endotracheal tube size, or intubation method. All cases of intubation-related VCP occurred in patients anesthetized with total intravenous anesthesia. However, this finding should be interpreted with caution because the retrospective design precludes establishing causality and potential confounders.

Intubation-induced VCP was observed more frequently than previously reported, particularly among underweight patients. Routine perioperative laryngeal assessment enables detection of asymptomatic cases and may help clarify risk factors. Careful preoperative evaluation and vigilant intraoperative management remain essential to reduce the risk of this underrecognized complication.