Surgeon-performed transcutaneous laryngeal ultrasonography after thyroidectomy: Diagnostic accuracy and learning curve

Introduction

Vocal cord paralysis is an uncommon complication after thyroidectomy, reported in approximately 3% to 4% of procedures. Flexible laryngoscopy is the gold standard for assessing postoperative vocal cord mobility, but its usage is limited because of expense, discomfort, and availability. Transcutaneous laryngeal ultrasonography has evolved as a noninvasive and widely available alternative.

Materials and Methods

We conducted a prospective cross-sectional study on adult patients receiving total or partial thyroidectomy by head and neck surgeons. The operating surgeon performed transcutaneous laryngeal ultrasonography postoperatively and compared the results to a blinded laryngoscopic examination. The sensitivity, specificity, predictive value, and likelihood ratios were calculated. For nondiagnostic tests, best- and worst-case scenarios were evaluated. A learning curve study was also conducted.

Results

A total of 146 patients with 239 nerves at risk were included. Vocal cord paralysis was observed in 2.1% of nerves at risk. Transcutaneous laryngeal ultrasonography demonstrated a sensitivity of 80% and a specificity ranging from 94.4% to 99.6%, depending on the clinical scenario. The negative predictive value remained high (99.6%), whereas the positive predictive value ranged from 23.5% to 80%. After about 50 examinations, the learning curve stabilized, and the median examination length was 26.9 seconds.

Conclusion

Surgeons may conduct transcutaneous laryngeal ultrasonography with good diagnostic accuracy and efficiency, making it a cost-effective technique for postoperative vocal cord evaluation in thyroidectomy patients.