A prospective, assessor-blind evaluation of surgeon-performed transcutaneous laryngeal ultrasonography in vocal cord examination before and after thyroidectomy

Abstract

Introduction: Transcutaneous laryngeal ultrasonography (TLUSG) is a promising alternative to direct laryngoscopy in assessing perioperative vocal cord function. This study sought to evaluate the accuracy of TLUSG in assessing vocal cord function.

Methods: Altogether, 204 patients underwent TLUSG and direct laryngoscopy before and after elective thyroidectomy. For both examinations, vocal cord movements were independently graded. Grade I meant both vocal cords had normal movement; grade II meant ≥1 vocal cord had decreased movement; and grade III meant ≥1 vocal cord had no movement. Grade II or III on direct laryngoscopy was defined as vocal cord paresis or palsy (VCP). To assess accuracy, TLUSG findings were correlated with direct laryngoscopy findings.

Results: No patient had preoperative VCP, and 17 had unilateral postoperative VCP. The overall postoperative VCP rate was 5.1%. TLUSG failed to assess VCs in 11 (5.4%) postoperative patients. Of these, 2 had VCP and 9 had no VCP on direct laryngoscopy. Postoperative TLUSG had a sensitivity, specificity, positive predictive value, and negative predictive value of 93.3%, 97.8%, 77.8%, and 99.4%, respectively. Of the 175 patients with grade I on TLUSG, only 1 (<1%) had grade II VCP on direct laryngoscopy.

Conclusion: TLUSG is a promising, noninvasive tool for selecting patients to undergo direct laryngoscopy before and after thyroidectomy.