The importance of sonographic landmarks by transcutaneous laryngeal ultrasonography in post-thyroidectomy vocal cord assessment

Surgery. 2014 Dec;156(6):1590-6; discussion 1596. doi: 10.1016/j.surg.2014.08.061. Epub 2014 Nov 11.

Abstract

Introduction: During examination of the vocal cords (VC) using transcutaneous laryngeal ultrasonography (TLUSG), 3 sonographic landmarks (namely, false VC [FC], true VC [TC], and arytenoids [AR]) are often seen. However, it remains unclear which landmark provides a more reliable assessment and whether seeing more landmarks improves the diagnostic accuracy and reliability.

Methods: We evaluated prospectively 245 patients from 2 centers. One assessor from each center performed all TLUSG examinations and their findings were validated by direct laryngoscopy. All 3 sonographic landmarks were routinely visualized whenever possible. The rate of visualization and diagnostic accuracy between the 3 landmarks were compared.

Results: Eighteen patients suffered postoperative VC palsy (VCP). Both centers had comparable visualization or assessability rate of ≥ 1 sonographic landmark (94.9 and 95.3%; P = 1.000) and 100% sensitivity on postoperative TLUSG. The rates of FC, TC, and AR visualization were 92.7%, 36.7%, and 89.8%, respectively. The sensitivity, specificity, and diagnostic accuracy and the proportion of true positives, false positives, and true negatives between using 1, 2, landmarks and 3 landmarks were comparable (P > .05).

Conclusion: Each sonographic landmark had similar reliability and diagnostic accuracy. Identifying all 3 sonographic landmarks was not mandatory and visualizing normal movement in one of the sonographic landmarks would be sufficient to exclude VCP.

Publication types

  • Comparative Study
  • Multicenter Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Anatomic Landmarks
  • Cohort Studies
  • Female
  • Humans
  • Laryngoscopy / methods*
  • Male
  • Middle Aged
  • Observer Variation
  • Postoperative Care / methods
  • Prospective Studies
  • Sensitivity and Specificity
  • Statistics, Nonparametric
  • Thyroidectomy / adverse effects
  • Thyroidectomy / methods*
  • Ultrasonography, Doppler / methods*
  • Vocal Cord Paralysis / diagnostic imaging
  • Vocal Cord Paralysis / etiology
  • Vocal Cords / diagnostic imaging*
  • Vocal Cords / physiology
  • Young Adult