Assessment of Vocal Cord Motion Using Laryngeal Ultrasound in Children: A Systematic Review and Meta-Analysis

OBJECTIVES: Laryngeal ultrasound is a nonirradiating, noninvasive method for assessing the upper airway in children. This systematic review and meta-analysis examine available evidence for accuracy of laryngeal ultrasound in diagnosing vocal cord immobility in infants and children after surgery and trauma affecting the vocal cords. DESIGN: Medical subject heading terms were used to search MEDLINE, Embase, Google Scholar, Web of Science, and the Cochrane Library for relevant citations. Publications from January 1, 2000, to June 30, 2020 were included in the search strategy. Study inclusion criteria consisted of randomized control trials and nonrandomized retrospective or prospective observational studies where vocal cord motion was evaluated by laryngeal ultrasound and compared with a reference test. Studies were excluded if there was insufficient data to compute a sensitivity/specificity table. Case reports, case series less than 10, and manuscripts not published in English were also excluded. PATIENTS: Studies which included subjects younger than or equal to 18 years were considered for full article review. SETTINGS: No restrictions on study settings were imposed in this systematic review. MEASUREMENTS AND MAIN RESULTS: The initial search returned 1,357 citations. After de-duplication, abstract, and full review, eight citations were included in the final meta-analysis. A bivariate random-effects meta-analysis was performed, which revealed a pooled sensitivity for laryngeal ultrasound in detecting vocal cord immobility of 91% (95% CI, 83–95%), specificity of 97% (95% CI, 82-100%), diagnostic odds ratio 333.56 (95% CI, 34.00–3,248.71), positive likelihood ratio 31.58 (95% CI, 4.50–222.05), and negative likelihood ratio 0.09 (95% CI, 0.05–0.19). CONCLUSIONS: Laryngeal ultrasound demonstrates high sensitivity and specificity for detecting vocal cord motion in children in a wide range of clinical settings. Laryngeal ultrasound offers a low-risk imaging option for assessing vocal cord function in children compared with the current gold standard of laryngoscopy.