Transcutaneous laryngeal ultrasonography: A promising tool for otolaryngologists during COVID-19

Abstract

Purpose: With the current COVID-19 outbreak, otolaryngologists are most exposed to the risk of infection due to the nature of the specialty.This is why they are required to find safer diagnostic alternatives minimizing aerosol-generating procedures. The aim of this study is to explore the accuracy of transcutaneous laryngeal ultrasonography (TLUSG) in order to assess vocal fold movement.

Materials and methods: We performed blindly both TLUSG and flexible fiberoptic laryngoscopy(FFL) on 38 patients, from March to June 2020. Patients were divided into two groups:the former with normally mobile vocal folds and the latter with unilateral vocal fold paralysis.

Results: On FFL findings, 10/38 patients (26,31%) had unilateral vocal fold paralysis; on TLUSG results, 9/38 patients (23.68%) presented impaired vocal fold motion. In comparison to laryngoscopy, the sensitivity, specificity, positive predictive value and negative predictive value of TLUSG for assessment of vocal fold mobility was 80%, 96.42%, 88.88%, 93.10% respectively. A significant association between the two techniques was found on the Chi-square test: X² = 19.7722 (p value <0.00001). Cohen's K value showed a substantial agreement: K = 0,79.

Conclusion: Although TLUSG could undoubtedly not replace laringoscopy, it represents a noninvasive and useful diagnostic tool for otolaryngologists especially during covid-19 pandemic.Data collected about its high sensitivity and specificity suggest that TLUSG could be a reliable method to screen vocal fold paralysis without performing aerosol-generating procedures, thus providing clear visualization of laryngeal real-time movements, even in non-compliant or high-risk infection patients. Our results allow us to consider TLUSG as part of the preoperative assessment of vocal folds in patients undergoing thyroidectomy.

Keywords: COVID-19; Flexible fiberoptic laryngoscopy; Otolaryngology; TLUSG; Transcutaneous laryngeal ultrasonography; Vocal fold paralysis.

Fig. 1

Sonographic view of normal vocal folds during quiet respiration (abduction); FVF: false vocal fold, TVF: true vocal fold, ARY: arytenoid, THY: thyroid cartilage.