Laryngeal ultrasound for evaluation of paediatric unilateral vocal fold immobility -- a retrospective cohort study in Aotearoa New Zealand and a survey of clinicians around the world

Abstract

Objective: Vocal fold immobility (VFI) is a cause of significant morbidity and mortality in the paediatric population. Laryngoscopy is the current first-line investigation for patients with suspected VFI. Laryngeal ultrasound (LUS) has recently emerged as an alternative method of identifying VFI. Compared to laryngoscopy, LUS is less invasive, does not require anaesthesia, and can be performed by non-otolaryngologists. The primary objective of this study is to evaluate LUS as a diagnostic method for the identification of unilateral VFI in a cohort of paediatric patients in Aotearoa New Zealand (NZ). The secondary objective is to estimate the frequency of use of LUS in the paediatric population around the world. Methods: A retrospective, single-centre cohort study was performed on all paediatric patients who had undergone laryngoscopy and LUS at Starship Children’s Health between 2020 to 2023 in Auckland, NZ. An eight-question survey was also developed and distributed to better understand clinicians’ use of LUS to diagnose paediatric VFI globally. Results: Twenty-three paediatric patients met the inclusion criteria. LUS demonstrated high sensitivity (100%), specificity (63%), positive predictive value (83%), and negative predictive value (100%) for detecting unilateral VFI within our patient population. Out of the eighty-seven respondents to the survey, nearly half utilise LUS in their clinical practice in the paediatric population. The main barrier for those who do not is lack of expertise, equipment, and training. Conclusions: These findings support the use of LUS as a safe and accurate diagnostic tool for the detection of unilateral VFI. Further studies in non-surgical populations and standardised guidelines for LUS technique and reporting are required.