Effect of injection laryngoplasty material on outcomes in pediatric vocal fold paralysis

BACKGROUND: While injection laryngoplasty is becoming increasingly common in children, there has not been clearly established guidelines for the choice of injection material. This study evaluates for variability in post-surgical outcomes between different materials used for injection laryngoplasty in the treatment of pediatric unilateral vocal cord paralysis. METHODS: In this cohort study, a retrospective chart review was performed for all patients undergoing injection laryngoplasty for unilateral vocal cord paralysis at our tertiary-care children’s hospital between January 2010 and December 2019. Patients with vocal cord paresis or bilateral vocal cord paralysis were excluded from this study. Demographics, pre- and post-injection clinic visits, and operative reports were reviewed to compare outcomes between injection materials, including the number of injections required, inter-surgical interval, and rate of vocal improvement. RESULTS: Forty-four patients were included in the analysis. Half of the patients were female, and half were male. A total of 97 injections were observed, with 32 patients receiving multiple injections. The mean age at first injection was 7 years. The most common causes of vocal fold paralysis were iatrogenic (n=21, 48%) and idiopathic (n=9, 20%). Thirty-nine percent (n=17) had a history of cardiac surgery. Forty-five percent of injections used Radiesse(®) voice/Prolaryn(®) plus, 35% used Radiesse(®)/Prolaryn(®) voice Gel, and 20% used Cymetra™. The material used was not associated with a difference in post-operative outcomes, including number of injections, (P=0.10; 0.29), inter-surgical interval (P=0.27; 0.29), or rate of voice improvement (P=0.86; 0.36). CONCLUSIONS: Neither material choice nor demographic factors were associated with a difference in outcomes following injection laryngoplasty or a change in the inter-surgical interval. Further research is needed to develop standardized protocols for injection laryngoplasty in this population.