Characteristics, natural evolution and surgical treatment outcomes of unilateral laryngeal paralysis versus ankylosis: A longitudinal cohort study

International audienceAims: Although unilateral laryngeal immobility (ULI) can results from paralysis or ankylosis of the cricoarytenoid joint, no comparative study exists to date. Aim of this study was to compare clinical features, aetiologies, spontaneous recovery and evolution after surgical treatment of ULI according to its mechanism. Methodology: Longitudinal observational cohort study between 1992 and 2017 in a tertiary care referral centre and university teaching hospital. All adult patients with isolated ULI were included. Presenting symptoms and demographic data were recorded at baseline. During follow-up, natural recovery and, if a surgical treatment was performed, treatment failure rate were noted. Results: 994 patients were included, 56.4% of male and with a mean age of 58 years. Overall, 91% had paralysis and 9% had ankylosis. Dysphonia was the main symptom in both groups (>96%). Dyspnoea was more frequent in patients with ankylosis (26.1% vs 4.2% in those with paralysis) whereas dysphagia was more frequent in those with paralysis (31.1% vs 20% in those with ankylosis). With a mean follow-up of 2.3 years (±5.1), spontaneous recovery did not differ according to ULI’s aetiology (hazard ratio 1.43, 95% confidence interval 0.85-2.40). Overall, 37.1% underwent a surgical treatment, and paralysis was associated with a lower odd of treatment failure (hazard ratio 0.27, 95% confidence interval 0.10-0.70) over a mean follow-up of 3.1 years (±4.1). Conclusion: ULI resulting from paralysis or ankylosis differ in their symptoms and responses to surgical treatment, whereas natural evolution was similar