Laryngeal reinnervation for unilateral vocal fold paralysis in adults; a systematic review of the literature for the clinician

Abstract

Purpose: Unilateral vocal fold paralysis (UVFP), resulting from recurrent laryngeal nerve injury, significantly impairs phonation and reduces quality of life. Laryngeal reinnervation, including ansa-to-recurrent (ansaNSR) and nerve-muscle pedicle reinnervation combined with arytenoid adduction (NMPR + AA), has gained attention as a durable treatment option. This systematic review aims to evaluate the outcomes of laryngeal reinnervation, identify predictive factors and highlight knowledge gaps relevant to clinical practice. Methods: A systematic search of PubMed, Embase, Web of Science, the Cochrane Library and Emcare identified 42 studies. Outcome measures included perceptual, acoustic, aerodynamic, videostroboscopic and patient-reported outcomes. The risk of bias was assessed using the Methodological Index for Non-Randomized Studies (MINORS) tool. Weighted mean improvements were calculated for clinically relevant parameters. Results: We included forty-two studies (N = 1 859 patients) in our review. These studies demonstrated high rates of voice improvement, primarily based on data from the ansaNSR (N = 1 369) and NMPR + AA (N = 278) techniques. Age and duration of denervation emerged as the most influential predictive factor. Younger patients (< 60 years) and those with shorter denervation periods (< 2 years) had better outcomes, although successful results were also observed beyond these thresholds. The predictive value of preoperative laryngeal electromyography (LEMG), etiology of UVFP and clinical presentation remains inconclusive. Conclusion: Laryngeal reinnervation (ansaNSR and NMPR + AA) is effective for UVFP, offering durable voice improvements with minimal complication rates. Future research should focus on standardizing outcome measurements, clarifying predictive factors and refining patient selection to enhance clinical decision-making.