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

## TL;DR

This systematic review evaluates laryngeal reinnervation techniques for treating vocal fold paralysis, finding they offer durable voice improvements with minimal complications.

## Contribution

The study systematically reviews outcomes and predictive factors for laryngeal reinnervation in unilateral vocal fold paralysis, guiding clinical decision-making.

## Key findings

- AnsaNSR and NMPR+AA techniques show high rates of voice improvement in patients with unilateral vocal fold paralysis.
- Younger patients (<60 years) and those with shorter denervation periods (<2 years) tend to have better outcomes.
- Standardized outcome measurements and clearer predictive factors are needed to refine patient selection.

## Abstract

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.

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.

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.

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.

The online version contains supplementary material available at 10.1007/s00405-025-09737-7.