Laryngeal Reinnervation with Refined Nerve-Muscle Pedicle Implantation Using Electromyography and Coronal Reconstructed Images

Abstract

Objectives:

Evaluate the long-term efficacy of laryngeal reinnervation with refined nerve-muscle pedicle (NMP) flap implantation combined with arytenoid adduction for unilateral vocal fold paralysis (UVFP) using laryngeal electromyography (LEMG), coronal images, and assessment of phonatory function.

Methods:

We retrospectively reviewed 16 UVFP patients who received refined NMP implantation with arytenoid adduction. Videostroboscopy, perceptual evaluation, acoustic analysis, aerodynamic analysis, LEMG, and coronal imaging were performed pre- and 2 years after surgery. For LEMG analysis, a four-point scale was employed to grade motor unit (MU) recruitment where 4+ represented absent recruitment, 3+ represented greatly decreased recruitment, 2+ represented moderately decreased recruitment, and 1+ represented mildly decreased activity with less than full interference pattern. Coronal images were assessed for differences in thickness of the vocal folds during phonation and inhalation.

Results:

Phonatory function results were significantly improved postoperatively for all patients. In LEMG findings, preoperative MU recruitment evaluation results were 1 patient for 1+, 5 for 2+, 1 for 3+, and 3 for 4+. Postoperative MU recruitment evaluation results were 7 patients for 1+, 3 for 2+, and none for 3+ and 4+. Thinning of the affected fold was evident during phonation in 15 of 16 patients preoperatively. The affected fold was at an equal volume with the healthy fold in 8 of 16 patients postoperatively.

Conclusions:

LEMG findings and coronal imagine demonstrates that refined NMP implantation results in successful reinnervation of laryngeal muscles in UVFP patients. Refined NMP implantation may provide near-normal voice function and restored laryngeal muscle tone and volume.