Intrinsic laryngeal muscle reinnervation using the muscle-nerve-muscle technique.
OBJECTIVE
This study was performed to investigate the muscle-nerve-muscle reinnervation technique in the larynx, in which a nerve conduit implanted into an innervated muscle conducts axonal sprouting into a denervated muscle while maintaining function of the donor muscle.


METHODS
In this study, the muscle-nerve-muscle technique was used to direct superior laryngeal nerve axons to reinnervate intrinsic laryngeal muscles by implanting the recurrent laryngeal nerve stump into the cricothyroid muscle in 8 dogs. In 4 of the dogs, the recurrent laryngeal nerve trunk to the adductor muscles was divided so that all axonal sprouting was directed to the posterior cricoarytenoid muscle. Six-month electromyography data were obtained from 6 of the 8 dogs.


RESULTS
All 6 dogs showed evidence of successful reinnervation of the thyroarytenoid or posterior cricoarytenoid muscles with action potentials that corresponded to spontaneous respiratory efforts, while the donor cricothyroid muscles retained their phasic contraction. These responses were obliterated when the recurrent laryngeal nerve conduit was divided. Histologic examination of the intrinsic laryngeal muscles demonstrated successful reinnervation.


CONCLUSIONS
The results confirm that intrinsic laryngeal muscles may be successfully reinnervated by the superior laryngeal nerve with the muscle-nerve-muscle technique, without sacrifice of function of the cricothyroid muscle. This method offers an alternative source of appropriately firing axons for laryngeal reinnervation procedures.
Department of Otolaryngology-Head and Neck Surgery, Washington University School of Medicine, St Louis, Missouri 63110, USA.
Indranil
I
Debnath
Jason T
JT
Rich
Randal C
RC
Paniello
D000818:Animals; D004195:Disease Models, Animal; D004285:Dogs; D004576:Electromyography; D005260:Female; D007821:Laryngeal Muscles / Q000294:innervation / Q000503:physiopathology / Q000601:surgery*; D007828:Laryngoscopy / Q000379:methods*; D009119:Muscle Contraction / Q000502:physiology; D019651:Plastic Surgery Procedures / Q000379:methods*; D012009:Recurrent Laryngeal Nerve / Q000601:surgery*; D016896:Treatment Outcome; D014826:Vocal Cord Paralysis / Q000503:physiopathology / Q000601:surgery*; D014827:Vocal Cords / Q000293:injuries* / Q000601:surgery