Attempted reinnervation of the equine larynx using a muscle pedicle graft.

This research article focused on trying to restore the function of a paralyzed larynx in ponies using a muscle pedicle graft method, but found that the technique was not particularly effective.

Overview of the Study

• The research studied the effects of the muscle pedicle graft in ponies diagnosed with laryngeal hemiplegia, a condition that paralyzes the larynx or the windpipe.
• The laryngeal hemiplegia was created artificially through a process called left recurrent laryngeal neurectomy, where the nerve supplying the larynx was surgically cut in 4 ponies.

Method of Reinnervation

• Reinnervation, or the restoration of nerve supply, was attempted by grafting muscle from the right cricoarytenoideus dorsalis muscle (one of the muscles of the larynx) to the same muscle on the left side that had been denervated.

Results of the Study

• Out of the four ponies, three experienced no return of the abductor (or opening) function of the larynx and the grafted muscle did not survive.
• However, in the fourth pony, the abductor function returned and the muscle graft survived. Also, there was evidence of reinnervation across the site where the nerve had been cut.

Conclusion

• Despite partial success in one pony, the overall findings suggest that muscle-to-muscle neurotization of the paralyzed equine larynx, using the cricoarytenoideus dorsalis muscle, does not seem to be an effective clinical procedure.
• This conclusion is based on the failure of graft survival and the lack of return of abductor function in the majority of the cases in the study.