REGENERATION OF THE RECURRENT LARYNGEAL NERVS USING A WOVEN POLYGLYCOLJCACID (PGA) TUBE COATE WITH COLLAGEN

Abstract

A) Purpose: The recurrent laryngeal nerve is one of the most difficult nerves to regenerate functionally. Therefore, no reconstruction of the recurrent laryngeal nerve is commonly performed after the surgical removal associated with head or neck cancer. We report the animal experiment on regeneration of the recurrent laryngeal nerve using woven PGA tube coated with collagen. B) Methods: The animal experiment was performed using 10 adult beagle dogs divided into 2 groups. In group I (n=G), the left recurrent laryngeal nerve was excised 10mm around about 20mm distal portion from the cricoid cartilage. This gap was bridged with a woven PGA tubs coated with collagen (5mm in diameter and 20mm in length). This bioabsorbable tube has no antigenicity. In control group II (n=4), the left recurrent laryngeal nerve was excised the same portion as in grous I and the great auricular nerve was auto-grafted to the gap. In order to estimate morphological and functional recovery of the nerve, not only fiberscopic observation for vocal cords but also the test for axona transport and EMG were performed. C) Result: The recurrent laryngeal nerve was morphologically and functionally regenerated in one of the group I. In other dogs of this grous vocal cord atrophy were prevented in some degree. In group II, functional recovery of the recurrent laryngeal nerve was not observed. Atrophy of the vocal cord was more severe than that of dogs in group I. These results suggest that a woven PGA tube coated with collagen may be useful for functional regeneration of the recurrent laryngeal nerve.