Repair of the recurrent laryngeal nerve: Experimental study.

Abstract

Intraoperative lesions of the recurrent laryngeal nerve (RLN) are rare, but have serious consequences. The authors present a new technique for repairing the RLN based on an experimental study using a vein-muscle graft between the tops of the RLN. The goal is to restore normal movements of the vocal cord. Nine animals were operated on, six in the nerve reconstruction group (NRG) and three in the control group (CG). Eleven months later, the vocal cord movements were analysed, the voice was recovered and the histological analysis of the graft was carried out. The results showed that all the goats (100 %) of the NRG regained movement of the vocal cords. In addition, in five animals, the reinnervation occurred with movements symmetrical to those of the other vocal cord and in another animal, they were almost symmetrical. The results for analysis of voice evolution of the NRG goats, obtained with objective and subjective tests, showed a good recovery of the “normal voice”. As for the histological study, only 50 % of the NRG cases demonstrated complete regeneration of the RLN. The results also showed that there was a selective / discriminative nervous tropism. Abductor and adductor fibres were attracted to similar ones on the other top, effectively reinnervating the laryngeal muscles. The method tested in this study, which was applied for the first time to repair RLN, is effective, inexpensive, simple and leaves no anatomical or functional sequelae. It is possible to extrapolate the results to humans.