AN EXPERIMENTAL COMPARISON OF DIFFERENT KINDS OF LARYNGEAL MUSCLE REINNERVATION

In this study, we attempted to determine which method was the best for reinnervating the laryngeal adductor muscles by comparing nerve sutur e, nerve implantation, and nerve-muscular pedicle (NMP) transfer, as w ell as the length of time that could elapse after denervation and stil l allow for successful reinnervation with the ansa cervicalis. Reinner vation was performed in 36 dogs, at 6-, 8-, 10-, 12- and 18-month inte rvals after denervation via the three methods of muscle reinnervation described above. We noted some return of adduction in the cases using nerve suture before a 10-month interval after denervation, and with ne rve implantation and NMP transfer before the 8-month intervals. The va riable adduction was caused by reinnervation of the adductor muscles f rom the ansa cervicalis, as demonstrated by laryngeal spontaneous and evoked electromyography,the strength of muscle contraction, and histol ogic findings, Adduction was not observed in the cases after the above -mentioned intervals but partial improvement of the bulk and strength of the reinnervated vocal cord was still achieved. An analysis of the experimental results showed that nerve suture was superior to nerve im plantation and the NMP technique. Little difference was noted between nerve implantation and the NMP technique.