[Experimental study on simultaneous selective reinnervation of the adductors and the abductor muscle for the treatment of the laryngeal paralysis].

OBJECTIVE: The aim of this study is to estimate the value of a new surgical procedure in the treatment of the chronic unilateral laryngeal paralysis. METHODS: The recurrent laryngeal nerve of the left side of the dog was totally cut and served as a model of unilateral laryngeal paralysis at the first step of the research. The adductor and abductor branches of the recurrent laryngeal nerve were then, selected and cut. Afterwards, they were micro-sutured respectively with one branch of ansa cervicalis and phrenic nerve immediately (group 1) and 4 months later (group 2). Six months after this reinnervation, the laryngeal physiologic function of the lateral crico-arytenoid muscle (LCA) and the posterior crico-arytenoid muscle (PCA) have been checked by the methods of electromyography (EMG) and direct laryngoscopy. All the data have been analysed by the statistic methods. RESULTS: Among all the data of EMG, only the wave amplitude of action potential of the LCA muscle of the group 2 was diminished (p < 0.05). Under the direct laryngoscopy, the adductor movement of the left vocal cord of the group 2 was also lightly reduced. But the adductor and abductor movements of the left vocal cord were synchronous with the mouvements of the right vocal cord. CONCLUSION: Though the result of nervous reinnervation of a four month's laryngeal paralysis was not so good by comparison with that of an immediate reinnervation, this surgical procedure can however on the clinical point of view, reach a satisfactory level. The duration maximum of the reinnervation operation after laryngeal paralysis, is, at the present, not clear. It is necessary for us to make further studies.