[Animal experiment studies of collateral reinnervation of denervated laryngeal musculature].

The course of atrophy of type I and type II muscle fibers of the posterior cricoarytenoid muscle, the lateral cricoarytenoid muscle and the medial thyroarytenoid muscle of 9 dogs have been investigated after resection of the ipsilateral recurrent laryngeal nerve after 2, 4 and 10 months. Using ATP-ase staining the histochemical results revealed a predominant atrophy of type II fibers, a reactive hypertrophy of type I fibers after a period of 4 months and a pattern of type-grouping with signs of a complete reinnervation in all laryngeal muscles within 10 months. The existence of a supplementary innervation of the intrinsic laryngeal muscles in dogs and its implication on experiments in laryngeal reinnervation are discussed.