QUANTITATIVE HISTOLOGICAL ASSESSMENT OF SKELETAL MUSCLE HYPOTROPHY AFTER NEUROTOMY AND SCIATIC NERVE REPAIR IN RATS

Reinnervation of skeletal muscles, wich occurs in time, is considered a factor in preventing muscle atrophy and potentially successful functional recovery. Morphometry of denervated muscles makes it possible to assess the dynamics of muscle atrophy after various methods of repairing of a damaged peripheral nerve. The aim - evaluate histological changes and morphometry of m. gastrocnemius in rats after complete neurotomy and nerve repair techniques. In rats the sciatic nerve was crossed and sutured with 4 epineural sutures, 2 sutures with DuraSeal, and 2 sutures with Tisseel. On the 14th, 30th, and 60th day histological changes of m.gastrocnemius were examined and morphometry was performed based on two parameters: muscle fiber diameter and collagen density. Skeletal muscles morphometry was performed after sciatic nerve neurotomy and subsequent microsurgical repair. Muscle fiber wasting was already detected on the 14th day after epineural suture with DuraSeal, and in the Tisseel group - on the 30th day after sciatic nerve damage. The average diameter of muscle fibers in the DuraSeal group increased significantly by the day 60 due to the appearance of hypertrophied fibers. In areas of wasting, connective tissue density increased, which did not change quantitatively during the experiment, while the use of DuraSeal and Tisseel delayed the development of fibrosis for up to the 30th day. Application of DuraSeal and Tisseel with epineural suture delays the development of fibrosis and wasting in denervated muscles during the reinnervation period.