EPINEURIAL SUTURES, POLYETHYLENE GLYCOL HYDROGEL AND FIBRIN GLUE IN THE SCIATIC NERVE REPAIR IN RATS: FUNCTIONAL AND MORPHOLOGICAL ASSESSMENTS IN EXPERIMENT.

Mechanical damage to the peripheral nerve is a fairly common type of injury, which is characterized by a complex of long-term neurological disorders and require significant financial costs. The aim of this work is to evaluate the efficiency of sciatic nerve (SN) regeneration after neuroraphy using epineural suture (ES), polyethylene glycol hydrogel (PEG), and fibrin glue (FG). The studies were carried out on 30 white outbred male rats, which were divided into six experimental groups: Group №1: intact rats; Group №2: Sham operated; Group №3: complete transection of the SN; Group №4: nerve repair with ES; Group №5: nerve repair with PEG; Group №6: nerve repair with FG. Functional recovery was assessed at 1, 2, 3, 4 postoperative weeks using a walking-track analysis with subsequent determination of the sciatic nerve functional index (SFI). At 4 weeks, electroneuromyography, histological and morphometric analyzes were performed. The combined analysis indicated that PEG significantly improved functional recovery, both in the SFI index and in the skeletal muscle M-response. Compared to ES and PEG, the use of FG was reflected in a lower significance of the indicators compared to PEG. Statistical analysis indicates a positive effect of PEG and FG on nerve regeneration, although significantly greater remyelination (analysis based on fiber diameter) was confirmed only in the PEG group, which explains the faster functional recovery of the limb. PEG in the form of a hydrogel is a more promising agent in microsurgical restoration of damaged nerves as an adhesive, it promotes rapid nerve regeneration, denervated muscle re-innervation and functional limb recovery.