BACKGROUND
The relevance of the study is due to the growing need to improve approaches to surgical replacement of extensive defects of nerve trunks due to the increasing number of high-energy injuries to large nerves of the extremities. One of the ways to restore the anatomical integrity of damaged nerves is to connect their proximal and distal ends using conduits made of materials of biological and synthetic origin.
OBJECTIVE
The aim of the study is to evaluate the effectiveness of restoring tissue innervation lost due to trauma after replacing extensive nerve defects with synthetic conduits based on polylactide with polypyrrole in an experiment on laboratory animals.
MATERIAL AND METHODS
Under experimental conditions, modeling of an extensive defect of the sciatic nerve was performed on 10 laboratory animals (rats), followed by its replacement using a synthetic conduit based on polylactide with polypyrrole. In the postoperative period, the nature of changes in the functional state of nerves restored using experimental implants was assessed by clinical, electrophysiological and morphological methods.
RESULTS
Analysis of the behavioral characteristics of laboratory animals in the postoperative period indicated a high degree of their adaptability to experimental trauma. According to the results of electroneuromyography, animals in the experimental group showed a persistent loss of nerve conduction throughout the observation period. Morphologically, in the area of the experimental surgical intervention there were signs of the formation of a terminal neuroma of the proximal segment of the nerve located inside the conduit. The structure of the distal segment of the nerve sutured to the conduit was characterized by signs of completed secondary degeneration of the nerve fibers. No myelinated nerve fibers were identified in the distal segment. The conduit itself at the later stages of observation was a substance with unclear boundaries with signs of resorption of the main substance.
CONCLUSION
Connecting the ends of the nerve damaged in the experiment made it possible to prevent retraction of the proximal and distal ends of the nerve sewn into the conduit, and also prevented their involvement in the postoperative scar. Regenerating nerve fibers from the proximal end of the nerve sewn into the conduit filled the internal lumen of the implant and formed a neuroma. Thus, connecting the ends of the damaged nerve using a conduit made of polylactide with polypyrrole helps to maintain relatively favorable conditions for subsequent reconstructive operations on the nerves. The use of a conduit made of polylactide with polypyrrole to connect the ends of damaged nerves as an independent surgical technique requires the development of methods for stimulating the directed growth of regenerating nerve fibers from the proximal segment for reinnervation of the distal segment of the restored nerve.
