Ultrastructural changes of injured sciatic nerve after neurosurgical reconstruction and long-term electrostimulation in rabbits

Peripheral nerve injury is an extremely important problem during the war in Ukraine. In the overall pattern of injury, 5% of patients have peripheral nerve injuries and 1% have brachial plexus injuries. Under conditions of hostilities, this indicator increases to 70% or more. The victims are mainly young people of working age, which indicates the great medical and socio-economic significance of the problem. Materials and methods. The study was conducted on 28 rabbits Group 1 (n=7): suture of the sciatic nerve and implantation of the non-working antenna of the electrical stimulation device. Group 2 (n=7): sciatic nerve suture + implantation of an electric stimulator antenna in the same route as in group 1 and the beginning of stimulation on the 2nd day. Group 3 (n=7): sciatic nerve suture + implantation of an electric stimulator antenna in the same route as in group 1 and the beginning of stimulation 3 weeks after operation, when the first signs of regeneration occurred. Group 4 (n=7): autograft of the sciatic nerve + implantation of an electric stimulator antenna and the beginning of stimulation at a time point that will coincide with the beginning of signs of reinnervation of the effector muscle. Сontrol of regeneration was carried out in 12 weeks. The axial cylinder (AC) diameter, myelin thickness (MS) and MS/AC ratio were analyzed using electron mycroscopy. Results. It was showed a statistically significant increase of AC and MS indicators in the study group 2 relatively to comparison group 1, respectively, by 1.8 and 1.75 times. The increase of AC and MS in group 2, relatively to the comparison group and a visual decrease at the ultrastructural level of the number of destructively changed myelin sheaths (strengthening of reparative and regenerative processes) were detected. Conclusion. Therefore, long-term invasive electrostimulation of the damaged peripheral nerve has a positive effect on the regeneration of the neuromuscular complex.