Histological evaluation of the effects of epidermal growth factor on regeneration of Acute Sciatic nerve injury in rabbit model

Peripheral nerve injuries are one of the most common and costly injuries especially in the young population. In this study, it is aimed to determine the histological role of EGF in nerve regeneration with a damage made on sciatic nerve in the rabbit model. We used 18 New Zealand rabbits (9 in control group and 9 in experimental group). Each group was divided into two groups consisting of 5 rabbits planned for diameter measurement and 4 rabbits planned for spatial measurement. The sciatic nerve exploration in the right flank of each animal, full-thickness nerve damage and than epineural repair were made by a single researcher. 10 µg/kg EGF was given to the repair area of the experimental group and five more EGF injection were given to the experimental group every other day postoperatively. In the control group, we used saline solution. Rabbits were observed for 8 weeks. During follow-up, 2 rabbits died. At the end of 8 weeks, the nerve tissue of each animal was evaluated histologically and morphologically. In the experimental group consisting of 5 rabbits, the mean thickness of connective tissue (epineurium+ mesoneurium) was 156,867 µm; while, in the control group, the thickness was 25,170 µm. In the other groups, the numerical increase in epineurium and mesoneurium areas were detected in the EGF (+) group as a result of the comparative spatial measurements. Epineurium and mesoneurium enlargement was observed in the EGF-given group. Adipocyte and capillary increase was seen in connective tissue. As a result, EGF increases epineurium and mesoneurium diameters in peripheral connective tissue in acute peripheral nerve injury regeneration. However, further studies are needed to understand this effect clinically and physiologically.