The Healing Effect of Silicone Gel on Sciatic Nerve Injuries in Experimental Rat

BACKGROUND Peripheral nerve repair is often complicated by fibroblastic scar formation, nerve dysfunction, and traumatic neuroma formation. Use of silicone may improve outcomes of these repairs. In this study, we tried to evaluate effectiveness of silicone gel on rats' sciatic nerve repair, axon regeneration and scar formation around and in the nervous tissues. METHODS This experimental study was performed on 18 rats. They underwent bilateral sciatic nerve dissection. Then, right and left damaged sciatic nerves were sutured. In left side, silicone gel was applied. Two months later, both sides were evaluated regarding to myelin fiber diameter (µm), total fascicular area (mm(2)), axon diameter (µm), myelin thickness (µm), G- ratio (axon diameter/myelin thickness), connective tissue area, ratio of connective tissue area/fascicular area, neuroma and foreign body formation in liver and lungs and spleen reaction. Results of right and left sides were compared. RESULTS Silicone was significantly more effective in increasing myelin thickness in the side that silicone was applied) than the control side. It was not associated with inflammation, scar formation, granuloma, and neuroma formation. No foreign body reaction occurred in liver, spleen and lungs after silicone application; but axonal regeneration did not improve with after its use. CONCLUSION According to our findings, it seems that silicone application in the cases with significant complications or in the cases that nerve graft is not possible would be an ideal option.