Stimulation Effect of Low Level Laser Therapy on Sciatic Nerve Regeneration in Rat

Abstract Introduction: Recent studies exhibited that low-level laser therapy (LLLT) accelerates regeneration process of injured peripheral nerve tissue. The objective of this study was investigat the effect of LLLT (780 nm) on regeneration of the injured right sciatic nerve of male Wistar rat.Methods: In this research work, the effect of LLLT (780nm) on the regeneration process and reconstruction of peripheral in injured right side sciatic nerve was investigated. Twelve adult male Wistar rats underwent surgery in aseptic condition under general anesthesia to induce a lesion to their right side sciatic nerve. Only the experimental group was treated by laser, before suturing the location. The damaged nerve was directly irradiated with (2J, 100 mW, 40 s). Irradiation procedure terminated on 21 days with little improvement (4 J, 200 mW, 40 s) across the skin surface of experimental group. Rats were selected randomly from each group to be sacrificed on different periods and histopathological examination was carried out on the extracted  nerves.Results: Significant acceleration of revascularization and angiogenesis of the injury site was observed in the experimental group. Furthermore, a reduction of hemorrhages and increase in blood supply was observed. Also, Wallerian degeneration decreased while higher axonal density compared to the control rats was observed. Moreover, the cross-section analysis of the injured area on the 14th and 21st days as post-surgery showed that the nerve sheath diameter in the lesion area of the experimental group was reduced. While the ratio between thicknesses increased in the control group.Conclusion: The current study suggests that laser phototherapy at 780 nm could accelerate the regeneration process of injured peripheral nerves tissue. Keywords: Low-level laser therapy Peripheral nerve regeneration Wallerian degeneration Axonal growth Revascularization Sciatic nerve.