Double-blind randomized study evaluating regeneration of the rat transected sciatic nerve after suturing and postoperative low-power laser treatment

This double-blind randomized study evaluated the therapeutic effect of low- power laser irradiation (LPLI) on peripheral nerve regeneration, after comp lete transection and direct anastomosis of the rat sciatic nerve. After thi s procedure, 13 of 24 rats received postoperative LPLI, with a wavelength o f 780 nm laser, applied transcutaneously, 30 min daily for 21 consecutive d ays, to corresponding segments of the spinal cord and to the injured sciati c nerve. Positive somatosensory evoked responses were found in 69.2 percent of the irradiated rats (p = 0.019), compared to 18.2 percent of the non-ir radiated rats. Immunohistochemical staining in the laser-treated group show ed an increased total number of axons (p = 0.026), and better quality of th e regeneration process, due to an increased number of large-diameter axons (p = 0.021), compared to the non-ir radiated control group. The study sugge sts that postoperative LPLI enhances the regenerative processes of peripher al nerves after complete transection and anastomosis.