OBJECTIVETo explore the pathological mechanism in the repair of chronic spinal cord injury with free grafting of autoperipheral nerve tissues in rats.

METHODSThe SD rats were used to establish SCI model with modified Allen method. The rats were divided into two groups at 12 weeks after the injury, each group had 20 rats. In the experimental group, the sural nerves were removed epineurium and transplanted into SCI lesion by using microsurgical technique; and in the control group, the rats were treated without any operation. The survival and differentiation of the grafts, and the ability of repairing host spinal cord were observed under the light microscope at the postoperative 4th and 12th week. Regeneration rates of nerve tracts in spinal cord were evaluated by using HRP tracing technique at the postoperative 4th and 12th week. The morphological changes were observed at section of spinal cord and the motor functions of both hind legs of rats were detected.

RESULTSIn the control group, spinal cord exhibited degeneration with cicatrices and cavitates. In the experimental group, peripheral nerve was almost survived, fused with the spinal tissue and axons could regrow into or span the place of injured spinal cord. Higher number of labeled nerve tracts in spinal cord were observed in experimental group, there was significant difference when compared with the control group. Motor function of hind legs of rats recovered significantly in the treatment group.

CONCLUSIONAutoperipheral nerve graft tissues transplantation could survive and integrate with the host and have repairing effects on chronic spinal cord injury in rats.