Immediate versus delayed primary repair of the sciatic nerve in a nerve transaction model in rats

BACKGROUND: The debate continues concerning surgical timing in a peripheral nerve injury. This study aims to evaluate the result of immediate versus delayed primary (after seven days) repair of peripheral nerve injury. METHODS: In this study, Wistar rats were divided into four groups as follows: The nerve was sharply transected in Group 1, 2 and 4. It was immediately sutured in Group 1 and sutured seven days later in Group 2, and it was not sutured in Group 4. In Group 3, the left sciatic nerve was only explored. Eight weeks later, tissue samples were extracted from the injured nerve area. Both gastrocnemius muscles were weighed. The nerve samples were examined for axon degeneration. Myelin vacuolization, axon irregularity, and edema/inflammation parameters were evaluated. RESULTS: There were not any significant differences in the score of axon degeneration and the weight of the gastrocnemius muscle between the immediate and delayed primary repair groups. However, these parameters were significantly better in both repair groups than to be in the control group and significantly worse than to be in the sham-operated group. CONCLUSION: To delay the repair about one week did not affect the histological results and weight of the muscle that was innervated by the sectioned nerve comparing to be in the immediate repair in a sciatic nerve transaction model in rats.