Is there a role for a collagen conduit and anti-inflammatory agent in the management of partial peripheral nerve injuries?

PURPOSE: The purpose of this study was to investigate the effect of a collagen conduit and an anti-inflammatory agent in the treatment of acute partial sciatic nerve injuries in a rat chronic constrictive injury (CCI) model.

MATERIALS AND

METHODS

Adult male Sprague-Dawley rats were divided into 5 groups: group 1 (nerve damage with no treatment), group 2 (nerve damage and collagen tube), group 3 (nerve damage and collagen tube treated with anti-inflammatory agent), group 4 (sham surgery), and group 5 (naive rat). Each group consisted of 10 study animals. The nerve injury model used was the CCI model. Behavioral responses to thermal and mechanical stimuli were tested at 3, 7, and 14 days after surgery. Transverse sections of nerve tissue were harvested at day 14 and evaluated by standard error of mean (SEM).

RESULTS

Tactile allodynia measurements showed initial increases in the threshold at day 3, followed by a significant decrease at day 7, and consistently remained lower than baseline by day 14. Heat allodynia measurements at day 3 showed a statistically significant decrease in threshold compared with the CCI group. However, at days 7 and 14, the threshold was not statistically different from the CCI group threshold. Groups with and without anti-inflammatory agents at day 7 showed a statistically significant decrease in threshold to both heat and tactile allodynia from day 3, indicating that groups with collagen and anti-inflammatory treatment had significant decreases in both heat and tactile allodynia. A similar relationship was observed at day 14. Transverse sections of nerve tissue evaluated by SEM of nerve tissue revealed a broad distribution of axons in group 1, with the greatest interaxonal distance in cross sections. Group 2 displayed less interaxonal distance compared with group 1, and group 3 had the least interaxonal distance.

CONCLUSIONS

This study demonstrated a statistically significant decrease in pain secondary to the application of a collagen conduit and anti-inflammatory agent. Behavioral testing and SEM data also support the finding of a decrease in edema in the presence of a collagen conduit, with the greatest decrease being in the presence of both collagen conduit and anti-inflammatory agent.