The experimental investigation of the effects of scar preventing agents on peripheral nerve healing in a rat peripheral nerve injury model

Introduction: There are numerous experimental studies on the changes in nerve cells after peripheral nerve injuries and on new techniques that augment regeneration. However, regeneration after nerve injuries is still a challenge. The aim of this study is to investigate the effects of hyaluronic acid and transexamic acid on nerve healing. Materials and Methods: Eighteen female Wistar rats were operated under ketamine anesthesia. The right hind extremities were operated. In Group 1, the right sciatic nerve was transected with scissors and primary neural repair was performed. In Group 2, hyaluronic acid was applied on the repair site after the transection and the repair. In Group 3, the combination of both hyaluronic acid and transexamic acid was applied on the repair site after the transection and the repair. Several analyses were performed on the rats on the fourth postoperative week. Sciatic function index (SFI) and electromyography (EMG) were performed as functional tests. The rats were sacrificed and the gastrocnemius wet muscles were weighed. Nerve slices were taken from the proximal and distal parts of the transected sciatic nerves and microscopic evaluation was performed. Results: The data were evaluated statistically with the Kruskal-Wallis method. The SFI and EMG values were higher in Group 2 and Group 3 than in Group 1 and these differences were statistically significant (p<0.05). A statistically significant difference was not found between Group 2 and Group 3 (p>0.05). A statistically significant difference was not found in the right / left gastrocnemius wet muscle ratio between the groups (p>0.05). Group 3 demonstrated significantly lower values than Group 1 in the macroscopic adhesion scoring test (p<0.05). However, a statistically significant difference was not found between Group 1 and Group 2 and between Group 2 and Group 3 (p>0.05). Conclusion: The hyaluronic acid group was superior to the control group in both functional and microscopic tests. Additionally, the group with the combination of hyaluronic acid and transexamic acid was superior to the control group in the macroscopic adhesion scoring system. In conclusion, hyaluronic acid may be utilized locally after nerve repair alone or in combination with transexamic acid. Safety and affordability are among the advantages of this application. Keywords: Peripheral nerves, hyaluronic acid, tranexamic acid, rat model