The Security Study Of Topical Application Mitomycin C In Preventing Epidural Adhesion

ObjectiveInvestigation the effect of mitomycin C (MMC)on the wound healing and sciatic nerve in order to provide the experimental foundation in preventing epidural adhesion. MethodsThe first experiment:50 adult male SD rats were used as the animal model in this study,which were divided into 5 groups at random(10 rats in each group): Laminectomy was performed at L1 in all of rats. Cotton pads soaked with saline and various concentrations mitomycin-C (0.1mg/ml, 0.3mg/ml, 0.5mg/ml and 0.7mg/ml) were applied to the exposed dural for 5 minutes. Two weeks postlaminectomy the rats were killed. The vertebral column including the back scar tissue and muscles was obtained to make paraffin sections by HE and Masson staining. The number of the fibroblast and blood capillaries was counted on the HE staining slice and the immunohistochemical slice. The number of the fibroblast and the expression of VEGF and blood capillaries were counted by a computer image analysis system.The second experiment: One hundred adult rats were randomly divided into two groups:Group A and Group B. Both lower extremities sciatic nerve were exposed in the two groups. In the group A, Cotton pads soaked with 0.1mg/ml,0.3 mg/ml MMC, 0.5mg/ml,0.7mg/ml MMC, saline winded to the sciatic nerve for 5 minutes at both of the sciatic nerve. In the group B, The Left sciatic nerves were served as the control sides and the right sciatic nerves were regarded as the experimental side. Cotton pads soaked with0.1mg/ml,0.3 mg/ml MMC, 0.5mg/ml,0.7mg/ml MMC, saline winded to the right sciatic nerves for 5 minutes.Results①L ess cell counts and the expression of VEGF were found in wound tissue in C, D, E group compared with balanced saline solution and A group two weeks after surgery (P<0.05).②A significantly difference was observed between the treated-MMC and control groups regarding the amount of the fibroblasts number (P<0.05). The fibroblasts number of group D, E was less than that of group B, C. There was a significant difference between group D, E and group B, C (P<0.05).③Loose epidural scar tissue was observed at the laminectomy site in the D and E group. The dense epidural scar tissue was observed in the A, B and C group. The dense scar tissue with adherence to the dural and surrounding muscles was noted in the control group.④Compared with those before surgery and control group , postoperative (1,2,3,5 days) thermal withdrawal latency was not statistically different(P>0.05).⑤Compared with those before surgery and control group , postoperative latency of the motor nerve conduction and the amplitude of muscle action potential were not statistically different (P>0.05) Conclusion①In our study,Locally applied mitomycin-C at above of 0.3mg/ml can inhibit the wound healing.②In our study, No obvious adverse effects in the topical application low of 0.7mg/ml MMC on sciatic nerve was found.