The Effect Of Mitomycin C And Hydroxycamptothecin In Preventing Epidural Scar Adhesion After Lumbar Laminectomy

ObjectiveTo compare the effect of topical application of mitomycin C(MMC)and hydroxycamptothecin(HCPT)in preventing postlaminectomy epidural scar adhesion;to find an effective method to prevent epidural scar adhesion in the clinic.Methods36 adult male SD rats were used as the animal model in this study,which were divided into 3 groups at random(12 rats in each group):MMC group,HCPT group and control group. Laminectomies were performed in lumbar 1 segment of every rat. The cotton pads soaked with different drugs(MMC:0.1mg/ml; HCPT:0.1mg/ml;saline:9mg/ml)were applied to the operative sites for 5 minutes,then rinsed the operative sites with saline for 3 times.The surgical cut was sew up in order of layer. Somatosensory evoked potential(SEP)was detected before or after administration.The BBB locomotion test was evaluated for neurobehavioral assessment according to the preoperatively and postoperatively.The rats were killed 4 weeks after surgery. The effect of epidural adhesion was observed with macroscopic and histological evaluation after 4 weeks.Macroscopic observation was made to evaluate epidural scar adhesion by dissecting six rats in each group.The degree of epidural adhesion was evaluated according to Rydell standard.The vertebral column including the back scar tissue and muscles was obtained to make paraffin sections by H&E and Masson staining.The number of the fibroblast was counted on the HE staining slice and the area of epidural scar was measured on the Masson staining slice by a computer image analysis system.Data were compared using One-Way ANOVA followed by multiple comparisons.P value＜0.05 was considered significant in all statistical analysis.ResultsThe SEP and BBB locomotion test did not change significantly from those obtained before and after administration (p＜0.05).The score of BBB locomotion test was all 21 before and after operation.By macroscopic observation,no epidural scar adhesion was found in the MMC group and the scar tissue could be separated.In HCPT group,dural adherence was incomplete.However,epidural scar was thick and connected with dura mater tightly in the control group. The light microscopy observation and image analysis:Little epidural scar was found and no obvious adhesion was formed in MMC group.The number of fibroblast and the area of epidural scar in MMC group was obviously less than that in control group(p＜0.05).Incompleted epidural adhesion was found in HCPT group.The number of fibroblast and the area of epidural scar in HCPT group was also less than that in control group(p＜0.05).Marked epidural scar was found and severe epidural adhesion formed in control group.ConclusionEpidural scar adhesion usually formed after laminectomy. Topical and transitory application of MMC and HCPT could inhibit fibroblast proliferation and reduce epidural adhesion.In this experimental model,MMC than HCPT can reduce epidural scar tissue and prevent epidural adhesion.No obvious side effect was found in the laminectomy sites.