Experimental Study On Prevention Of Scar Adhesion Formation After Lumbar Operation Using Different Spinal Epidural Covering

[Objective] To evaluate different epidural covering effect on scar formation after spinal operation, and to explore its mechanism.[Methods]80Wistar rats were randomly divided into four groups, experimental group1(collagen sponge plus dexamethasone); experimental group2(pure collagen sponge); experimental group3(gelatin sponge); control group (no epidural covering). After anesthesia, incision were made in the back of the rats, L1-L5laminectomy were performed to leave0.3cm x1.5cm defects on the dura matter. Epidural placement of collagen sponge and dexamethasone were made in group1animal, epidural placement of collagen sponge in group2, epidural placement of gelatin sponge in group3and just directed suture in control group.12weeks after operation, we observe the epidural scar formation and and the dura adhesion and evaluated it by developed Rydell-balazs criteria and Nuss-baum criteria. Application of immunohistochemistry and Western blot analysis showed expression of epidural scar and surrounding tissues in TGF-β1, VEGF, the differences between groups were compared,[results] During out study no rats died so that all animal fulfill the study successfully,through macroscopic and microscopic observation we performed classification by Rydell-balazs criteria and Nuss-baum criteria, the results revealed that epidural scar adhesion of group1and groups2was obviously less than that in group3and the control group; while no significant difference were detected between group1and2and that of group3and control group. Immunohistochemistry and Western blot analysis showed the TGF-β1and VEGF in epidural scar and surrounding tissues in group1and2were significantly less than that of group3and control group; but no significance were detected between group1and2and between group3and control group.[Conclusion] Animal experimentation of rats lumbar surgery revealed that collagen sponge can significantly reduce the formation of postoperative epidural scar adhesion12weeks after surgery while if combined with local injection of dexamethasone would not enhance this effect; the local use of gelfoam could not reduce the formation of epidural scar adhesion.; further immuno-chemical exam and western-blot test demonstrate that the expression of TGF-β1and VEGF in the scar and surrounding tissue significantly lower in the rats who were applied wtih collagen sponge, which should be an important mechanism its prevention of epidural scars.