Laminectomy membrane formation was suppressed by high-molecular-weight hyaluronan *
Introduction: An ideal artificial material for inhibiting peridural fibrosis（Laminectomy membrane）has now been developed. A novel material that can prevent peridural fibrosis（LM）, which causes residual symptoms after laminectomy, is now expected. Purpose: To evaluate the effect of high-molecular-weight hyaluronan（HMW-HA, SuvenylR on the formation of LM. Materials and Methods: An L6 laminectomy was performed on111rabbits. The treated group（41rabbits）received HMW-HA in the defect left by the laminectomy and the70other rabbits which did not receive HMW-HA constituted the control group. The animals were sacrificed48hours, 1, 2, 4, 5, 8 and 12weeks postoperatively in the control group, and48hours, 1, 2, 4 and 5weeks in the treated group, and specimens were evaluated histologically. Results: In the control group, the fibroblast density had gradually decreased at the two weeks postoperatively, and it had decreased significantly at eight weeks postoperatively（P＜0.01）. The ratio of LM in a spinal canal was low in the control group at eight weeks postoperatively（P＜0.01）. The adhesion of LM to the dura was extensive from one week postoperatively, and continued thereafter. In the treated group, the fibroblast density, the ratio of LM in a spinal canal, and adhesion to the dura were significantly smaller than they were in the control group. Conclusion: LM forms immediately after operation, and it should decrease within five weeks. It is important to control LM within five weeks after surgery. LM was suppressed by the use of SuvenylR within this period. (Accepted on October ４，2005)
