Postlaminectomy Adhesion of the Cauda Equina

STUDY DESIGN: Effects of the systemic administration of anti-inflammatory drugs on cauda equina adhesion after lumbar laminectomy were evaluated in rats. OBJECTIVES: To obtain basic data on preventive measures for lumbar adhesive arachnoiditis. SUMMARY OF BACKGROUND DATA: Laminectomy-induced cauda equina adhesion has been proved by rat experiments and postoperative serial magnetic resonance imaging tests in humans. In rats, laminectomy induces an increase in vascular permeability, resulting in cauda equina adhesion. METHODS: Wistar rats laminectomized from L5 to L6 were divided into three groups: the control group received only vehicle solutions, the indomethacin group received oral indomethacin for 7 days, and the steroid group was administered intraperitoneal methylprednisolone for 3 days. At 24 hours and 3 weeks and 6 weeks after laminectomy, cauda equina adhesion and leakage of a protein tracer from the nutrient vessels were histologically compared in the three groups. RESULTS: Both indomethacin and methylprednisolone significantly suppressed cauda equina adhesion and protein leakage from the nutrient vessels at 24 hours after laminectomy. Rats treated with the anti-inflammatory drugs showed diminution of cauda equina adhesion and the neural degeneration at 3 weeks and 6 weeks after laminectomy. CONCLUSIONS: Anti-inflammatory drug administration before and after laminectomy suppressed cauda equina adhesion as well as facilitating recovery from cauda equina adhesion.