Postlaminectomy Adhesion of the Cauda Equina in Rats : A Pathophysiological Study for its Prevention

目的。椎板切除诱导的马尾神经粘连已被大鼠实验和男性术后系列磁共振成像所证实。对大鼠马尾神经粘连与临床症状的相关性进行分析。此外，对腰椎粘连性蛛网膜炎的预防措施进行了评估。对L5~L6椎板切除的Wistar大鼠进行了感觉、运动和排尿功能的系列评估。为预防马尾神经粘连，将大鼠分为3组：对照组仅给予溶媒溶液，消炎痛组给予消炎痛7d，激素组给予甲基强的松龙3d。在椎板切除后24小时、3周和6周，比较3组的马尾神经粘连和滋养血管蛋白示踪剂渗漏的情况。甩尾法测定的热刺激阈值显示马尾神经粘连大鼠的热刺激阈值延长。其他症状显示，高岭土或高岭土在椎板切除术后无明显变化。在椎板切除后24小时，吲哚美辛和甲基强的松龙均显著抑制马尾神经粘连和营养血管的蛋白质渗漏。在椎板切除后3周和6周，经抗炎药物治疗的大鼠马尾神经粘连减轻，神经变性减少。大鼠椎板切除后马尾神经粘连导致热感觉减退。椎板切除前后应用抗炎药物可抑制马尾神经粘连，促进马尾神经粘连的恢复。

Purpose. Laminectomy-induced cauda equina adhesion has been proved by rat experiments and postoperative serial magnetic resonance imagings in men. In rats, correlation between cauda equina adhesion and clinical symptoms were analyzed. In addition, the preventive measures for lumbar adhesive arachnoiditis were evaluated.Methods. Wistar rats laminectomized from L5 to L6 were serially assessed for sensory, motor and urinary functions. For the prevention of cauda equina adhesion, rats were divided into 3 groups : Rats in the control group received only vehicle solutions, those in the indomethacin group orally received indomethacin for 7 days, and those in the steroid group were intraperitoneally administered methylprednisolone for 3 days. At 24 hours, 3 and 6 weeks after laminectomy, the cauda equina adhesion and leakage of a protein tracer from the nutrient vessels were histologically compared in the 3 groups.Results. Threshold for thermal stimulation assessed by tail flick test showed elongation in rats with cauda equina adhesion. Other symptoms revealed no significant changes after laminectomy with or without kaolin implementation. 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 and 6 weeks after laminectomy.Conclusion. Cauda equina adhesion after laminectomy brought about thermal hypesthesia in rats. Anti-inflammatory drug administration before and after laminectomy suppressed cauda equina adhesion, and facilitated the recovery of cauda equina adhesion.