Esperimental and clinical study on spontaneous regression mechanisms of lumbar disc herniation

在实验研究中，使用成年杂种犬。在全麻下摘除尾侧椎间盘，将其分为髓核和纤维环。L6椎板切除后，暴露L7神经根，在避免机械压力的情况下，将先前收获的髓核组织放入髓核内。分别于1周和3周后处死动物。取自尾椎的髓核标本作为对照。术后1周和3周，髓核组织退缩，周围组织有血管生成，并可见T细胞和巨噬细胞。髓核内，脊索细胞、软骨细胞和巨噬细胞表达IL-1β、肿瘤坏死因子-α、i-NOS和基质金属蛋白酶-3。神经根内未见神经纤维变性或炎性细胞，包括T细胞和巨噬细胞。在临床研究中，我们对腰椎间盘突出症手术标本进行光镜观察，并用免疫组织化学技术研究巨噬细胞的定位和功能。21.7%的同种异位脱垂的腹股沟疝组织中有明显的血管形成和巨噬细胞浸润。在所有患有韧带突出和隔离性疝气的患者中，在疝气组织内可见巨噬细胞，许多巨噬细胞存在于新形成的血管周围。连续切片检查证实巨噬细胞表达IL-1、β和MMP3。巨噬细胞通过产生多种化学介质，在细胞外基质的分解和清除中发挥重要作用。综上所述，髓核组织引起的炎性改变被认为是减少突出和消除神经根病的重要因素，而炎症区产生的化学因素似乎不是引起神经根病的主要原因。

In the experimental study, adult mongrel dogs were used. Under general anesthesia, the caudal vertebral disc was removed and divided into nucleus pulposus and annulus fibrosus. After laminectomy at L6, the L7nerve root was exposed and the previously harvested nucleus pulposus tissue was placed on in while avoiding mechanical pressure. The animals were sacrificed 1 week and 3 weeks later. Nucleus pulposus samples removed from the caudal vertebrae were used as a control. At 1 and 3 weeks after surgery, the nucleus pulposus tissue showed involution and there was angiogenesis from the surrounding tissue along with the appearance of T cells and macrophages. Within the nucleus pulposus, the notochordal cells, chondrocytes, and macrophages were positive for IL-1 β,TNF-α,i-NOS, and MMP-3. Degeneration of nerve fibers or the appearance of inflammatory cells, including T cells and macrophages, was not observed in the nerve root.In the clinical study, we examined surgical lumbar disc herniation specimens by light microscopy, and investigated the localization and function of macrophages using immunohistochemical techniques. Vascularization and macrophage infiltration of the hernia tissue were evident in 21.7% from subligamentous extrusion hernias. In all of the patients with trasligamentous extrusion and sequestration hernias, macrophages were seen inside the hernia tissue, with many being present around newly formed blood vessels. Examination of serial sections confirmed that macrophages were positive for IL-1βi-NOS, and MMP-3. The macrophages that infiltrate herniated tissue play an important role in the breakdown and removal of extracellular matrix by producing various chemical mediators. In conclusion, inflammatory changes induced by nucleus pulposus tissue are considered to be an important factor in reducing herniation and resolving radiculopathy, while it seems unlikey that chemical factors produced within the inflammatory zone are the principal cause of radiculopathy.