An experimental study of morphological analysis in post-operative spinal tissue

• Main Authors: Wang-Sheng Yang, 楊萬生
• Other Authors: Chi-Yu Tseng
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/55350401881271637306

碩士 === 國立成功大學 === 細胞生物及解剖學研究所 === 94 === Degenerative conditions of the lumbar spine include degenerative disc disease, herniated nucleus pulposus (HNP), lumbar canal stenosis, and degenerative instability. As many as 40% of patients, however, fail to experience satisfactory long-term relief of symptoms after primary procedures. Failed back surgery syndrom (FBSS) has become a common entity. FBSS is a group of disorders with persistent or recurrent symptoms following spinal surgery, with the hallmarks of back pain, sciatica, and functional impairment. FBSS is characterized by severe chronic and disabling pain that generally is resistant to physiotherapy and pharrmacologic treatment. There are many causes of FBSS; among of the most common is epidural fibrosis. There are numerous reports suggesting that fibrosis and adhesions can cause compression or tethering of nerve root, which may cause recurrent radicular pain and physical impairment. However, the importance of epidural scarring in relation to persistent neurological deficits or post-surgical pain is debatable. Recently it has been suggested that mechanical compression of nerve roots in lumbar disc herniation may not be the only cause of clinical symptoms such as radicular pain and dysfunction. Therefore, we make hypotheses that epidural fibrosis can induce post surgical pain but the cause may be not due to the mechanical compression of spinal nerve or cauda equina only. We performed an experimental study of morphological analysis in post operative spinal tissue using animal models of Wistar mouse which were applied to study FBSS in many other laboratories. Under light microscopy screening exam with H & E stain, we found (1) The scar formation and adhesion is increasing with time course and size of lamina opening, (2) The scar adhesion has minimal dura compression effect, (3) The scar adhesion may induce neovascularization and axon swelling in cauda equina area, (4) The pathological effects are time, volume and distance dependent, (5) The scar adhesion can induce dura mater thickening and the thickness difference between dura-adhesion(-) and dura-adhesiion (+) is statistical significantly, (6) The scar adhesion has no pathological effect to DRG , the relative normal DRG implicate that the post operation recurrent neuropathic pain may be not due to DRG injury or damage by scar adhesion. In our current study, we found that the post operative scarring tissue has no apparent compression effect to spinal tissue, but it can really induce some pathological change to dura mater and nerve root in cauda equina area. We conclude that epidural fibrosis may relate to FBSS but the cause may be not due to the mechanical compression of spinal nerve or cauda equina only.