[Experimental study on the post-laminectomy deterioration in cervical spondylotic myelopathy--influences of the meningeal treatment and persistent spinal cord block].
Free, rhythmical movement of cerebrospinal fluid (CSF) is regarded as the inhibitory factor of subarachnoidal adhesion. When the block of CSF flow remains after the laminectomy for cervical spondylotic myelopathy, danger of postoperative subarachnoidal adhesion and ensuing deterioration of operative results is present. Such risk may increase when the meningeal treatment is combined with the laminectomy. The experimental study was practiced on dogs to confirm the surmise mentioned above. First, the gradual anterior cord compression was made at the C4 and C6 levels to produce multiple block of CSF flow. Then, 3 types of posterior surgical decompression, i.e. simple laminectomy, dura mater resection, and arachnoid resection were performed at the C6 level. The fourth type of posterior decompression was also performed, that is, the arachnoid resection at the C6 level accompanied with simple laminectomy up to the level of C4 in order to know the influence of the improvement of CSF passage. Dogs were classified into 4 groups according to the type of the posterior surgery and sacrificed after a certain period to examine the changes around the spinal cord mainly at the C6 level. The results and conclusions are as follows. In the presence of anterior spinal cord compression and CSF flow disturbance, the cord was compressed again by the laminectomy membrane when the dura mater was resected and not compressed when it was preserved. And when the arachnoid was also resected, the scar tissue adhered to the dorsal aspect of the cord and tightly compressed it. The improved CSF passage diminished the extent of subarachnoidal adhesion and the degree of cord compression. From these results, it may be concluded that the laminectomy for the cervical myelopathy should be done sufficiently so as to improve the CSF passage, and at the same time, the meningeal treatment should be avoided as long as possible.
D000818:Animals; D004285:Dogs; D007796:Laminectomy / Q000009:adverse effects*; D008578:Meninges / Q000601:surgery*; D009192:Myelography; D011183:Postoperative Complications; D013116:Spinal Cord / Q000473:pathology; D013117:Spinal Cord Compression / Q000134:cerebrospinal fluid / Q000209:etiology / Q000601:surgery*; D013130:Spinal Stenosis / Q000150:complications*