[Comparative study on the pre-and postoperative myelogram in anterior lumbar surgery].

In order to investigate the change of the dural tube and radicular sheath after anterior surgery, metrizamide myelography was performed in 32 cases of lumbar disc herniation, 12 of spondylolytic spondylolisthesis, and 9 of degenerative spondylolisthesis. Postoperative myelography was performed 3 to 8 weeks after surgery. The improved postoperatively in radicular sheath was 67% of the cases of disc herniation, 60% of spondylolytic spondylolisthesis, and 36% of degenerative spondylolisthesis. Postoperatively, no abnormal findings of dural tube were observed in the lateral view in 80% of the cases of disc herniation, and 78% of those of spondylolytic spondylolisthesis. Improvement of myelographic findings of the dural tube seemed to be related to the clinical results of surgery for disc herniation and degenerative spondylolisthesis. These facts indicated that anterior surgery is a reliable procedure to obtain surgical decompression and favorable clinical results.