Pathological changes in the spinal cord of a model of acute cauda equina compression / 中国组织工程研究

ABSTRACT

BACKGROUND:Animal studies have shown that cauda equina compression can induce apoptosis of lumbosacral spinal cord anterior horn motor neurons. OBJECTIVE:To explore the pathological change in lumbosacral spinal cord after acute cauda equina compression in dogs. METHODS:A total of 27 dogs were randomly divided into nine groups, with three dogs in each group. There were one normal control group, seven experimental groups and one sham surgery group. In the experimental group, an empty water sac was implanted above epidural fat below L6 vertebral plate. Compression was given by injecting water at 4, 8, 12, 24, 48, 72 and 168 hours. In the sham surgery group, an empty water sac was implanted, but compression was not given. At the time of compression, the spinal cord sent out by cauda equina nerve and adjacent to the head end was subjected to histopathological examination. RESULTS AND CONCLUSION:(1) Results of light microscopeat 4-48 hours of compression, spinal cord anterior horn motor neurons did not alter. At 72 hours, motor neurons became smal , cel membrane shrank and separated from surrounding tissues. Cel s were homogenous and darkly stained. At 168 hours, motor neurons disappeared, but spinal cord sections of the adjacent head end did not shown abnormal motor neurons in the spinal cord anterior horn. (2) Results of electron microscopeat 12 hours, spinal cord tissue began to swel , and the swel ing aggravated with prolonged time of compression. The swel ing of glial cel s was apparent. At 168 hours, myelin sheath structure dissolved;axons showed vacuolization;axoplasm spil ed, and exhibited inflammatory injury-like changes. (3) Apoptotic results of spinal cord anterior horn motor neuronsapoptosis appeared at 12 hours of compression, became increased, and showed an increased trend at 168 hours.