Edema and circulatory disturbance in the spinal cord compressed by epidural neoplasms in rabbits.

An experimental model of spinal cord compression by epidural neoplasms was produced in rabbits by injecting a VX2 tumor-cell suspension anterior to the T-13 vertebral body. With this experimental model, edema and circulatory disturbance of the spinal cord compressed by epidural tumors were studied. The characteristic histopathological findings in the compressed spinal cord were edema and axonal swelling in the white matter. Water content and uptake of intravenously injected 99mTc pertechnetate in the compressed spinal cord were significantly greater than in the spinal cord distant from the tumor, and increased in proportion to the degree of neurological loss. Microangiography and fluorescein angiography demonstrated stenosis or obstruction of the epidural venous plexus and impairment of venous drainage in the compressed spinal cord at the early stage of neurological symptoms. It is suggested that venous stasis and subsequent vasogenic edema in the spinal cord play an important role in the symptomatology of metastatic epidural spinal cord compression.