Comparison of intraosseous vertebral venography and Pantopaque myelography in the diagnosis of surgical conditions of the lumbar spine and nerve roots.

Abstract

Despite the widespread use and proclaimed safety of Pantopaque myelography (1–7) many still adopt a reluctant attitude toward its indiscriminate and repeated employment or condemn it as a screening procedure. The basis for this hesitancy are reports of occasional adverse reactions of the leptomeninges with early or late sequelae in the spinal canal or intracranial cavity. A method without the disadvantages associated with the introduction of a potentially irritating substance into the subarachnoid space but with comparable accuracy, even if limited to lesions of the lumbar spine, would indeed constitute a valuable addition to our diagnostic armamentarium. It was our feeling that intraosseous vertebral venography might hold such promise. We therefore set out to compare its potentialities with those of Pantopaque myelography in the diagnosis of such surgical lesions of the lumbar spine and nerve roots as disk protrusion, spondylolisthesis, symptomatic spina bifida occulta, tumors of the cauda equina, epidural tumors, and metastatic tumors of the vertebral column. Anatomic Considerations The blood from the medulla spinalis, nerve roots, meninges, vertebral column, and paravertebral muscles is drained by multiple veins constituting a network extending over the entire length of the spine. These venous plexuses are located in part outside and in part inside the spinal canal (Fig. 1). The external vertebral venous plexus surrounds the vertebral column and is best developed in the cervical region, an anatomic peculiarity which has been roentgenographically verified (8, 9). Its posterior division is located along the spinous processes and the posterior surface of the transverse processes, extending also between the posterior paravertebral muscles. The anterior division is situated laterally and anteriorly to the vertebral bodies and is linked to its posterior counterpart as well as to the internal vertebral plexus (Fig. 1). The external vertebral venous plexus assumes important collateral circulatory duties in the presence of some obstruction to the blood flow within the internal vertebral venous plexus. The internal vertebral venous plexus, which we prefer to call the epidural plexus, is located within the spinal canal between the dura and the bony surfaces of the vertebrae. The epidural veins run along the entire length of the spine and their anatomical continuity with the intracranial dural sinuses has been confirmed by Batson (10). The veins of the internal vertebral plexus surround the spinal dura and form two pairs of well developed longitudinal channels connected with each other by a series of venous rings, one opposite each vertebra.