By studying the systematization of superficial veins in 70 human spinal cords, it is possible to recognize three different systems: anterior, posterior and lateral. The anterior spinal venous system is formed by an antero-medial trunk extending from the filum terminale to the medulla oblongata, and by two antero-lateral spinal trunks placed in the cranial part of the spinal cord. The posterior, spinal venous system is formed by a postero-medial spinal trunk, extending from the sacral spinal cord to the medulla oblongata, and by two postero-lateral venous trunks, in the thoracic region. The lateral spinal venous system forms an anastomotic system between the anterior and posterior venous systems; it is especially well developed in the lumbar enlargement. In this venous disposition, it can be recognized three types of networks: transversal, longitudinal and arciform, more or less intertwined according to the considered spinal levels.
Collateral Circulation Histological Techniques