Fig. 2.

Schematic representation of the connections of the vertebral venous system (VVS) with the vena cava system showing the vertebral vein (1), subclavian vein (2), segmental thoracic (intercostal) and lumbar veins (3), intervertebral vein (4), hemiazygos vein (5), internal thoracic vein (6), superior vena cava (7), inferior vena cava (8), azygos vein (9), ascending lumbar vein (10), sacral venous plexus (11), and the renal vein (12). Reproduced from Groen et al. [62] with permission from Lippincott Williams & Wilkins