The adrenal and renal veins of man and their connections with azygos and lumbar veins.

There exist many variations in the manner of formation, dimensions and place of termination of the central adrenal veins. In addition, some superficial adrenal veins may be substantial in size and may themselves drain directly into the renal veins and/or into other vessels which communicate with azygos and lumbar veins. This provides a route for venous adrenal blood to the heart via the azygos system and the superior vena cava rather than via the inferior vena cava. Variations in the formation and disposition of the renal veins are also described and the patterns of communication between somatic veins (including veins of the azygos and lumbar systems) and the left renal vein are illustrated and discussed in relation to the findings of others.