Corpus: Lumbar veins

The lumbar veins are four paired, segmental veins located along the inner dorsal abdominal wall. They correspond to the posterior intercostal veins and run alongside their corresponding arteries.

The lumbar veins drain directly into the inferior vena cava. On the left side, they pass behind the aorta and cross the spinal column. The second lumbar vein on the left side may also drain into the renal vein.

Additionally, the lumbar veins on each side are interconnected and linked to the azygos and hemiazygos veins via the ascending lumbar vein, providing collateral circulation.