Common Iliac Vein
The human anatomy defines the common iliac veins as a result of the formation of the internal iliac veins and external iliac veins (ventral to the sacroiliac articulation), and when the two iliac veins are together, they form the inferior vena cava in the abdomen at the level of 5th lumbar vertebrae. Common iliac veins are responsible for draining blood from the lower limbs and pelvis. They are accompanied by common iliac arteries along their course. Both common iliac veins receive the iliolumbar, while in some people, the lateral sacral veins. The middle sacral vein is also received by the left common iliac vein. None of the common iliac veins contain valves.
