The double retro-aortic left renal vein

The renal veins drain the kidney into the inferior vena cava and unite in a variable fashion to form the renal vein. The left renal vein is normally located in front of the aorta. However, the retro-aortic renal vein may course posterior to the aorta due to embryological developmental anomalies. During educational dissection, a rare variation of the left renal vein was found in a 66-year old male cadaver. The double retro-aortic renal veins coursed behind the aorta to drain into the inferior vena cava. The superior retro-aortic renal vein drained into the inferior vena cava at the lower border of the L2 vertebra, and the inferior retro-aortic renal vein drained into the inferior vena cava at the upper border of the L4 vertebra. Such a variant is rare, and is a clinically important observation which should be noted by vascular surgeons, oncologists, and traumatologists.