Retro-aortic inverted left renal vein: a rare anomaly found in a renal donor.

Awareness of the renal vascular anatomy including variants of the renal vein is important for abdominal and renal surgeries, such as renal transplantation. The complex embryological development of the renal vein results in the following variations: additional renal veins on the left side, circum-aortic renal collar and retro-aortic renal veins. In this report, we present a case of a 35-year-old renal donor who had a rare renal vein anomaly that had been shown by computed tomography (CT) angiography. The left renal vein was single, and just before draining into the inferior vena cava (IVC) made two branches craniocaudally, which both passed posteriorly to the aorta and entered separately into the IVC.