Congenital anomaly of left renal vein.

Double left renal vein is a rare venous anomaly. In 6.5% of cases double left renal vein, one in front (preaortic) and another behind the abdominal aorta (retroaortic) has been reported. The development of renal vessels is very complicated. There are extensive changes which occur in subcardinal, supracardinal and sacrocardinal veins during development that may lead to congenital venous anomalies. Here, we report a case of congenital venous anomaly of persisting retroaortic left renal vein.