Double inferior vena cava: a report of three cases.

Double inferior vena cava (IVC) is a congenital anomaly resulting from the persistence of the embryonic venous system. The majority of cases are clinically silent and diagnosed incidentally on imaging for other reasons. However, these venous anomalies may have significant clinical implications, especially during retroperitoneal surgery and in the treatment of thromboembolic diseases. We report three cases of double IVC and review the relevant literature. The clinical importance of recognising double IVC is discussed.