[Double inferior vena cava discovered by examination of traumatic rupture of congenital hydronephrotic renal pelvis: a case report].

A case of double inferior vena cava associated with congenital hydronephrosis is reported. A 6-year-old girl was referred to our hospital with the chief complaint of severe left flank pain of sudden onset which occurred after she fell down some steps. Abdominal computerized tomographic (CT) scan revealed a huge perinephric urinoma, severe left hydronephrosis with obstructive atrophy and double inferior vena cava. Left nephrectomy was performed under a diagnosis of traumatic rupture of the left renal pelvis associated with left congenital hydronephrosis and double inferior vena cava. Rupture of the renal pelvis and ureteropelvic junction obstruction with severe parenchymal thinning were found. The postoperative course was uneventful. Double inferior vena cava is a relatively rare anomaly and most cases in recent years have been incidentally found by ultrasonography and CT scan. Urologists should keep in mind the possibility of this anomaly of the inferior vena cava, especially when reforming left nephrectomy.