Congenital anomalies and anatomical variants of the inferior vena cava and left renal vein: noninvasive diagnosis with duplex Doppler sonography

The sonographic findings in five patients with congenital anomalies of the interior vena cava and left renal vein are presented. We encountered two patients with duplication and two with transposition of the inferior vena cava, and one with a retroaortic left renal vein, In four cases the findings were confirmed by demonstrating venous flow within the anomalous vascular structures using duplex Doppler equipment. The diagnostic capabilities of sonographic imaging and Doppler analysis of blood flow allow noninvasive recognition of these vascular anomalies. In our opinion, invasive studies are needed only when retroperitoneal structures are difficult to assess by ultrasound because of obesity and/or abundant overlying intestinal gas.