Hepatic and postrenal segment anomalies of inferior vena cava

ABSTRACT

Postrenal segment anomalies of inferior vena cava such as bilateral inferior vena cava and left-sided inferiorvena cava can simulate lymphadenopathy on CT scan and these anomalous veins need consideration in retroperitonealoperations such as procedures for prevenetion of venous embolism, splenorenal shunt operation and aorticprosthetic repalcement. Retrocaval ureter is a rare cause of obstructive uropathy or medical deviation of ureter.We analysed 16 cases of postrenal segment anomalies daignosed by CT, vena cavography, retrograde pyelography andultrasonography including six rare positional anomalies at hepatic segment of inferior vena cava diagnosed bycardiac angiography. The results were as follows. 1. Postrenal segment anomalies were 6 cases of bilateral IVC, 8cases of left-sided IVC and 2 cases of retrocaval ureters. On CT scan, 3 cases of bilateral IVC and 4 cases ofleft-sided IVC were accompained by malignant tumors, but caval veins could be discriminated from enlarged nodesbecause of continuous tubular nature of vein on consecutive sections with homogeneous strong enhancement. Twocases of retrocaval ureters showed hydroureteronephrosis due to ureteral compression by IVC. 2. Hepatic segmentanomalies were 6 cases. Five cases of IVC on left side of vertebral crossed midline at live to enter right-sidedright atrium and one case of IVC on right side crossed midline to enter left-sided right atrium. Four cases ofcomplex cardiac anomalies, 4 cases of asplenia and 2 cases of situs ambigus were associates with these anomalies.