How common is IVC duplication? What does it look like on a cavogram?
IVC duplication occurs in 0.2% to 0.3% of patients. In a patient with a duplicated IVC, the left common iliac vein does not join with the right common iliac vein but instead extends cranially to join the left renal vein. Simultaneous injections of the right and left femoral veins reveal two IVCs. The one on the right extends from the right common iliac vein into the right atrium. The one on the left extends from the left common iliac vein and joins with the left renal vein, which then empties into the right-sided IVC. If one understands this anatomy, one can appreciate why refluxing contrast material down both common iliac veins during a cavogram excludes the presence of a duplicated IVC.