Unusual drainage of the inferior caval vein in left atrial isomerism

Two of the 26 cases of left atrial isomerism in our clinical material had an unusual drainage of the inferior caval vein. In one, the inferior caval vein crossed from left to right infradiophragmatically and then drained into the right-sided morphologically left atrium. In the second case, there was azygos continuation to both right and left superior caval veins. These variations have major surgical significance.