Preaortic iliac venous confluence. Marsupial vena cava. Case report.

Anomalous anatomic location of a large venous system is a very important assessment before aortic operations. Ours was an anatomical finding of a case of preaortic iliac confluence, a variation also known as 'marsupial vena cava'. As abdominal aortic surgery is currently performed routinely, rare anatomical anomalies must be spotted, in order to avoid injury to surrounding organs.