Retrocaval ureter and preaortic iliac venous confluence in a patient with an abdominal aortic aneurysm

Anomalous anatomic location of a large venous system poses a potential haza rd in aortic operations. We encountered a patient with an infrarenal abdomi nal aortic aneurysm who was also found at preoperative contrast-enhanced co mputed tomography to have a retrocaval right ureter and a preaortic iliac v ein confluence. This combined anomaly has not previously been reported exce pt for one postmortem case. As abdominal aortic surgery is currently perfor med routinely, care must be taken to avoid injury to surrounding organs due to rare anatomic anomalies.