Two types of major venous anomalies associated with abdominal aneurysmectomy: a report of two cases.

We report herein the cases of two patients with major venous anomalies associated with abdominal aneurysmectomy, one being an isolated left-sided vena cava and the other, a retroaortic left renal vein, and discuss the clinical significance of such anomalies. In the first patient, an isolated left-sided vena cava was correctly diagnosed preoperatively by contrast-enhanced computed tomography (CE-CT) and digital subtraction angiography (DSA) which revealed that the vena cava crossed the normal portion of the aorta and the right renal vein ran cephalad. In the second patient, a retroaortic left renal vein was also preoperatively diagnosed with CE-CT and DSA. In both patients, dissection was performed, taking care to avoid injury to anomalous venous tributaries, and graft replacement for abdominal aneurysm was successfully carried out. Thus, careful preoperative evaluations using such imaging techniques as CE-CT, DSA, and venographic studies, are important for establishing the presence of an associated venous anomaly preoperatively to ensure the success of abdominal aneurysmal surgery.