Images in vascular medicine

Abstract

A 63-year-old male, with history of hypertension, diabetes mellitus and hypercholesterolemia, underwent an ultrasound scan for prostate hypertrophy, which revealed an abdominal aortic aneurysm (AAA). An abdominal CT scan confirmed the presence of a 5.5 cm diameter AAA and disclosed duplication of the inferior vena cava (IVC) (Panel A; arrows). The right-sided IVC followed the normal IVC anatomy, whereas the left-sided IVC originated in the pelvis from the left common iliac vein, ascended along the posterior-lateral aspect of the abdominal aorta, passed anterior to the AAA neck where it joined the left renal vein and then entered the right-sided IVC. At surgery, the left-sided IVC (Panel B: black arrow left-sided IVC; white arrow left renal vein; bent arrow left spermatic vein) was dissected free of the AAA neck and the AAA was replaced with a 20 mm Dacron tube graft. The postoperative course was uneventful and the patient was discharged on the seventh postoperative day. Duplication of the IVC is estimated to occur in 2 3% of autopsy series. The abnormality is caused by failure of regression of the caudal left supracardinal vein during the first embryologic trimester, which results in persistence of both left and right supracardinal veins. Several variations of double IVC have been described. The left-sided IVC may pass anterior or posterior to the aorta or may ascend along the lateral aspect of the aorta and empty into the left renal vein. The left-sided IVC can also be poorly developed or segmental. The presence of double IVC poses hazards to the surgeon during abdominal aortic surgery. Preoperative diagnosis is desirable and can be made on a CT scan. Ultrasound scan and venography of the vena cava is rarely recommended. It should be noted, however, that CT scans are routinely performed for patients scheduled for AAA repair but not for patients undergoing reconstruction for aortoiliac occlusive disease. Familiarity with the anatomy of the most common types of major venous anomalies is therefore mandatory for all vascular surgeons to reduce the risk of severe venous hemorrhage associated with these anomalies.