Duplication of the inferior vena cava and retroaortic left renal vein in a patient with large abdominal aortic aneurysm

Abstract

Duplication of the inferior vena cava (IVC) is a congenital anomaly in which two large veins on both sides of the aorta join at the level of the renal arteries to become one vessel.1 It is a rare anatomic variant that has been reported to occur in 0.2–3% of the population.1 The anomalous veins are typically thin walled, dilated and tortuous.2 As a result, manipulation of these veins during abdominal aortic surgery places the patient at high risk of massive hemorrhage.1,3 A 65-year-old Caucasian male was suffering from back pain radiating into both legs. He had been a smoker for 30 years, but did not suffer from hypertension, diabetes or any cardiac problems. Laboratory parameters were normal. After neurological examination, computed tomography (CT) of the lumbar spine was ordered. The radiological report revealed disc herniation at the level of L4–L5. An aneurysm of the abdominal aorta (AAA) was also diagnosed. The patient was referred for vascular surgery consultation and computed tomographic angiography (CTA) was subsequently performed. An aneurysm of the abdominal aorta and both common iliac arteries was confirmed, beginning 45 mm below the renal arteries with a maximum diameter of 95 mm (Panel A1) as well as a duplication of the IVC (PanelA2, arrows) and retroaortic left renal vein (PanelA2, arrowhead). The width of the inferior vena cavae at the level of termination was 19.4 mm (right IVC) and 10.8 mm (left IVC). Other measurements are presented in the anatomical schematic (Panel B). The patient underwent open surgical repair of the AAA with aorto-bifemoral reconstruction. Endovascular repair was considered, but due to arterial tortuosity and atherosclerosis of the external iliac arteries, open repair was performed. The patient experienced substantial intraoperative bleeding (approximately 400 mL), which was managed by autotransfusion. Injury was identified in the proximal segment of the left IVC, and repair was performed with venorrhaphy. The patient’s subsequent postoperative recovery was uneventful. Duplication of the IVC may complicate open aortic surgery and may also potentially predispose to venous thrombosis.2,3 This case highlights the importance of the detection of vascular variant anatomy which can help in the Images in Vascular Medicine