Duplication of inferior vena cava (IVC) is a rare variant of abdominal vessels and is normally located on both sides of abdominal aorta. The IVC is formed trough a complex process of embryogenesis from the sixth to the tenth week of gestation (II month); this is a complicated procedure involving development, regression, anastomosis and replacement of three pairs of venous channels (posterior cardinal, subcardinal and supracardinal). Improper completion of the process of embryogenesis may result in four anatomic anomalies: 1) duplication of IVC; 2) left-sided IVC; 3) retroaortic left renal vein and 4) circumaortic left renal vein.
These anomalies are most often asymptomatic but their understanding is essential for correct interpretation of the results of different immaging techniques and for effective performance of surgical and medical procedures concerning the IVC directly or indirectly.
In recent years, clinics and radiology of congenital anomalies of IVC have increased in importance in planning abdominal surgery, liver or kidney transplatation, or new interventional procedures such as the positioning of IVC filters to prevent pulmonary embolism, varicocele scleroterapy and venous renal sampling. In the past, radiologic assessment of this rare anomalies was performed only with angiography, which remains the most accurate diagnostic method. Today, besides angiography, less invasive examinations can be performed, i.e., US, CT, MRI.
In this case, contrast-enhanced CT allowed a clear definition of anatomy of this anomaly and enabled the correct diagnosis.