Duplication of the inferior vena cava from a division of the left external iliac vein

Duplication of the inferior vena cava was detected in a 71-year-old Thai male cadaver with unknown cause of death. Two inferior vena cavae located on each side of the lumbar vertebrae were identified. The right inferior vena cava was formed by fusion of the right and left common iliac veins and had a normal course, while the left inferior vena cava arose from the left branch of the left external iliac vein and ascended parallel to the abdominal aorta. To our knowledge, no similar case has been previously reported. The left inferior vena cava joined the left renal vein to become the preaortic trunk before joining the right inferior vena cava. Tributaries of the inferior vena cava were observed and followed. Development of the duplication of the inferior vena cava was reviewed. Anatomical and developmental comprehension of the duplication of the inferior vena cava is important for clinicians in planning for retroperitoneal surgery.