Left inferior vena cava with regressed right inferior vena cava.

A left inferior vena cava was found in the cadaver of an 88-year-old Japanese man during a student dissection course at Kumamoto University School of Medicine. The right common iliac vein ascended obliquely toward the left behind the right common iliac artery and united with the left common iliac vein to form the inferior vena cava in front of the fifth lumbar vertebral body behind the left common iliac artery. The inferior vena cava ascended on the left side to the aorta, and after the left renal vein joined to it at the level of the third lumbar vertebral body, it turned obliquely to the right and crossed superficially to the aorta. At the right side of the aorta, the common stem of the third lumbar vein and the posterior renal vein was joined to the oblique part. The inferior vena cava then ascended, receiving the right renal vein as it would normally. The inferior vena cava is thought to develop symmetrically but this left inferior vena cava shows a persistence of the left channel of the infrarenal part, which normally disappears. Although the common stem of the veins that joined to the oblique part on the right side did not continue to the right common iliac vein, gross anatomical findings suggested it to be the remnant of the right inferior vena cava.