Renal arterial collar

Dissection of a 60-year-old male cadaver revealed double renal arteries on both the sides. On right side, the superior and inferior renal arteries were arising from the abdominal aorta at the level of L1 and L2 vertebrae respectively. From their origin, the superior renal artery was passing behind the inferior vena cava and the inferior renal artery was passing in front of inferior vena cava to enter into the hilum of the right kidney. Thus both superior and inferior renal arteries were forming an arterial collar around the inferior vena cava. On the left side, the two renal arteries were arising together from the abdominal aorta. The embryological basis for the above variation is probably due to the persistence of multiple mesonephric branches of dorsal aorta passing dorsal and ventral to the developing inferior vena cava (subcardinal part). Such arterial collar around the inferior vena cava may compress it causing obstruction to the venous return from the lower part the body.