High bifurcation of abdominal aorta upon horseshoe kidney at the level of upper L2 vertebral body: a rare case report.

A high-positioned bifurcation of abdominal aorta upon a horseshoe kidney at the level of upper L2 vertebral body was detected during contrast enhanced abdominal computed tomography scan. The isthmus was clamped between the two elevated and extended common iliac arteries. The right renal artery arose from right common iliac artery supplying the superior and medium segments of right kidney. The left renal artery originated from right common iliac artery and branched off into three main arteries supplying the medium segment of right kidney, the inferior segment of right kidney and the lower half part of left kidney, respectively. The left accessory renal artery arose from abdominal aorta supplying the upper half part of left kidney. The inferior mesenteric artery arose from right common iliac artery. Lumbarization anomaly, scoliolosis, asymmetric pelvis and serious hydronephrosis of left kidney were also found. We describe this rare case of variations and discuss the possible embryonic development mechanism.