Trifurcation of the abdominal aorta into one common internal iliac trunk and two external iliac arteries.

This paper describes a novel and previously unreported variation of the aortoiliac arterial tree, discovered incidentally during the angiography of a patient with suspected peripheral arterial disease. The abdominal aorta trifurcated into two external iliac arteries and one common internal iliac trunk, which descended along the midline axis of the abdominal aorta before dividing into two internal iliac arteries. Variations in the aortoiliac division are exceedingly rare, with embryological evidence suggesting that this anomaly may have resulted from the convergence of the umbilical arteries along the midline during later stages of development, after the external iliac arteries had branched off.