common iliac artery
The common iliac arteries (CIAs) are the large paired terminal branches of the abdominal aorta.
The abdominal aorta bifurcates anterolateral (to the left side) of the L4 vertebra, into the right and left common iliac arteries.
The common iliac arteries (CIAs) enter the pelvis on the medial aspect of the psoas muscle. The left CIA is shorter than the right. The right CIA passes anterior to the left common iliac vein and then anterior and parallel to the right common iliac vein. The left CIA course is more simple, running parallel and lateral to the left common iliac vein. The CIA bifurcates at the point where the ureter crosses it anteriorly into its terminal branches, the internal iliac artery and external iliac artery, at the level of the pelvic brim, anterior to the sacroiliac joint.
In addition to the terminal branches, the common iliac arteries also give branches to the surrounding tissues, peritoneum, psoas muscle, ureter, and nerves. Occasional branches are the iliolumbar and accessory renal arteries.