Common iliac arteries
Branch · L4 Iliac crest plane Divide L5–S1
Terminal branches of the aorta, formed at its bifurcation at L4 (a little below the umbilicus, in the plane of the iliac crests). Each runs down and laterally to divide in front of the sacroiliac joint at L5–S1 into the internal iliac (pelvis, perineum, gluteal region) and external iliac (lower limb, becoming the femoral artery beneath the inguinal ligament).
Traced from the start
- Abdominal aorta
- Common iliac arteries
Detail
- Level
- Aortic bifurcation L4; common iliac bifurcation at L5–S1 on the pelvic brim
- Terminal branches
- Internal iliac, external iliac
- Relations
- Ureter crosses the common iliac bifurcation in front; the left common iliac vein passes behind the right common iliac artery to form the IVC at L5
When it goes wrong
Aortoiliac atherosclerotic occlusion
Leriche syndrome: buttock and thigh claudication, absent femoral pulses and erectile dysfunction from loss of internal iliac flow
Right common iliac artery compressing the left common iliac vein against L5
May–Thurner syndrome: left leg deep vein thrombosis, typically in a young woman
Ureteric stone passing down the ureter
Commonly impacts at the pelvic brim where the ureter crosses the common iliac bifurcation, one of the three natural constrictions
Practise this structure
1 question in the bank tagged Arterial Supply.