Common iliac artery anatomy


The common iliac arteries originate around the fourth lumbar vertebra in the lower back, where the abdominal aorta divides (bifurcation). From there, it descends into the pelvis, where it ends at the level of the edges of the pelvis. Here it is divided into two main branches: the internal and external iliac arteries.

Mainly, the common iliac arteries supply blood to the bones, organs, muscles, and other structures of the abdomen and pelvis. These arteries play an important role in the circulation of the lower extremities.

Common iliac artery disease or injury can have serious medical consequences. An example is a common iliac artery aneurysm, which causes the artery to swell and rupture.


The common iliac arteries are the link between the aorta and the arteries in the pelvis and lower extremities.

Structure and location

There are two common iliac arteries that separate from the abdominal aorta (which draws blood from the heart). One goes to the left and the other to the right.

The arteries reach the level of the fourth vertebra in the spine, then move downward and along the sides of the body. They enter the pelvis through the psoas muscle, which connects the lower spine to the upper leg bone (thigh bone ).

Each common iliac artery runs parallel to its corresponding vein (common iliac veins).

In front of the sacroiliac joint (the junction of the sacrum and the iliac bone of the pelvis), the common iliac artery divides into two main terminal branches: the external and internal iliac arteries.

  • Internal iliac artery : runs behind the tube that carries urine from the kidneys to the bladder (ureter) in its upper part, this artery runs through the body with a corresponding vein in front of it. The artery branches into the back (back) and front ( front ) of the body and supplies blood to various groups of muscles, bones, nerves, and organs in and around the pelvis.
  • External iliac artery Also arising at the sacroiliac joint, the external iliac artery travels down the pelvis to the inguinal (inguinal) ligament and divides into two branches. After separation, the external iliac artery is renamed the femoral artery and serves as the main source of blood supply to the lower extremities.

The left common iliac artery is often slightly shorter than the right and runs parallel to the left common iliac vein. The latter passes in front of the vein and then parallel to the right common iliac vein. / Getty Images

Anatomical variations

The most common variations of the common iliac arteries occur in the internal iliac branch.

Although the artery generally originates at the level of the lumbosacral joint at the base of the spine, it sometimes exits higher at the fifth lumbar vertebra . In other cases, it occurs at the tip of the coccyx ( sacrum or S1).

Doctors also observed a different origin of the first large branch of the internal iliac artery (obturator artery). It can also occur in the lower part of the artery of the inferior epigastric artery or the cystic artery.

The ilio-lumbar artery (which supplies blood to the abdominal cavity) may also appear earlier than usual in the trunk of the internal iliac artery .


The main task of the common iliac artery is to carry oxygenated blood to the pelvis and lower extremities. Through its branches, the internal iliac artery supplies blood to the pelvic region, groin, and surrounding muscles and bones.

The internal branch provides the muscles of the buttocks ( gluteus maximus and minor); abdomen; uterus and vagina or prostate; and the genitals have a constant supply of blood.

Through the external iliac artery, blood flows to the muscles, nerves, and bones of the legs. The femoral artery (what becomes the external iliac artery after passing through the pelvis) provides blood supply to the tibia , femur, and other bones of the lower extremities.

The anterior and posterior tibial arteries, which branch off the external iliac artery, supply blood to the knee, lower leg, feet, and toes.

Clinical relevance

Disease or injury to the common iliac arteries can have serious consequences.

An example is the common iliac artery aneurysm, which occurs when a portion of an artery swells or "swells" as a result of weak walls. This type of aneurysm represents approximately 10-20% of abdominal aneurysms .

The condition can also cause swelling of the kidneys ( hydronephrosis ) and compression of the sciatic nerve (which runs from the base of the spine through the pelvis to the lower extremities).

Shock and severe abdominal pain are often asymptomatic if a common iliac artery aneurysm ruptures .

Endovascular aneurysm treatment (EVAR) is a specialized, minimally invasive surgical procedure to repair damaged or inflamed parts of an artery. A device called an endovascular graft ("endograft") is implanted where it can expand and close a leak or break in an artery.

The procedure is done through small incisions and a special camera that can see inside the artery (endoscopic surgery), and the recovery period is usually shorter than with open surgery.

Even if the procedure is minimally invasive, it is very important that surgeons work carefully when performing any operations near the artery, as damaging it can have serious consequences .

These arteries are especially vulnerable to injury during abdominal or pelvic surgery (such as a hysterectomy to remove the uterus). Because the common iliac artery is critical for supplying blood to the lower extremities, surgeons may close it (bandage it) to prevent serious blood loss (bleeding) .

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