The iliolumbar artery commonly arises from the posterior trunk of the internal iliac artery (Read more!). It then arches backward and travels laterally towards the sacroiliac joint and iliac fossa. It goes posterior to the external iliac vessels and crosses the medial border of the psoas major muscle, traveling between the obturator nerve and the lumbosacral plexus.

The iliolumbar artery arises within the pelvic cavity and makes its way to the iliac fossa. Once the artery reaches the sacral ala and passes behind the psoas major muscle, it gives off the lumbar branch. It continues to travel further and soon after gives off another branch - the spinal branch. And finally, it turns even more laterally toward the iliac fossa and terminates by giving off the iliacus branch.

Here is a quick breakdown of all the branches of the iliolumbar artery:

The iliacus branch of the iliolumbar artery also forms several anastomoses with the branches of the superior gluteal artery, deep circumflex iliac artery, and lateral circumflex femoral artery. All these anastomoses are crucial for the blood supply of the abdominal wall and gluteal region muscles.

Overall, the iliolumbar artery ranges between 0.35 to 0.55 inches (9 to 14 mm) in length and 0.05 to 0.18 inches (1.20 to 4.6 mm) in diameter, with a mean length of 0.49 inches (12.50 mm) and mean diameter of 0.11 inches (2.67 mm). Most commonly, each person has one iliolumbar artery on either side of the body. However, some cases have been reported to have two arteries. Sometimes, the iliolumbar artery may be absent. Interestingly, this artery is seen forming common trunks with the lateral sacral artery and the obturator artery.

Note: The iliolumbar artery most commonly arises from the posterior division of the internal iliac artery. However, some variations have been reported. It also may arise from the common iliac artery or the external iliac artery. In addition, it may arise from different sites on the internal iliac artery (e.g., before the bifurcation or from the bifurcation point). Rarely, it arises from the sciatic artery, lateral sacral artery or obturator artery. In females, this artery is seen also arising from the superior gluteal artery.

Unlock with Premium

Iliolumbar artery