Iliolumbar artery

The iliolumbar artery is a branch of the posterior trunk of the internal iliac artery.

The iliolumbar artery turns upward behind the obturator nerve and the external iliac vessels, to the medial border of the psoas major, behind which it divides into a lumbar and an iliac branch:

• The lumbar branch (ramus lumbalis) supplies the Psoas major and Quadratus lumborum, anastomoses with the last lumbar artery, and sends a small spinal branch through the intervertebral foramen between the last lumbar vertebra and the sacrum, into the vertebral canal, to supply the cauda equina

• The iliac branch (ramus iliacus) descends to supply the Iliacus; some offsets, running between the muscle and the bone, anastomose with the iliac branches of the obturator; one of these enters an oblique canal to supply the bone, while others run along the crest of the ilium, distributing branches to the gluteal and abdominal muscles, and anastomosing in their course with the superior gluteal, iliac circumflex, and lateral femoral circumflex arteries.