Obturator artery

Course

The obturator artery is a branch of the anterior division of the internal iliac artery. It originates in the pelvis, just below the umbilical artery. The artery then courses anteroinferiorly over the pelvic wall, being superior to the obturator vein and inferior to the obturator nerve.

The medial side of the artery is crossed by the ureter in both sexes, and additionally by ductus deferens in the males. The artery then reaches the superior part of the obturator foramen, via which it enters the obturator canal. After traversing the obturator canal, the obturator artery emerges in the medial compartment of the thigh.

Branches and supply

Along its course, the obturator artery gives off several branches which are usually grouped as the branches within the pelvis (pelvic branches) and branches within the thigh (extrapelvic branches).

The pelvic branches of the obturator artery are the:

• The iliac branches supply the iliac bone and iliacus muscle and anastomose with the iliolumbar artery.
• The vesical artery supplies the medial part of the urinary bladder. Sometimes this branch can be large enough to replace the inferior vesical artery and supply its vascular territory as well.
• A pubic branch arises around the obturator canal. It runs across the pubic bone and anastomoses with its contralateral counterpart and the pubic branch of the inferior epigastric artery.

The extrapelvic branches of the obturator artery are the:

• The anterior branch of obturator artery follows the inner margin of the inferior pubic ramus to anastomose with the posterior branch of femoral artery and medial circumflex femoral artery. It supplies the obturator externus muscle, hip adductors and the skin over the medial thigh.
• The posterior branch supplies muscles attached to the ischial tuberosity such as the ischiocavernosus muscle.
• The acetabular branch traverses the ligament of the head of the femur and supplies the femoral head. This branch usually arises from the posterior branch.

Learn more about the arteries of the sacrum with our other articles, videos, labeled diagrams and quizzes.

Anatomical variations

The origin of the obturator artery may significantly vary among individuals. The artery may arise from the main stem or from the posterior trunk of the internal iliac artery, from the superior gluteal artery, or from the external iliac artery.

In some cases, the obturator gives off an accessory obturator artery that forms an anastomosis with the external iliac artery. This "aberrant" obturator artery is usually referred to as the corona mortis or crown of death artery. The name of the vessel testifies to the importance of this feature; during surgical procedures, it can get accidentally injured and cause significant bleeding which is particularly difficult to stop.

In approximately 20% of the population, the enlarged pubic branch of the inferior epigastric artery may replace the obturator artery and its referred to as the replaced obturator artery.