Inferior epigastric artery

Origin and course

The inferior epigastric artery arises from the external iliac artery immediately superior to the inguinal ligament. It ascends medially to the deep inguinal ring towards the midline while running posterior to the spermatic cord and anterior to the transversalis fascia. Below the arcuate line, the inferior epigastric vessels pierce the transversalis fascia on each side of the rectus sheath and enter the rectus abdominis muscle. The artery then runs within the rectus sheath, between the transversalis fascia and the posterior wall of the rectus abdominis. During its course above the arcuate line, the inferior epigastric artery is reflected on the parietal peritoneum as bilateral raised ridges called the lateral umbilical folds. The artery ends at the level of the umbilicus where it anastomoses with the superior epigastric artery.

The inferior epigastric artery, together with its accompanying veins, forms the lateral border of the Hesselbach’s triangle. This is an important anatomical landmark which outlines the site of the occurrence of direct inguinal hernias.

Branches and supply

Along its course, the inferior epigastric artery gives off several branches, including muscular branches, anastomotic branches, cutaneous branches, the cremasteric artery and a pubic branch.

• Muscular branches: supply the parietal peritoneum, rectus abdominis, the medial portions of the transversus abdominis, internal abdominal oblique and external abdominal oblique muscles. These branches anastomose with the circumflex iliac and lumbar arteries.
• Anastomotic branches: these anastomose with the lower six posterior intercostal arteries at the level of the lateral border of the rectus sheath, posterior to the rectus abdominis.
• Cutaneous branches: these run anteriorly across the anterior abdominal muscles and pierce the aponeurosis of the external oblique muscle, emerging on the subcutaneous tissue where they anastomose with the superficial epigastric artery. These branches supply the skin of the anterior abdominal wall.
• Cremasteric artery: runs within the spermatic cord in males and supplies its layers, as well as the cremaster muscle. The cremasteric artery in females is rudimentary and accompanies the round ligament of uterus.
• Pubic branch: arises near the femoral ring and runs inferiorly behind the pubic bone to reach the obturator foramen. It anastomoses with the pubic branch of the obturator artery.

Anatomical variations

Several anatomical variations are identified in the origin and branching of the inferior epigastric artery. The inferior epigastric artery may occasionally arise from the femoral artery, obturator artery or from the external iliac artery as a common trunk with the obturator artery.

As already mentioned, the pubic branch of the inferior epigastric artery anastomoses with the obturator artery. A common variation, that occurs in about 20% of people, involves the pubic branch that is larger than the obturator artery and takes over the majority of the blood flow to the obturator artery. The pubic branch of the inferior epigastric artery is then considered as the site of origin of the obturator artery, and is referred to as the aberrant or replaced obturator artery. The inferior epigastric may also be doubled. Relatively often, the artery can be referred to as the deep inferior epigastric artery when a superficial one is present.

Test your knowledge on the neurovasculature of the abdominal wall with this quiz.