Inferior epigastric artery
In human anatomy, inferior epigastric artery refers to the artery that arises from the external iliac artery. It anastomoses with the superior epigastric artery. Along its course, it is accompanied by a similarly named vein, the inferior epigastric vein. These epigastric vessels form the lateral border of Hesselbach's triangle, which outlines the area through which direct inguinal hernias protrude. Structure. The inferior epigastric artery arises from the external iliac artery, immediately above the inguinal ligament. It anastomoses with the superior epigastric artery. It curves forward in the subperitoneal tissue, and then ascends obliquely along the medial  margin of the abdominal inguinal ring; continuing its course upward, it pierces the transversalis fascia, and, passing in front of the linea semicircularis, ascends between the rectus abdominis muscle and the posterior lamella of its sheath. It finally divides into numerous branches, which anastomose, above the umbilicus, with the superior epigastric branch of the internal thoracic artery and with the lower intercostal arteries. As the inferior epigastric artery passes obliquely upward from its origin it lies along the lower and medial margins of the abdominal inguinal ring, and behind the commencement of the spermatic cord. The vas deferens, as it  leaves the spermatic cord in the male, and the round ligament of the uterus in the female, winds around the lateral and posterior aspects of the artery. Clinical significance. Hernia. The inferior epigastric artery may lie close to an inguinal hernia, so acts as a useful landmark. Surgery. The inferior epigastric artery may be damaged during laparoscopic surgery. It may also be damaged when manually finding the peritoneum beneath the rectus abdominis muscle.