Inguinal hernia is a hernia (rupture) causing intestines or organ parts to protrude through a congenital or acquired opening in the abdominal wall. It commonly affects males. Acquired inguinal hernia is an abdominal hernia in which a “peritoneal sac” containing intestines bulges through an opening in the abdominal wall (hernia canal). It protrudes through the external (=lateral) or internal (=medial) inguinal ring. Hernia protruding in to the inner inguinal ring lateral to the epigastric vessels and passing through the inguinal canal is called indirect inguinal hernia (external, lateral or oblique hernia). It protrudes through the inguinal fossa medial to the epigastric vessels directly through the abdominal wall to the external inguinal ring. With an incidence of 30-40% it is the less common type. The natural-sized model shows the left inguinal region of a male with an indirect inguinal hernia, opened in layers. The two illustrations on the base show a comparison of the diagrammatic anatomy of a direct (left) and indirect (right) inguinal hernia.
