The Septum Inguinalis: A Clue to Hernia Genesis?

Purpose: Double ipsilateral inguinal ("pantaloon") hernias and also the more advanced "combined" inguinal hernia involve disruption of the inguinal floor. In the case of pantaloon hernias, the medial boundary of the internal ring remains intact but in combined hernias this is fully disrupted, producing a single hernial protrusion. Deepening the pathophysiology of these hernias may be helpful in addressing hernia genesis, thus improving strategies for the treatment of this disease. Materials and Methods: A cohort of 22 patients who underwent inguinal hernia repair showed double ipsilateral (pantaloon) hernia, comprising distinct direct and indirect protrusions separated by a tissue septum. In 19 patients, the septal arrangement dividing the 2 hernias showed macroscopically evident structural damages, then excised and histologically studied. Different tissue markers were used for the identification of the structural damages. Results: Macroscopically, the divisor septum represents the boundary between internal ring and Hesselbach's triangle. Anteriorly it is composed by fibers of the internal oblique and transverse muscles, which form a complex with the inferior epigastric vessels on the corresponding posterior side of the inguinal floor. In the patient cohort studied, this anatomical structure showed a progressive sufferance characterized by chronic compressive damage. Conclusion: The anatomical structure which separates the indirect and direct components of a pantaloon hernia, herein referred to as the "septum inguinalis", has been shown progressively alter in both macro- and microscopically until it f undergoes disruption with development of a combined hernia. Understanding of this anatomical concept may help surgeons to perform sound repairs of these complex hernias.