On the extraperitoneal origin of hernia

Abstract

Inguinal hernia is generally represented as a bulge of an inflated balloon. The transversalis fascia is considered the laminar containment which separates the peritoneal cavity and the ambient atmosphere. Embryologically, the processus vaginalis develops by a process in the extraperitoneal compartment which involves the peritoneum by traction from outside, rather than by pressure from inside. In the living adult, the transversalis fascia separates solid fatty-fascial compartments which are integrated through their threedimensional architecture into a single laminar wall structure of holding strength, ie, the external oblique aponeurosis. The transversalis fascia and the deep inguinal ring are not exposed to or weakened by an atmospheric pressure gradient; they are exposed to the wear and tear of the upright position, ageing, and obesity or weight-loss. Erosive processes in the extraperitoneal fatty-fascial compartment may cause a sliding of the retroperitoneal fat and retroperitoneally fixed organs. This retroperitoneal slide pulls upon the peritoneum, not vice versa.The concept of extraperitoneal origin of groin hernia is supported by the fact that a small prosthesis sublayed to the external oblique aponeurosis is at least as effective a repair as a much larger prosthesis sublayed to the transversalis fascia.