[Application of membrane anatomy theory in totally extraperitoneal inguinal hernia repair]

Trocar placement and camera-dissection in the midline is the most commonly applied method for total extraperitoneal inguinal hernia repair (TEP), for which the theory of membrane anatomy has guiding significance. We hereby applies the theories and concepts, such as "fascia lining", "multi-layer", "inter-fascial planes", "combined inter-fascial plane" and "plane transition", to elucidate the key steps of TEP, for instance, space creation, hernia sac dissection, mesh flattening. Camera-dissection is performed along the posterior sheath of the rectus abdominis. Firstly, the camera enters retro-rectus space locating between the rectus abdominis and the transversalis fascia (TF). There are inferior epigastric vessels and their branches in the retro-rectus space, thus over-dissection should be avoided. Secondly, the camera goes downward through the TF into the pre-peritoneal space. The pre-peritoneal space is divided into the parietal plane and visceral plane by pre-peritoneal fascia (PPF). Both bladder and spermatic cord components locate on the visceral plane. Dissection of the median area should be implemented on the parietal plane, namely "surgical space", to protect the bladder. The parietal plane is the "holy plane" of TEP. Dissection of the indirect hernia area should be implemented on the visceral plane, namely "anatomical space", to protect the spermatic cord components. The reduction of direct hernia could be understood as the easy separation of TF and PPF. The reduction of indirect hernia is relatively difficult separation of peritoneum and spermatic cord components. During the transition of parietal and visceral planes, PPF (especially the pre-peritoneal loop) should be dissected for complete parietalization, in order to flatten the mesh.