Nerve-identifying inguinal hernia repair: A surgical anatomical study

Background: Pain syndromes of somatic and neuropathic origin are considered to be the main causes of chronic pain after open inguinal hernia repair. Nerve-identification during open hernia repair is suggested to be associated with less postoperative chronic pain. The aim of this study was to define clinically relevant surgical anatomical zones facilitating efficient identification of the three inguinal nerves during open herniorrhaphy. Method: Through dissection of 18 inguinal areas of embalmed and unembalmed human cadavers, identification zones were developed for the inguinal nerves (in particular for the genital branch of the genitofemoral nerve). Results: The iliohypogastric nerve was identifiable running approximately horizontally and ventrally to the internal oblique muscle perforating the external oblique aponeurosis at a mean of 3.8 cm (range 2.5-5.5 cm) cranially from the external ring. When present, the ilioinguinal nerve was identifiable running ventrally and parallel to the spermatic cord, dorsally from the aponeurosis of the external oblique muscle. Identification of the genital branch of the genitofemoral nerve was more comprehensive. The course of the genital branch is laterocaudal at the level of the internal inguinal ring. Conclusion: Based on the newly defined identification zones, peroperative identification of all inguinal nerves is possible. Further research is warranted to assess clinical feasibility of these zones and to evaluate the influence of (facultative) division, preservation or omittance of the identification of inguinal nerves on the incidence of chronic pain.