General notions of anatomy, pathophysiology, and surgical techniques of inguinal hernia repair

Abstract

Inguinal hernia is the most common type of abdominal wall hernia and is characterized by the protrusion of intra-abdominal structures through defects located in the inguinal canal region. Its formation has a multifactorial etiology involving weakening of the transversalis fascia, alterations in collagen metabolism, and factors associated with chronic increases in intra-abdominal pressure. The present study aimed to review the main anatomical, pathophysiological, and technical-surgical aspects related to inguinal hernia repair. This narrative literature review was conducted through searches in the PubMed, Virtual Health Library (VHL), and SciELO databases using descriptors related to inguinal hernia, inguinal canal anatomy, hernia pathophysiology, and open and laparoscopic surgical techniques. Scientific articles, systematic reviews, meta-analyses, international guidelines, and textbooks published in Portuguese, English, and Spanish were included. Direct hernias are mainly associated with weakening of the posterior wall of the inguinal canal, especially the transversalis fascia, whereas indirect hernias are associated with persistence of the processus vaginalis and protrusion of the hernia sac through the deep inguinal ring. Alterations in the ratio between type I and type III collagen and overexpression of matrix metalloproteinases contribute to reduced abdominal wall resistance. Inguinal hernias are mainly classified as indirect, direct, and recurrent, presenting distinct anatomical characteristics and surgical implications. Among repair techniques, the open Lichtenstein hernioplasty is based on the placement of a polypropylene mesh over the posterior wall of the inguinal canal through an anterior approach and remains widely used due to its technical reproducibility, lower cost, and possibility of being performed under local anesthesia. The laparoscopic TAPP and TEP approaches position the mesh in the preperitoneal space to cover the myopectineal orifice, differing mainly in whether the peritoneal cavity is entered. Laparoscopic techniques are associated with lower immediate postoperative pain, earlier functional recovery, and lower incidence of chronic inguinal pain, especially in bilateral and recurrent hernias. However, they also present greater technical complexity, longer operative time during the initial learning curve, and greater dependence on surgeon experience, particularly in TEP. The choice of surgical technique depends on the anatomical characteristics of the hernia, the patient’s clinical condition, the surgical team’s experience, and the availability of institutional resources.