Optimal mesh size for endoscopic inguinal hernia repair - A study in a porcine model

Background: Although the recurrence rate for endoscopic herniorraphy is low (0-3%), it can still be improved. In addition to using an expert technique that will minimize the risk of recurrence, it is essential that the mesh be large enough to cover the hernial defect adequately. To gain an impression of the optimal mesh size for such repairs, we performed an experimental study in a porcine model. Methods: To mimic inguinal hernial defects, circular holes of different diameters were cut in the pigs' abdominal walls after the peritoneum was lifted from the transverse fascia. The abdominal walls were positioned in a hermetically sealed chamber in which air pressure was applied to replicate intraabdominal pressure. Measurements were obtained to relate the protrusion of the mesh to the following three variables: intraabdominal pressure, defect size, and mesh overlap over the defect after positioning of the mesh between the abdominal wall and the peritoneum. Results: Mesh protrusion increased as defect size and intraabdominal pressure increased. Mesh protrusion decreased as overlap of the mesh over the defect increased. Protrusion was found to level off when the mesh overlapped the defect by 3 cm and adequate positioning of the mesh was maintained. Conclusion: Recurrences after endoscopic inguinal hernia repair due to inadequate mesh size and mesh protrusion can be reduced by using a mesh that overlaps the defect by greater than or equal to3 cm.