Adhesions after intraperitoneal mesh repair in pigs: Prolene" vs. Vypro"

Newly developed meshes with low weight and large pores such as Vypro (Ethicon, Norderstedt) were exactly adapted to the physiology of the human abdominal wall and proved to reduce chronic inflammatory processes. It was hypothesized that the reduced inflammatory response to a Vypro mesh would lead to reduced adhesion formation following intraperitoneal implantation in comparison with a Prolene mesh (Ethicon). To test this hypothesis, 20 25-kg pigs underwent resection of a 10 x 10-cm section of the full-thickness anterior abdominal wall, excluding subcutaneous and cutaneous surface. The fascial defect was repaired using a 20 x 20-cm piece of either Vypro or Prolene mesh, which was sutured in inlay position with 4-0 Prolene single sutures at the edges. The main endpoint was the presence and degree of intra-abdominal adhesions to the mesh after 3 months. The amount of adhesions was calculated as a percentage of the mesh square and classified into four grades. There were no significant differences in the amount and grade of adhesions between the groups. Adhesions were less intensive in the Vypro group, but this difference was not significant. Dense adhesions between the liver and the mesh and small-bowel obstruction were observed only in the Prolene group. From the results of this study, Prolene and Vypro meshes cannot be recommended for intraperitoneal placement in hernia surgery because of their adhesion potential and risk of bowel obstruction.