Characteristics of different mesh types for abdominal wall repair in an experimental model of peritonitis

Background: The use of synthetic mesh to repair a potentially contaminated incisional hernia may lead to higher failure rates. A biological mesh might be considered, but little is known about long-term results. Both biological and synthetic meshes were investigated in an experimental model of peritonitis to assess their characteristics in vivo.
Methods: Male Wistar rats were randomized into five groups and peritonitis was induced. A mesh was implanted after 24h. Five meshes were investigated: Permacol™ (cross-linked collagen), Strattice™ (non-cross-linked collagen), XCM Biologic® (non-cross-linked collagen), Omyra® Mesh (condensed polytetrafluoroethylene) and Parietene™ (polypropylene). The rats were killed after either 30, 90 or 180days. Incorporation and shrinkage of the mesh, adhesion coverage, strength of adhesions and histology were analysed.
Results: Of 135 rats randomized, 18 died from peritonitis. Some 180days after implantation, both XCM Biologic® and Permacol™ had significantly better incorporation than Strattice™ (P=0·003 and P=0·009 respectively). Strattice™ had significantly fewer adhesions than XCM Biologic® (P=0·001) and Permacol™ (P=0·020). Thirty days after implantation, Permacol™ had significantly stronger adhesions than Strattice™ (P<0·001). Shrinkage was most prominent in XCM Biologic®, but no significant difference was found compared with the other meshes. Histological analysis revealed marked differences in foreign body response among all meshes.
Conclusion: This experimental study suggested that XCM Biologic® was superior in terms of incorporation, macroscopic mesh infection, and histological parameters such as collagen deposition and neovascularization. There must be sufficient overlap of mesh during placement, as XCM Biologic® showed a high rate of shrinkage. Surgical relevance: The use of synthetic mesh to repair a potentially contaminated incisional hernia is not supported unequivocally, and may lead to a higher failure rate. A biological mesh might be considered as an alternative. There are few long-term studies, as these meshes are expensive and rarely used. This study evaluated the use of biological mesh in a contaminated environment, and investigated whether there is an ideal mesh. A new non-cross-linked biological mesh (XCM Biologic®) was evaluated in this experiment. The new non-cross-linked biological mesh XCM Biologic® performed best and may be useful in patients with a potentially contaminated incisional hernia.