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Background: When repairing an abdominal wall defect, sometimes a prosthetic mesh needs to be placed directly on the parietal peritoneum. Although the standard mesh for this purpose is the laminar implant expanded polytetrafluoroethylene (PTFE), it is gradually being replaced by the laminar collagen-based meshes. This study was designed to assess the intraperitoneal behavior of three of these biomeshes, mainly in terms of their susceptibility to adhesion formation., Methods: Two 3-cm × 3-cm fragments of prosthetic material were placed on the parietal peritoneum in male New Zealand White rabbits in the following combinations: PTFE and CollaMend(®), PTFE and Permacol(®), or PTFE and Surgisis(®). The meshes were fixed at the four corners with individual 4/0 polypropylene sutures. Adhesion formation was quantified by sequential laparoscopy and image analysis performed at 3, 7, 14, and 90 days postimplant. All animals were killed at 90 days and the mesh specimens were subjected to microscopy and immunohistochemistry., Results: Intensely vascularized adhesions to all the implants were observed, although Surgisis showed the lowest percentage of adhesions at each follow-up time. Adhesions had stabilized by 7-14 days. The PTFE meshes were enveloped by a layer of macrophages and connective tissue, bounded by a monolayer of mesothelial cells. Permacol and CollaMend showed similar histological behavior, including cell ingrowth through their fenestrations with no signs of degradation detected at 90 days. In contrast, the Surgisis mesh at 90 days was practically replaced with neoformed tissue., Conclusions: No difference in susceptibility to adhesion formation was noted in the crosslinked collagen meshes compared to PTFE meshes. The noncrosslinked collagen mesh Surgisis showed the best behavior in that it induced fewer adhesions. Ninety days after implant, a more intense macrophage response was observed in CollaMend and Permacol than in PTFE or Surgisis.

Introduction: The intraperitoneal behavior of a prosthetic material used to repair a hernia is key to the success of the postimplant repair process. This study was designed to laparoscopically examine the real-time behavior of three composite meshes incorporating a chemical adhesion barrier when placed in contact with the visceral peritoneum. Material and Methods: The defects of 7 ×× 5 cm were created in the ventral abdominal wall of 18 New Zealand White rabbits and repaired using Parietex Composite®® ( n == 6), Sepramesh®® ( n == 6), or Proceed®® ( n == 6). At 24 hr, 3, 7, and 14 days postimplant, adhesion formation was quantified by subjecting photographs obtained during laparoscopy to image analysis. At 14 days, specimens of the implants and surrounding host tissue were obtained for histologic, morphometric, and immunohistochemical analyses. Results: There were no cases of infection and/or rejection of the implant. Adhesion formation followed by laparoscopy 3, 7, and 14 days after implant was significantly lower for Parietex®® than the other biomaterials. Degradation of the chemical barrier occurred earliest in Sepramesh®®, this barrier being most stable at 14 days for the Parietex®® implants. Macrophage counts were significantly greater for Sepramesh®®. The thickness of the neoformed peritoneum formed on the three implants varied significantly ( p < .05): 276.89 ±± 38.87 μμm, 84.49 ±± 19.05 μμm, and 161.97 ±± 47.05 μμm, respectively for Paritex®®, Sepramesh®®, and Proceed®®. Conclusions: (a) The most stable barrier against biodegradation was that of Parietex®®; (b) the first postimplant week was the most critical period for adhesion formation; and (c) all three biomaterials showed good intraperitoneal behavior. [ABSTRACT FROM AUTHOR]