Evaluation of the acute scarring response to the implant of different types of biomaterial in the abdominal wall.

Since the short-term, acute scarring process induced by a biomaterial may condition the evolution of the repair process, the present investigation evaluates the behavior of polytetrafluoroethylene (PTFE) and polypropylene (PL) biomaterials in the initial stages of repair. Three PTFE biomaterials (Mycro Mesh, Dual Mesh and Soft Tissue Patch) and one PL biomaterial (Marlex) were employed to repair defects created in the abdominal wall of New Zealand rabbits. Animals were sacrificed at 3 or 7 days. Specimens were obtained for light and scanning electron microscopy, and immunohistochemical analysis using the RAM-11 monoclonal antibody for rabbit macrophages. The PL implants showed substantial adhesion formation with viscera. Lower adhesion formation was detected in the PTFE implants. The evolution of the acute phase of the repair process was similar for each PTFE biomaterial. At 3 days post implant, an incipient neoperitoneum was detected which was fully established after 7 days. The behavior of the PL implant was similar, although a greater amount of reticular granulation was detected. The neoformed peritoneum was irregular. Few RAM-11-labeled macrophages were detected in all cases. The acute phase of the tissue repair process induced by the implant of PTFE and PL biomaterials generally proceeds along similar lines to a normal repair process. However, the use of microporous, laminar materials seems to favor the early establishment of a well-defined neoperitoneal layer. Copyright 2000 Kluwer Academic Publishers