INTERFACE FORMED BETWEEN VISCERAL PERITONEUM AND EXPERIMENTAL POLYPROPYLENE OR POLYTETRAFLUOROETHYLENE ABDOMINAL-WALL IMPLANTS

The objective of this work was to study the healing process at the int erface between biomaterial and visceral peritoneum. Implants of polyte trafluoroethylene (ePTFE) and polypropylene prostheses were introduced into the abdominal wall of New Zea la nd rabbits. The behaviour of th e biomaterials was analysed using light and scanning electron microsco py and immunohistochemistry in which a specific anti-rabbit macrophage monoclonal antibody (RAM 11) was employed. According to macroscopic o bservation,there was significantly fewer adhesions prosthesis-viscera to ePTFE than to polypropylene implants. After ePTFE implantation, res toration of the peritoneum took place in an orderly fashion. When poly propylene was used, the peritoneum formed was a disorderly tissue in w hich small areas of haemorrhage and necrosis could be seen to coincide with the appearance of adhesions. The number of labelled macrophages peaked 14 days after ePTFE or polypropylene implantation, after wh ich it decreased gradually. It is concluded that, given the low rate of a dhesion provoked by PTFE, this material is ideal for im-plants contigu ous to the peritoneal cavity viscera. The macrophage response does not determine the use of one material or the other. The structure of the newly formed peritoneum and development of adhesions depends on the po rosity of the biomaterial.