USE OF NONPOROUS POLYTETRAFLUOROETHYLENE PROSTHESIS IN COMBINATION WITH POLYPROPYLENE PROSTHETIC ABDOMINAL-WALL IMPLANTS IN PREVENTION OF PERITONEAL ADHESIONS

One of the drawbacks of using macroporous polypropylene prostheses in the repair of the abdominal wall is the formation of adhesions with th e viscera. However, polytetrafluoroethylene (PTFE) has low adhesion fo rmation, although it provides less resistance to traction in the repai red zone. The aim of the present study was to reduce the formation of adhesions to a polypropylene implant Prolene(R) (PL) by introducing a nonporous expanded PTFE layer (Preclude Dura-Substitute(R)) (PR) betwe en the polypropylene prosthesis and the abdominal viscera. The scarrin g process and resistance to traction in the repaired zone were also ev aluated. Thirty-six rabbits were divided into three groups and mere tr eated as follows: group I, a PR patch (7 x 5 cm) was secured to the pa rietal peritoneum; group II, an abdominal wall defect (7 x 5 cm) was c reated and repaired using a PL patch; group III, an abdominal wall def ect was as in group LT and was repaired using a combined PR/PL prosthe sis. Specimens were evaluated at 14, 30, 60, and 90 days postimplant f or extent of adhesion formation and morphological analysis was perform ed using light and scanning electron microscopy. Biomechanical resista nce of the implant was evaluated using strips comprising prosthetic ma terial and anchorage tissue. Group I and group III prostheses showed l oose adhesions only, but group II adhesions were firmly attached. The mean surface areas covered by adhesions were 0.08 cm(2) (group I), 7.6 7 cm(2) (group II), and 0.1 cm(2) (group III). PR implants (group I) m ere encapsulated by organized tissue. In group II the formation of dis organized tissue invading the prosthesis was observed. In group III th e PR impeded the growth of disorganized scar tissue and the lower surf ace of the implant was covered by an orderly neoperitoneum, Resistance to traction of the double implants (group III) (mean +/- SD, 33.32 +/ - 0.9 N) was similar to that of the Prolene implants (group II) (33.76 +/- 0.46 N) (Mann-Whitney U test, p < 0.05). We concluded the presenc e of a PR layer between the PL implant and viscera greatly reduced the incidence of adhesion formation without affecting the high resistance to traction provided by the PL implant or the evolution of the scarri ng process. (C) 1997 John Wiley & Sons, Inc.