[Biologic tolerance of prolene prosthesis in inguinal hernia repair]

The aim of this study was to evaluate the efficacy, safety and durability of a calibrated inguinal hernioplasty polypropylene prosthesis, particularly in relation to the microbiological phenomena that may set in the vicinity of the polypropylene plugs and mesh employed. Over the period from January 1994 to December 2002, 1416 operations were carried out for inguinal hernia. In 5 of these patients we conducted an immunological study to assess serum cytokine concentrations. In addition, we incubated peripheral blood mononuclear cells for 24 or 72 hours in RPMI 1640 medium added with 10% FCS, with or without 0.5 cm2 of polypropylene. We then evaluated cytokine levels in the supernatant of these cultures. It proved impossible, either in vivo or in vitro, to detect appreciable levels of IL-10 or IP-10. Serum levels of IFN-gamma, TNF-alpha, IL-18 and IL-6 increased in the postoperative phases as compared to the preoperative period. In the study performed in vitro, in the presence of prosthetic material there was a remarkable increase in the production of TNF-alpha and INF-gamma both in basal conditions and after an appropriate mitogenic stimulus. The results of this study allow us to speculate that the use of polypropylene induces remarkable chemotactic activity in the tissues adjacent to the prosthesis. The in-vitro study data suggest that the presence of polypropylene may stimulate the immunocompetent cells of patients with prosthetic implants.