Efficacy of a novel synthetic material to close exposed fascial defects

Background. After developing a synthetic composite material (TMS-1) made from a porous polypropylene mesh (placed in apposition to fascia) coated on the 'visceral' side with solid polyurethane, we compared its efficacy with that of porous polytetrafluoroethylene, polypropylene, and primary fascial closure when the repairs were left exposed to the environment. Methods. We created 1 cm² abdominal wall defects in each of the four abdominal quadrants of rats (n = 12). We used porous polytetrafluoroethylene, polypropylene, and TMS-1 to repair three defects; the fourth we primarily closed. The skin was left open in all cases, leaving the fascial closures exposed. A second group of rats (n = 24) had the same operation, except that peritonitis was induced using a standard fecal inoculation technique. When the rats were killed 2 weeks later, a 'blinded' observer using a standard scale assessed the surface area and severity of adhesions formed. Results. When compared with the other synthetic materials, the surface area of adhesions formed was significantly less after primary closure in clean conditions; in contaminated conditions, it was less than porous polytetrafluoroethylene, polypropylene, and the same as TMS-1. Furthermore, in contaminated conditions, the severity of adhesions beneath TMS-1 was the same as primary closure and significantly less than those beneath the polypropylene. Conclusion. The overall superiority of TMS- 1 over porous polytetrafluoroethylene and polypropylene in septic conditions justifies further experiments to define its long-term efficacy in the repair of large defects.