In vitro and in vivo assessment of silver-coated polypropylene mesh to prevent infection in a rat model

The purpose of this study is to determine the effect of silver coating of polypropylene implants on infection in hernia surgery. Silver-coated and non-silver-coated large pore monofilament polypropylene mesh implants were compared with and without infection (four groups). The implants were inserted in the abdominal wall of female Wistar rats. An Escherichia coli strain was inoculated intraoperatively in the two infected groups. The implants were removed, and clinical, bacteriological, and histological analyses were performed at 2, 15, and 30 days postoperatively. Eighty-four rats were studied. All inoculated rats (n = 21) in the non-silver-coated polypropylene group presented periprosthetic E. coli infection, compared with only five inoculated rats in the silver-coated polypropylene group (p < 0.0001). Erosion was significantly higher in the infected than in the non-infected silver-coated polypropylene groups (p < 0.01). There was no histological difference between the four groups. Silver-coated implants appear effective against bacterial infection in our rat model, with good histological tolerance but delayed healing.