Searching for the best polypropylene mesh to be used in bowel contamination

There is still some concern about the use of polypropylene in case of infection or contamination. The biocompatibility of the recently introduced light-weight polypropylene meshes seems to be promising. This experimental study was designed to evaluate three different weights and pore sizes of polypropylene meshes in a contamination model.

Thirty rabbits were operated through a pararectal incision. The abdomen, wound and mesh were contaminated with faecal fluid aspirated from the appendix. Groups of ten animals were studied according to three different pore sizes of polypropylene mesh implanted as an inlay technique: very large pore, large pore and medium pore. Five animals of each group were sacrificed on days 21 and 90. Incisional surgical site infection and microbiologic cultures on the 21st and 90th days were the main outcome measures. Tissue integration, shrinkage and biomechanical properties were also tested.

Two rabbits died on day 1. There were six incisional surgical site infections (21.4%). Four animals had positive cultures with no macroscopic infection. None of the surviving rabbits with very large pore mesh had clinical infection or positive microbiologic cultures. Very large pore meshes shrank significantly more on day 21. There were no differences in the tensiometric test results.

In our experimental model, low-weight, very large pore polypropylene meshes seem to be the best polypropylene mesh in case of intestinal contamination. These results encourage clinical investigation on the use of low-weight, very large pore polypropylene meshes in the treatment and prevention of hernias in the presence of clean-contaminated or contaminated fields.