Evaluation of a knitted polytetrafluoroethylene mesh placed intraperitoneally in a New Zealand white rabbit model

Abstract

Background: The intraperitoneal application of surgical mesh remains a controversial issue because of possible complications, especially adhesion and fistula formation. This study aimed to assess the potential of a knitted polytetrafluoroethylene (PTFE) mesh for intraabdominal implantation.

Methods: Twenty-eight 5 × 5 cm samples of knitted macroporous PTFE mesh and light-weight polypropylene mesh (LW-PP) were implanted intraperitoneally in 14 New Zealand white rabbits in a randomized manner and fixed using eight polypropylene stitches. After 90 days, the adhesion formation, adhesion score, shrinkage, strength of fixation to the abdominal wall, and histologic biocompatibility were assessed.

Results: No intraoperative or anesthesia-related complications or mesh infection were recorded. The average area covered by adhesions was 4.7 ± 7.2% for the PTFE and 36.4 ± 36.1% for the LW-PP. The median adhesion score was 0 for the PTFE and 8 for the LW-PP. Shrinkage was 36.9 ± 12.9% for the PTFE mesh and 12.6 ± 8.72% for the LW-PP. The mesh-to-abdominal wall fixation strength was almost the same for both materials (PTFE 3.6 ± 1.9 vs. LW-PP 3.6 ± 2.9). The inflammatory cell count was almost the same for the two groups, with no statistically significant difference. The width of the inner granuloma was equal (PTFE 10.5 ± 0.9 vs. LW-PP 11.1 ± 0.9). The outer granuloma was reduced significantly in the PTFE group (PTFE 23.0 ± 2.1 vs. LW-PP 33.6 ± 7.9). One of the animals in the PTFE group died on postoperative day 12 because of ileus. The reason was an adhesion of the small intestine to the polypropylene fixation stitch, which caused small intestine strangulation.

Conclusions: The knitted PTFE mesh induces fewer intraperitoneal adhesions of lower density than the light-weight polypropylene mesh. The strength of the knitted PTFE mesh fixation to the abdominal wall is comparable with that of the light-weight polypropylene mesh, but the shrinkage is greater. The biocompatibility of the knitted PTFE mesh is comparable with that of the light-weight polypropylene implant.