Introduction: Prior publications have demonstrated chemical and physical alteration of hernia mesh analyzed after explantation from the body. The specific alteration documented is oxidative degradation of polypropylene mesh fibers. An animal study recently published has demonstrated that adipose tissue attachment is present instead of reparative fibrous tissue infiltration in an average of 10.9-18.9% of the intramesh healing for a variety of clinically used knitted polypropylene mesh products; 8.0% for knitted polyester meshes. This study also found that in comparison to the knitted mesh products, non-woven polypropylene mesh reduced adipose tissue attachment to 1% or less, which was a statistically significant difference.
Materials and methods: Samples of explanted polypropylene mesh from eight patients were analyzed for the presence of adipose tissue attachment, reparative fibrous tissue infiltration, and oxidative changes. Greater adipose tissue attachment areas were compared with areas of greater reparative fibrous tissue infiltration for evidence of oxidative changes in the mesh to determine if the areas of higher adipose tissue attachment correlated with an increase in oxidative changes.
Results: Intra mesh healing of clinically explanted knitted meshes demonstrated adipose tissue content from 0.0% to 49.1% per analyzed segment. The oxidation index, a measure of the degree of oxidative degradation in that portion of the mesh, was higher in seven of the eight areas of greater adipose tissue attachment than areas of greater reparative fibrous tissue infiltration.
Conclusion: Adipose tissue attachment does occur in knitted and woven polypropylene hernia meshes. The presence of adipose tissue may contribute to an increase in oxidative changes in knitted polypropylene hernia mesh fibers.