Page 260 - Prevention and Treatment of Incisional Hernia- New Techniques and Materials

Chapter 12
allowing bacteria to in ltrate when macrophages cannot(21). Also small pores induce a M1 pro-in ammatory reaction, known to induce tissue turnover and thereby negatively in uencing incorporation of meshes in the abdominal wall(5, 22). This was macroscopically con rmed(13). Higher numbers of M2 macrophages are associated with a better outcome in wound healing than with a predominant M1-reaction(17, 23). We found high levels of CD206(M2)- positive cells around Parietene Composite® and Sepramesh® which are meshes known for a good biocompatibility in vivo with low adhesion formation(14). C-Qur® is coated with triglycerides and Omega 3-fatty acids.
Cardiovascular research showed that triglycerides can enhance an in ammatory response in endothelial cells. Whether this is also the case in the foreign body reaction is not investigated, however this can be a possible explanation for the found chronic in ammation reaction(24). We expected more distinguished di erences between the meshes regarding the M1/M2 ratio, however macrophages are a heterogeneous population of cells, M1 and M2 being two extremes in the spectrum(25, 26). Subtle di erences in this ratio might have been missed. Due to poor incorporation of some of the meshes we did not have equal group sizes leading to a lower probability of nding signi cant di erences. Sepramesh® at day 28, C-Qur® and Omyramesh® at day 90, and Strattice® at both time points had a very low sample size due to no ingrowth in the surrounding tissues which made it impossible to draw conclusions. Therefore these meshes for these time points were not included in our analysis. No di erences were found for mast cells. This is likely due to the time point of analysis for we did our rst analysis 28 days after implantation. The amount and presence of mast cells is indicative for an acute in ammatory reaction(7, 27) and therefore di erences could not be detected in these experiments. Future studies with increased sample numbers and time points are needed to obtain more insight in the precise foreign body reaction and thereby the di erent performances of meshes in a contaminated environment.
For surgery in an environment at risk of contamination, the choice of a speci c mesh is important. More insight in mesh-dependent cellular immune responses can help surgeons choose between the various commercially available meshes for implantation in a contaminated environment.
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