Influence of a New Monofilament Polyester Mesh on Inflammation and Matrix Remodeling

Synthetic mesh is widely used for hernia repairs, but mesh-induced chronic inflammatory responses may lead to postoperative complications. We previously showed an elevated response to multifilament polyester (PE) versus monofilament polypropylene (PP) and polytetrafluoroethylene (PTFE) meshes, but it is unclear whether this discrepancy is due to the differences in chemical composition or filament structure. This study compares the influence of a newly available monofilament PEmesh to that of multifilament PE, monofilament PP, and monofilament PTFE on the expression of genes important in inflammation and extracellular matrix remodeling in a rat model. Full thickness abdominal wall defects were corrected with onlay repair or suture repair with no mesh. Explants were harvested 7 or 90 days after repair and divided for histology and mRNA analyses using real-time quantitative polymerase chain reaction arrays to profile expression at the tissue-mesh interface. Monofilament PE elicited a reduced foreign body reaction compared to multifilament PE, corresponding with reduced mRNA expression of important inflammatory cytokines and matrix metalloproteinases (MMPs). Unexpectedly, monofilament PE also resulted in markedly reduced mRNA expression of tumor necrosis factor and MMPs 3 and 9 compared to the widely-used monofilament PP mesh. Findings from this study revealed that both chemical composition and filament structure are important mesh characteristics that may affect a patient's wound healing response and clinical outcome, and should be considered by the surgeon when choosing a particular mesh. Although clinical studies are warranted, results in a rodent model suggest that monofilament PE may be more beneficial than the multifilament form for certain hernia repairs.