Macroporous condensed poly(tetra fluoro-ethylene). II. In vivo effect on adhesion formation and tissue integration

This study investigated the in vivo correlation between construct parameters (surface area, pore size) and polymer chemistry in modulating mesh-intestinal adhesions and mesh-abdominal wall integration of condensed poly(tetra fluoro-ethylene) (cPTFE) in hernia repair. A defect created by excising a 2 cm circular section of the abdominal wall from a rat was repaired with cPTFE or either one of the following synthetic meshes: expanded PTFE (ePTFE), ePTFE + polypropylene (PP), PP or PP + oxidized regenerated cellulose (ORC). The intestinal adhesion and abdominal wall integration were studied quantitatively by measuring the pull-out force required to separate each mesh from the respective tissue at 1 and 3 months postimplantation. The hydrophobic, large pore meshes, such as cPTFE and ePTFE + PP led to reduced adhesions. Further, the presence of ORC contributed to reduction in adhesions of the more hydrophilic PP + ORC mesh. The large pore size, thinner meshes such as cPTFE and PP + ORC led to better tissue integration compared to the other meshes tested. Through hydrophobic chemistry, low profile, and increased pore size, cPTFE balances the rapid resolution of the inflammatory and wound healing response that resists adhesion formation, with efficient integration within the surrounding abdominal tissue.