Reherniation after repair of the abdominal wall with expanded polytetrafluoroethylene.

Defects of the abdominal wall that are not amendable to primary closure have to be bridged by synthetic materials. The use of a nonabsorbable expanded polytetrafluoroethylene (ePTFE) soft-tissue patch is advocated for this purpose. To investigate the suitability of the ePTFE patch, abdominal wall defects in 30 rats were repaired with ePTFE and compared with polypropylene (PP) mesh. Herniations and adhesions were scored, qualitatively and quantitatively, eight weeks after implantation and the patches were histologically examined. Herniations, all observed at the fascia and patch interface, were significantly more frequent in abdominal wall defects repaired with ePTFE (60 percent) than with PP (zero percent) (p < 0.001, chi-square test). Adhesion formation was less frequently found in rats treated with ePTFE and adhesions were less strongly attached. Histologic examination revealed no ingrowth of fibro-collagenous tissue into the ePTFE patch, whereas the PP mesh was completely incorporated into fibrocollagenous tissue, which was continuous with the adjacent fascia. We conclude that this study confirms our clinical experience that reherniations at the fascia and patch interface in abdominal wall defects closed with an ePTFE soft-tissue patch are the result of insufficient ingrowth of fibrocollagenous tissue into the patch, which results in an insufficient anchorage of the patch to the fascia.