Improved tissue ingrowth and anchorage of expanded polytetrafluoroethylene by perforation: an experimental study in the rat.

Although an expanded polytetrafluoroethylene patch is a suitable synthetic material to repair large abdominal wall defects, lack of tissue ingrowth into the patch may give rise to herniation at the fascia-patch interface. This study was undertaken to determine whether perforations and/or ethanol pretreatment improved tissue ingrowth into the polytetrafluoroethylene patch. Patches were implanted subcutaneously in 12 rats and evaluated 6 wk (n = 4) or 12 wk (n = 8) after implantation. Tissue ingrowth was only demonstrated into perforated patches. Stress-strain measurements showed that perforation caused a 25% decrease in the mechanical strength of the material. It was concluded that perforation might improve the anchorage of the polytetrafluoroethylene patch to the adjacent aponeurosis and thereby prevent herniation when the polytetrafluoroethylene soft tissue patch was used for the repair of abdominal wall defects.