Histologic changes in transplanted expanded polytetrafluoroethylene in an animal model

Abstract

Several materials have been used for nasal augmentation surgery. Expanded polytetrafluoroethylene (e-PTFE) (Gore-Tex; W. L. Gore & Associates, Flagstaff, AZ) has proven to be an ideal synthetic material for nasal augmentation. Gore-Tex contains numerous pores that stabilize an implant, but this advantage has been tempered by unpredictable outcomes. The purpose of this study was to evaluate morphologic and histologic changes in nonreinforced Gore-Tex in a rabbit model. In vivo study using a rabbit model. To analyze histologic changes, we used 20 New Zealand white rabbits. Gore-Tex was implanted into the nasal dorsum of the rabbits. Then, en bloc specimens containing the implant and surrounding soft tissues were sampled 1, 3, 6, and 12 months after implantation. We evaluated the three-dimensional size of the implants over time using light and electron microscopy to investigate histologic and morphologic changes. Following gross analysis, none of the implants were lost or extruded, and there was no evidence of wound infection. Diminution rates of thickness, width, and height in the implants were 22%, 2%, and 5%, respectively. Histologically, connective tissue growth was observed in all specimens, and the internodal space decreased owing to connective tissue ingrowth over time. Neovascularization was observed 3 months after implantation, and degenerative changes were also observed after 6 months. Gore-Tex should be carefully trimmed for use in augmentation because of its potential to decrease in size over time. Additional studies are necessary before these results can be applied in clinical practice.