PHEMA as a fibrous capsule-resistant breast prosthesis

The presence of a silicone (poly-dimethyl siloxane) breast prosthesis in a breast reconstruction patient typically leads to fibrous tissue encapsulation of the prosthesis. Fibrous capsular contracture forces the prosthesis into a hardened sphere. The initially satisfactory cosmetic result can thus be changed into a deformed mass of inappropriate compliance. It is the author's hope with the present study to identify a material for implantation with a diminished tendency to form fibrous encapsulation, to improve the long-term results of prosthetic implants. The purpose of this investigation was to compare the early capsule production quality of poly-2-hydroxyethyl methacrylate (PHEMA) and poly-dimethyl siloxane (silicone). Each of five rats subcutaneously underwent implantation with both a disk of poly-dimethyl siloxane (control) and a similar disk of PHEMA. In this study, the extent of fibrous encapsulation was assessed at 6 weeks after implantation of the two disk types. The five disks of poly-dimethyl siloxane were embedded in fibrous tissue, whereas there was no apparent fibrous tissue surrounding the implants of PHEMA. The author concludes that the results for PHEMA were superior to those for silicone at 6 weeks with regard to fibrous encapsulation (p = 0.0312).