Long-term study of reactions to various silicone breast implants in rabbits.

A long-term study of the fixation and the encapsulation of soft alloplastic implants in rabbits was done-with examination of the capsules at one, 6, 12, and 18 months. No evidence of hematoma, infection, or carcinogenesis was observed. The type of filling in the prosthesis had no demonstrable effect on the encapsulation. The mobility of the prostheses correlated directly with the capsules evoked by plain silicone, perforated silicone-backed, Dacron-backed, and polyurethane-covered prostheses (in order of decreasing mobility). A patch on the base of a given prosthesis did not influence the amount or character of the capsule formed around the remainder of that prosthesis. The results of this study are discussed in the light of past information, to point out the need for further basic research on these problems.