Histomorphologic evaluation of guinea pig skin and soft tissue after controlled tissue expansion

To evaluate the histologic changes attendant on tissue expansion in the guinea pig, self-inflating implants were placed in the dorsal subcutaneous space and the tissue response was sequentially studied at periods ranging from 1 to 18 weeks. Fixation artifacts have been minimized. The cellular response is relatively benign. The epidermis does not undergo thinning during expansion, although dermis and panniculus carnosus become significantly thinner. Atrophy of panniculus muscle is demonstrable. This study supports the hypothesis that tissue expansion results in a net gain of donor tissue.