[Forum on tissue expansion. Tissue expansion and radiotherapy. Changes in epidermal mitotic index induced by expansion and/or irradiation in the rat].

In order to study the influence of irradiation during skin expansion, an experimental protocol using 15 laboratory rats was undertaken. The present experiment was designed to evaluate the mitotic activity of the epidermis by in vitro autoradiography. The mitotic activity was assessed by the Labelling Index. Experimental data concerning expansion were shown to be consistent with the literature. When a high dose of radiation was delivered to the skin during expansion, a significant increase was observed in the mitotic activity of the epidermis. The range of variation was equivalent to that expected in normal skin. This is the first experimental result in favour of irradiation during skin expansion. However, no conclusion can be drawn concerning the clinical applications (immediate breast reconstruction using tissue expansion) due to the limitations of the present experiment.