Relationship between Tamoxifen and the Absorption of Subfascial Autologous Fat Grafts.

Abstract

In the lipofilling procedures used in breast reconstruction, there is an unpredictability in the rate of reabsorption of the grafted fat. The objective of this study was to analyze the effect of tamoxifen, a medication commonly prescribed for patients with breast cancer, as a possible alternative to reduce the rate of autologous fat graft resorption. The fatty cushion of the inguinal region of 20 female adult Wistar rats was removed and then autografted, using a standard volume of 0.2 ml in the subfascial plane of the dorsal region. The subject animals were randomized into two groups, the control and study groups. The study group animals were administered 20 mg/kg/day of tamoxifen citrate over a period of 21 days, by means of gavage. At the end of the experiment, the animals were killed and the grafts underwent morphologic and histopathologic analysis, with emphasis on the predominant inflammatory response pattern and collagen maturation. The rats undergoing treatment with tamoxifen (study group) presented higher values in relation to the weight and volume of fat grafts compared with the initial values and the control group. Histologic analysis using hematoxylin and eosin staining showed that resolution of the inflammatory process was faster in the control group. Analysis using the picrosirius method demonstrated higher percentages of immature collagen versus mature collagen. Use of tamoxifen reduced the rates of resorption and fibrosis of the injected fat, resulting in better integration of the autologous fat graft.