Pathomorphological changes in tissues with various methods of transplantation of adipose tissue (experimental study)

Purpose of the study. To evaluate the pathomorphological changes in surrounding tissues during adipose tissue transplantation after various techniques of its mechanical processing. Material and methods. Animals were divided into 4 groups, 6 animals in each group. Group 1 – intact animals (without exposure); Group 2 – control (saline solution); Group 3 consisted of animals that were implanted subdermally, through an incision with a diameter of 1 mm, a fragment of fat, previously extracted from a skin incision in the groin area. In group 4, fat crushed using a scalpel was injected under the skin using a syringe, once. Sections were stained using the Mallory method, hematoxylin and eosin, and methylene blue. Results. In the epidermis, an increase in the thickness of the cellular epidermal layers was observed, mainly due to an increase in the rows of cells of the granular layer. During the study, an increase in the rows of cells of the spinous layer and mitotic figures (metaphase plates) was also noted in skin samples of experimental animals. The thickness of the dermis increased mainly due to the reticular layer. In the skin of animals in the experimental groups, the proportion of microvasculature vessels increased compared to the control groups, which is physiologically significant. The thickness of the fat autograft was noticeably greater in the third group, where a large fat fragment was implanted, however, in this group, almost all rats observed pathological reactions in the form of leukocyte, predominantly lymphocytic, infiltration and necrosis of varying severity. In animals of the fourth group, infiltration containing lymphocytes and fibroblast-like cells was also observed but were less pronounced than in the third. In group 4, where fat, minced with a scalpel, was implanted once, relatively large round-shaped fat fragments were detected in only two animals. These fragments were accompanied by moderate lymphocytic infiltration and limited focal tissue necrosis. Conclusion. Transplanted autologous minced fat into rats one month after surgery in the experiment showed a better survival effect compared to transplantation of a whole piece of fat. © 2025 Elsevier B.V., All rights reserved.