Histological study of the role of fat injection in scar remodeling following burn injury

Background:Fat grafting had been shown clinically to improve the quality of burn scars. The mechanism of fat graft survival was not clear, and the role of adipose-derived stem cells and preadipocytes in fat survival remains to be determined. Aim of the work : To clinically and histologically evaluate the role of fat grafting in postburn mature scars. Patients and methods: This study was conducted on 20 postburn mature scars. Patients’ ages ranged from 18 to 38 years. Patients were selected randomly to be treated with structural fat graft. It was performed twice for the same scar at a 3-month interval. The abdomen and buttocks were the most commonly chosen donor sites. Fat was processed according to Coleman’s technique and injected at the dermohypodermal junction. Results: Fat grafting proved to have a significant role in scar remodeling. This was measured clinically by Vancouver Scar Scale and proved by histological examination of skin biopsy. The skin biopsies taken from scar sites preoperatively and 3 and 6 months after injection showed significant changes in epidermal thickness, appearance of newly formed vessels, healthy collagen deposition, and new hair follicles and sweat and sebaceous glands surrounded by fat cells. Conclusion: The autotransplanted harvested fat after centrifugation led to the formation of new healthy collagen bundles and new dermal and epidermal cells replacing the diseased ones. This could be attributed to the presence of adipose-derived stem cells, which are considered the key to the scar remodeling process.