Fat Graft Retention: Adipose Tissue, Adipose-Derived Stem Cells, and Aging

Over the past 30 years, there has been a dramatic increase in the use of autologous fat grafting for soft-tissue augmentation and to improve facial skin quality. Several studies have highlighted the impact of aging on adipose tissue, leading to a decrease of adipose tissue volume and preadipocytes proliferation and increase of fibrosis. Recently, there has been a rising interest in adipose tissue components, including Adipose-derived Stem/Stromal Cells (ASCs) due to their regenerative potential, including inflammation, fibrosis and vascularization modulation. Due to their differentiation potential and paracrine function, ASC has been largely used for fat grafting procedures as they are described to be a key component in fat graft survival. However, many parameters as surgical procedures of adipose tissue biology could change clinical outcomes. Variation on fat grafting methods lead to numerous inconsistent clinical outcomes. Donor-to-donor variation could also be imputed to ASCs, tissue inflammatory state or tissue origin. In this review, we aim to analyze (1) the parameters involved on the graft survival, and (2) the effect of aging on adipose tissue components, especially ASCs, that could lead to a decrease of skin regeneration and fat graft retention.