Since the 1980s, there has been an increased interest in autogenous fat grafting for breast augmentation. However, concerns over graft survival and interference with breast cancer screening have limited its application.

Since its introduction, refinements in harvesting and grafting techniques have improved results. The available literature consists primarily of case reports and series. There are no controlled trials, and outcomes thus far have not been measured in a standardized way. The limited data relating to breast cancer screening did not note a significant interference. Concerns have been raised that the placement of mature adipocytes and adipocyte-derived stem cells into the hormonally-active environment of the breast may potentiate breast cancer, but there are no clinical trials that investigate this possibility and a consensus regarding the basic science is still developing. Large multicenter, controlled, prospective trials are necessary to further investigate the many issues relating to the application of autogenous fat grafting for augmentation of the breast.

Injective transfer of autologous aspirated fat is a popular option for soft tissue augmentation, but several issues require attention, including unpredictability and a low survival rate due to partial necrosis. In this study, histologic features and yield of adipose-derived stromal (stem) cells (ASCs) were compared between human aspirated fat and excised whole fat. Aspirated fat contained fewer large vascular structures, and ASC yield was lower in aspirated fat. Aspirated fat was transplanted subcutaneously into severe combined immunodeficiency mice with (cell-assisted lipotransfer; CAL) or without (non-CAL) vascular stromal fractions containing ASCs isolated from adipose tissue. The CAL fat survived better (35% larger on average) than non-CAL fat, and microvasculature was detected more prominently in CAL fat, especially in the outer layers. DiI-labeled vascular stromal fraction cells were found between adipocytes and in the connective tissue in CAL fat, and some of these cells were immunopositive for von Willebrand factor, suggesting differentiation into vascular endothelial cells. Another experiment that used vascular stromal fractions taken from green fluorescent protein rats also suggested that ASCs differentiated into vascular endothelial cells and contributed to neoangiogenesis in the acute phase of transplantation. These findings may partly explain why transplanted aspirated fat does not survive well and suggest clinical potential of the CAL method for soft tissue augmentation.

Background. Autologous fat transfer for soft tissue augmentation has been increasing in recent years. Graft longevity may vary greatly from patient to patient, requiring repeat procedures, often using frozen adipose tissue. Storage usually involves placing syringes of fat directly into a –20°C freezer. However, the viability of fat frozen in this way is controversial. Objective. This study tested methods for the optimal storage of adipose tissue harvested by tumescent liposuction. Materials and Methods. Aliquots of washed adipose tissue were frozen directly at –20°C or mixed with cryoprotectants, frozen at 1°C/min, and subsequently stored in liquid nitrogen vapor phase. Aliquots were subsequently thawed, and adipocyte viability was determined by staining and culture methods. Results. Viability of adipocytes frozen at –20°C was very low when analyzed by staining, and no cultures could be established from any of the specimens. In contrast, viable adipocytes were recovered from samples that were controlled-rate frozen in the presence of cryoprotectants and stored in nitrogen vapor. Conclusion. Our results indicate that fat frozen at –20°C is not viable and thus provides no advantage over inert fillers. The methods here described could readily be transferred to the clinical setting after further laboratory study.

Abstract: Current practice of autologous fat transfer for soft tissue augmentation is limited by poor long-term graft retention. Adipose-derived regenerative cells (ADRCs) contain several types of stem and regenerative cells, which may help improve graft retention through multiple mechanisms. Using a murine fat transplantation model, ADRCs were added to transplanted fat to test whether ADRCs could improve the long-term retention of the grafts. This study showed, at both 6 and 9 months after transplantation, ADRCs not only increased graft retention by 2-fold but also improved the quality of the grafts. ADRC-supplemented grafts had a higher capillary density, indicating ADRCs could promote neovascularization. Further cell tracking and gene expression studies suggest ADRCs may promote angiogenesis and adipocyte differentiation and prevent apoptosis through the expression of various growth factors, including VEGFA and IGF-1. Taken together, these results suggest a potential clinical utility of ADRCs in facilitating autologous fat transfer for soft tissue augmentation.