Adipose-derived stem cell enrichment is counter-productive for the majority of women seeking primary aesthetic breast augmentation by autologous fat transfer: A systematic review

Background: Autologous lipotransfer (AL) is a popular method despite unpredictable retention rates. Higher retention rates have been reported when co-administering adipose-derived stem cells (ASCs), a process called cell-assisted lipotransfer (CAL). Our hypothesis is that CAL might indeed limit volume gain in most women seeking aesthetic breast augmentation because it doubles the amount of fat required without consistently improving the outcome. Methods: Electronic databases were searched for articles published between January 2008 and October 2019 in English and German. All original articles evaluating fat viability following autologous breast augmentation in vivo were included. Based on the reported retention rates, potential volume gains were estimated for CAL and AL. Results: A total of 23 studies were selected. The AL retention rate varied from 39% to 76%, whereas CAL increased this rate at best by 24%. The body mass index (BMI) ranged from 18.8 to 23.4 (20.4 +/- 1.6) in the study population, whereas the BMI of women in the same age group is 28.7 (+/- 8.4). We calculated that, starting from 200 ml of harvested fat and after two sessions of AL of 100 ml each, the volume retained would be at most 152 ml. In contrast, after one session of CAL of 100 ml, while the remaining 100 ml are used to isolate ASCs, a maximum of 95 ml of fat would remain. Conclusion: The volume gain after two sessions of AL is far superior to that after one session of CAL for the same volume of harvested fat. This is an important practical consideration for women with low BMI, as the extra fat required to isolate ASCs is not counterbalanced by an increase in the retention rate. Therefore, two sessions of AL may be preferable to maximize the volume gain. (C) 2020 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.