Fat Grafting With Expanded Adipose-Derived Stromal Cells for Breast Augmentation: A Randomized Controlled Trial.

BACKGROUND: The main challenge with fat grafting is loss of some of the graft to postsurgery resorption. Previous studies suggest that adipose-derived stromal cells (ASCs) can improve the volume retention of fat grafts but there is a lack of randomized trials to support the use of ASCs in clinical practice. OBJECTIVES: This trial aimed to investigate whether ASCs improve fat graft volume retention in patients undergoing breast augmentation with lipofilling. METHODS: This was a double-blind, randomized controlled trial of breast augmentation with ASC-enriched fat grafting. Healthy women aged 30 to 45 years were enrolled. First, the participants underwent liposuction to obtain fat for culture expansion of ASCs. Then, the participants were randomly assigned to undergo a 300- to 350-mL breast augmentation with ASC-enriched fat grafting (10 × 106 ASCs/mL fat graft) to 1 of their breasts and placebo-enriched fat grafting of identical volume to the contralateral breast. The primary outcome was fat graft volume retention after a 1-year follow-up measured with MRI. The trial is registered at www.clinicaltrialsregister.eu (EudraCT-2014-000510-59). RESULTS: Ten participants were included in the trial; all completed the treatment and follow-up. No serious adverse events occurred. Fat graft volume retention after 1 year was 54.0% (95% CI, 30.4%-77.6%) in the breasts treated with ASC-enriched fat grafting (n = 10) and 55.9% (95% CI, 28.9%-82.9%) in the contralateral breasts treated with placebo-enriched fat grafting (n = 10) (P = 0.566). CONCLUSIONS: The findings of this trial do not support that ASC-enriched fat grafting is superior to standard fat grafting for breast augmentation.

New Validated Method for Measuring Fat Graft Retention in the Breast with MRI.

In this study, we present a new method for measuring fat graft volume retention in the breast based on magnetic resonance imaging scans and a validation study to assess its accuracy and precision. The method was validated by 4 observers using the magnetic resonance imaging scans of 14 patients undergoing breast augmentation with fat grafting. The method was translated into software and was used to measure the change in breast volume from a preoperative scan to a postoperative scan recorded within 3 hours after the surgery, which was compared with the injected fat graft volume. The new method measured the injected fat graft volumes with an average systematic overestimation of 6.3% (SD, 10.5). The median interobserver variation was <7%. We propose that this new method can be a good alternative to previous techniques for clinical research purposes. The software can be made available upon request free of charge for use on the MeVisLab platform.

Cell-Enriched Fat Grafting Improves Graft Retention in a Porcine Model: A Dose-Response Study of Adipose-Derived Stem Cells versus Stromal Vascular Fraction.

BACKGROUND: Cell-enrichment of fat grafts has produced encouraging results, but the optimal concentrations and types of added cells are unknown. The authors investigated the effects of enrichment with various concentrations of ex vivo-expanded adipose-derived stem/stromal cells and stromal vascular fraction on graft retention in a porcine model. METHODS: Adipose-derived stem/stromal cells were culture-expanded, and six fat grafts (30 ml) were prepared for each minipig (n = 13). The authors investigated grafts enriched with 2.5 × 10 to 20 × 10 adipose-derived stem cells/ml and stromal vascular fraction and nonenriched control grafts. Each pig served as its own control. Magnetic resonance imaging was performed immediately after grafting and 120 days postoperatively before the pigs were euthanized, and histologic samples were collected. RESULTS: The authors recorded an enhanced relative graft retention rate of 41 percent in a pool of all cell-enriched grafts compared to the nonenriched control (13.0 percent versus 9.2 percent; p = 0.0045). A comparison of all individual groups showed significantly higher graft retention in the 10 × 10-adipose-derived stem/stromal cells per milliliter group compared with the control group (p = 0.022). No significant differences were observed between the cell-enriched groups (p = 0.66). All fat grafts showed a significantly better resemblance to normal fat tissue in the periphery than in the center (p < 0.009), but no differences in overall graft morphology were observed between groups (p > 0.17). CONCLUSIONS: Cell-enriched fat grafting improved graft retention and was feasible in this porcine model. No significant differences in graft retention were observed among the various adipose-derived stem/stromal cell concentrations or between adipose-derived stem/stromal cell and stromal vascular fraction enrichment. Future studies using this model can help improve understanding of the role of adipose-derived stem/stromal cells in cell-enriched fat grafting.

The current gold standard breast volumetry technique seems to overestimate fat graft volume retention in the breast: A validation study.

BACKGROUND: MRI is generally considered as the gold standard for measuring breast volume because of its high accuracy of the modality. Many techniques used to measure total breast volume have been validated, but none of these techniques have been validated for their ability to measure the volume retention of fat grafts in the breast. In this study, the authors investigated the accuracy of the most common MRI technique used to measure fat graft retention in the breast by measuring the volume changes after breast augmentation. METHODS: Patients undergoing breast augmentation with either breast implants or fat grafting underwent MRI scans before and after surgery. Blinded observers measured the change in breast volume from the MRI scans. The difference between the measured change in breast volume and the volume of the breast augmentation was used to determine the accuracy of the MRI technique. RESULTS: Twenty-eight patients with a total of 56 breasts were included. In total, 168 measurements of change in breast volume were performed by the observers. The MRI measurements of change in breast volume overestimated the true volumes of the breast augmentations by an average of 50.8%, and only 8 of the 168 individual measurements had measurement errors below 50 mL. CONCLUSION: The MRI technique, which is considered as the gold standard for the quantification of fat graft volume retention, was associated with a significant measurement error. These findings have potential implications for the interpretation of previously published results of studies based on this technique.

A Novel Porcine Model for Future Studies of Cell-enriched Fat Grafting.

BACKGROUND: Cell-enriched fat grafting has shown promising results for improving graft survival, although many questions remain unanswered. A large animal model is crucial for bridging the gap between rodent studies and human trials. We present a step-by-step approach in using the Göttingen minipig as a model for future studies of cell-enriched large volume fat grafting. METHODS: Fat grafting was performed as bolus injections and structural fat grafting. Graft retention was assessed by magnetic resonance imaging after 120 days. The stromal vascular fraction (SVF) was isolated from excised fat and liposuctioned fat from different anatomical sites and analyzed. Porcine adipose-derived stem/stromal cells (ASCs) were cultured in different growth supplements, and population doubling time, maximum cell yield, expression of surface markers, and differentiation potential were investigated. RESULTS: Structural fat grafting in the breast and subcutaneous bolus grafting in the abdomen revealed average graft retention of 53.55% and 15.28%, respectively, which are similar to human reports. Liposuction yielded fewer SVF cells than fat excision, and abdominal fat had the most SVF cells/g fat with SVF yields similar to humans. Additionally, we demonstrated that porcine ASCs can be readily isolated and expanded in culture in allogeneic porcine platelet lysate and fetal bovine serum and that the use of 10% porcine platelet lysate or 20% fetal bovine serum resulted in population doubling time, maximum cell yield, surface marker profile, and trilineage differentiation that were comparable with humans. CONCLUSIONS: The Göttingen minipig is a feasible and cost-effective, large animal model for future translational studies of cell-enriched fat grafting.