Retention Rate Of Fat Grafts Research Articles

Adipose stem cells regulate lipid metabolism by upregulating mitochondrial fatty acid β-oxidation in macrophages to improve the retention rate of transplanted fat

BackgroundAt present, fat transplantation is widely used in the plastic surgery industry, but the long-term preservation rate of transplanted fat decreases because of complications such as oil cysts due to the inability in macrophages to metabolize absorption. In cell-assisted lipotransfer technology, adipose-derived stem cells (ASCs) can influence the inflammatory response of grafts through the immunoregulation in macrophages, and the lipid metabolism in macrophages plays an important role in this process. Therefore, we hypothesized ASCs could improve the retention rate of fat grafts by regulating the progress of lipid metabolism in macrophages.MethodsWe established fat transplantation and ASC-assisted fat transplantation model in C57BL/6 mice in vivo, and bone marrow-derived macrophages cocultured with apoptotic adipocytes were treated with or without ASCs in vitro. Graft retention, tissue structure, fibrosis, macrophage phenotype transformation, lipid deposition, mitochondrial morphology, oxygen consumption rate (OCR), fatty acid β-oxidation (FAO) level, and ATP production were assessed. Additionally, fat transplantation and ASC-assisted fat transplantation model was treated with etomoxir which inhibits mitochondrial FAO. Macrophages pretreated with etomoxir were co-cultured with apoptotic adipocytes and treated with or without ASCs. The method aboved was used for detection and verification.ResultsIn vivo, ASC-assisted fat transplantation improved macrophage mitochondrial expression and FAO level, promoted the early transformation of M2 macrophages, reduced the long-term lipid deposition of macrophages, and improved the retention rate of fat grafts. In vitro, ASCs up-regulated the level of mitochondrial FAO, OCR and ATP production in macrophages, reduced lipid deposition of macrophages and promoted M2 macrophages polarization by paracine function. The ability of ASCs in group pretreated with etomoxir to reduce the foaming of macrophages, promote the transformation to M2 macrophages, and improve the retention rate of fat transplantation was weakened.ConclusionsASCs increased the retention rate of transplanted fat by upregulating mitochondrial FAO to promote M2 polaration in macrophages. In addition, ASCs up-regulate mitochondrial FAO by paracrine effect to reduce foam cells formation and promote M2 transformation in macrophages in vitro.

Adenosine washing improves the retention rate of fat grafts under conditions of obesity

Background Fat grafting is a commonly employed aesthetic procedure for contour enhancement. However, outcome prediction is challenging due to the complex regeneration and remodeling processes involved. We investigated whether adenosine improves engraftment and fat graft survival under conditions of obesity.Methods Fat was harvested from mice fed a high-fat diet. This fat was washed with either Krebs-Ringer bicarbonate HEPES buffer (the vehicle group) or a buffer containing 500 nM adenosine (the adenosine wash group). Subsequently, the fat was transplanted into normal mice at 0.2 mL per mouse. In both groups, 50% of the mice were sacrificed at 1 week and the remainder at 4 weeks post-transplantation. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis was conducted during week 1. In week 4, micro-computed tomography, immunofluorescence staining, and RT-qPCR were performed. A sample of the initially harvested fat was set aside for lipolysis assay.Results Adenosine washing improved fat graft retention volumes by up to 50%. One week post-transplantation, the expression of adipogenic and angiogenic genes was found to be upregulated in the adenosine wash group. After 4 weeks, immunofluorescence staining revealed greater adipocyte integrity and an increased number of vessels. Furthermore, adenosine appeared to modulate inflammation by stabilizing the lipolysis rate.Conclusions Adenosine washing increased the fat graft survival rate under conditions of obesity. Clinically, this suggests a simple, cost-effective adjuvant method for improving fat graft survival in individuals with obesity. Further research is warranted to elucidate the underlying mechanisms and explore the applicability of this technique for autologous transplantation.

Tracking Fat Grafts by Magnetic Resonance Imaging: A Comparative Study of Adolescent and Adult Patients with Stable Localized Scleroderma.

The optimal timing of reconstruction for patients with facial localized scleroderma is uncertain. The purpose of this study was to compare the outcomes of autologous fat transplantation in adolescent and adult patients with stable localized scleroderma. Adolescent (age 10-19 years) and adult (age >19 years) patients with no previous surgery were enrolled (n = 10, each group). Preoperative magnetic resonance imaging (MRI), blood tests and dermatological assessments were used for disease activity assessment. All patients underwent autologous fat transplantation for anatomic facial fat restoration with preoperative MRI planning. Preoperative, immediate and one-year postoperative 3D Dixon MRI scans with image registration and fusion techniques were used for fat graft tracking. Patient satisfaction was assessed with a 5-point Likert scale. There was no significant difference in sex, body mass index, disease severity, or volume of injected fat between the two groups (p > 0.05), except for age (p < 0.05). The one-year postoperative fat graft retention rate was not significantly different, with 36.6 ± 2.4% (ranging from 25.3 to 49.3%) in the adolescent group and 32.9 ± 1.7% (ranging from 27.3 to 40.1%) in the adult group (p > 0.05). Surgical outcomes were favorable in all patients, with satisfaction scores of 3.8 ± 0.2 points in the adolescent group and 3.6 ± 0.2 points in the adult group (p > 0.05). In stable localized scleroderma, the initial autologous fat transplantation was equally effective for facial contour deformity improvement, with no significant difference in fat graft retention or satisfaction.

Brown Adipose Tissue Promotes Autologous Fat Grafts Retention Possibly Through Inhibiting Wnt/β-Catenin Pathway.

In plastic surgery, autologous fat grafts (AFG) play an important role because of their abundant supply, biocompatibility, and low rejection rate. However, the lower retention rate of fat grafts limits their widespread use. Brown adipose tissue (BAT) can promote angiogenesis and regulate the level of associated inflammation. This study explored whether BAT has a facilitative effect on fat graft retention. We obtained white adipose tissue (WAT) from c57 mice and combined it with either BAT from c57 mice or phosphate-buffered saline (PBS) as a control. These mixtures were injected subcutaneously into the back of thymus-free nude mice. After 12 weeks, fat grafts were harvested, weighed, and analyzed. We found that the BAT-grafted group had higher mass retention, more mature adipocytes, and higher vascularity than the other group. Further analysis revealed that BAT inhibited M1 macrophages; down-regulated IL-6, IL-1β, and TNF-β; upregulated M2 macrophages and Vascular endothelial growth factor-A (VEGFA); and promoted adipocyte regeneration by inhibiting the Wnt/β-catenin pathway, which together promoted adipose graft retention. The study demonstrated that BAT improved adipose graft retention by promoting angiogenesis, inhibiting tissue inflammation levels and the Wnt/β-catenin pathway. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Physical Expansion Preconditioning Promotes Host-Derived Adipocyte Dedifferentiation and Migration into Fat Grafts in a Murine Model.

The unstable recipient conditions after fat grafting remain an obstacle for tissue volumization. The interaction between fat grafts and recipient sites is not fully understood. The authors hypothesize that recipient-derived adipocytes undergo dedifferentiation and migrate into fat grafts in tissue regeneration. To observe the participation from recipient fat pad, the authors established a recipient adipocyte-tracing model where 0.2 mL of inguinal fat from 10 8-week-old C57BL/6 mice was grafted to 10 tamoxifen-treated AdipoqCre;mT/mG mice. Next, to evaluate the impact of physical force on recipient fat and fat graft, a murine internal expansion model was established by implanting a 1-mL internal expander on the inguinal fat pad of the lineage tracing mice that received fat graft from C57BL/6 mice. Transplanted adipose tissue was collected and analyzed by immunostaining of green fluorescent protein (GFP), tdTomato, perilipin, and CD31. In the observing model, immunostaining revealed that both GFP+ and tdTomato + cells from the recipient fat pad presented in fat grafts. Among the GFP + cells, most of them were perilipin + adipocytes and other perilipin - cells co-expressed octamer-binding transcription factor 4, indicating dedifferentiated adipocytes. In the internal expansion model, internal expansion increased GFP + cells in fat graft. Both octamer-binding transcription factor 4-positive/GFP + (0.23 ± 0.01 versus 0.12 ± 0.04) and perilipin + /GFP + (0.17 ± 0.02 versus 0.06 ± 0.01) cells were increased in the expanded group, compared with control. Host-derived adipocytes participate in fat graft regeneration through migration and dedifferentiation, which could be enhanced by internal expansion to increase fat graft retention rate. Further study using a larger animal model is needed, because this is a murine study. Surgeons are encouraged to use physical expansion preconditioning of the recipient site. Subsequent and multiple fat grafting into the fat layer is encouraged to obtain satisfactory soft-tissue volumization.

Effects of Melatonin on Fat Graft Retention Through Browning of Adipose Tissue and Alternative Macrophage Polarization.

Melatonin is a widely used drug that can affect adipocyte inflammation, resulting in adipose tissue browning. Inducing the browning of white fat and changing the inflammatory microenvironment of early transplanted fat have positive effects on the retention rate of fat grafts. This study aimed to evaluate the effects of melatonin on fat graft retention, determine whether it is related to adipose tissue browning and the inflammatory microenvironment, and explore the underlying mechanisms. A C57BL/6 mice fat transplantation model was established. The mice were divided into a control group (ethanol), a high-dose group (40 mg/kg/day melatonin), a medium-dose group (20 mg/kg/day melatonin), and a low-dose group (10 mg/kg/day melatonin). They were also given oral gavage treatment for 2 weeks. The grafted fat was collected 2, 4, and 12 weeks after treatment. The medium-dose and high-dose melatonin groups had significantly higher fat graft retention rates than the control group at 12 weeks. The medium-dose melatonin group had smaller multilocular adipocytes, which enhanced the expression of uncoupling protein 1 and increased neovascularization in the grafted fat. The medium-dose group also had a higher distribution of M2 macrophages. These findings suggest that melatonin administration can improve the retention of fat grafts through polarization of macrophages toward the anti-inflammatory type and induction of adipose tissue browning. This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

A Preliminary Exploratory Study of Autologous Fat Transplantation in Breast Augmentation With Different Fat Transplantation Planes.

BackgroundAutologous fat transfer is common in breast augmentationor reconstruction. However, AFG recipient site in the breast for fat grafting has not been carefully investigated.MethodsForty female patients requiring breast augmentation with fat grafting were randomly assigned into two groups. The retromammary group received 2/3 fat into the retromammary space and the other 1/3 into the subcutaneous and retropectoral planes. The retropectoral group received 2/3 fat into the retropectoral plane and the other 1/3 into the subcutaneous and retromammary planes. The fat grafting result at 6 months was assessed by 3D laser surface scanning and then ultrasound. Any complications were recorded during follow-up. Samples from a patient who underwent fat grafting for 6 months was obtained and histological examination was conducted.ResultsNo significant difference in the retention rate after 6 months was observed between the two groups (retromammary group: 35.9% ± 6.6; retropectoral group: 39.3% ± 5.1, p = 0.1076). The retromammary grouphad a higher incidence of oil cyst formation than the retropectoral group. Histological examination showed that there were more oil cysts and mac2 positive macrophage infiltration in the fat cells in retromammary group, while retropectoral group had more small-size adipocytes.ConclusionAlthough fat grafting into the retropectoral plane did not provide a superior fat graft retention rate, it did lower the incidence of complications. The retropectoral space show great potential to become a favorable recipient site.

Alternatively activated macrophages at the recipient site improve fat graft retention by promoting angiogenesis and adipogenesis.

The inflammatory response mediated by macrophages plays a role in tissue repair. Macrophages preferentially infiltrate the donor site and subsequently, infiltrate the recipient site after fat grafting. This study aimed to trace host‐derived macrophages and to evaluate the effects of macrophage infiltration at the recipient site during the early stage on long‐term fat graft retention. In our novel mouse model, all mice underwent simulated liposuction and were divided into 2 groups. The fat procurement plus grafting (Pro‐Grafting) group was engrafted with prepared fat (0.3 ml). The pro‐Grafting+M2 group was engrafted with prepared fat (0.3 ml) mixed with 1.0 × 106 GFP+M0 macrophages, and then, 2 ng IL‐4 was injected into the grafts on Day 3. In addition, 1.0 × 106 GFP+M0 macrophages were injected into the tail vein for tracing in the Pro‐Grafting group. As a result, GFP+macrophages first infiltrated the donor site and subsequently infiltrated the recipient site in the Pro‐Grafting group. The long‐term retention rate was higher in the Pro‐Grafting+M2 group (52% ± 6.5%) than in the Pro‐Grafting group (40% ± 3.5%). CD34+ and CD31+ areas were observed earlier, and expression of the adipogenic proteins PPAR‐γ, C/EBP and AP2 was higher in the Pro‐Grafting+M2 group than in the Pro‐Grafting group. The host macrophages preferentially infiltrate the donor site, and then, infiltrate the recipient site after fat grafting. At the early stage, an increase in macrophages at the recipient site may promote vascularization and regeneration, and thereby improve the fat graft retention rate.

Bone marrow mesenchymal stem cells enhance angiogenesis and promote fat retention in fat grafting via polarized macrophages

BackgroundFat grafting is one of the most common soft tissue filling methods in plastic surgery. Bone marrow mesenchymal stem cell (BM-MSC) transplantation is an effective method for improving graft retention. However, the role of BM-MSCs in fat transplantation is not completely clear.MethodsHuman fat particles, together with BM-MSCs or PBS as a control, were subcutaneously transplanted into the backs of nude mice. Samples were taken on days 14, 30 and 90 post-grafting to calculate the fat graft retention rate, and tissue staining was evaluated. Furthermore, macrophages were treated with BM-MSC conditioned medium (BM-MSC-CM) to identify the beneficial component secreted by these stem cells.ResultsIn this study, we found that BM-MSCs improved retention by enhancing angiogenesis in fat grafting. Further analysis revealed that BM-MSCs could significantly inhibit the expression of the proinflammatory M1 macrophage markers interleukin (IL)-1β, tumor necrosis factor-α (TNF-α) and IL-6 in the early stages of fat grafting and promote the expression of the anti-inflammatory M2 macrophage markers Arg1, IL-10 and VEGF. Furthermore, our results showed that IL-10 secreted by BM-MSCs induced M2 macrophage polarization in vitro.ConclusionsBM-MSC transplantation can improve the fat retention rate and promote angiogenesis, which may be related to M2 macrophages. These results help elucidate the role of BM-MSCs in fat grafting.

A Novel Fat Making Strategy With Adipose-Derived Progenitor Cell-Enriched Fat Improves Fat Graft Survival.

A low survival rate is one of the main challenges in fat grafting. This study aimed to evaluate whether microfat obtained by a novel strategy promoted the survival and retention of fat grafts. A 5-mm-diameter blunt tip cannula with large side holes (~30 mm2/hole) was used to obtain macrofat. A novel strategy based on a newly invented extracorporeal cutting device was then used to cut the macrofat into microfat, which was named adipose-derived progenitor cell enrichment fat (AER fat); Coleman fat was used as the control. Aliquots (0.5 mL) of both types of fat were transplanted into 10 nude mice and analyzed 10 weeks later. Western blotting, flow cytometry, and immunofluorescence were performed to assess the AER fat characteristics and underlying mechanisms. The retention rate of fat grafts in AER fat-treated animals was significantly higher than that in the Coleman group (mean [standard deviation] 54.6% [13%] vs 34.8% [9%]; P < 0.05) after 10 weeks. AER fat contained more dipeptidyl peptidase-4-expressing progenitor cells (3.3 [0.61] × 103 vs 2.0 [0.46] × 103 cells/mL; P < 0.05), adipose-derived plastic-adherent cells (6.0 [1.10] × 104 vs 2.6 [0.17] × 104 cells/mL; P < 0.001), and viable adipocytes than Coleman fat. Moreover, histologic analysis showed that AER fat grafts had better histologic structure and higher capillary density. AER fat transplantation is a potential strategy to improve the survival and long-term retention of fat grafts. AER fat contained more dipeptidyl peptidase-4-expressing progenitor cells.

A Systematic Review on Extracellular Vesicles-Enriched Fat Grafting: A Shifting Paradigm.

Recent evidence confirms that mesenchymal stem cells (MSCs) facilitate angiogenesis mainly through paracrine function. Extracellular vesicles (EVs) are regarded as key components of the cell secretome, possessing functional properties of their source cells. Subsequently, MSC-EVs have emerged as a novel cell-free approach to improve fat graft retention rate. The authors sought to provide a systematic review of all studies reporting the utilization of MSC-EVs to improve graft retention rate. A systematic search was undertaken employing the Embase, PubMed, and Cochrane Central Register of Controlled Trials databases. Outcome measures included donor/receptor organism of the fat graft, study model, intervention groups, evaluation intervals, EV research data, and in vitro and in vivo results. Of the total 1717 articles, 62 full texts were screened. Seven studies reporting on 294 mice were included. Overall, EV-treated groups showed higher graft retention rates compared with untreated groups. Notably, retention rate was similar following EV and MSC treatment. In addition to reduced inflammation, graft enrichment with EVs resulted in early revascularization and better graft integrity. Interestingly, hypoxic preconditioning of MSCs improved their beneficial paracrine effects and led to a more proangiogenic EV population, as observed by both in vitro and in vivo results. MSC-EVs appear to offer an interesting cell-free alternative to improve fat graft survival. Although their clinical relevance remains to be determined, it is clear that not the cells but rather their secretome is essential for graft survival. Thus, a paradigm shift from cell-assisted lipotransfer towards "secretome-assisted lipotransfer" is well on its way.

A Prospective Study of the Efficacy of Cell-Assisted Lipotransfer with Stromal Vascular Fraction to Correct Contour Deformities of the Autologous Reconstructed Breast.

Autologous lipotransfer has increasingly become popular for breast reconstruction. Moreover, owing to the emergence of information regarding the efficacy of stromal vascular fraction (SVF) in terms of oncological safety and survival rate, procedures based on cell-assisted lipotransfer (CAL) have been widely employed recently. However, quantitative data of CAL with SVF are lacking. We evaluated the efficacy of CAL using SVF on survival rate in breast reconstruction. A 12-month prospective study was conducted for 20 patients (20 breasts) requiring breast asymmetry correction due to volume deficit following autologous breast reconstruction using a transverse rectus abdominis myocutaneous flap or latissimus dorsi flap after total mastectomy. After the patients were equally divided into two groups-fat graft with SVF (Group 1, n = 10) and without SVF (Group 2, n = 10)-, the variance of breast volume was measured using three-dimensional scanning to analyze fat graft retention rate. Moreover, patient satisfaction and complications were investigated. Fat graft retention rate was higher in Group 1 than in Group 2 at both postoperative 6months (73.8% vs. 62.2%; p = 0.03) and 12months (65.4% vs. 48.4%; p = 0.03). Group 1 showed higher patient satisfaction. Regarding complications, fat necrosis occurred in 1 patient each in both groups. However, locoregional recurrence was not observed in any patient during follow-up. CAL with SVF is effective in increasing survival rates of autologous fat grafts for correction of volume deficit after breast reconstruction. Moreover, it is associated with improved patient satisfaction in terms of the esthetic aspect. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Mechanical Signals Induce Dedifferentiation of Mature Adipocytes and Increase the Retention Rate of Fat Grafts.

Mature adipocytes dedifferentiate in vivo on application of a soft-tissue expander. Dedifferentiated adipocytes can proliferate and redifferentiate. This study used tissue expanders to pretreat adipose flaps, to increase the retention rate after fat graft. A soft-tissue expander and silicone sheet were implanted beneath the left and right inguinal fat pads of rats, respectively. After 7 days of expansion, the adipose tissue derived from the pads was transplanted beneath dorsal skin. Samples were harvested at various time points, and histologic, immunohistochemical, and gene expression analyses were conducted. Mature adipocytes were cultured in vitro under a pressure of 520 Pa. Changes in cell morphology, the cytoskeleton, and expression of mechanical signal-related proteins were investigated. Pressure in adipose flaps increased to 25 kPa on expansion. Mature adipocytes dedifferentiated following expansion. At 1 week after transplantation, the expression of vascular endothelial growth factor (p < 0.05) was higher in the expanded group. The retention rate at 12 weeks after transplantation was higher in the expanded group (56 ± 3 percent) than in the control group (32 ± 3 percent) (p < 0.05), and the surviving/regenerating zones (p < 0.01) were wider. The lipid content of mature adipocytes gradually decreased on culture under increased pressure, and these cells regained a proliferative capacity. This was accompanied by increased expression of mechanical signal--related proteins (p < 0.05). Mechanical signals may induce dedifferentiation of mature adipocytes. Dedifferentiated adipocytes increase the retention rate of fat grafts by acting as seed cells.

Discussion: Mechanical Signals Induce Dedifferentiation of Mature Adipocytes and Increase the Retention Rate of Fat Grafts.

Discussion: Mechanical Signals Induce Dedifferentiation of Mature Adipocytes and Increase the Retention Rate of Fat Grafts.

Discussion: Mechanical Signals Induce Dedifferentiation of Mature Adipocytes and Increase the Retention Rate of Fat Grafts.

Discussion: Mechanical Signals Induce Dedifferentiation of Mature Adipocytes and Increase the Retention Rate of Fat Grafts.

Commentary on: Improving the Retention Rate of Fat Grafts in Recipient Areas via Botulinum Toxin A Treatment.

Commentary on: Improving the Retention Rate of Fat Grafts in Recipient Areas via Botulinum Toxin A Treatment.

Predictors of Autologous Free Fat Graft Retention in the Management of Craniofacial Contour Deformities.

Autologous free fat graft outcomes are not always predictable, and variables that can potentially influence fat graft retention are still not well understood or investigated. The purposes of this study were to assess fat graft retention in the management of craniofacial contour deformities and to identify possible predictive factors of this retention. A prospective analysis was conducted using consecutive patients with unilateral craniofacial contour deformities who underwent autologous free fat grafting between 2012 and 2015. Standardized ultrasonographic craniofacial soft-tissue thickness measurements were adopted to determine the fat graft retention. Bivariate and multivariate analyses were performed to identify independent predictors of 12-month postoperative fat graft retention. One hundred forty-two patients were enrolled. There was significant (all p < 0.05) and progressive reduction in fat graft retention within the first 3 postoperative months, and the retained fat graft was maintained (all p > 0.05) from 3 to 12 months postoperatively, with a 12-month fat graft retention rate of 67.7 percent. Age, Parry-Romberg syndrome, previous craniofacial bone surgery, grafted volume, and forehead unit were independently negative (all p < 0.05) predictors of fat graft retention, whereas cheek unit was an independently positive (all p < 0.05) predictor of retention. Craniofacial fat graft retention is achievable but remains somewhat unpredictable, with age, Parry-Romberg syndrome, previous bone surgical intervention, grafted volume, and recipient sites affecting retention. Risk, III.

Minimal Invasive Rhinoplasty: Fat Injection for Nasal Dorsum Contouring.

To determine the graft retention rate of fat injection rhinoplasty in the nasal dorsum region using 3dMD System. Thirteen consecutive patients (12 women and 1 man) treated by the corresponding author (F.C.S.C.) between April of 2014 and December of 2015 for autologous fat injection rhinoplasty at the nasal dorsum region to improve facial esthetics were included in this study. Preoperative and postoperative 3-dimensional (3-D) photography images taken 3 months after fat injection rhinoplasty were superimposed at the level of forehead to measure the volume changes at the nasal dorsum region. The same evaluator repeated the measurements 1 week after the initial measurements. Pearson correlation test was used to determine the intraobserver correlation. Twenty-six scans from 13 patients were analyzed. The amount of fat injected for nasal dorsum augmentation was 1.67 ± 0.95 mL (range, 0.6-3.3 mL). The volume changes calculated using the 3dMD system was 0.74 ± 0.42 mL for the first measurements and 0.74 ± 0.43 mL for the second measurements. The Intraobserver consistency was high with Cronbach α = 0.96 (P < 0.001). The mean volume change according to 3-D photography was 0.74 ± 0.42 mL (range, 0.21-1.53 mL). The mean retention rate was 44.54% (range, 21-74%). In this pilot study, we reported the fat graft retention rate for nasal dorsum augmentation using 3-D photography. Future studies with a larger sample size, longer-term follow-up, and different anatomical regions will be beneficial to better understand the long-term fat graft retention rate.