Autologous fat transplantation: volumetric tools for estimation of volume survival. A systematic review

A Machine Learning-Based Model for Breast Volume Prediction Using Preoperative Anthropometric Measurements

BACKGROUND

Accurate assessment of breast volume is helpful in preoperative planning and intraoperative judgment in both cosmetic and reconstructive breast surgery. In this prospective study, a formula was derived using machine learning algorithm (Gradient Boosted Model).

METHOD

A prospective study was performed on 39 female-to-male transgender patients. Bilateral mastectomy was done for all patients. Preoperative anthropometric measurements were performed on 78 breasts of these patients. Weight of breasts was calculated postoperatively with digital scale (weight), and then volume of breasts was calculated with the calibrated container (water displacement technique). Authors built a model based on Python CatBoostClassifier. Finally, an android application was built for ease of real-time utilization.

RESULTS

Eight anthropometric measurements were collected preoperatively as independent variables. Breast vertical perimeter at lower half, upper pole, sternal notch to nipple and nipple to IMF had most correlation with volume and weight. Based on machine learning model, the following formula established: Breast volume = (breast width) × 24.69 + (nipple to IMF) × 49.03 - (sternal notch to nipple) × 1.34 + (anterior axillary line to medial border) × 6.57 - (upper pole) × 1.27 - (chest perimeter IMF) × 5.63 + (chest perimeter nipple) × 10.40 + (breast vertical perimeter at lower half) × 9.20 - 1133.74. The R2 of the model is 0.93, and RMSE is 62.4.

CONCLUSION

Our formula is an accurate method for preoperative breast volume assessment. We built an android App (Breast Volume Predictor) for the real-time utilization of resulting formula. It is available at Google Play Store for free download.

LEVEL OF EVIDENCE IV

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 .

Volume retention rate after breast autogenous fat grafting and related influencing factors: A systematic review and meta-analysis

The volume retention of breast autologous fat grafting is unpredictable, and the volume retention rate and related influencing factors have not been systematically reviewed. Therefore, this systematic review and meta-analysis aimed at evaluating the volume retention rate and related influencing factors of breast autologous fat grafting, which is for reconstructive or esthetic purposes. Literature search was conducted using the PubMed, Embase, Cochrane Library, and Web of Science databases from inception of study to December 2022. Sensitivity analysis was performed for all outcomes. Begg's test was performed to test publication bias. Subgroup analysis was performed based on population, method of fat preparation, method of volume measurement, number of fat grafting, and injected fat grafting volume. A total of 25 studies were included in this systematic review and meta-analysis. The follow-up time ranged from 3 to 36 months. Results showed that the pooled volume retention rate at the latest follow-up point was 54% [95% confidence interval (CI): 48.5%-59.5%]. Based on the fat preparation methods, the pooled rate was 51.5% (95%CI: 41.5%-61.5%) for centrifugation, which was higher than that for sedimentation [38.7% (95%CI: 30.9%-46.5%)]. In addition, the enrichment of stromal vascular fraction obtained after centrifugation was found to be associated with higher volume retention rate (weighted mean difference: 17.36, 95%CI: 8.84-25.87). Our findings may provide guidance for evaluating the volume retention rate of breast autologous fat grafting in clinical settings. Further studies are needed to verify our findings.

A Scoping Review: Autologous Fat Grafting to Improve Volume and Aesthetics of Cleft Lip Deformity

A frequent problem following cleft lip repair is insufficient lip volume and unappealing aesthetics. Autologous fat grafting is a method of improving the appearance of post-correction deformity. The aim of this review is to evaluate the effectiveness of autologous fat grafting in improving the aesthetics of cleft lip deformity. The benefits of adipose-derived stem cells (ADSCs), benefits and complications of fat grafting, timing of grafting, and harvest and transplant techniques will be examined. This review process used "PubMed" and "Google Scholar" as primary databases. Searches were performed using combinations of key terms: "Fat Graft," "Cleft Lip," "Vermillion," "Autologous Fat Transplantation," and "Adipocyte Derived Stem Cell." Reviews of reference lists for additional pertinent data were performed. Autologous fat grafting may be performed during primary repair or as a secondary correction. Statistically significant improvements in appearance were observed in some or all measured variables regardless of repair timing. Both timing options show favorable outcomes; however, there is more evidence in support of grafting as a secondary correction. Some degree of graft reabsorption will occur, lending evidence to the practice of overcorrecting to accommodate losses. Graft retention is stabilized by the 12-month mark. The presence of ADSCs within the graft aids in graft stabilization and retention. Despite a lack of longitudinal data to examine graft retention throughout a patient's lifetime, autologous fat grafting appears to be a safe and minimally invasive method of repairing deformity secondary to cleft lip repair supported by follow-up data as far as two years postoperatively with minimal reported complications.

Streamlining the Fat: A Systematic Review of Active Closed Wash and Filtration in Autologous Fat Grafting After Breast Reconstruction

Although fat grafting in breast reconstruction continues to grow in popularity, the optimal technique remains elusive and outcomes are varied. This systematic review of available controlled studies utilizing active closed wash and filtration (ACWF) systems sought to examine differences in fat processing efficiency, aesthetic outcomes, and revision rates. A literature search was performed from inception to February 2022 following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) in Ovid MEDLINE (Wolters Kluwer, Alphen aan den Rijn, the Netherlands), Ovid Embase (Wolters Kluwer), and Cochrane Library (Wiley, Hoboken, NJ). Two independent reviewers screened the studies for eligibility with Covidence software. Bibliographies and citing references from selected articles were screened from Scopus (Elsevier, Amsterdam, the Netherlands). The search identified 3476 citations, with 6 studies included. Three studies demonstrated a significantly higher volume of graftable fat harvested in a significantly lower mean grafting time with ACWF than with their respective controls. With respect to adverse events, 3 studies reported significantly lower incidences of nodule or cyst formation with ACWF with respect to control. Two studies reported a significantly lower incidence of fat necrosis with ACWF vs control, with this trend upheld in 2 additional studies. Three studies reported significantly lower revision rates with ACWF with respect to control. No study reported inferiority with ACWF for any outcome of interest. These data suggest that ACWF systems yield higher fat volumes in less time than other common techniques, with decreased rates of suboptimal outcomes and revisions, thereby supporting active filtration as a safe and efficacious means of fat processing that may reduce operative times. Further large-scale, randomized trials are needed to definitively demonstrate the above trends.

LEVEL OF EVIDENCE: 4

Exosomes Derived from Human Adipose-Derived Stem Cells Cannot Distinctively Promote Graft Survival in Cryopreservation Fat Grafting

BACKGROUND

Cryopreserved fat has limited clinical applications due to its rapid absorption, high degree of fibrosis, and risk of complications after grafting. Many studies have verified that Adipose-derived mesenchymal stem cell-derived exosomes (ADSC-Exos) can improve fresh fat graft survival. This study assessed whether ADSC-Exos could improve the survival of cryopreserved fat grafts.

METHODS

Exosomes were isolated from human ADSCs were subcutaneously engrafted with adipose tissues stored under different conditions (fresh; cryopreserved for 1 month) into the backs of BALB/c nude mice (n = 24), and exosomes or PBS were administered weekly. Grafts were harvested at 1, 2, 4, and 8 weeks, and fat retention rate, histologic, and immunohistochemical analyses were conducted.

RESULTS

At 1, 2, and 4 weeks after the transfer, cryopreserved fat grafts in groups of exosome-treated showed better fat integrity, fewer oil cysts, and reduced fibrosis. Further investigations of macrophage infiltration and neovascularization revealed that those exosomes increased the number of M2 macrophages at 2 and 4 weeks (p<0.05), but had limited impact on vascularization (p>0.05). It's important to note that no significant differences (p>0.05) were observed between the two groups in both histological and immunohistochemical evaluations at 8 weeks post-transplantation.

CONCLUSIONS

This study suggests that ADSC-Exos could improve the survival of cryopreserved fat grafts in the short term (within 4 weeks), but the overall improvement was poor (after 8 weeks). This suggests that the utility of using ADSC-Exos to treat cryopreserved adipose tissue grafts is limited.

NO LEVEL ASSIGNED

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 .

Total Breast Reconstruction with Lipofilling after Traditional Mastectomy without the Use of Tissue Expanders

BACKGROUND

Lipofilling can be used to reconstruct a breast without additional implants or autologous composite grafts. However, methods to maximize retention of the transferred fat remain under debate. Here, the authors present their experience of breast reconstruction with lipofilling without concomitant use of tissue expanders.

METHODS

Patients who had completed breast reconstruction with lipofilling between June of 2010 and June of 2016 were reviewed. Those with obtainable follow-up magnetic resonance imaging scans were included in this cross-sectional study. The hospital records were reviewed for details of the lipofilling operations. Magnetic resonance imaging scans were evaluated for the volume retention and quality of the transferred fat. The patients were asked to assess the appearance and sensitivity of the reconstructed breast, the recovery time, and any adverse effects at the fat donor area.

RESULTS

Thirty-eight women with 41 reconstructed breasts were included in the study. The median age at follow-up was 62 years (range, 48 to 78 years). They had undergone a median of four (range, two to six) lipofilling procedures with a median total volume 690 mL (range, 369 to 1350 mL). After a median follow-up of 2.1 years (range, 0.4 to 6.8 years), the median proportion of transferred fat retained was 58% (range, 14% to 119%), representing a reconstructed breast volume of 76% (range, 17% to 100%) of the contralateral breast. Oil cysts larger than 10 mm were detected in 7%. Most patients reported being satisfied with the reconstructed breast and experienced few side effects.

CONCLUSIONS

Breast reconstruction with lipofilling can be performed with an acceptable number of procedures and no preoperative skin expansion. It extends the option of autologous breast reconstruction to women unsuited for major reconstructive procedures.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Progress and obstacles in transplantation of brown adipose tissue or engineered cells with thermogenic potential for metabolic benefits

Transplantation of brown adipose tissue (BAT), engineered thermogenic progenitor cells, and adipocytes have received much attention for the improvement of obesity and metabolic disorders. However, even though the thermogenic and metabolic potential exists early after transplantation, the whitening of the brown fat graft occurs with metabolic function significantly impaired. In this review, specific experiment designs, graft outcomes, and metabolic benefits for the transplantation of BAT or engineered cells will be discussed. The current advancements will offer guidance to further investigation, and the obstacles appearing in previous studies will require innovation of BAT transplantation methods.

Challenges in developing a quantitative method of measuring breast development using 3D imaging: An example of a novel method for use in induced breast development with exogenous oestrogen

OBJECTIVE

Optimal breast development is an essential part of exogenous oestrogen treatment in females undergoing pubertal induction. We set out to develop a novel technique using three-dimensional (3D) imaging to determine change in breast volume that is applicable when no pre-existing breast contours are present.

DESIGN

A prospective observational study.

PATIENTS

The imaging methodology was developed using a single male subject to assess reproducibility and validity. The technique was then applied to 29 participants undergoing pubertal induction with exogenous oestradiol who were recruited from Paediatric Gynaecology and Reproductive Endocrinology clinics at University College London Hospital.

MEASUREMENTS

Breast images were taken using a 3D photographic system. Two images, taken at different times, were manually superimposed to produce a differential breast volume. The initial step of method development set out to show that volume change was not secondary to positioning artefact or image manipulation. This was established by using images of a male participant taken on different occasions. The technique was then used to assess reproducibility in participants undergoing pubertal induction treatment.

RESULTS

Good intraobserver reproducibility (intraclass correlation (ICC) 0.77) was demonstrated with static image manipulation. Validity of the imaging technique was established as there was no significant difference between the known reference volume produced by computer generated warping and that calculated by manual image manipulation. There was excellent intraobserver reproducibility for breast volume calculation in participants undergoing induced breast development (ICC 0.99).

CONCLUSIONS

3D imaging is a promising novel tool to provide quantitative breast volume assessment in individuals undergoing breast induction with exogenous oestradiol treatment.

Effects of miR126 Expressing Adipose-Derived Stem Cells on Fat Graft Survival and Angiogenesis

BACKGROUND

Fat transplantation supported by supplementation with ASCs has become a reliable procedure for treating soft tissue defects. However, the unpredictable survival rates for grafted fat remains a challenge with post-transplantation ischemia causing tissue loss. MiR126, which regulates VEGF signaling, is an endothelial cell-specific miRNA known to play an essential role in angiogenesis. We hypothesized that increased miR126 expression in grafted ASCs may promote fat survival within an autologous fat transfer model.

METHODS

Rat adipose-derived stem cells were isolated, expanded ex vivo for three passages and then transduced with miR126. We used PCR to verify lentiviral transduction and ELISA to confirm VEGF expression. We then mixed autologous fat tissues from our rat model with transduced ASCs, augmented with a nonsense control or miR126 expression vector. These mixtures were used in the fat grafting procedure, completed via subcutaneous injection at three paravertebral points in each rat. Fat grafts were then harvested on days 4, 7, 14, and 28 post-transplant and evaluated for survival, neovascularization, and protein expression via western blot.

RESULTS

VEGF expression levels in ASCs, Con-ASCs, and miR126-ASCs were not significantly different. However, miR126-ASCs experienced significantly improved survival on days 7, 14, and 28 when compared with the other groups. These ASCs also presented with the greatest capillary density on days 7, 14, and 28 post-transplantation as well as increased p-ERK and p-AKT expression when compared to the other groups.

CONCLUSION

This data suggests that miR126 augmentation of ASCs may help to enhance the survival and angiogenic capacity of transplanted fat tissues, and that this augmentation was not dependent on VEGF but rather the activation of the ERK/AKT pathway.

NO LEVEL ASSIGNED

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 .

Retropectoral Fat Graft Survival in Mammoplasty: Evaluation by Magnetic Resonance Imaging

BACKGROUND

Fat grafting is used in combination with mammoplasty to improve filling of the upper pole of the breasts. Its effectiveness remains in question due to unpredictable results. Difficulty in isolating the grafted fat and differentiating it from host tissues may hinder assessment of graft integration. The plane between the pectoral muscles is free of fat and has already been described with respect to placement of breast implants and fat grafting in breast surgeries. This study sought to evaluate via magnetic resonance imaging (MRI) the integration and retention of retropectoral fat grafts in mammoplasty.

METHODS

Thirty patients with breast flaccidity who desired to undergo mammoplasty were selected. Fat collected from the abdomen was separated by sedimentation and transferred to the retropectoral region after undermining of the breast and resection of excess tissue. The patients underwent MRI preoperatively and at three and six months after surgery. Fat volumes were calculated by multiplying the values for the major vertical, horizontal, and anteroposterior axes by the constant 0.523.

RESULTS

Twenty-five patients completed the study. The mean volume grafted was 116.4 ± 22.5 ml per breast. Six months after surgery, the mean fat graft volume in the retropectoral plane was 48.1 ± 25.71 ml, and the integration rate was 40.82% (range, 32.2-49.4%). The rate of complications related to fat grafting was 8%.

CONCLUSIONS

In mammoplasty, retropectoral fat grafting showed good integration rates and is a safe and predictable approach that can contribute to improving the outcomes of aesthetic and reconstructive breast surgeries.

LEVEL OF EVIDENCE IV, COHORT ANALYTIC STUDY

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 .

Volumetric Effect and Patient Satisfaction after Facial Fat Grafting

BACKGROUND

Facial fat grafts decrease in volume after transplantation. This observation is based on overall facial three-dimensional analyses, because there is sparse information on volume changes in well-defined aesthetic areas. The authors aimed to assess the overall and, more specifically, the local volumetric effects of facial fat grafting and relate these effects to patient satisfaction up to 1 year after treatment.

METHODS

All consecutive adult female patients who were scheduled for facial fat grafting without additional surgical procedures were asked to participate. All patients underwent the same fat grafting method. An algorithm-based personalized aesthetic template was applied to define specific aesthetic areas on the preoperative three-dimensional image. Objective outcome parameters [i.e., three-dimensional volume differences, patient satisfaction (FACE-Q questionnaire)] were measured at baseline and at 6 weeks, 6 months, and 12 months after fat grafting.

RESULTS

Of 33 female patients who underwent a facial fat graft procedure, 23 patients had complete three-dimensional data and were eligible for analysis. The highest volume gain was observed 6 weeks after grafting and was followed by a gradual loss thereafter. Overall and in the zygomatic area, a substantial gain in volume was still present 1 year after grafting, whereas this effect was lost in the lip area. FACE-Q scales Satisfaction with Facial Appearance Overall and Satisfaction with Cheeks improved too, whereas scores for Lines: Lips returned to baseline levels. The improvement in FACE-Q scales was in agreement with the objective change in volume.

CONCLUSION

Gain in overall and local volumetric effects is accompanied by comparable changes in patient satisfaction.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Prediction of Implant Size Based on Breast Volume Using Mammography with Fully Automated Measurements and Breast MRI

BACKGROUND

Determination of implant size is crucial for patients with breast cancer undergoing one-stage breast reconstruction. The purpose of this study is to predict the implant size based on the breast volume measured by mammography (MG) with a fully automated method, and by breast magnetic resonance imaging (MRI) with a semi-automated method, in breast cancer patients with direct-to-implant reconstruction.

PATIENTS AND METHODS

This retrospective study included 84 patients with breast cancer who underwent direct-to-implant reconstruction after nipple-sparing or skin-sparing mastectomy and preoperative MG and MRI between April 2015 and April 2019. Breast volume was measured using (a) MG with a fully automated commercial software and (b) MRI with an in-house semi-automated software program. Multivariable regression analyses including breast volume and patient weight (P < 0.05 in univariable analysis) were conducted to predict implant size.

RESULTS

MG and MRI breast volume was highly correlated with both implant size (correlation coefficient 0.862 and 0.867, respectively; P values < 0.001) and specimen weight (correlation coefficient 0.802 and 0.852, respectively; P values < 0.001). Mean absolute difference between the MR breast volume and implant size was 160 cc, which was significantly higher than that between the MG breast volume and implant size of 118 cc (P < 0.001). On multivariable analyses, only breast volume measured by both MG and MRI was significantly associated with implant size in any implant type (all P values < 0.001).

CONCLUSION

Breast volume measured by MG and MRI can be used to predict appropriate implant size in breast cancer patients undergoing direct-to-implant reconstruction in an efficient and objective manner.

Preliminary report of de novo adipogenesis using novel bioabsorbable implants and image evaluation using a porcine model

Our bioabsorbable poly-l-lactic acid (PLLA) mesh implants containing collagen sponge are replaced with adipose tissue after implantation, and this is an innovative method for breast reconstruction. In this preliminary study, we investigated the formation of adipose tissue and evaluated the process via multimodal images in a porcine model using an implant aggregate to generate the larger adipose tissue. The implant aggregate consists of PLLA mesh implants containing collagen sponge and a poly-glycolic acid woven bag covering them. We inserted the implant aggregates under the porcine mammary glands. Magnetic resonance imaging (MRI), ultrasonography (USG), and 3-dimensional (3D) surface imaging and histological evaluations were performed to evaluate the formation of adipose tissue over time. The volume of the implant aggregate and the formed adipose tissue inside the implant aggregate could be evaluated over time via MRI. The space within the implant aggregate was not confirmed on USG due to the acoustic shadow of the PLLA threads. The change in volume was not confirmed precisely using 3D surface imaging. Histologically, the newly formed adipose tissue was confirmed on the skin side of the implant aggregate. This implant aggregate has the ability to regenerate adipose tissue, and MRI is an appropriate method for the evaluation of the volume of the implant aggregation and the formation of adipose tissue.

Volumetry in Breast Reconstruction: Always New, Always Better?

Although breast surgeries for aesthetic or reconstructive purposes are regularly performed, no focus has been laid on establishing an adequate and reliable volumetry method. While CT and MRI scan represent methods that are already in clinical use, the 3D scan  is a novel and promising tool, easy to use with the possibility to measure the anatomic breast volume in an upright position. Nevertheless, its reliability is broadly underinvestigated. LEVEL OF EVIDENCE V : 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 .

Optimizing Surgical Outcomes with Small-Volume Silicone Implants Associated with Autogenous Fat Grafting in Primary and Revision Breast Augmentation Surgery: Soft Weight Hybrid (SWEH) Concept

BACKGROUND

Simultaneous association of autologous fat grafting (AFG) with silicone implants, defined as a hybrid procedure, has been proposed for breast augmentation (BA). In some patients, larger-volume implants may result in larger incisions, with long-term effects including implant palpability, soft tissue atrophy, and secondary ptosis. Some patients do not want large volume implants, or have insufficient soft tissue coverage. Recent improvements in AFG have led to new surgical options in BA for addressing these cases.

OBJECTIVES

This study combines AFG in BA using small-volume implants, known as the SWEH (soft weight hybrid) approach, and evaluates aesthetic advantages and outcomes following primary/secondary BA.

METHODS

25 patients (50 breasts) underwent SWEH procedures; this approach was indicated when the overlying tissue was insufficient to adequately cover the implant and patients refused large-volume implants. Three-dimensional images were obtained using a Divina 3D scanner system (AX3 Technologies, Miami, USA) to assess breast volume (BV) and intermammary distance (IMD) during follow-up.

RESULTS

Mean patient age was 29.3 years (range: 21-42) and mean body mass index was 19.3 kg/m² (15.3-27.2). The most common implant (SmoothSilk surface Round/Ergonomix style) volume was 180 cc (175-215), and patients received a mean volume of 125 cc of fat (89-168)/breast in the subcutaneous tissue. Preoperative average BV measurements were 236.85 cc (170-335). At 3 and 12 months post-procedure, the average BV values were 488.82 and 478.73cc, respectively (p=0.475). The average preoperative IMD was 31.76 mm (range, 22-43); at 3 and 12 months post-procedure, the average IMD was 20.47 and 20.94 mm, respectively (p=0.61). Postoperative complications included subcutaneous banding in the axilla (n = 1; 4%) and hypertrophic scarring (n = 1; 4%). Breast imaging exams were performed; in 2 breasts (8%) localized oil cysts were observed; no cases of suspicious calcifications, fat necrosis, or lumps were seen. Fat retention rate (1 year) was calculated by the difference between the BV expected with 100% fat intake and the real BV observed. In our sample we observed an average of 72.7 (range: 69.2-77.3, SD: 2.63) and 76.7 (range: 72.3-79.9, SD: 2.18) percent of fat intake on the right and the left breast respectively. No rippling, implant malposition, or infection was observed during a mean follow-up of 22 months (6-40).

CONCLUSIONS

SWEH is a useful surgical alternative that combines the benefits of AFG and implant-based augmentation, particularly with regard to soft tissue coverage, and avoids the limitations of larger-volume implants. The association of small-volume gel implants and smaller scars can yield satisfactory aesthetic outcomes.

LEVEL OF EVIDENCE IV

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 http://www.springer.com/00266 .

Regen Fat Code: A Standardized Protocol for Facial Volumetry and Rejuvenation

BACKGROUND

Facial aging is a degenerative process that impairs contour and angle prominence. Rejuvenation is based on tissue replacement, volumization of the atrophic areas, and improving flaccidity and cutaneous photoaging.

OBJECTIVES

The aim of this study was to apply structural fat grafting to manage volumetric deficits of the face, following a new systematic protocol called "Regen Fat Code" (RF Code) that was created to standardize structural lipotransfer methods.

METHODS

This is a prospective clinical trial involving 80 healthy candidates for facial rejuvenation who were split into 2 groups. Group A underwent only structural lipotransfer; Group B underwent replacement of deep facial structures by face-lifting plus structural lipotransfer. Structural lipotransfer followed the protocol "RF Code" and 3 clinical tools were adopted for pre- and postoperative facial volumetric analysis.

RESULTS

Total volume (mL) of lipotransfer in Groups A and B ranged between 1 and 20 mL (mean [standard deviation], 12 [5] mL), distributed to the different areas as follows: nasolabial fold, 3.32 [0.92] mL; superior lip, 2.0 [0.62] mL; inferior lip, 2.76 [0.71] mL; malar, 8.51 [5.25] mL; inferior eyelid, 1.2 [0.54] mL; and chin, 7.18 [1.99] mL. Areas with less mobility showed a lower absorption index than dynamic areas.

CONCLUSIONS

The development of the RF Code protocol demonstrated the potential of grouping many parameters based on the lipotransfer method used to volumize and regenerate atrophic areas of the face. The protocol is easy to apply, and allows different volumizing and regenerative effects to be proposed, according to the demands of each surgical area.

LEVEL OF EVIDENCE: 4

The Impact of N-Acetylcysteine on Autologous Fat Graft: First-in-Human Pilot Study

BACKGROUND

Our goal was to determine whether N-acetylcysteine (NAC) administered to the tumescent solution can reduce oxidative stress and increase autologous fat graft (AFG) viability.

METHODS

The study included 15 women with a mean age of 31.8 years (range 23-39 years) who underwent breast asymmetry correction with AFG harvested from both thighs. One thigh was infiltrated with a standard tumescent fluid (control graft) and other with a NAC-enriched tumescent fluid (NAC-treated graft). Each participant had breast MRI imaging before and 6 months after the procedure. Also, adipose tissue samples from each graft were subjected to biochemical analysis, flow cytometric assay and qRT-PCR to determine the markers of oxidative stress, angiogenesis and adipogenesis.

RESULTS

Concentration and activity of superoxide dismutase in the NAC-treated grafts turned out to be significantly higher than in the control grafts, in both fresh (p = 0.041 and p = 0.023, respectively) and frozen samples (p = 0.004 and p = 0.003, respectively). The level of nitric oxide in frozen samples from the control grafts was significantly higher than in the NAC-treated grafts (p = 0.009). iNOS was the only qRT-PCR target showing significant intergroup differences, with higher transcription levels observed in the control grafts (p = 0.027). Breast volumetric analysis demonstrated that the NAC-treated group had a 12.19% lower resorption rate than the control group, although it was found to be statistically insignificant (p = 0.149). No postoperative complications were observed during a 6-month follow-up.

CONCLUSIONS

Some results of this study are promising. Further studies on larger groups are needed to determine NAC impact on AFG.

LEVEL OF EVIDENCE IV

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 .

TRIAL REGISTRY NAME

The Impact of N-Acetylcysteine on Volumetric Retention of Autologous Fat Graft for Breast Asymmetry Correction.

REGISTRATION IDENTIFICATION NUMBER

NCT03197103. URL FOR THE REGISTRY: https://clinicaltrials.gov/ct2/show/NCT03197103?term=acetylcysteine&amp;rank=6.

Prediction of the Postoperative Fat Volume Retention Rate After Augmentation Mammoplasty with Autologous Fat Grafting: From the Perspective of Preoperative Inflammatory Level

BACKGROUND

Postoperative fat volume retention rate (PFVRR) after augmentation mammoplasty with autologous fat grafting is highly variable on an individual basis and challenging to be predicted. However, at present, there is a lack of further research on the relevant preoperative patient's self-related influencing factors. The early inflammatory response degree, directly influenced by preoperative inflammatory level, is an indispensable part of angiogenesis, which is a key factor in adipocyte survival.

METHODS

A retrospective review was conducted of patients who underwent breast augmentation with autologous fat grafting performed by a senior surgeon. Preoperative patient demographics and laboratory findings relevant to inflammatory level, such as monocyte to lymphocyte ratio (MLR), were included as the independent variables. The PFVRR more than 3 months after the operation was included as the dependent variable. Key factors influencing the PFVRR were analyzed.

RESULTS

Sixty-three patients were included. The total volume of bilateral fat injection was 375.00 (range, 320.00-400.00) mL, and the long-term bilateral volumetric change was 106.98 (range, 69.90-181.58) mL. The mean PFVRR was 35.36% ± 15.87%, and the preoperative MLR was an independent positive influencing factor of it, while the lymphocyte (L) count was negative. By ROC curve analysis, a value of MLR equal to 0.23 was the diagnostic cut-off point for whether PFVRR was greater than 50%, and its area under the curve was 0.870, with a sensitivity of 93.33% and a specificity of 81.25%. The other hematological parameters and demographics such as age, body mass index, and donor site were not significantly correlated with the PFVRR.

CONCLUSION

Preoperative peripheral blood inflammatory indicators can influence the PFVRR, with the MLR positively and L count negatively. Based on the diagnostic threshold of MLR = 0.23 derived from this study, clinicians can make reasonable predictions of whether half of the injected fat volume would be retained based on preoperative blood routine tests that are readily available.

LEVEL OF EVIDENCE IV

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 .

Non-Surgical Touch-Up with Hyaluronic Acid Fillers Following Facial Reconstructive Surgery

The use of hyaluronic acid (HA) injectable fillers has become increasingly widespread in facial recontouring and rejuvenation. We report our experiences to emphasize the role of HA fillers as tools beyond aesthetic treatments in cases of post-surgical facial sequelae. HA fillers are generally used for aesthetic rejuvenation, but one potential new horizon could be their application in trauma, reconstructive, and craniofacial surgery. This study was conducted retrospectively, evaluating medical reports of patients treated at the Maxillofacial Surgery Unit, University of Campania “Luigi Vanvitelli”, Naples, for lip incompetence, trauma, oncological, reconstructive, and craniosynostosis surgery sequelae. Visual analog scale (VAS) evaluation was performed to assess patient satisfaction. No major complications (i.e., impending necrosis or visual loss) were reported. Bruising and swelling was reported for 48 h after lip injection. At the immediate VAS evaluation, 67% of the patients were “extremely satisfied” and 33% “satisfied”. In those 33%, VAS scores changed to “extremely satisfied” at 6–9 weeks and 3–6 months of VAS evaluation (contextually to improvement in tissue flexibility, elasticity, and aesthetic appearance). Results indicate that this minimally invasive approach achieves a high level of aesthetic enhancement, improving patient satisfaction. The concept of HA filler applications could be a frontier that may be applicable to other areas of reconstructive facial plastic surgery.

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

BACKGROUND

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.

METHODS

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.

RESULTS

Fat graft retention rate was higher in Group 1 than in Group 2 at both postoperative 6 months (73.8% vs. 62.2%; p = 0.03) and 12 months (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.

CONCLUSIONS

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.

LEVEL OF EVIDENCE IV

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.

Autologous Fat Grafting for Oncologic Patients: A Literature Review

Autologous fat grafting (AFG) serves as an effective method to address volume defects, contour irregularities, and asymmetry in both aesthetic and reconstructive procedures. In recent years, there has been growing concern about the potential of cancer recurrence and interference with cancer surveillance in oncologic patients receiving AFG. The adipose tissue contains adipose-derived stem cells (ASCs), a specific type of mesenchymal stem cells, that facilitate secretion of numerous growth factors which in turn stimulate tissue regeneration and angiogenesis. As such, it has been theorized that ASCs may also have the potential to stimulate cancer cell proliferation and growth when used in oncologic patients. Multiple research studies have demonstrated the ability of ACSs to facilitate tumor proliferation in animal models. However, clinical research in oncologic patients has yielded contradictory findings. Although the literature pertaining to oncologic safety in head and neck, as well as sarcoma, cancer patients remains limited, studies demonstrate no increased risk of tumor recurrence in these patient populations receiving AFG. Similarly, both the efficacy and safety of AFG have been well established in breast cancer patients through numerous clinical studies. More recently, preclinical research in animal models has shown that AFG has the potential to facilitate tissue regeneration and improve joint contracture following irradiation. Ultimately, further research is needed to elucidate the safety of AFG in a variety of oncologic patients, as well as explore its use in tissue regeneration, particularly in the setting of radiotherapy. Level of Evidence: 4.

Effects of concentrated growth factor and nanofat on aging skin of nude mice induced by D-galactose

This investigation studied the effect of concentrated growth factor and nanofat on aging skin of nude mice induced by D-galactose. BALB/c mice were randomly divided into five groups: 5 mice in the control group were fed normally without any intervention, 9 mice were treated with concentrated growth factor (CGF), 9 mice were treated with nanofat (NF), 9 mice were treated with CGF+NF, and 9 mice in the model group (no treatment after subcutaneous injection of D-galactose). Relevant indicators are measured and recorded. In skin and serum, SOD and GSH content in the model group were significantly lower than those in other groups (P<0.05), and the MDA of the three treatment groups was significantly lower than that of the model group (P<0.05). Compared with the control group, the contents of total collagen, type I collagen and type III collagen in the NF group and model group were decreased in different degrees (P<0.05); the contents of elastin and elastic fiber in the skin of nude mice in the model group and NF group were significantly decreased. Compared with the model group, he number of CD31 and VEGF in the treatment group was significantly increased (P<0.01); the skin AGE content of three treatment groups was significantly lower (P<0.05). These findings suggest that concentrated growth factor and nanofat may have a significant effect on delaying aging skin induced by D-galactose in nude mice.

Comparative Study of Three-Dimensional Volume Measurement for Facial Fat Grafting

ABSTRACT

The three-dimensional (3D) volume measurement after facial fat grafting is of great significance to plastic surgeons. It has been ascertained that reliable results rely on the accurate measurement of 3D softwares. Some 3D softwares in literatures have proposed various ways to optimize each step of the procedure, including the pre- and post-operative image acquisition, alignment, calculation, and analysis. Good image alignment between pre- and post-scan is essential to quantify the volumetric change. Once the pre- and post-operative image alignment has slightly bias or deviation, the subsequent volume measurement would also be affected. To our knowledge, 2 types of 3D software have been widely applied in clinic, primarily based on the image-automatically alignment and image-manually alignment. This study aimed to compare the accuracy, repeatability, and reproducibility of the Geomagic Qualify 12.0 software and the 3-Matic 7.0 software in a relatively ideal model of virtual facial fat grafting. A simulated facial fat grafting was first performed for 10 preoperative patients diagnosed with progressive hemifacial atrophy, and the known volumetric change was named as the true value (T value). Then, the facial volumetric change of every case was remeasured 10 times with above 2 kinds of software separately. The mean volumetric change was calculated as Q value and M value. The paired t test, intraclass correlation coefficient, and Bland-Altman analysis showed that the Geomagic Qualify 12.0 software demonstrated a statistically higher accuracy, repeatability, and reproducibility in comparison with the 3-Matic 7.0 software.

Clinical Assessment of Breast Volume: Can 3D Imaging Be the Gold Standard?

Background:

Three-dimensional (3D) camera systems are increasingly used for computerized volume calculations. In this study we investigate whether the Vectra XT 3D imaging system is a reliable tool for determination of breast volume in clinical practice. It is compared with the current gold standard in literature, magnetic resonance imaging (MRI), and current clinical practice (plastic surgeon’s clinical estimation).

Methods:

Breast volumes of 29 patients (53 breasts) were evaluated. 3D images were acquired by Vectra XT 3D imaging system. Pre-existing breast MRI images were collected. Both imaging techniques were used for volume analyses, calculated by two independent investigators. Breast volume estimations were done by plastic surgeons during outpatient consultations. All volume measurements were compared using paired samples t-test, intra-class correlation coefficient, Pearson’s correlation, and Bland–Altman analysis.

Results:

Two 3D breast volume measurements showed an excellent reliability (intra-class correlation coefficient: 0.991), which was comparable to the reliability of MRI measurements (intra-class correlation coefficient: 0.990). Mean (SD) breast volume measured with 3D breast volume was 454 cm³ (157) and with MRI was 687 cm³ (312). These volumes were significantly different, but a linear association could be found: y(MRI) = 1.58 × (3D) – 40. Three-dimensional breast volume was not significantly different from volume estimation made by plastic surgeons (472 cm³ (69), P = 0.323).

Conclusions:

The 3D imaging system measures lower volumes for breasts than MRI. However, 3D measurements show a linear association with MRI and have excellent reliability, making them an objective and reproducible measuring method suitable for clinical practice.

[Long-term evaluation after autologous fat transplantation for breast augmentation]

Background The transplantation of autologous fat is an increasingly common but not standardized procedure in aesthetic and reconstructive surgery. Until now only studies about the short-term results after transplantation with autologous fat have been published. In this publication we present our results of a long-term study after fat transplantation.Patients/Material and Methods 14 patients underwent an MRI investigation which was done before and 5-9 years (mean 6 years) years after aesthetic breast lipofilling according to BEAULI-protocol. The difference in volume was calculated with the open source software OsiriX. Two groups were analyzed separately to calculate the influence of body weight changes in final volume gain. In the first group patients with a stable BMI (increase of less than 1 kg/m²⁾ were included. The second group includes patients with a BMI gain exceeding more than 1 kg/m². The mean increase in BMI was 1,6 kg/m² (minimum 0 - maximum 3,9). None of the patients lost weight.Results Depending on the desired amount of breast augmentation the patients underwent between one to four operations. An average of 176 ml fat was transplanted per breast and surgery. In the first group a mean volume survival of 74 % (IQR 58 % - 92 %) was observed. In the second group an increase of 135 % (IQR 105 % - 318 %) of the volume of transplanted fat was observed. After an intermediate weight loss one of the patients regained her initial weight.Conclusion In this study the transplantation of autologous fat renders good long-term results. There is a significant correlation between change of weight and fat transplant volume survival over the years. This also explains the very high increase in breast volume in some patients. Autologous fat transplantation seems to be a safe and efficient method for breast augmentation. For further statements studies with larger number of cases are necessary.

The Impact of N-Acetylcysteine on Autologous Fat Graft: First-in-Human Pilot Study

BACKGROUND

Our goal was to determine whether N-acetylcysteine (NAC) administered to the tumescent solution can reduce oxidative stress and increase autologous fat graft (AFG) viability.

METHODS

The study included 15 women with a mean age of 31.8 years (range 23-39 years) who underwent breast asymmetry correction with AFG harvested from both thighs. One thigh was infiltrated with a standard tumescent fluid (control graft) and other with a NAC-enriched tumescent fluid (NAC-treated graft). Each participant had breast MRI imaging before and 6 months after the procedure. Also, adipose tissue samples from each graft were subjected to biochemical analysis, flow cytometric assay and qRT-PCR to determine the markers of oxidative stress, angiogenesis and adipogenesis.

RESULTS

Concentration and activity of superoxide dismutase in the NAC-treated grafts turned out to be significantly higher than in the control grafts, in both fresh (p = 0.041 and p = 0.023, respectively) and frozen samples (p = 0.004 and p = 0.003, respectively). The level of nitric oxide in frozen samples from the control grafts was significantly higher than in the NAC-treated grafts (p = 0.009). iNOS was the only qRT-PCR target showing significant intergroup differences, with higher transcription levels observed in the control grafts (p = 0.027). Breast volumetric analysis demonstrated that the NAC-treated group had a 12.19% lower resorption rate than the control group, although it was found to be statistically insignificant (p = 0.149). No postoperative complications were observed during a 6-month follow-up.

CONCLUSIONS

Some results of this study are promising. Further studies on larger groups are needed to determine NAC impact on AFG.

TRIAL REGISTRY NAME

The Impact of N-Acetylcysteine on Volumetric Retention of Autologous Fat Graft for Breast Asymmetry Correction.

REGISTRATION IDENTIFICATION NUMBER

NCT03197103. URL FOR THE REGISTRY: https://clinicaltrials.gov/ct2/show/NCT03197103?term=acetylcysteine&rank=6 LEVEL OF EVIDENCE IV: 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.

Methods used for evaluation of volume retention rate in autologous fat grafting for breast augmentation: a systematic review

BACKGROUND

Autologous fat grafting has gained popularity in breast augmentation. Various methods can be used to estimate the volume retention rate. This systematic review aimed to establish whether the type of method used for measuring breast volume is a factor that influences the reported volume retention rate.

METHODS

Studies were identified using the electronic databases PubMed, Embase, Cochrane Central Register of Controlled Trials, and Web of Science from inception of the database up to February 2019. Articles describing autologous fat grafting for breast augmentation were selected based on pre-determined inclusion and exclusion criteria. The characteristics of the included studies were summarized, and the reported volume retention rate from the studies was compared. A quality assessment of all included articles was performed using the methodological index for non-randomized studies criteria.

RESULTS

A total of 618 articles were identified, of which 12 studies, with a total of 1337 cases, were eligible. The retention rate of injected adipose tissue varied when the method of fat grafting and volume analysis used were both the same, as well as when the method of fat grafting was the same but the method of volumetric evaluation used was different.

CONCLUSIONS

Currently, the tools available for estimating the volume retention rate come with limitations. In order to objectively evaluate the percentage of graft retention, a standard protocol that applies to the different methods should be established in the future.

Three-dimensional Volumetric Analysis of 3 Fat-Processing Techniques for Facial Fat Grafting: A Randomized Clinical Trial

Importance

Autologous fat grafting has revolutionized the field of facial soft-tissue augmentation, despite a lack of standardization. Objective data are needed to arrive at consensus regarding the best technique for optimal volume retention.

Objective

To compare 3 fat-processing techniques with 3-dimensional (3-D) technology to explore the optimal fat-processing technique for improving the volume retention of grafted fat.

Design, Setting, and Participants

From September 2015 to December 2016, patients with facial asymmetry were treated by initial facial fat grafting at the Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College. Sixty-three patients (21 per group) were randomized to 1 of 3 fat-processing techniques: sedimentation, centrifugation, and cotton pad filtration. Patients underwent 3-D scanning preoperatively and at 1, 3, 6, and 12 months postoperatively. Patients who did not complete preoperative or postoperative follow-up and 3-D imaging were excluded from the analysis.

Intervention

Autologous fat grafting to correct facial asymmetry.

Main Outcomes and Measures

The percentage volume maintenance of each fat-processing technique was measured with 3-D software and analyzed with variance analysis.

Results

Of the 63 randomized patients, 30 (7 men, 23 women; mean [SD] age at surgery, 22.2 [8.0] years) completed follow-up. The mean (SD) percentage volume maintenance of the 3 groups at 1, 3, 6, and 12 months postoperatively was, respectively, 49% (4%), 45% (3%), 43% (3%), and 41% (3%) for the cotton pad filtration group; 41% (3%), 38% (4%), 36% (4%), and 34% (3%) for the centrifugation group; and 37% (4%), 34% (4%), 31% (3%), and 31% (3%) for sedimentation group. The variance analysis showed that the cotton pad filtration group demonstrated a statistically significant higher percentage volume maintenance in comparison with the centrifugation and sedimentation groups.

Conclusions and Relevance

The use of 3-D technology provides an objective and accurate way to evaluate different fat-processing techniques. Autologous fat processed by cotton pad filtration had a significant higher volume retention than did that processed by centrifugation and sedimentation technique.

Trial Registration

chictr.org.cn Identifier: ChiCTR-IOR-14005599.

Level of Evidence

1.

Fat Grafting into Younger Recipients Improves Volume Retention in an Animal Model

BACKGROUND

Soft-tissue deficits associated with various craniofacial anomalies can be addressed by fat grafting, although outcomes remain unpredictable. Furthermore, consensus does not exist for timing of these procedures. Whereas some advocate approaching soft-tissue reconstruction after the underlying skeletal foundation has been corrected, other studies have suggested that earlier grafting may exploit a younger recipient niche that is more conducive to fat graft survival. As there is a dearth of research investigating effects of recipient age on fat graft volume retention, this study compared the effectiveness of fat grafting in younger versus older animals through a longitudinal, in vivo analysis.

METHODS

Human lipoaspirate from three healthy female donors was grafted subcutaneously over the calvaria of immunocompromised mice. Volume retention over 8 weeks was evaluated using micro-computed tomography at three experimental ages: 3 weeks, 6 months, and 1 year. Histologic examination was performed on explanted grafts to evaluate graft health and vascularity. Recipient-site vascularity was also evaluated by confocal microscopy.

RESULTS

The greatest retention of fat graft volume was noted in the youngest group compared with both older groups (p < 0.05) at 6 and 8 weeks after grafting. Histologic and immunohistochemical analyses revealed that improved retention in younger groups was associated with greater fat graft integrity and more robust vascularization.

CONCLUSION

The authors' study provides evidence that grafting fat into a younger recipient site correlates with improved volume retention over time, suggesting that beginning soft-tissue reconstruction with fat grafting in patients at an earlier age may be preferable to late correction.

Facial aesthetic fat graft retention rates after filtration, centrifugation, or sedimentation processing techniques measured using three-dimensional surface imaging devices

OBJECTIVE

How to increase the long-term retention rate of autologous fat grafting has been widely discussed. This study aimed to evaluate long-term fat graft retention rates for the most widely used fat processing methods in the area of facial esthetic surgery, including centrifugation, filtration, and sedimentation, using three-dimensional (3D) imaging.

DATA SOURCES

PubMed, Embase, Wiley/Cochrane Library, and Web of Science databases were comprehensively searched from inception to July 2018 according to the guidelines of the American Society of Plastic Surgeons Fat Graft Task Force Assessment Methodology.

STUDY SELECTION

Articles were screened using predetermined inclusion and exclusion criteria. Data collected included patient characteristics, follow-up devices, fat grafting techniques, and clinical outcomes. Patient cohorts were pooled, and fat graft retention rates were calculated. Complications were summarized according to different clinical characteristics.

RESULTS

Of 77 articles, 10 clinical studies met the inclusion criteria and reported quantified measurement outcomes with 3D imaging which provide precise volumetric data with approximately 2% standard deviation compared to real volumes. Data of 515 patients were included. Fat grafting retention varied from 21% to 82%. We found filtration and centrifugation techniques could result in better retention outcomes. However, retention varied within each processing technique, with no significant difference among the 3 techniques. Twenty-two complications were reported among 515 patients, including donor-site hematoma (1 case), mild post-operative erythema (2 cases), mild volumetric asymmetries (2 cases), chronic edema (2 cases), overcorrection (2 cases), skin irregularity (6 cases), and headache or dysesthesia (7 cases).

CONCLUSIONS

Filtration and centrifugation techniques may result in better fat grafting retention outcomes than gravity sedimentation; however, more accurate statistical evidence is needed. Controversies continue to exist with respect to the performance of the different fat-processing techniques in fat graft retention.

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.

Breast cancer research and treatment reconstruction of unilateral breast structure using three-dimensional ultrasound imaging to assess breast neoplasm

Purpose

To develop and evaluate the accuracy of a three-dimensional (3D) US method for assessing unilateral breast reconstruction and discuss the feasibility of breast ultrasound 3D reconstruction of the unilateral breast compared with 3D MRI.

Methods

Sixty-four breast lesions were collected for surgical resection. (1) MRI and US imaging were used to reconstruct the 3D models of the breast neoplasm. The diameters for maximum length, width, and depth of the negative tumor margins were used as the primary standards for comparison. (2) The measurement direction was determined by the largest gravity change between the two body positions. (3) The vertical distance from the midpoint of breast neoplasm to the ipsilateral nipple was calculated via MRI and US reconstruction.

Results

(1) Comparison of the measured size and histopathology of the breast neoplasm showed that US, MRI, and histopathology were highly correlated (p < 0.001). (2) When compared with the other two vertical directions, the direction with the largest gravity change had the greatest difference between MRI and US measurements. (3) The vertical distance from the breast neoplasm to the ipsilateral nipple and skin junction was significantly different (p > 0.05).

Conclusions

We have presented a novel US 3D reconstruction method for evaluating tumor size, which can provide a basis for investigated advanced visualization techniques for assessing breast tissue such as holographic presentation of 3D image data. These methods can provide physicians with a novel approach for making accurate surgical plans, for better communication with patients, and for more effective navigating throughout the operation.

Orbital Fat Injection: Technique and 5-Year Follow-Up

BACKGROUND

Orbital volume loss, early or late, is common after placement of an orbital implant or dermis fat graft, and there is currently no satisfactory long-lasting solution. Hyaluronic fillers are relatively easy to administer but are prone to migration and are temporary. Cannula-based orbital fat grafting has not gained the status of standard of care because of perceived low likelihood of success in the near term. This paper describes a technique for fat volume augmentation, its rationale, long-term follow-up, and a description of a complication unique to fat grafting in the orbit.

METHODS

Ten consecutive subjects with acquired anophthalmic enophthalmos were enrolled in two IRB (institutional review board)-approved protocols (10.27 and 12.01) undergoing a single session of autologous fat grafting to the orbit using a closed blunt cannula technique. Preoperative photography and non-contrast MRIs (magnetic resonance imaging) were obtained prior, immediately after, and at 1 year after injection. Yearly postoperative photography was performed on subjects with successful results.

RESULTS

Three of five subjects in IRB 10.27 clearly showed a clinically apparent increase in orbital volume at 1 year. One subject who failed to show improvement also sustained inadvertent injection into three extraocular muscles; she subsequently volunteered to enter IRB 12.01. Three of five subjects in IRB 12.01 did benefit, showing volume increase at 1 year, including the subject who had experienced intramuscular injection in 10.27. One subject in IRB 12.01 was lost to follow-up. Of the total of ten subjects enrolled, three showed no improvement and one was lost to follow-up; six subjects showed volume improvement at 1 year with two retaining the correction at 5 years and four showing variable diminution over 2-5 years. With the exception of the subject who sustained injection into extraocular muscles, none experienced complications.

CONCLUSION

A modified technique is recommended for orbital fat injection distinct from methods used elsewhere in the body. Theoretical limits of volumetric enhancement temper expectations in orbital fat grafting and should inform surgical planning. Cannula-based orbital fat grafting can be done safely and result in a gain of orbital fat volume at 1 year and in some cases up to 5 years.

LEVEL OF EVIDENCE IV

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 .

Exosomes from hypoxia-treated human adipose-derived mesenchymal stem cells enhance angiogenesis through VEGF/VEGF-R

BACKGROUND

We previously reported that co-transplantation of exosomes from hypoxia-preconditioned adipose mesenchymal stem cells (ADSCs) improves the neoangiogenesis and survival of the grafted tissue. This study aimed to investigate the molecular mechanism of this protective effect.

METHODS

Exosomes were collected from normoxia-treated (nADSC-Exo) or hypoxia--treated (hypADSC-Exo) human ADSCs, and their pro-angiogenic capacity was evaluated in human umbilical vein endothelial cells (HUVECs) and a nude mouse model of subcutaneous fat grafting. Protein array was used to compare the exosome-derived proteins between nADSC-Exo and hypADSC-Exo.

RESULTS

Compared with the nADSC-Exo group and untreated control, hypADSC-Exo treatment significantly promoted proliferation, migration and tube-formation capability of HUVECs. Protein array revealed that the levels of vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), fibroblast growth factor (FGF) and their receptors (VEGF-R2, VEGF-R3), and monocyte chemoattractant protein 2 (MCP-2), monocyte chemoattractant protein 4 (MCP-4) were significantly higher in the hypADSC-Exo than in the nADSC-Exo. In the nude mice model of fat grafting, immunofluorescence of CD31 showed that hypADSC-Exo dramatically improved neovascularization around the graft. Furthermore, compared with nADSC-Exo and control groups, cotransplantation of hypADSC-Exo significantly increased the protein expression of EGF, FGF, VEGF/VEGF-R, angiopoietin-1(Ang-1) and tyrosine kinase with immunoglobulin-like and EGF-like domains 1(Tie-1, an angiopoietin receptor) in the grafted tissue at 30 days after transplantation. Immunohistochemical analysis demonstrated that hypADSC-Exo treatment significantly increased VEGF-R expression in the grafted tissue.

CONCLUSIONS

Exosomes from hypoxia-treated human ADSCs possess a higher capacity to enhance angiogenesis in fat grafting, at least partially, via regulating VEGF/VEGF-R signaling.

Does Stromal Vascular Fraction Ensure a Higher Survival in Autologous Fat Grafting for Breast Augmentation? A Volumetric Study Using 3-Dimensional Laser Scanning

Background

Cell-assisted lipotransfer (CAL) has been considered a promising technique for promoting adipogenesis and angiogenesis in fat grafts.

Objectives

The author sought to objectively analyze the change of breast volume in patients who underwent stromal vascular fraction (SVF)-enriched fat grafting for breast augmentation and compared the clinical results with those who underwent conventional fat grafting without SVF by using 3-dimensional laser scanning.

Methods

From April 2015 to March 2016, 105 patients who underwent traditional fat grafting without SVF enrichment for breast augmentation were assigned to group A and served as the control. The other 101 patients who underwent SVF-enriched fat grafting for breast augmentation were assigned to group B. The charts of these patients were retrospectively reviewed.

Results

The survival rate of the transplanted fat was 67.9% in group A and 68.7% in group B at 12 months after the operation. Postoperative complication rate was 3.8% in group A and 5.9% in group B. The differences were statistically insignificant.

Conclusions

SVF does not ensure a higher survival rate in autologous fat grafting for breast augmentation. Considering the potential drawbacks of adipose-derived stem cells (ADSC) and the extra cost of the consumables, in particular the need for harvesting larger amount of fat which could be reserved for additional fat grafting at a later time to achieve even better improvement, the results of this study do not support the use of SVF in autologous fat grafting for breast augmentation in terms of graft survival and postoperative complications.

Level of Evidence 3

Outcome of Conventional Adipose Tissue Grafting for Contour Deformities of Face and Role of Ex Vivo Expanded Adipose Tissue-Derived Stem Cells in Treatment of Such Deformities

OBJECTIVES

To evaluate the outcomes of conventional fat grafting for facial contour deformities and to describe clinical outcome of a patient with contour deformity of face treated with ex vivo expanded adipose tissue-derived mesenchymal stem cells (ASCs) enriched fat graft.

PLACE AND DURATION OF STUDY

The Department of Plastic Surgery and Tissue Engineering and Regenerative Medicine Laboratory, King Edward Medical University/Mayo Hospital, Lahore, from September 2015 to September 2017.

METHODS

Patients with contour deformities of face requiring soft tissue augmentation were included. Fat was harvested, processed, and injected following a standard protocol. Both subjective and objective assessments were performed and complications were also noted.

RESULTS

Twenty-five patients underwent 51 fat-grafting sessions over a period of 24 months. Eighteen (72%) patients underwent multiple fat-grafting sessions. Mean (standard deviation) soft tissue thickness after 72 hours and 6 months of first fat graft session was 18.62 (7.2) and 12.88 (6.21) mm, respectively, which corresponds to 30.77 (13)% reduction of transplanted fat. Physician and patient assessment scores were 3.42 (0.92) and 4 (1.04), respectively. Few minor complications were observed. In the patient undergoing ex vivo expanded ASCs enriched fat graft, there was minimal decrease in soft tissue thickness of treated area (44 mm vs 42 mm) 6 months postoperatively and patient was highly satisfied with the outcome after the single session.

CONCLUSION

Conventional fat grafting is safe for correction of facial contour deformities. However, procedure needs to be repeated multiple times to produce satisfactory results. Beneficial effects of ex vivo expanded ASCs enriched fat grafting have a potential to alter the current treatment paradigm of fat grafting for soft tissue reconstruction.

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

Supplemental Digital Content is available in the text.

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.

Co-transplantation of exosomes derived from hypoxia-preconditioned adipose mesenchymal stem cells promotes neovascularization and graft survival in fat grafting

BACKGROUND

Adipose-derived stromal cells (ADSCs)-derived exosomes (ADSC-Exos) account for the proangiogenic potential of stem cell. This study aimed to investigate the effect of ADSC-derived exosomes (ADSC-Exos) on the survival in fat grafting.

METHODS

A nude mouse model of subcutaneous fat grafting was adopted. Hypoxic preconditioned ADSC-Exos and ADSC-Exos were injected around the grafted tissue. The fat graft sample was weighed and examined by hematoxylin and eosin (H&E) staining and immunohistochemistry. Laser Doppler flowmetry and CD31 immunofluorescence staining were used to analyze neovascularization.

RESULTS

ADSC-Exo and hypoxic ADSC-Exo groups had a significantly higher weight of fat graft and more perilipin-positive adipocytes than the control groups from 2 to 8 weeks after grafting, and the hypoxic ADSC-Exo group had better outcomes (all P < 0.05). H&E staining showed that ADSC-Exos attenuated infiltration of inflammatory cells around the fat grafts. Laser Doppler flowmetry showed that the two ADSC-Exo groups had better blood perfusion in the graft tissue than the control groups (all P < 0.05). Immunofluorescence demonstrated that the hypoxic ADSC-Exo group had significantly more CD31-positive cells than the ADSC-Exo group. In vitro study showed that hypoxic ADSC-Exos treatment significantly increased the migration (at 12 and 24 h) and in vitro capillary network formation (at 12 h) in the human umbilical vein endothelial cells (HUVECs) as compared with the ADSC-Exo group and control group (all P < 0.05).

CONCLUSIONS

Co-transplantation of ADSC-Exos can effectively promote the survival of graft, neovascularization and attenuated inflammation in the fat grafts. Hypoxia treatment can further enhance the beneficial effect of ADSC-Exos.

Should platelet-rich plasma be activated in fat grafts? An animal study

BACKGROUND

The adjunction of platelet-rich plasma with graft fat has been the subject of a few clinical trials which have demonstrated its value in adipocyte survival. The aim of this study was to assess the different efficacies between activated and non-activated PRP on adipose cells in vitro and for adipose tissue graft survival in vivo.

METHODS

The in vitro study assessed the effects of PRP on both the proliferation and adipocyte differentiation of adipose cells. For the in vivo study, 8 nude rats received 3 human fat injections as follows: 0.8 mL of fat + 0.2 mL of normal saline; 0.8 mL of fat + 0.2 mL of non-activated PRP; and 0.8 mL of fat + 0.2 mL of PRP activated with calcium chloride (CaCl₂). The quantitative assessment of adipocyte survival was implemented after 3 months using histomorphometric analysis. Histological and immunohistochemical analysis were also performed to evaluate angiogenesis, inflammation and quality of adipocytes in the grafted tissue.

RESULTS

We showed that activated PRP stimulated, in vitro, proliferation and differentiation of adipose cells. In vivo experiments indicated that CaCl₂-activated PRP was more efficient than non-activated to prolong the survival of fat grafts in nude rats. The mean percentage areas occupied by viable adipocytes in the PRP-free group, non-activated PRP group and activated PRP group were 13%, 14% and 24% (p = 0.05%), respectively. Histological and immunohistochemical analysis revealed protective effect of activated PRP on inflammation and adipocyte death.

CONCLUSION

This study showed that activation by CaCl₂ improves the beneficial effects of PRP for fat graft maintenance.

Bone marrow mesenchymal stem cell‑derived extracellular vesicles improve the survival of transplanted fat grafts

Autologous fat grafting is a promising surgical technique for soft tissue augmentation, reconstruction and rejuvenation. However, it is limited by the low survival rate of the transplanted fat, due to the slow revascularization of such grafts. Previous studies have demonstrated that bone marrow mesenchymal stem cell-derived extracellular vesicles (BMSC-EVs) are proangiogenic. The present study aimed to investigate whether BMSC-EVs could improve the survival of transplanted fat grafts. Extracellular vesicles were isolated from the supernatant of cultured rat bone marrow mesenchymal stem cells, and characterized by flow cytometry and scanning electron microscopy. Their proangiogenic potential was measured in vitro using tube formation and cell migration assays. Subsequently, human fat tissue grafts, alongside various concentrations of BMSC-EVs, were subcutaneously injected into nude mice. A total of 12 weeks following transplantation, the mice were sacrificed and the grafts were harvested. The grafts from the experimental group had a higher survival rate and an increased number of vessels compared with grafts from the control group, as demonstrated by tissue volume, weight and histological analyses. Reverse transcription-quantitative polymerase chain reaction analysis indicated that the expression levels of proangiogenic factors were increased in the experimental group compared with in the control group, thus suggesting that BMSC-EVs may promote neovascularization by stimulating the secretion of proangiogenic factors. The present study is the first, to the best of our knowledge, to demonstrate that supplementation of fat grafts with BMSC-EVs improves the long-term retention and quality of transplanted fat.