Autologous Fat Transfer for Facial Recontouring: Is There Science behind the Art?

Cutaneous hypersensitivity to chlorhexidine following facial fat grafting: a delayed intradermal response

Chlorhexidine (CHD) is commonly included in surgical antiseptics and can be associated with adverse reactions ranging from contact dermatitis to anaphylaxis. A 32-year-old female presented to the OR for facial fat grafting. Surgical sites were prepped with CHD gluconate or topical iodine. Donor and recipient sites were infiltrated with local anesthetic injection prior to fat harvest and facial injection. Eleven days later, she presented with new painful, pruritic rash over donor sites where CHD had been applied prior to local anesthetic infiltration. Treatment with topical clobetasol and prednisone taper resulted in complete symptom resolution. This patient's response most likely represented a delayed type IV, T-cell mediated hypersensitivity. CHD is a known trigger of allergic reactions. Infiltration of local anesthetic may introduce skin prep into the subcutaneous tissue akin to intradermal testing. For those with delayed cutaneous reactions, steroids may provide symptomatic relief.

In Vitro Characterization of Fat Grafts Processed Using the REVOLVE ENVI System versus Decantation

Background

This preclinical study evaluated benchtop/in vitro properties and fat viability and activity of grafts processed using the REVOLVE ENVI 600 system compared with decantation and evaluated properties of REVOLVE ENVI waste.

Methods

Lipoaspirate from six donors was processed using REVOLVE ENVI or decantation. The composition of each graft, hematocrit/red blood cell content, fat particle size/macrostructure, viable adipocyte count, and adipocyte activity were analyzed. Stromal vascular fraction was analyzed for viable progenitor cell count and colony-forming units.

Results

REVOLVE ENVI grafts had a higher mean (±SD) fat content at 85.6% ± 6.1% than decanted grafts at 72.1% ± 4.0% (P < 0.001), with negligible free oil (0.4% ± 1.1%) and cellular debris (<0.1%), whereas REVOLVE ENVI waste contained primarily aqueous fluid (91.0% ± 2.2%) with negligible viable fat. REVOLVE ENVI grafts had significantly lower hematocrit levels (P < 0.001) and contained significantly more large fat globules (P < 0.001) than decanted grafts or REVOLVE ENVI waste. The percentage of tissue particles of more than 1000 µm was highest for REVOLVE ENVI grafts at 61.6% ± 9.2% (decantation: 52.5% ± 13.4%; REVOLVE ENVI waste: 0.49% ± 1.50%), and the percentage of particles less than 200 µm was lowest for REVOLVE ENVI grafts at 15.7% ± 2.6% (decantation: 32.2% ± 8.9%; REVOLVE ENVI waste: 97.9% ± 4.5%). REVOLVE ENVI grafts contained 145.2% ± 36.0% more viable adipocytes, 145.7% ± 46.2% greater activity, 195.5% ± 104.2% more progenitors in SVF, and 363.5% ± 161.2% more SVF colony-forming units than decanted grafts.

Conclusion

Fat grafts processed using REVOLVE ENVI demonstrated greater viability and activity than decanted grafts in vitro.

Balancing beauty and science: a review of facial implant materials in craniofacial surgery

Facial reconstruction and augmentation, integral in facial plastic surgery, address defects related to trauma, tumors infections, and congenital skeletal deficiencies. Aesthetic considerations, including age-related facial changes, involve volume loss and diminished projection, often associated with predictable changes in the facial skeleton. Autologous, allogeneic, and alloplastic implants are used to address these concerns. Autologous materials such as bone, cartilage, and fat, while longstanding options, have limitations, including unpredictability and resorption rates. Alloplastic materials, including metals, polymers, and ceramics, offer alternatives. Metals like titanium are biocompatible and used primarily in fracture fixation. Polymers, such as silicone and polyethylene, are widely used, with silicone presenting migration, bony resorption, and visibility issues. Polyethylene, particularly porous polyethylene (MedPor), was reported to have one of the lowest infection rates while it becomes incorporated into the host. Polyether-ether-ketone (PEEK) exhibits mechanical strength and compatibility with imaging modalities, with custom PEEK implants providing stable results. Acrylic materials, like poly-methylmethacrylate (PMMA), offer strength and is thus mostly used in the case of cranioplasty. Bioceramics, notably hydroxyapatite (HaP), offer osteoconductive and inductive properties, and HaP granules demonstrate stable volume retention in facial aesthetic augmentation. Combining HaP with other materials, such as PLA, may enhance mechanical stability. 3D bioprinting with HaP-based bioinks presents a promising avenue for customizable and biocompatible implants. In conclusion, various materials have been used for craniofacial augmentation, but none have definitively demonstrated superiority. Larger randomized controlled trials are essential to evaluate short- and long-term complications comprehensively, potentially revolutionizing facial balancing surgery.

Quantifying outcomes of autologous fat transplantation in different facial deformities: A systemic review and meta-analysis

BACKGROUND

Autologous fat transplantation has become a common treatment for facial deformities. However, facial deformities are the result of complex diseases with different causes, and there has been no review on the effectiveness of autologous fat transplantation for facial deformities of different aetiologies.

METHODS

A systematic literature search of the Web of Science, Embase, and Medline Ovid databases was performed up to December 2022. Two investigators independently performed screening and data extraction according to Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines, followed by a meta-analysis using random-effects model for surgeon and patient satisfaction, facial symmetry, and complication rates. Twelve-month postoperative fat graft retention was estimated by meta-regression.

RESULTS

Thirty-one studies met the criteria, including 13 case series studies, 14 cohort studies, and four randomized clinical trials, with a total of 1572 patients. Follow-up visits within 6-12 months were performed in most of the studies. The results of the meta-analysis showed high overall surgeon satisfaction of 97% (95% CI: 92%-100%) and patient satisfaction of 95% (95% CI: 89%-99%), with a low complication rate of 3.4% (95% CI: 1.9%-5.9%). At 12 months postoperatively, a lower retention rate of 43% (95% CI: 28%-58%) was estimated in cases of acquired atrophic deformities compared with 64% (95% CI: 57%-71%) in cases of mixed deformities. Overall, autologous fat transplantation improved facial symmetry by 13% (95% CI: 8.4%-18%).

CONCLUSION

Autologous fat transplantation is generally a safe and effective procedure that can compensate for facial volume deficits and improve facial symmetry but may be less effective in cases of acquired atrophic facial deformities.

Facial Feminization Surgery: Anatomical Differences, Preoperative Planning, Techniques, and Ethical Considerations

Facial Feminization Surgery (FFS) is a transformative surgical approach aimed at aligning the facial features of transgender women with their gender identity. Through a systematic analysis, this paper explores the clinical differences between male and female facial skeletons along with the craniofacial techniques employed in FFS for each region. The preoperative planning stage is highlighted, emphasizing the importance of virtual planning and AI morphing as valuable tools to be used to achieve surgical precision. Consideration is given to special circumstances, such as procedure sequencing for older patients and silicone removal. Clinical outcomes, through patient-reported outcome measures and AI-based gender-typing assessments, showcase the efficacy of FFS in achieving proper gender recognition and alleviating gender dysphoria. This comprehensive review not only offers valuable insights into the current state of knowledge regarding FFS but also emphasizes the potential of artificial intelligence in outcome evaluation and surgical planning to further advance patient care and satisfaction with FFS.

Injectable pulverized electrospun poly(lactic-co-glycolic acid) fibers improve human adipose tissue engraftment and volume retention

Autologous adipose tissue is commonly used for tissue engraftment for the purposes of soft tissue reconstruction due to its relative abundance in the human body and ease of acquisition using liposuction methods. This has led to the adoption of autologous adipose engraftment procedures that allow for the injection of adipose tissues to be used as a "filler" for correcting cosmetic defects and deformities in soft tissues. However, the clinical use of such methods has several limitations, including high resorption rates and poor cell survivability, which lead to low graft volume retention and inconsistent outcomes. Here, we describe a novel application of milled electrospun poly(lactic-co-glycolic acid) (PLGA) fibers, which can be co-injected with adipose tissue to improve engraftment outcomes. These PLGA fibers had no significant negative impact on the viability of adipocytes in vitro and did not elicit long-term proinflammatory responses in vivo. Furthermore, co-delivery of human adipose tissue with pulverized electrospun PLGA fibers led to significant improvements in reperfusion, vascularity, and retention of graft volume compared to injections of adipose tissue alone. Taken together, the use of milled electrospun fibers to enhance autologous adipose engraftment techniques represents a novel approach for improving upon the shortcomings of such methods.

Assessing Adipocyte Viability and Surgeons' Work Efficiency by Comparing Different Liposuction Methods

Background

Autologous fat grafting is widely used in plastic and reconstructive surgery. Liposuction methods play a key role in surgeons' work efficiency, adipocyte viability, graft survival, and outcomes. We investigated the effect of four liposuction methods on adipocyte viability, debris, and surgeons' work efficiency by measuring the active energy expenditure and changes in heart rate.

Methods

Human lipoaspirate was harvested from patients' removed abdominal flaps using four different liposuction methods, and we counted calories per aspirated volume and surgeons' heart rate. Adipocytes were separated from the lipoaspirate immediately by digestion with 0.1% type I collagenase. After digestion, parts of the cells and debris were measured. Adipocytes were plated in an adipocyte maintenance medium containing Alamar blue reagent. The adipocyte metabolic activity was measured using a spectrophotometer.

Results

After evaluating the active energy expenditure and changes in surgeons' heart rate, the ultrasonic-assisted liposuction (UAL) method was determined to be the most ergonomic liposuction device for surgeons. In addition, adipocyte viability was higher in the UAL group than in the other groups, and debris was the lowest in the power-assisted liposuction 1 group (PAL1).

Conclusions

Adipocyte viability is crucial for improving fat grafting outcomes. This study revealed that the viability of adipocytes is best preserved using the UAL and PAL1 liposuction methods. The UAL and PAL1 methods caused the least damage to the cells. The UAL method yielded the best results for surgeons' work efficiency.

Safety and Aesthetics of Autologous Dermis-Fat Graft after Parotidectomy: A Multidisciplinary Retrospective Study

(1) Background: In surgical procedures for maxillofacial tumours, it is challenging to preserve functional and cosmetic properties in the affected patients. The use of fat grafting is considered as a valuable alternative to overcome postoperative aesthetic asymmetry problems. (2) Methods: In this study, we enrolled thirty patients with parotid gland tumours in which a partial or complete parotidectomy was performed with positioning in the parotid bed of autologous dermis-fat grafts. We evaluated the satisfaction rate of the patients and the objective efficacy in solving the deformity by comparing MRI data before and after surgery. (3) Results: Twenty-six patients showed a satisfying cosmetic result with proper facial symmetry between the affected side and the healthy one. Two patients presented mild postsurgical complications such as haematomas, and two patients reported temporary weakness of the facial nerve related to the parotidectomy. (4) Conclusions: Based on the imaging data obtained via MRI before and after surgery, we can assess that the employment of fat grafts in parotidectomy surgical procedures gives good cosmetic results and does not affect the post operative management and follow up of oncologic patients.

Stem Cell-Enriched Fat Grafts Versus Autologous Fat Grafts for Facial Reconstruction: A Systematic Review and Meta-analysis

OBJECTIVE

The aim of the study is to compare the outcomes of stem cell-enrichment fat grafting versus routine fat grafting for facial reconstruction purposes.

METHODS

A systematic review and meta-analysis were performed as per the Preferred Reporting Items for Systematic Reviews and Meta-analyses Guidelines and a search of electronic information was conducted to identify all randomized controlled trials, case control studies, and cohort studies comparing the outcomes of stem cell enrichment fat grafting versus routine fat grafting for facial reconstruction purposes. Volume retention and infection rate were primary outcome measures. Secondary outcome measures included patient satisfaction postsurgery, redness and swelling, fat necrosis, cysts, as well as operation time. Fixed and random effects modeling was used for the analysis.

RESULTS

Eight studies enrolling 275 subjects were selected. There was a significant difference between the stem cell enrichment fat grafting and routine grafting groups in terms of mean volume retention (standardized mean difference, 2.49; P < 0.00001). However, there was no significant difference between the 2 groups in the rate of infection (odds ratio, 0.36; P = 0.30). For all secondary outcomes, the intervention group had similar results compared with the control group except for the operation time, which was shorter in the latter.

CONCLUSIONS

Stem cell-enriched fat grafting is a superior option when compared with the routine fat grafting for facial reconstruction surgery because it improves the mean volume retention and does not worsen patient satisfaction and surgical complications.

Three-dimensional Quantitative Standards for Assessing Outcomes of Facial Lipotransfer: A Review

BACKGROUND

Reliable quantitative data are required to address the unpredictability of facial autologous fat grafting (AFG). Facial evaluation by 3D scanning technology is getting popular. However, this process lacks unified standards and the reliability assessments. This study aimed to summarize a set of standards to improve the 3D quantified reliability of AFG outcomes.

METHODS

A systematic review was used to collect the differences in and limitations of 3D assessments and analyze the effect of the quantification process on the AFG outcomes. Healthy subjects undergoing only one facial structural AFG and 3D assessments were included. The revealed specific issues guided the subsequent narrative review that involves 3D measurement and fat volume retention rate (FVRR) analysis. Criteria were formulated based on the narrative review.

RESULTS

The systematic review revealed the quantitative process to be operator-dependent. The intra-group FVRR in the postoperative 11+ month group varied significantly (P=.03). The review identified a set of 3D measurement standards, including two optimal software products, two necessary steps for preprocessing, and four testing criteria. We proposed a new calculation formula and parameter and recommended a segmental area analysis for assessing the outcomes of full-face fat grafting.

CONCLUSIONS

As far as the 3D evaluation of AFG outcomes is concerned, this is the first study to comprehensively analyze the process and set quantitative criteria. These standards would not only guide future research more reliably, but also provide fresh insight into the review of the past research. 3D measurement standards also apply to all face-related studies requiring 3D registration.

LEVEL OF EVIDENCE III

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 .

Cheek Augmentation in Gender-Affirming Facial Surgery

The cheek area is an important area in facial beauty. High cheekbones and full malar area is considered a desired feminine feature and therefore an essential component of gender-affirming facial surgery. The most common treatment options are injectable fillers, autologous fat grafting, and alloplastic cheek implants. Fillers are customizable and reversible and have minimal recovery but are not preferred because of need for maintenance and cost. Fat grafting has many desirable characteristics, such as abundance, customizability, biocompatibility, and relative low cost. However, evidence for its long-term longevity is lacking. Alloplastic implants are a reliable augmentation method but associated with implant related complications such as infection, migration, and visibility.

The General Registry of Autologous Fat Transfer: Concept, Design, and Analysis of Fat Grafting Complications

BACKGROUND

The American Society of Plastic Surgeons and The Plastic Surgery Foundation launched GRAFT, the General Registry of Autologous Fat Transfer, in October of 2015. This web-accessible registry addresses the need for prospective and systematic data collection, to determine the rates of unfavorable outcomes (complications) of fat grafting. Understanding and avoiding the factors that lead to complications can help establish safe practices for fat grafting.

METHODS

Data collected between October of 2015 and November of 2019 were summarized for age, sex, indications, processing techniques, and fat graft volume. Rates of complications for fat grafting to various anatomical areas were calculated.

RESULTS

The General Registry of Autologous Fat Transfer collected data on 7052 fat grafting procedures from 247 plastic surgery practices. The mean age of the patients in the registry was 51 years (range, 1 to 89 years), 94 percent were female, and 64 percent of the procedures were for aesthetic indications. Whereas the overall complication rate was low (5.01 percent), the complication rates for fat grafting to the breast and buttocks (7.29 percent and 4.19 percent, respectively) were higher than those for face and other areas (1.94 percent and 2.86 percent, respectively). Oil cysts (2.68 percent) and infections (1.64 percent) were the most common complications of breast fat grafting, whereas seroma (1.84 percent) and palpable mass (1.33 percent) were most common for fat grafting to buttocks. Palpable mass (0.54 percent) and infections (0.54 percent) were most common for fat grafting to face.

CONCLUSIONS

The General Registry of Autologous Fat Transfer provides a valuable tool for prospective tracking of fat grafting techniques and complications. Data collected in the registry show low rates of complications for all recipient areas treated with fat grafting.

CLINICAL RELEVANCE STATEMENT

GRAFT collects real world data on complications of autologous fat grafting procedures. The data collected over 4 years shows low rates of complications for fat grafting. The benchmarking tools available in GRAFT can help enhance techniques and safety of fat grafting.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

The Effect of Different Diameters of Fat Converters on Adipose Tissue and Its Cellular Components: Selection for Preparation of Nanofat

BACKGROUND

Nanofat is an autologous product prepared mechanically from harvested fat. In nanofat grafting, converters are employed for mechanical emulsification to facilitate fat injection. To date, the study of different converters has received scant attention regarding whether they affect the characteristics of nanofat in terms of the practical applications and indications.

OBJECTIVES

The authors set out to investigate the influence of different internal diameters of converters on biological functionality of nanofat during shuffling.

METHODS

The 3-dimensional finite element method was employed to simulate the process of mechanical emulsification of fat and to research the stress with 5 different converters (3.76 mm, 2.00 mm, 1.20 mm, 1.00 mm, 0.80 mm). An assessment of the morphology of emulsified fat was conducted. Isolated stromal vascular fraction (SVF) was analyzed for cellular components, number, and viability through flowcytometry and live/ dead staining. Adipocytic and angiogenic differentiation assay allowed assessment of differentiation capacity of the SVF.

RESULTS

The smaller the aperture of the converter, the greater the mechanical force on adipose tissue during mechanical emulsification, showing the different macroscopic and microscopic structure of the emulsified fat. No difference in viability or ratio of endothelial progenitor cells and other cells was found. Angiogenic and adipogenic differentiation capacity of the SVF significantly changed in 5 different converters.

CONCLUSIONS

The mechanical emulsification from different apertures of converters exerts different effects of adipose tissue structure, cell content, and multipotency differentiation but not its viability. Converters with different apertures can be selected according to clinical needs.

Hybrid Implant and Grafted Fat Breast Augmentation: Designing the Pathway to a Future With Breasts Free of Silicone Breast Implants

BACKGROUND

Fat grafting in breast augmentation surgery is becoming increasingly popular, allowing surgeons to fill the gaps that implant augmentation alone cannot. However, one of the current issues surrounding fat grafting is the lack of standardization.

OBJECTIVES

The objective of this study was to validate and summarize expert-based advice to help plastic surgeons better understand the benefits of utilizing fat grating to reduce implant size in their surgical planning.

METHODS

This was a prospective study of fat grafting in 56 patients who underwent fat transfer together with silicone breast implants. A 3-dimensional planning system was used to plan the procedure and also to analyze the fat retention and resorption rates. Pictures served as a basis for a questionnaire in which both patients and physicians were asked to rate their satisfaction.

RESULTS

Patients reported a satisfaction rate of "excellent" in 83.3% of cases and "good" in 16.7%. Physician satisfaction was rated as "excellent" in 84.5% of cases, "good" in 13.3%, and "fair" in 4.2% of cases. The mean fat volume grafted per breast was 113.63 mL. The mean absorption rate was 4.53%.

CONCLUSIONS

The procedure presented consistent and reproducible results. Hybrid breast augmentation can help design a pathway for a future with breasts free of silicone. This information is particularly relevant for women who have their first breast augmentation at an early age and will probably have 2 to 5 additional surgeries in their lifetime due to the nature of current silicone breast technology.

LEVEL OF EVIDENCE: 4

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.

Adipose matrix complex: a high-rigidity collagen-rich adipose-derived material for fat grafting

Due to the low percentage of collagen, the rigid support capacity of fat grafts remains unsatisfactory for some clinical applications. In this study, we evaluated a strategy in which adipose matrix complex (AMC) was collected via a mechanical process and transplanted for supportive filling of the face. Our AMC samples were collected from adipose tissue by a filter device consisting of a sleeve, three internal sieves, and a filter bag (100 mesh). AMC derived from adipose tissue had fewer cells than Coleman fat, but much higher levels of collagen and stiffness. Retention rates 90 days after transplantation in nude mice were higher for AMC than for Coleman fat (75±7.5% vs. 42±13.5%; P < 0.05). In addition, AMC maintained a higher stiffness (~6 kPa vs. ~2 kPa; P < 0.01) and stably retained a higher level of collagen. Our findings demonstrate that mechanical collection of AMC from adipose tissue is a practical method for improving fat graft retention and rigid support. This strategy has the potential to improve the quality of lipoaspirates for patients requiring rigid supportive filling.

Impact of Fat Graft Thickness and Harvesting Technique on Adipocyte Viability in a New Porcine Experimental Model: An Immunohistochemical Analysis

BACKGROUND

Autologous fat grafting (AFG) has been employed in surgical practice as a filling method. However, controversies remain on the specifics of this technique. So far, few relevant experimental large animal studies have objectively assessed factors related to AFG integration.

OBJECTIVES

This study utilized an experimental, medium-sized animal model to compare the feasibility of AFG collected employing 2 different techniques with instruments of distinct thicknesses.

METHODS

Twenty minipigs (Sus scropha domesticus) were subjected to AFG harvesting via en bloc resection utilizing 3- (Group I) and 5-mm-diameter (Group II) round punch blades (PBs) and liposuction (LS) with 3- (Group III) and 5-mm-diameter cannulas (Group IV). Both samples were grafted intramuscularly (biceps femoralis). Hematoxylin and eosin staining was employed to identify intact adipocytes, fat necrosis, fibrosis, inflammation, and oil cysts. Immunohistochemical staining (perilipin-A, tumor necrosis factor alfa, and cluster of differentiation number 31) was utilized to quantify the feasibility of adipocytes, tissue necrosis, and neoangiogenesis, respectively.

RESULTS

Hematoxylin and eosin analysis showed that fat necrosis and histiocyte presence were significantly lower in the AFG harvested utilizing a PB than in LS. For perilipin-A, a statistical difference was observed between subgroups I and III (P = 0.001) and I and IV (P = 0.004). Instrument diameter had no effect on graft integration in comparisons between groups II and III (P = 0.059) and II and IV (P = 0.132).

CONCLUSIONS

In this experimental study, fat collected utilizing a PB demonstrated higher adipocyte viability than fat collected with LS. The diameter of the collection instruments, whether PB or LS, had no effect on graft integration.

Primary Observation of the Causes of Temporal Hypertrophy Secondary to Fat Grafting and the Effect of Liposuction on the Hypertrophy

OBJECTIVE

In Asia, the temporal hollowing is considered to be a sign of bad fortune and aging. Many people demand to correct the temporal hollowing with fat grafting. Subsequently, the temporal hypertrophy secondary to fat grafting become more and more. This study attempted to preliminarily explore the causes of temporal hypertrophy and observe the safety and effectiveness of liposuction in correcting temporal hypertrophy.

METHODS

A diagnostic criteria for temporal hypertrophy was established, and 55 of 78 patients who complained of temporal swelling were defined as temporal hypertrophy, and filled out a questionnaire which included patients' basic information, preoperative, intraoperative, and postoperative problems related to fat grafting, as well as their acceptance of liposuction. Analyze the results of the questionnaire to explore which factors are associated with hypertrophy. Practice liposuction on patients who are willing to try liposuction. Postoperative complications were observed to determine the safety of liposuction. The patients, doctors, and bystanders were followed up 3 months postoperative to investigate the satisfaction of the operation for analyzing the effectiveness of liposuction for temporal hypertrophy.

RESULTS

Before fat grafting, 13 (23.6%) patients without significant temporal hollowing and 42 (76.4%) patients with obvious temporal hollowing; 28 (50.9%) patients with 1 fat grafting, 20 (36.4%) with 2 fat gratings, 7 (12.7%) with 3 fat grafting. The mean time between 2 fat gratings was 4.8 months. The fat donor sites: 50 (90.9%) patients in thigh, 4 (7.3%) in abdomen, and in 1 (1.8%) in waist. The average onset time of hypertrophy in 55 patients was 13.1 months after the last fat grafting. The average onset time of temporal hypertrophy of the weight-gain group (25.7 months) was significant later than that of the weight-invariant group (7 months) (P < 0.01).No irregularities, skin necrosis, hematoma, or infection was found in all patients. One patient showed the damage to temporal branch of facial nerve on right side, which fully recovered at 1 week postoperative. 7 (22.6%) patients, 10 (32.3%) doctors, and 8 (25.8%) laypersons reported satisfactory results; 14 (45.2%) patients, 15 (48.4%) doctors, and 14 (45.2%) laypersons reported mostly satisfactory results; 10 (32.3%) patients, 6 (19.4%) doctors, and 9 (29.0%) laypersons reported dissatisfactory results.

CONCLUSIONS

To prevent temporal hypertrophy, the following points are important: to rationally choose of indication of temporal fat grafting, to wait 1 to 2 years before next fat grafting, to maintain weight stability after fat grafting, to practice conservative fat grafting, to prudently choose fat donor site. Liposuction is safe for temporal hypertrophy, but it is not easy to operate and difficult to correct all cases. Therefore, a superior treatment plan should be explored.

Physical, Biochemical, and Biologic Properties of Fat Graft Processed via Different Methods

Clinical use of autologous fat for correction of soft-tissue defects in cosmetic and reconstructive procedures has grown in popularity. Graft processing is implicated as one of the variable factors affecting quality, viability, and subsequent graft survival. This study analyzed the in vitro physical and biologic characteristics of lipoaspirate processed using different techniques.

Methods

Fresh lipoaspirates from patients with informed consent were processed by 4 methods: decantation, centrifugation, the REVOLVE System, and PureGraft. Processed fat grafts were analyzed for yield, composition, tissue particle size and morphology, and viability and function of adipocytes and stem cells. Fat tissue harvested from waste containers of REVOLVE and PureGraft and trapped on REVOLVE paddles was also evaluated.

Results

Grafts produced by the filtration systems contained the highest percentage of fat tissue, whereas those from decantation contained the lowest percentage, although they have the highest volume yield. In addition, grafts from REVOLVE and PureGraft showed more large-sized particles (>1000 μm) than those from decantation or centrifugation. REVOLVE also preserved significantly higher populations of viable and functional adipocytes and stromal vascular fraction cells when compared with other processing methods. Tissue particles in waste containers of REVOLVE and PureGraft were mostly (>85%) <300 μm and demonstrated a minimal number of viable adipocytes and stem cells. Fat tissues trapped on REVOLVE paddles contained a higher percentage of noninjectable and fibrous collagen bundles.

Conclusion

Different processing methods result in fat grafts with varying physical and biologic properties, which may contribute to fat graft viability and retention in vivo.

The role of a shelf-ready, human-derived, soft tissue injectable adipose matrix for facial volume correction

BACKGROUND

Synthetic soft tissue fillers frequently used to restore facial volume do not provide a regenerative framework, limiting their sustained efficacy. Autologous fat transfer for facial rejuvenation supports tissue regeneration but has unpredictable outcomes depending on the quality of harvesting, processing, and implantation.

AIMS

Exploration of the pros and cons of available tissue fillers and the role of an injectable Allograft Adipose Matrix (AAM) for facial rejuvenation.

METHODS

The results of a literature review conducted by two clinicians with extensive experience in this field were discussed by a panel of dermatologists and surgeons who regularly treat patients with signs and symptoms of facial aging. A manuscript was prepared and reviewed by the panel taking into account the evidence and their clinical experience treating patients for facial rejuvenation.

RESULTS

Facial rejuvenation needs to address the volume deficiency and repositioning of ptotic soft tissues. Frequently used synthetic fillers are suitable candidates for improving the facial appearance of fine lines and for molding. A better understanding of facial volume loss has allowed the use of adipose fat cells for facial rejuvenation. The injectable AAM is readily available and provides a regenerative framework for sustainable results. Prospective clinical and randomized studies support the effective and safe use of AAM for facial rejuvenation.

CONCLUSION

AAM may offer an alternative to synthetic fillers and autologous fat implantation in the face without the cumbersome process of fat harvesting and processing. More robust studies are to confirm the positive results obtained in smaller studies using the soft tissue bio stimulatory injectable.

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.

Cryopreservation of lipoaspirates: in vitro measurement of the viability of adipose-derived stem cell and lipid peroxidation

As the storage time of the fat tissue passes by, lipid peroxidation and creation of by‐products may take place. The objective of this study was to evaluate the cell viability and functional changes of adipose‐derived stem cells (ADSCs) in the cryopreserved lipoaspirates at different temperatures in accordance with lipid peroxidation. Lipoaspirates acquired from liposuction were divided into four different temperature groups and stored at 4°C, −20°C, −80°C, and −196°C. After isolating ADSC from each sample, gross cell morphology and cell viability were compared with doubling time and colony‐forming unit (CFU) formation ability. Acid value, that is, thiobarbituric acid value was measured to assess lipid peroxidation. No viable ADSC was observed in −20°C and −196°C samples for past 1 week and a superior number of the live cells were detected in the 4°C group compared with the −80°C group. However, the persistence of cell division and CFU formation after 1 week was only observed in adipocytes stored at −80°C. Lipid peroxidation mainly occurred at 4°C and −20°C storage samples. If the lipoaspirates were planned to be cryopreserved, it is advised to store at −80°C. However, the number of actually functional ADSCs is very low. Furthermore, even in the cryopreserved status, continuous lipid peroxidation and by‐product creation took place, suggesting shorter preservation period as possible in the clinics.

Impact of growth factor content on proliferation of mesenchymal stromal cells derived from adipose tissue

Autologous adipose tissue (AT) transfer has gained widespread acceptance and is used for a broad variety of regenerative clinical indications. It is assumed that the successful outcome of AT transfer essentially depends on the amount of autocrine-generated growth factors (GF). It is supposed that several GF enhance and improve the anatomic and functional integration of the transplanted AT grafts at the site of implantation. In the present study we have investigated for the first time the correlation between the concentration of GF of freshly isolated AT and the proliferation and migration capacity of mesenchymal stroma cells (MSCs) derived from the respective AT sample. We here show that the proliferation and migration capacity of MSCs strongly depends on the GF content of the AT the cells were isolated from but in an inversely proportional manner. The lower the GF content of an AT sample was, the higher was the proliferation and migration capacity of the respective MSC population contained in the AT and vice versa. Furthermore, we found that supplementation with recombinant GFs only in the case of AT samples with low but not with higher growth factor contents led to a significant enhancement of proliferation and migration of the AT-resident MSCs. As we further show, this inefficiency of GFs to enhance MSC proliferation and migration in AT samples with high GF contents indicates a GF-mediated negative feedback mechanism leading to an impaired GF signaling in MSC obtained from those AT samples. Our results might explain why the successful use of AT grafting is frequently limited by low and unpredictable survival rates, and we suggest to use the knowledge of GF content of harvested AT as a predictive clinical parameter for risk assessment of the therapeutic outcome of autologous AT transfer.

Power-Assisted Liposuction and Lipofilling: Techniques and Experience in Large-Volume Fat Grafting

BACKGROUND

Power-assisted liposuction and lipofilling (PALL) is a simple and reproducible surgical technique for large volume fat grafting.

OBJECTIVES

The authors share their 7-year experience with their large-volume fat transfer technique, PALL.

METHODS

A total of 417 patients who underwent PALL-related surgeries involving the breast and buttock were evaluated in a retrospective study. Liposculpting and fat harvesting were performed with power-assisted liposuction. Fat was transferred with simultaneous power-assisted vibration and tunnelization to provoke expansion of the recipient site. Following lipofilling, additional external vibration of the recipient site was performed to enhance diffusion of the injected fat.

RESULTS

Liposuction volumes up to 5000 mL were recorded, and injection volumes ranged from 300 to 900 mL per side for each session. Operating times ranged from 45 to 120 minutes. Patients were followed-up for 1 to 4 years. No major complications were recorded.

CONCLUSIONS

PALL is an efficient, safe, and reproducible procedure with myriad applications in aesthetic and reconstructive surgery.

Level of Evidence: 4.

Clinical Evaluation of an Off-the-Shelf Allogeneic Adipose Matrix for Soft Tissue Reconstruction

Biomaterials derived from human adipose extracellular matrix have shown promise in vitro and in animal studies as an off-the-shelf adipogenic matrix for sustained volume replacement. Herein, we report the results of a randomized prospective study conducted with allograft adipose matrix (AAM) grafted into the pannus of presurgical abdominoplasty patients 3 or 6 months before scheduled surgery. This is the first report of a longitudinal histologic analysis of AAM in clinical use.

METHODS

Ten healthy patients undergoing elective abdominoplasty were recruited to receive AAM before surgery. Enrolled subjects were randomized into either a 3-month follow-up cohort or a 6-month follow-up cohort. Subjects were monitored for adverse events associated with AAM grafting in addition to undergoing serial biopsy. Following surgical excision of the pannus, representative samples from the AAM surgical sites were stained and evaluated with hematoxylin and eosin for tissue morphology, Masson's trichrome for collagen, and perilipin for adipocytes.

RESULTS

All subjects tolerated AAM with no severe adverse events reported. At 3 months following implantation, AAM remained visible within the confines of the subjects' native surrounding adipose tissue with sparse adipocytes apparent within the matrix. By 6 months, AAM had remodeled and was primarily composed of perilipin-positive adipocytes. Histologic analysis confirmed tissue remodeling (hematoxylin and eosin), adipogenesis (perilipin), and angiogenesis (Masson's trichrome) occurred with the presence of AAM.

CONCLUSIONS

AAM is a safe, allogeneic, off-the-shelf regenerative matrix that is adipogenic and noninflammatory and promotes angiogenesis.

Prevention and Management of Serious Complications After Facial Fat Grafting

Facial fat grafting is increasing worldwide. Although there are few reports in the literature on complications following facial lipofilling, rare but serious complications include embolic risk to local end organs such as the skin and eye, and the central nervous system. Treatment strategies are outlined. The key to prevention of complications is understanding the regional anatomy. It is imperative to adhere to the safe and efficacious techniques to minimize risk. Every surgeon who performs facial fat grafting should establish a systematic method to deliver safe, consistent, and long-term results for their patients.

Principles and Applications of Fat Grafting in Plastic Surgery

Autologous fat transplantation has become increasingly popular in recent years. Its biocompatable properties and availability made it a widely used treatment modality for soft tissue augmentation and volume replacement in both reconstructive and aesthetic plastic surgery. Multiple protocols and clinical applications have been described in the literature, with wide variations in the harvesting, processing, and injection techniques. In this review, the authors will discuss the basic principles and clinical applications of fat grafting in plastic and reconstructive surgery. The article will then conclude with a discussion of fat grafting limitations as well as potential future applications, giving the reader a well-rounded understanding of autologous fat transfer.

Autologous fat transfer for facial recontouring in Parry-Romberg syndrome

BACKGROUND

Parry-Romberg syndrome (PRS) is a rare condition involving self-limited progressive facial hemiatrophy.

AIMS

To analyze esthetic results of fat graft used for correcting soft-tissues atrophy in PRS patients, in the aspect of volume restoration and skin rejuvenation, to present our experience in redefining facial contours in PRS and modification of fat graft accusation technique (based on Coleman's technique).

PATIENTS/METHODS

A prospective evaluation study was designed to analyze esthetic results (contour and skin condition), complications, and subjective satisfaction of eight patients with PRS treated with fat graft.

RESULTS

All patients underwent two (n = 6) or three (n = 2) procedures in 3 months intervals (the mean 3.7 months). No major postoperative complications were observed. The authors evaluated their esthetic results concerning face contour and symmetry as good (in four patients) and very good (in four patients). Subjective assessment showed high patients' satisfaction with the final result of face contouring (the mean VAS [0-5]-4.75).

CONCLUSIONS

Our experience shows that fat grafting in patients with PRS is safe and gives satisfactory results in the aspect of volume restoration and skin quality improvement. Modified technique of graft preparation (112 g for 3 minutes) enables to obtain less dense fat graft, which is more appropriate in case of PRS patients with thin atrophic skin.

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.

Increased Angiogenic and Adipogenic Differentiation Potentials in Adipose-Derived Stromal Cells from Thigh Subcutaneous Adipose Depots Compared with Cells from the Abdomen

BACKGROUND

Adipose-derived stromal cells (ADSCs) may play a pivotal role by differentiating into multilineage cells or by secreting growth factors or cytokines in cell-assisted lipotransfer, which participates in adipose tissue regeneration. The angiogenic potential of various ADSCs from different anatomical regions remains uncertain.

OBJECTIVES

The authors sought to offer appropriate choices of sources of adipose-derived stromal cells for cell-assisted lipotransfer and tissue engineering.

METHODS

ADSCs were harvested from subcutaneous adipose depots in the abdomen and thighs. The expression of adipocyte-specific markers was evaluated, and Oil Red O staining was performed to assess the capacity for adipogenic differentiation. Angiogenic differentiation potential was evaluated by detecting the expression of vascular endothelial growth factor, vascular endothelial growth factor 2, and CD31. A tube formation assay was also performed to analyze the angiogenic differentiation capacity.

RESULTS

ADSCs from the thigh showed more significant angiogenic and adipogenic potential. More lipogenesis was identified in ADSCs from the thigh, and this was accompanied by the enhancement of adipocyte markers. Angiogenesis was more vigorous in the thigh-derived stromal cells, and ADSCs from the thigh depot showed more junctions and longer tubule formation on Matrigel in vitro.

CONCLUSIONS

Thigh-derived ADSCs exhibited greater capacity for adipogenic and angiogenic differentiation and would be a better option for cell-assisted lipotransfer and tissue engineering.

Effect of Decantation Time on Viability and Apoptosis in Adipocytes After Liposuction

BACKGROUND

The effect of decantation time on viability and apoptosis in adipocytes has not been described. The objective of the study was to describe viability and apoptosis in adipocytes up to 2 h after harvesting.

METHODS

Twenty patients who underwent esthetic liposuction from the abdomen were included. The lipoaspirate was obtained from the infra-umbilical area with the tumescent technique. Liposuction was performed with a 60-ml syringe and a 3-ml cannula. Lipoaspirates were centrifuged at 50 g for 5 min at 0, 60 and 120 min after harvesting. One gram of fat was digested with 0.1% type 1 collagenase and incubated at 37 degrees for 30 min. Adipocytes were counted on 10 random microscopic fields. Apoptosis was determined by TUNEL assay. A fluorescence microscope was used to visualize the staining nuclei and cells.

RESULTS

Regarding viability, immediately after harvesting, 57.6 ± 18.9% of the cells were viable, whereas 60 min after liposuction the viability decreased to 51.62 ± 8.8% and 120 min after liposuction the percentage of viable cells was 46.8 ± 16.9%. The percentage of apoptotic cells at time 0 was 38.2 ± 8.0%, whereas it was 51.24 ± 8.1% at 60 min and 62.9 ± 16.1% at 120 min after collection.

CONCLUSIONS

Apoptosis and mortality of adipocytes after liposuction increase directly proportional to the time of decantation. Lipoinjection should be performed as soon as possible after harvesting.

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 .

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.

Current Therapeutic Strategies for Adipose Tissue Defects/Repair Using Engineered Biomaterials and Biomolecule Formulations

Tissue engineered scaffolds for adipose restoration/repair has significantly evolved in recent years. Patients requiring soft tissue reconstruction, caused by defects or pathology, require biomaterials that will restore void volume with new functional tissue. The gold standard of autologous fat grafting (AFG) is not a reliable option. This review focuses on the latest therapeutic strategies for the treatment of adipose tissue defects using biomolecule formulations and delivery, and specifically engineered biomaterials. Additionally, the clinical need for reliable off-the-shelf therapies, animal models, and challenges facing current technologies are discussed.

Objective Evaluation of Eyebrow Position After Autologous Fat Grafting to the Temple and Forehead

BACKGROUND

Fat grafting can be used to correct age-related volume loss in the face. However, the degree of rejuvenation is difficult to be evaluated.

OBJECTIVES

The author sought to objectively verify the change in patients' eyebrow position after fat grafting to the upper face.

METHODS

The charts of 175 consecutive patients who underwent autologous fat grafting to the forehead and temple were reviewed. Perioperative changes in the heights of medial, middle, and lateral segments of the eyebrow and the eyebrow slant were recorded and compared. Key prevention strategies to avoid potential complications were discussed.

RESULTS

The eyebrow slant was increased by 2.4° after the operation which was statistically significant (p < 0.05). On the other hand, the medial eyebrow height was decreased, while the middle and lateral eyebrow heights were increased after the surgery which were of no significance. No major complications such as vision loss or vascular compromise were noted.

CONCLUSIONS

Simultaneous autologous fat grafting to the temple and forehead significantly increased the slant of the eyebrows and corrected the loss of upper facial fullness as well. Collectively, these changes made the patient look younger and aesthetically more pleasant.

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 .

Injectable facial fillers: imaging features, complications, and diagnostic pitfalls at MRI and PET CT

Injectable fillers are widely used for facial rejuvenation, correction of disabling volumetric fat loss in HIV-associated facial lipoatrophy, Romberg disease, and post-traumatic facial disfiguring. The purpose of this article is to acquaint the reader with the anatomy of facial fat compartments, as well as with the properties and key imaging features of commonly used facial fillers, filler-related complications, interpretation pitfalls, and dermatologic conditions mimicking filler-related complications. The distribution of facial fillers is characteristic and depends on the anatomy of the superficial fat compartments. Silicone has signature MRI features, calcium hydroxyapatite has characteristic calcifications, whereas other injectable fillers have overlapping imaging features. Most fillers (hyaluronic acid, collagen, and polyalkylimide-polyacrylamide hydrogels) have signal intensity patterns compatible with high water content. On PET-CT, most fillers show physiologic high FDG uptake, which should not be confounded with pathology. Abscess, cellulitis, non-inflammatory nodules, and foreign body granulomas are the most common filler-related complications, and imaging can help in the differential diagnosis. Diffusion weighted imaging helps in detecting a malignant lesion masked by injected facial fillers. Awareness of imaging features of facial fillers and their complications helps to avoid misinterpretation of MRI, and PET-CT scans and facilitates therapeutic decisions in unclear clinical cases.

KEY POINTS

• Facial fillers are common incidental findings on MRI and PET-CT scans. • They have a characteristic appearance and typical anatomic distribution • Although considered as safe, facial filler injections are associated with several complications • As they may mask malignancy, knowledge of typical imaging features is mandatory. • MRI is a problem-solving tool for unclear cases.

Literature Review to Optimize the Autologous Fat Transplantation Procedure and Recent Technologies to Improve Graft Viability and Overall Outcome: A Systematic and Retrospective Analytic Approach

OBJECTIVE

Investigation and evaluation of the current methods and steps of autologous fat transplantation to optimize the viability of fat grafts and procedure outcome in quest of a more standardized protocol.

METHODS

A thorough literature search was performed across the CNKI, Wan Fang, PubMed, Ovid and EMBASE databases from the year 1970 to December 2014, collecting and classifying all of the autologous fat transplantation-related reports and articles, and after screening, a critical retrospective analysis was performed on the included data.

RESULTS

A total of 65 articles were included in the study. However, there were limited numbers of cases dealing with procedure-related steps such as the selection of donor sites, fat acquisition, graft treatment and methodology of transplant, resulting in a significant lack of evidence support, furthermore urging the need for more standardized protocol for the steps of autologous fat transplant to improve graft viability and overall outcome while decreasing procedure-related morbidity.

CONCLUSION

No good evidence was obtained to optimize the donor site, acquisition, processing and transplantation steps of the whole process of autologous fat transplantation. Tissue engineering and stem cell research have the potential to revolutionize the future of reconstructive surgery by replacing tissue, obviating the need for donor site morbidity. However, the use of stem cell therapies to expand and grow tissue for reconstruction must occur in the context of risk management. Balancing ease of harvest with yield and efficacy has been a delicate and often difficult trade-off which has prompted the scientific community to investigate alternative sources. However, there is much hope in the evaluation and implementation of multimodality approaches for autologous fat transplant, including thriving technologies such as ultrasound-assisted, water jet-assisted, nanotechnology-assisted liposuction in combination with revolutionary fat treatment technologies such as the VASER system.

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 .

A promising tool for surgical lipotransfer: a constant pressure and quantity injection device in facial fat grafting

BACKGROUND

The purpose of this study was to preliminarily assess a constant pressure and quantity fat granule injection device for minimal invasive properties in clinic.

METHODS

A retrospective controlled study was carried out, from October 2013 to January 2015, on 76 female healthy patients aged between 26 and 53 years at the General Hospital of Lanzhou Military Command, China. To achieve small volume, high thrust, and precision requirements of facial fat grafting, an integrated handheld controller and motor design was adopted, reducing the volume and weight of the fat transplantation injection device. The 76 patients underwent 90 procedures each side of the face; each patient was treated with the aforementioned device on the face's left side, while a conventional hand-push injection device was used on the right side as control. The outcome was assessed on pre- and postoperative images, with 6-24 months follow-up.

RESULTS

The current device consistently allowed deposition of fat threads at about 55 μL/cm after cannula withdrawal; the volume of fat injected could be precisely adjusted to 0.04 mL/s. This device had the advantages of small-volume injection and convenient operation. The patients exhibited a good, stable shape and a smooth contour line in both sides. The long term satisfaction was higher for the left side than for the right one. Nodules and unevenness occurred only on the right side. Ecchymosis occurred significantly less frequent on the left side than the right one. Intraoperative pain was significantly lower for the left side than the right one.

CONCLUSIONS

This device offered superior control compared with the conventional one and constitutes a promising tool for surgeons practicing lipotransfer.

Orthognathic Surgery with Simultaneous Autologous Fat Transfer for Correction of Facial Asymmetry

BACKGROUND

Most patients treated with orthognathic surgery for facial asymmetry would value improvement in residual soft-tissue asymmetry. Autologous fat transfer is widely used to augment facial soft tissue. The authors assessed the effect of combining orthognathic surgery with autologous fat transfer for treating patients with facial asymmetry.

METHODS

In this retrospective study, 15 consecutive adults underwent combined orthognathic surgery and autologous fat transfer between January of 2013 and December of 2015. Lower facial profile symmetry was assessed using postoperative standard frontal photographs.

RESULTS

Lower facial symmetry was much improved by combining orthognathic surgery and autologous fat injection.

CONCLUSION

The combined use of orthognathic surgery and autologous fat transfer is a promising technique for improving facial symmetry in patients with facial asymmetry.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Facial skin rejuvenation by autologous dermal microfat transfer in photoaged patients: Clinical evaluation and skin surface digital profilometry analysis

Cumulative long-term exposure to solar ultraviolet radiation promotes premature skin aging characterized by wrinkle formation and reduced skin elasticity. In this study, we assessed whether microfat transfer could improve dermal and subcutaneous tissue thickness loss associated with photoaging. Twenty-one patients affected by facial photoaging (photodamage grade II-IV; age range 35-62 years; 19 females, 2 males; all of Caucasian origin) were treated using minimally invasive autologous dermal white fat transfer harvested with a recently designed microcannula. The results were determined by clinical assessment and patient self-evaluation and quantified by the Antera 3D^® dermal digital device for noninvasive, objective, reliable, and accurate assessment of facial skin texture, color, and wrinkle characteristics. Compared with the pretreatment condition, the increment in soft tissue volume and improvement in skin quality and texture were assessed by a dermatologist after treatment. In addition, instrumental evaluation by digital skin profilometry of the treated areas revealed a 41% reduction in average wrinkle depth (7.29 ± 1.04 × 10^-2 mm pretreatment vs. 4.31 ± 1.16 × 10^-2 mm at 90 days posttreatment; p < 0.001), improved skin texture, more homogeneous and uniform skin color, and declined facial hemoglobin and melanin concentrations. The majority of patients (above 90%) reported improvements in self-perception. No significant complications were reported throughout the study. In conclusion, by using digital profilometry analysis as an objective and innovative tool to determine the outcome of treatment, we demonstrated that autologous microfat transfer is a safe and well-tolerated procedure with measurable beneficial effects on facial skin aging.