Autologous fat grafting: Harvesting techniques

Histological Properties of Adipose Tissue as an Autologous Tissue Filler Harvested from Different Donor Areas and Impact of Centrifugation

Background

As a burgeoning technique in reconstructive and aesthetic surgery, lipofilling's success is hindered by the unpredictability of graft integrity and quality. This study addresses the critical need to enhance consistency and reproducibility by exploring the clinical utility of adipose tissue from specific body areas, considering the influence of patient-specific factors and mechanical processing on fat graft integrity and morphology.

Methods

In a prospective, randomized, single-blind study, 52 patients undergoing surgical reconstruction due to significant deformities were enrolled. Lipoaspiration from four areas was performed. Adipose tissue was compared using five parameters of tissue damage and 10 parameters of graft integrity, assessed immediately postcollection and after centrifugation. The study aimed to evaluate the structural integrity and clinical applicability of adipocytes.

Results

Morphological assessment revealed no significant differences in adipose tissue quality across donor sites, suggesting consistent graft quality regardless of the harvesting location. Centrifugation induced more morphological damage than noncentrifuged samples, but the overall graft integrity was maintained due to increased cell density. Higher graft acceptance parameters were noted in noncentrifuged samples compared with centrifuged ones.

Conclusions

Despite centrifugation-induced morphological changes, adipose tissue integrity remains relatively unaffected, supporting a flexible approach to donor site selection. The consistent quality of adipose tissue underscores the potential for autologous fat transplantation across various clinical scenarios. Optimizing graft processing techniques is crucial for enhancing the predictability and efficacy of lipofilling.

Increased Total Antioxidant Capacity Value Improves Survival of Fat Grafts in Rat Model

BACKGROUND

Although studies aiming to increase fat graft survival continue, in this study, the authors aimed to investigate the effects of different antioxidants on total antioxidant capacity (TAC) and their effect on graft survival.

METHODS

Thirty-two male Wistar rats were divided into four equally sized groups, including a control group and three antioxidant groups receiving either melatonin (10 mg/kg), zinc (2 mg/kg), or vitamins E and C (100 mg/kg). Autologous fat grafts (1.7 ± 0.4 g) were transferred to the dorsal subcutaneous region, and total antioxidant capacity was measured on days 0 and 1, week 1, and monthly until the third month. Transferred graft volume and mass (1.3 ± 0.4 g) were measured using the liquid overflow method and precision scales at the end of the study. Routine hematoxylin and eosin staining and immunohistochemistry against perilipin were performed for semiqualitative analysis and H-score for viable adipose cells, respectively.

RESULTS

Collected fat grafts measured significantly less in weight and volume and the survival rate was lower in the control group ( P < 0.01). The control group exhibited a reduction in TAC, whereas all groups receiving antioxidants had an increase in TAC during the first week ( P = 0.02, P = 0.008, and P = 0.004 for melatonin, zinc, and vitamins, respectively). Immunohistochemistry of the antioxidant group demonstrated a statistically significant excess and reactivity of cells staining with perilipin antibodies.

CONCLUSION

In this animal study, the beneficial effect of antioxidants on fat graft survival can be related to the significant increase in TAC following the first week of their administration.

CLINICAL RELEVANCE STATEMENT

Antioxidants improve fat graft survival and quality in this rat model, by increasing total antioxidant capacity in the first week of administration.

Sellar Reconstruction With a Bioabsorbable Plate After Endoscopic Transsphenoidal Pituitary Adenoma Resection: Safe and Efficacious

OBJECTIVE

To report outcomes of a large cohort of patients who underwent endoscopic endonasal transsphenoidal surgery (EETS) for resection of a pituitary adenoma with subsequent Resorb-X plate (RXP) sellar reconstruction.

METHODS

A retrospective review of 620 EETS operations performed at a single academic center between 2005 and 2020 was conducted.

RESULTS

A total of 215 EETS operations of 208 patients were identified between 2012 and 2020 who underwent reconstruction with the RXP after EETS for pituitary tumor resection with a final pathologic diagnosis of pituitary adenoma. Analysis of pooled data revealed a mean preoperative tumor volume of 6.8 cm3 (range: 0.038-51.03 cm3). Postoperative cerebrospinal fluid leak occurred in 2 patients (0.93%). Postoperative meningitis occurred in 1 patient (0.47%). There were no cases of RXP extrusion.

CONCLUSIONS

The rate of postoperative CSF leak and meningitis after use of the RXP for sellar reconstruction compares favorably to other methods, including use of autologous grafts and flaps. Use of RXP during EETS is a safe and efficacious method of sellar reconstruction and may obviate the need for autologous tissue reconstruction after pituitary adenoma resection.

Autologous Fat Grafting in Breast Augmentation: A Systematic Review Highlighting the Need for Clinical Caution

BACKGROUND

Autologous fat grafting (AFG) is a breast augmentation method for treating volume and contour abnormalities. This systematic review aims to summarize complications, radiologic safety, volume retention, and patient satisfaction associated with AFG.

METHODS

The PubMed, Embase, Google Scholar, Cochrane Central Register of Controlled Trials, Wiley library, clinical key/Elsevier, and EBSCO databases were searched for relevant studies from January of 2009 to March of 2022. Articles describing AFG for breast augmentation were selected based on predetermined inclusion and exclusion criteria. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were adhered to, and the study was registered on the International Prospective Register of Systematic Reviews. The Risk of Bias in Nonrandomized Studies of Interventions assessment was used to assess the quality of studies and the risk of bias was measured using the Cochrane Risk of Bias Assessment Tool for Nonrandomized Studies of Interventions.

RESULTS

A total of 35 studies comprising 3757 women were included. The average follow-up duration was 24.5 months (range, 1 to 372 months). The overall complication rate was 27.8%, with fat necrosis making up 43.7% of all complications. Average fat volume injected was 300 mL (range, 134 to 610 mL), and average volume retention was 58% (range, 44% to 83%). Volume retention was greater with supplementation of fat with platelet-rich plasma and stromal vascular fraction. The most common radiologic changes were fat necrosis (9.4%) and calcification (1.2%). After 1 year of follow-up, patient satisfaction was, on average, 92% (range, 83.2% to 97.5%). The included studies were of good quality and consisted of a moderate risk of bias.

CONCLUSIONS

AFG was associated with an overall complication rate of 27.8%. Additional supplementation of fat with platelet-rich plasma and stromal vascular fraction may improve graft survival. Despite poor volume retention being a persistent drawback, patient satisfaction remains high.

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.

Fat transplant: Amazing growth and regeneration of cells and rebirth with the miracle of fat cells

BACKGROUNDS AND OBJECTIVE

During fat transplantation, adipose tissue is removed from the body and injected into different areas under the skin. The goal of this review article is to look into the efficacy and applicability of fat transplantation in regenerative medicine and rejuvenation, including Nanofat, Microfat, and Millifat.

METHODS

As a search strategy and study selection, we searched the PubMed and Medline databases until 2023 using related keywords (e.g., Nanofat, Microfat and Millifat, Regenerative Medicine, and Rejuvenation).

RESULTS

Autologous fat transplantation has no risk of an allergic reaction or rejection of the transplant by the individual. Autologous adipose tissue is considered an ideal filler for facial rejuvenation and is suggested as the most biocompatible and non-immunogenic skin filler. Adipose tissue transplant may have semi-permanent to permanent effects. According to recent reports, adipose tissues possess a high percentage of mature stem cells. The effect of regenerating adipose tissue and its intrinsic cells can be described as an obvious process. Variations in the sizes of adipose tissues can result in different results depending on the surgical site. Based on topographic assessment, graft fats are assigned depending on the anatomical locations and the size such as Millifat (2-2.5 mm), Microfat (1 mm), and Nanofat (500 μm or less).

CONCLUSION

Some characteristics of fat tissue increase its effectiveness, such as increasing stem cells, growth factors, cytokines, and compounds effective in repair, regeneration, and rejuvenation.

Comparative Analysis of a New Automatic System and Four Existing Techniques for Autologous Fat Grafting

Background

Autologous fat grafting is increasingly used worldwide and is a very attractive technique in many ways. However, treatment duration and postinjection tissue resorption remain problematic elements, which are largely related to the preparation method used. Moreover, few scientific studies objectively compare different fat preparation methods. This study analyzes the efficiency and quality of lipoaspirates prepared with a new filtration/centrifugation system (Adipure) in comparison with several existing techniques.

Methods

Patient lipoaspirates were processed by five different techniques: decantation, centrifugation, Macrofill, Puregraft, and Adipure. Adipose tissue was evaluated in vitro for tissue resorption and oil formation, as well as in vivo after subcutaneous injections in immunodeficient mice. Adipose grafts were collected after 1 month, weighed, and analyzed by histology with a detailed scoring method.

Results

Decanting gives inferior results to all other techniques, in terms of amount of tissue and oil in vitro, or graft weight and histological analysis in vivo. Methods using classical Coleman centrifugation (1200g), or a modified one (400g) associated with washes (Macrofill) produce very similar results, both in vitro and in vivo. Techniques using filtration systems (Puregraft and Adipure) produce less oil overall and have a higher grafting efficiency. The best results regarding grafting efficiency and oil quantity are found with the Adipure device.

Conclusions

A combination of filtration and very low-speed centrifugation potentiates the advantages of these techniques, in terms of graft efficiency. The adipose tissue purification being done in a few minutes, in an automatic way, undoubtedly provides a strong advantage for the use of this new system.

Lipofilling Enriched with Adipose-Derived Mesenchymal Stem Cells Improves Soft Tissue Deformities and Reduces Scar Pigmentation: Clinical and Instrumental Evaluation in Plastic Surgery

BACKGROUND

Scars and soft tissue deformities (S-STDs), often resulting from hemifacial atrophy, trauma, and outcomes of burns, were usually associated with hyperpigmentation of overlying skin.

OBJECTIVES

This study aimed to evaluate the long-term effects of fat grafting commonly called "Lipofilling" enhanced with adipose-derived mesenchymal stem cells (Lipofilling-AD-MSCs) for treating S-STDs with pigmentary changes.

METHODS

A cohort study has been performed. 50 patients affected by S-STDs with hyperpigmentation treated with Lipofilling-AD-MSCs and 50 patients treated with Lipofilling not enhanced (Lipofilling-NE) were prospectively assessed. The pre-op evaluation included a clinical evaluation, a photographic assessment, magnetic resonance imaging, and ultrasound. Post-op follow-up was performed at 1, 3, 7, 12, 24, 48, weeks, and then annually.

RESULTS

Improvement in volume contours and pigmentation was clinically assessed. All people who underwent the treatments (Lipofilling-AD-MSCs and Lipofilling-NE) were satisfied with the improving pigmentation, texture, and volume contours with some differences. However, the results reported displaying a better trend in patients treated with Lipofilling-AD-MSCs to be more satisfied than patients treated with Lipofilling-NE (p < 0.0001).

CONCLUSIONS

In conclusion, Lipofilling-AD-MSCs was the preferred option for improving the contour deformities related to increased pigmentation of scars.

LEVEL OF EVIDENCE IV

Evidence obtained from cohort studies.

Effects of Autologous Microfragmented Adipose Tissue on Healing of Tibial Plateau Levelling Osteotomies in Dogs: A Prospective Clinical Trial

The aim of this study was to evaluate the effects of autologous microfragmented adipose tissue (MFAT) applied after mechanical fragmentation and assess these effects radiographically in bone healing in dogs subjected to tibial plateau levelling osteotomy (TPLO). Twenty dogs with unilateral cranial cruciate ligament disease were enrolled and randomly assigned to the treatment group (MFAT) or the control group (NT). The MFAT group underwent TPLO and autologous MFAT intra-articular administration, while the NT group underwent TPLO alone. Adipose tissue was collected from the thigh region, and MFAT was obtained by mechanical fragmentation at the end of the surgery. The patients were subjected to X-ray examination preoperatively, immediately postoperatively (T0), and at 4 (T1) and 8 (T2) weeks postoperatively. Two radiographic scores that had previously been described for the evaluation of bone healing after TPLO were used. A 12-point scoring system (from 0 = no healing to 12 = complete remodelling) was used at T0, T1, and T2, while a 5-point scoring system (from 0 = no healing to 4 = 76-100% of healing) was used at T1 and T2. The median healing scores were significantly higher at T1 and T2 for the MFAT group compared with the NT group for the 12-point (p < 0.05) and 5-point (p < 0.05) scoring systems. The intra-articular injection of autologous microfragmented adipose tissue can accelerate bone healing after TPLO without complications.

Experimental study on clinical and morphological determination of the optimal cannula diameter for lipoaspirate harvest from rabbit inguinal fat pad

Determining the most appropriate cannula diameter for lipoaspirate harvesting is important, both in terms of the quality and composition of the material obtained, and the ease of practical use of the cannula. The size of the cannula is one of the main factors affecting the qualitative characteristics of the obtained lipoaspirate sample for further use of adipose tissue. The purpose of the investigation was to clinically and histomorphometrically determine the optimal cannula diameter for lipoaspirate samples collection from rabbit inguinal fat pad in an experimental study. The methods of Animal models, Surgical procedures, Macroscopic examination, Histological examination, and Morphometric study were applied. There is a direct correlation between the percentage of connective tissue fibres in the lipoaspirate and the diameter of the cannula. The lack of clear criteria for selecting a lipoaspiration cannula is one of the limitations to obtaining generally accepted lipoaspiration protocols with subsequent use of adipose tissue. In this study, the animal experiment determined the most ideal cannula diameter suitable for collecting the largest amount of lipoaspirate for subsequent use.

Syringe Suction Yields Greater Adipocyte Viability for Fat Grafting: Fact or Fiction?

ABSTRACT

Autologous fat grafting is a technique that can be used for cosmetic and reconstructive indications such as oncologic defects, aging, trauma, and congenital malformations. However, there is no standardized technique, and one of the main challenges is the unpredictable rate of fat resorption. When using fat grafting, it is crucial to understand the different factors that contribute to adipocyte viability. A literature search, using PubMed, was conducted in 2022 with variations of the terms "autologous fat grafting," "fat harvesting," "fat processing," and "fat injection." Articles in the English language that presented original data about different factors that may affect adipocyte viability for fat grafting were included in this review. Syringe suction harvests (lower pressures), compared with other methods with higher pressures, were found to have increased adipocyte counts and viability, but this did not translate clinically during in vivo studies. The studies have shown that, despite our efforts in optimizing fat harvest, processing, and injection, no statistical or clinical differences have been found. Additional studies are still needed to determine a universal protocol for optimal fat graft survival.

Male Pectoralis Major Muscle Augmentation with Autologous Fat Transplantation Using VASER Lipoaspirate: Evaluation with MRI

The popularity of autologous fat grafts has increased for the reshaping, contouring, and augmentation of the male breast tissue. However, long-term maintenance of tissue viability and the ways for assessment serve as hot-spot topics in the field. This study was designed to evaluate the viability of fat grafts obtained by a vibration amplification of sound energy at resonance (VASER)-assisted lipoaspiration procedure using a magnetic resonance imaging-based approach.

Methods

This is a prospective examination of 20 male patients (40 breasts) who underwent VASER-assisted liposuction and fat grafting surgery, and long-term fat graft viability was evaluated by magnetic resonance imaging scans.

Results

Participants had an average age of 34.85 ± 7.37 years with a mean BMI of 26.73 ± 2.63 kg/m². The mean fat graft volume injected was 542.63 ± 144.78 mL on the right, and 548.95 ± 140.36 mL on the left side. On the magnetic resonance imaging follow-up, the mean intrapectoral adipose tissue thickness was 20.34 ± 6.31 mm on the right, and 18.94 ± 8.27 mm on the left sides and tissue viability was preserved in all cases. The mean follow-up duration was 22 ± 9.8 (range 14-44) months.

Conclusion

VASER-assisted lipoaspiration and autologous fat grafting of the major pectoralis muscle provide a satisfactory outcome and long-term maintenance of the grafted adipose tissue.

Current Fat Grafting Practices and Preferences: A Survey from Members of ISPRES

Fat grafting has established its niche in a wide spectrum of aesthetic and reconstructive procedures. A consensus-based method of harvest, processing, enrichment, injection, and assessment is lacking, despite the rising trends in its application. We conducted a survey among plastic surgeons to evaluate and identify trends of fat grafting practices.

High-Quality Lipoaspirate Following 1470-nm Radial Emitting Laser-Assisted Liposuction

BACKGROUND

Laser-assisted liposuction (LAL) has been used to maximize viable adipocyte yields in lipoaspirates, although optimizing tissue processing methods is still a challenge. A high-quality lipoaspirate has been a key factor for extended graft longevity.

OBJECTIVE

To assess the viability and potency of stromal vascular fraction (SVF) cells and adipose-derived stem cells (ASCs) in fat samples from lipoaspirates harvested with a novel 1470-nm diode, radial emitting LAL platform. Two processing methods, enzymatic and nonenzymatic, were compared.

METHODS

Laser-assisted liposuction lipoaspirates harvested from 10 subjects were examined for cell viability after processing by enzymatic or nonenzymatic methods. Isolated SVF cells were cultured with an ASC-permissive medium to assess their viability and proliferation capacity by cell proliferation assay. Flow cytometric analysis with ASC-specific markers, gene expression levels, and immunofluorescence for ASC transcription factors were also conducted.

RESULTS

Lipoaspirates showed high SVF cell viability of 97% ± 0.02% and 98% ± 0.01%, averaged SVF cell count of 8.7 × 10 6 ± 3.9 × 10 6 and 9.4 × 10 6 ± 4.2 × 10 6 cells per mL, and averaged ASC count of 1 × 10 6 ± 2.2 × 10 5 and 1.2 × 10 6 ± 5 × 10 5 cells per mL in nonenzymatic and enzymatic methods, respectively. The ASC-specific markers, gene expression levels, and immunofluorescence for ASC transcription factors confirmed the adipose origin of the cells.

CONCLUSIONS

The laser lipoaspirates provide a high yield of viable and potent SVF cells and ASCs through both nonenzymatic and enzymatic processes. Improved purity of the harvested lipoaspirate and high ASC content are expected to result in extended graft longevity. Furthermore, eliminating enzymatic digestion may provide advantages, such as reducing process time, cost, and regulatory constraints.

Role of adipose tissue grafting and adipose-derived stem cells in peripheral nerve surgery

The application of autologous fat grafting in reconstructive surgery is commonly used to improve functional form. This review aims to provide an overview of the scientific evidence on the biology of adipose tissue, the role of adipose-derived stem cells, and the indications of adipose tissue grafting in peripheral nerve surgery. Adipose tissue is easily accessible through the lower abdomen and inner thighs. Non-vascularized adipose tissue grafting does not support oxidative and ischemic stress, resulting in variable survival of adipocytes within the first 24 hours. Enrichment of adipose tissue with a stromal vascular fraction is purported to increase the number of adipose-derived stem cells and is postulated to augment the long-term stability of adipose tissue grafts. Basic science nerve research suggests an increase in nerve regeneration and nerve revascularization, and a decrease in nerve fibrosis after the addition of adipose-derived stem cells or adipose tissue. In clinical studies, the use of autologous lipofilling is mostly applied to secondary carpal tunnel release revisions with promising results. Since the use of adipose-derived stem cells in peripheral nerve reconstruction is relatively new, more studies are needed to explore safety and long-term effects on peripheral nerve regeneration. The Food and Drug Administration stipulates that adipose-derived stem cell transplantation should be minimally manipulated, enzyme-free, and used in the same surgical procedure, e.g. adipose tissue grafts that contain native adipose-derived stem cells or stromal vascular fraction. Future research may be shifted towards the use of tissue-engineered adipose tissue to create a supportive microenvironment for autologous graft survival. Shelf-ready alternatives could be enhanced with adipose-derived stem cells or growth factors and eliminate the need for adipose tissue harvest.

Adipose-derived stromal vascular fraction (SVF) in scar treatment: a systematic review protocol

BACKGROUND

Autologous adipose-derived stromal vascular fraction (SVF) is an emerging therapy that is being pioneered as a potential treatment for keloids and hypertrophic scars. Up to this point, there isn't a cure for keloids and hypertrophic scars yet they comprise the commonest benign skin disorders. Despite published studies reporting potential therapeutic benefits of SVF, their use and efficacy on scar improvement are not clearly described. The aim of this review is to describe the clinical practice involved in harvesting, processing, utilization of SVF, and associated efficacy in scar treatment.

METHODS

We shall include published clinical articles evaluating the efficacy of SVF on improving scar characteristics and assessment scores among adults with keloids or hypertrophic scars. Article search of Medline/PubMed, Cochrane Library and Embase using Mesh terms of "scars" and "stromal vascular fraction" combined with the Boolean operators ("AND", "OR") will be performed by two independent researchers following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) statement. The primary outcome measure will be the mean difference in the Scar characteristics including Scar assessment scores, scar thickness among others.

DATA SYNTHESIS

Descriptive data synthesis and mean differences between treatment arms will be calculated for the primary outcome of the scar assessment scores. In case more than three studies provide consistent characteristics of the scar assessment scores, a meta-analysis will be conducted.

DISCUSSION

Evidence obtained from the systematic review will form the foundation upon which further clinical trials research will be conducted in evaluating the efficacy of autologous adipose-derived stromal vascular fraction in keloid and hypertrophic scar. The systematic review has been submitted to the PROSPERO database and is currently under review.

Fat Grafting: Basic Science, Techniques, and Patient Management

In this review, a summary of the rich history of autologous fat grafting is provided, and a comprehensive summary of the science and theory behind autologous adipocyte transplantation, as well as the techniques commonly used is described. These include recipient site preparation, harvesting, processing, and engraftment. In addition, important considerations for preoperative and postoperative management are discussed to maximize graft retention. Special considerations in grafting to the breast, face, and buttocks are also summarized.

Adipose-Derived Stem Cells for Facial Rejuvenation

The interest in regenerative medicine is increasing, and it is a dynamically developing branch of aesthetic surgery. Biocompatible and autologous-derived products such as platelet-rich plasma or adult mesenchymal stem cells are often used for aesthetic purposes. Their application originates from wound healing and orthopaedics. Adipose-derived stem cells are a powerful agent in skin rejuvenation. They secrete growth factors and anti-inflammatory cytokines, stimulate tissue regeneration by promoting the secretion of extracellular proteins and secrete antioxidants that neutralize free radicals. In an office procedure, without cell incubation and counting, the obtained product is stromal vascular fraction, which consists of not only stem cells but also other numerous active cells such as pericytes, preadipocytes, immune cells, and extra-cellular matrix. Adipose-derived stem cells, when injected into dermis, improved skin density and overall skin appearance, and increased skin hydration and number of capillary vessels. The main limitation of mesenchymal stem cell transfers is the survival of the graft. The final outcomes are dependent on many factors, including the age of the patient, technique of fat tissue harvesting, technique of lipoaspirate preparation, and technique of fat graft injection. It is very difficult to compare available studies because of the differences and multitude of techniques used. Fat harvesting is associated with potentially life-threatening complications, such as massive bleeding, embolism, or clots. However, most of the side effects are mild and transient: primarily hematomas, oedema, and mild pain. Mesenchymal stem cells that do not proliferate when injected into dermis promote neoangiogenesis, that is why respectful caution should be taken in the case of oncologic patients. A longer clinical observation on a higher number of participants should be performed to develop reliable indications and guidelines for transferring ADSCs.

Autologous fat grafting in the face and neck: Multinational trends and knowledge of the safety, applications, and indications considering oncologic risk potential

BACKGROUND

Autologous fat grafting (AFG) is evolving in both aesthetic and reconstructive applications, since the body of evidence for its use has expanded. The earliest controversies were evident in lipofilling for oncological breast reconstruction, and to this day, some countries do not allow it for fear of inducing tumourigenesis in an oncologically ablated field.

METHODS

We sought to review contemporary harvesting and processing techniques for AFG in the craniofacial region, therefore distributed a survey to evaluate the clinical impact of oncological risk across four European countries.

RESULTS

We found no significant geographical differences between the German-speaking and the English groups concerning their harvesting and processing technique. Half of our respondents discuss the possibility of pro-oncologic behavior of AFG.

CONCLUSION

AFG harvesting and processing techniques do not considerably vary by geography. Further studies should evaluate oncologic risk potential of AFG in head and neck tumor sites, especially because there is no excellent article regarding this phenomenon.Level of Evidence: V.

Cosmetic Fat Transplantation: A Review

AIM

To review current techniques used in fat grafting to optimise graft persistence and achieve optimal cosmetic outcomes.

BACKGROUND

Fat transplantation has been used extensively in the reconstruction and cosmetic industry for many years. However, there is significant adipocyte loss and reabsorption rates, leading to the loss of external cosmetic volume and the need for repeat procedures. Adipocyte loss can occur at all four stages of transplantation and this review discusses each of these methods with the aim being to optimise graft outcome.

RESULTS

Several new techniques have been discussed including liposuction techniques, fat processing, and assisted fat grafting which show an improvement in adipocyte survival, revasculisation and graft outcomes.

CONCLUSION

There have been many improvements in fat grafting and the implementation of these will optimise surgical outcomes but there are still strategies to improve further. However, there is still a lack of standardised techniques and training. More research is needed in the areas of fat processing and the use of additives to the fat graft. More clinical research is needed in the fat placement technique, which has very little published evidence and current techniques are mostly anecdotal by cosmetic surgeons.

'Fat chance': a review of adipose tissue engineering and its role in plastic and reconstructive surgery

Soft tissue reconstruction remains a continuing challenge for plastic and reconstructive surgeons. Standard methods of reconstruction such as local tissue transfer and free autologous tissue transfer are successful in addressing soft tissue cover, yet they do not come without the additional morbidity of donor sites. Autologous fat transfer has been used in reconstruction of soft tissue defects in different branches of plastic surgery, specifically breast and facial defect reconstruction, while further maintaining a role in body contouring procedures. Current autologous fat transfer techniques come with the drawbacks of donor-site morbidity and, more significantly, resorption of large amounts of fat. Advancement in tissue engineering has led to the use of engineered adipose tissue structures based on adipose-derived stem cells. This enables a mechanically similar reconstruct that is abundantly available. Cosmetic and mechanical similarity with native tissue is the main clinical goal for engineered adipose tissue. Development of novel techniques in the availability of natural tissue is an exciting prospect; however, it is important to investigate the potential of cell sources and culture strategies for clinical applications. We review these techniques and their applications in plastic surgery.

Metformin downregulates miR223 expression in insulin-resistant 3T3L1 cells and human diabetic adipose tissue

AIMS AND DESIGNS

Metformin, an anti-diabetic drug, is the first line medication for the treatment of type 2 diabetes mellitus and some studies show its relationship with micro-RNAs. This study set up to determine the effect of metformin on miR223 expression and content of AKT/GLUT4 proteins in insulin resistant signaling in 3T3L1 cells and adipocyte of human diabetic patients.

MATERIALS AND METHODS

Subcutaneous adipose tissues were taken from newly diagnosed diabetic patients (HOMA-IR > 1.8), before and after three months treatment with 500 mg of metformin twice a day. Cellular homogenate was prepared and miR223 expression and AKT/GLUT4 protein expression were determined by quantitative real-time PCR and western blotting. The results were compared to insulin resistant 3T3L1 adipocytes that were treated with 10 mM Metformin.

RESULTS

MiR223 expression was significantly overexpressed both in insulin-resistant 3T3L1 adipocytes compared to non-insulin resistant adipocytes and in human diabetic adipose tissue, compared to non-diabetics (P value < 0.01). Metformin treatment downregulated miR223 expression in both adipocytes and human diabetic adipose tissue. In contrast the IRS/PI3-K/AKT pathway signaling components, Akt and GLUT4 increased in insulin-resistant 3T3L1 adipocytes and human diabetic adipose tissue after three months of metformin treatment.

CONCLUSIONS

Metformin reduced insulin resistance in adipocytes by reduction of miR223 expression and improving of IRS/Akt/GLUT4 signaling pathways. Plasma miR223 expression of human diabetic patients was reduced by metformin treatment. These results point to a novel mechanism of miR223 in insulin resistance.

Efficacy and Safety of Subcutaneous Temporal Autologous Micro-fat Augmentation

BACKGROUND

Autologous fat grafting is a rapidly developing soft tissue filling technique that has been playing an increasingly important role in facial contouring and rejuvenation surgeries. However, this technique is accompanied by many side effects and risks. In particular, there is still much room for improvement in regard to the surgical method of temporal augmentation with autologous fat, which is highly popular among Chinese people. Better surgical methods can achieve better outcomes while curbing surgical risks.

DESIGN AND METHODOLOGY

We reviewed 39 patients who consecutively underwent subcutaneous temporal autologous micro-fat argumentation surgery at Peking University People's Hospital from February 19, 2016, to May 13, 2019, to correct temporal hollowness. Each patient's Visual Analogue Scale (VAS) satisfaction score and Hollowness Severity Rating Scale (HSRS) score before and after surgery were precisely recorded, and any complaints about perioperative complications were meticulously collected to assess the efficacy and safety profile of the novel technique.

RESULTS

All 39 patients included in this study were female. We performed 86 subcutaneous temporal autologous micro-fat argumentation surgeries, with an average follow-up of 20.4 ± 9.6 months. The average fat filling volume in the right temporal region was 6.29 ± 2.55 mL, and that in the left temporal region was 6.34 ± 2.71 mL. The average VAS satisfaction score increased from 4.44 ± 1.33 before the surgery to 8.08 ± 0.77 after the surgery, and the average HSRS score dropped from 1.82 ± 0.72 before the surgery to 0.36 ± 0.49 after the surgery. Four patients were encountered with minor complications of intraoperative bleeding and congestion, which were all completely ameliorated after conservative therapies.

CONCLUSION

In the present study, we found that the reported surgical method of subcutaneous temporal autologous micro-fat augmentation successfully improved the temporal hollowness of the patients, boasting good surgical results and high patient satisfaction with minimal short- and long-term complications, illustrating that it is an effective, safe and promising novel surgical technique worthy of wider clinical application.

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 .

Human Adipose Tissue Cryopreservation: Impact of Different Calf Serum Concentrations on Tissue Viability

Adipose tissue, which is harvested in large quantities during liposuction, has no blood supply and becomes necrotic within a few hours, if not immediately transplanted. Cryopreservation of adipose tissue allows these samples to be stored and used in diverse fundamental experiments, especially in fat-grafting animal tests that could provide a theoretical basis for clinical applications. Traditionally, fetal bovine serum (FBS) has been added as a cryoprotectant (CPA) to maintain the maximum viability of different tissues after freezing and thawing. Calf serum (CS) comes from the same species as FBS but is more economical compared with FBS-containing medium. The optimal concentration of CS in CPA for banking adipose tissue has not been studied. Here, we studied the cell survival rate, cell viability, tissue structural integrity, number of adipose-derived stem cells and blood vessels, and survival after transplantation into nude mice via ultrastructural evaluation of adipose tissue cryopreserved for 6 months in condition A (60% CS, 15% dimethyl sulfoxide [DMSO], 25% Dulbecco's modified Eagle's medium [DMEM]) and condition B (30% CS, 15% DMSO, 55% DMEM). Our results indicate that CS in addition to CPA results in adequate preservation of adipose tissue, especially when a higher concentration of CS (60%) is used in the CPA.

Mechanical emulsification of lipoaspirate by different Luer-Lok connector changes the viability of adipose derived stem cells in Nanofat

Nanofat grafting is a fat transfer procedure that uses a thin needle to smooth out wrinkles, thereby achieving the goal of skin rejuvenation. The Luer-Lok connector is one of the most common methods for obtaining Nanofat. In the present study, we compared three different Luer-Lok connectors (2.0 mm, 1.5 mm and 1.1 mm in diameter) in terms of their impact on the viability of adipose-derived stem cells (ADSCs) to determine the optimal size of the connector for efficient Nanofat grafting. We observed that a smaller diameter of the Luer-Lok connector created a higher mechanical shear force, which broke more fat cells during the emulsifying procedure, thereby reducing the viability of ADSCs from the stromal vascular fraction (SVF). Nanofat obtained from the 2-mm Luer-Lok connector had a better effect on skin rejuvenation than the 1.5-mm and 1.1-mm connectors. Therefore, this study presents an advance in the simple procedure of preparing Nanofat based on a previous technique and provides evidence that a procedure associated with less trauma may be a better choice.

Adipogenesis for soft tissue reconstruction

PURPOSE OF REVIEW

It has been increasingly common to use adipose tissue for regenerative and reconstructive purposes. Applications of autologous fat transfer and different stem cell therapies have significant limitations and adipose tissue engineering may have the potential to be an important strategy in the reconstruction of large tissue defects. A better understanding of adipogenesis will help to develop strategies to make adipose tissue more effective for repairing volumetric defects.

RECENT FINDINGS

We provide an overview of the current applications of adipose tissue transfer and cellular therapy methods for soft tissue reconstruction, cellular physiology, and factors influencing adipogenesis, and adipose tissue engineering. Furthermore, we discuss mechanical properties and vascularization strategies of engineered adipose tissue, and its potential applications in the clinical settings.

SUMMARY

Autologous fat tissue transfer is the standard of care technique for the majority of surgeons; however, high resorption rates, poor perfusion within a large volume fat graft and widely inconsistent graft survival are the main limitations. Adipose tissue engineering is a promising field to reach the first goal of producing adipose tissue which has more predictable survival and higher graft retention rates. Advancements of scaffold and vascularization strategies will contribute to metabolically and functionally more relevant adipose tissue engineering.

Autologous Fat Grafting for Craniofacial Reconstruction in Oncologic Patients

Due to the anatomical and functional complexity of the region, craniofacial tumor removal requires some of the most challenging surgical approaches, often complemented with advanced chemo-radiotherapy techniques. However, these modern therapies often lead to sequelae that can drastically reduce the quality of life for the surviving patients. Recent advances in the field of regenerative medicine opened new avenues for craniofacial reconstruction following head and neck cancer treatment. One of the most promising recent strategies relies on the use of autologous fat transplant. In this mini review, we briefly present some of the fat’s biological properties that make it an ideal tissue for craniofacial reconstruction following cancer treatment. We then outline the recent advances that led to a better understanding of the detailed anatomy of the craniofacial fat depots. Furthermore, we provide a succinct review of the methods used for fat harvesting, processing and engrafting in the craniofacial area after head and neck tumor removal, discussing their main applications, advantages and limitations.

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.