What is the current optimal fat grafting processing technique? A systematic review

Improving the Retention of Low-Volume Autologous Fat Grafting: A Comparative Analysis of Lipoaspirate Processing Techniques for Facial Feminization

Background

Outcomes following autologous fat grafting have historically been unpredictable because of variability in fat retention rates. The novel poloxamer wash, absorption, mesh filtration system (PWAS) uses proprietary technology to stabilize and concentrate lipoaspirate. Its use in low-volume fat grafting has not been reported.

Objectives

The authors in this study aimed to compare PWAS technology with traditional lipoaspirate processing techniques in low-volume fat grafting procedures.

Methods

Medical charts were reviewed to determine a consecutive cohort of patients who underwent fat grafting for facial feminization. All patients had obtained preoperative and postoperative 3-dimensional facial imaging. Patients were grouped based on the method of lipoaspirate processing. The analysis software was used to measure changes in facial volume, and percent retention was calculated.

Results

Between September 2021 and February 2023, 11 facial fat grafting procedures were performed using the PWAS, and 5 performed using traditional lipoaspirate osmotic filtration with Telfa. Age and BMI were statistically similar between both the groups (P > .1). The average volume of lipoaspirate that was grafted was 23.4 mL (standard deviation [SD] 10.9 mL) and similar between both the groups (P > .1). The mean follow-up duration was 7.1 months (SD 3.1 months): 7.2 months, SD 3.5 months in the PWAS group vs 7.0 months, SD 2.2 months in the osmotic filtration group (P > .5). The average fat volume retention rate was 73.1% (SD 6.8%) in patients in whom the PWAS was used when compared with 46.1% (SD 5.2%) in patients in whom osmotic filtration was used (P > .01).

Conclusions

For patients undergoing low volume fat grafting, the PWAS technology may result in improved fat retention rates when compared with traditional lipoaspirate processing with Telfa.

Level of Evidence 4

Supplementation of Facial Fat Grafting to Increase Volume Retention: A Systematic Review

BACKGROUND

For decades, facial fat grafting has been used in clinical practice for volume restoration. The main challenge of this technique is variable volume retention. The addition of supplements to augment fat grafts and increase volume retention has been reported in recent years.

OBJECTIVES

The aim of this systematic review was to investigate which supplements increase volume retention in facial fat grafting as assessed by volumetric outcomes and patient satisfaction.

METHODS

Embase, Medline, Ovid, Web of Science Core Collection, Cochrane Central Register of Controlled Trials, and Google Scholar were searched up to November 30, 2020. Only studies assessing volume after facial fat grafting with supplementation in human subjects were included. Outcomes of interest were volume or patient satisfaction. The quality of the studies was assessed with the Effective Public Health Practice Project tool.

RESULTS

After duplicates were removed 3724 studies were screened by title and abstract. After reading 95 full-text articles, 27 studies were eligible and included for comparison. Supplementation comprised of platelet-rich plasma, platelet-rich fibrin, adipose tissue-derived stromal cells or bone marrow-derived stromal cells, cellular or tissue stromal vascular fraction, or nanofat. In 13 out of 22 studies the supplemented group showed improved volumetric retention and 5 out of 16 studies showed greater satisfaction. The scientific quality of the studies was rated as weak for 20 of 27 studies, moderate for 6 of 27 studies, and strong for 1 study.

CONCLUSIONS

It remains unclear if additives contribute to facial fat graft retention and there is a need to standardize methodology.

LEVEL OF EVIDENCE: 4

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.

The Importance of Protecting the Structure and Viability of Adipose Tissue for Fat Grafting

BACKGROUND

Fat grafting is widely used for soft-tissue augmentation; however, the related clinical outcome remains variable and technique-dependent. The mechanisms underlying fat graft survival are not fully understood, particularly regarding the contributions of different cell types, such as functional adipocytes. This study evaluated the importance of adipose tissue structure and viability in fat grafting and, to some extent, revealed the effect of adipocytes in fat grafting.

METHODS

Human lipoaspirate was harvested using suction-assisted liposuction and processed using three separate methods: cotton-pad filtration, soft centrifugation (400 g for 1 minute), and Coleman centrifugation (1200 g for 3 minutes). Then all samples were subjected to second cotton-pad concentration. Adipose tissue structure and viability, the numbers of adipose-derived stem cells, and their proliferation and multilineage differentiation abilities were compared in vitro. The volume retention rate and fat graft quality were evaluated in vivo.

RESULTS

Cell structure destruction and viability decline were more evident in the Coleman centrifugation group compared to the cotton-pad filtration group and the soft centrifugation group. However, no intergroup differences were observed in the numbers, proliferation, or multilineage differentiation abilities of adipose-derived stem cells. After transplantation, the volume retention rates were similar in the three groups. However, greater structural and functional damage was associated with poorer graft quality, including decreased levels of graft viability, vessel density, and vascular endothelial growth factor secretion and increased levels of vacuoles, necrotic areas, fibrosis, and inflammation.

CONCLUSIONS

Protecting adipose tissue structure and viability is crucial for improving fat grafting outcomes.

CLINICAL RELEVANCE STATEMENT

The protection of the structure and viability of adipose tissue should be ensured throughout the whole process of fat grafting to reduce complications and improve graft quality.

Washing Lipoaspirate Improves Fat Graft Survival in Nude Mice

BACKGROUND

The optimal fat processing technique of fat grafting has not been determined. We have proved the importance of washing lipoaspirate to remove blood, but the necessity of washing when there is no obvious bleeding during liposuction is not clear.

OBJECTIVES

The purpose of this study is to further investigate the effect of washing on fat graft survival and the underlying mechanisms, from the perspective of inflammation, oxidative stress and apoptosis.

METHODS

To exclude the influence of blood, de-erythrocyte infranatant (dEI) isolated from lipoaspirate was obtained. Purified fat processed by cotton pad filtration mixed with dEIs after sedimentation (sedimentation group), washing (washing group) or phosphate buffer solution (control group) was transplanted to nude mice subcutaneously. Samples were harvested at 1 day and 1, 3, 8 weeks after transplantation. Volume and weight retention, histologic examination, immunostaining of perilipin-1, CD31, CD45 and Ly6g, mRNA expression of PPAR-γ, C/EBPα, VEGF, bFGF, IL-6, IL10, TNF-α, TGF-β, Bax and Bcl-2, and protein contents of 8-iso-PGF2α, IL-6, IL10, TNF-α and TGF-β were all compared among groups.

RESULTS

After transplantation, volume and weight retention, histologic scores, viable adipocytes and vascularization were all improved in the washing group, with increased expression of adipogenic and angiogenic genes. Compared with the sedimentation group, the washing group had milder inflammation, lower levels of oxidative stress and apoptosis.

CONCLUSIONS

Washing lipoaspirate to eliminate mixed components can improve fat graft survival and promote adipogenesis and angiogenesis, possibly by relieving inflammation, reducing oxidative stress injury and inhibiting apoptosis.

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 47 these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors http://www.springer.com/00266 .

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.

Fate of Fat Grafting In Vivo and In Vitro: Does the Suction-Assisted Lipectomy Device Matter?

BACKGROUND

Recently, there has been increasing research interest in identifying the effect of liposuction procedures on fat graft survival in order to clarify whether different harvest techniques affect the quality of fat grafts.

OBJECTIVES

The aim of this study was to investigate the effect of 2 liposuction methods on the survival and regeneration potential of grafted fat tissue. The proliferation and differentiation potentials of adipose-derived stem cells (ASCs) isolated by both methods was also investigated.

METHODS

Fat grafts were collected from patients who underwent liposuction procedures by 2 different methods: traditional suction-assisted liposuction (TSAL) and vibration amplification of sound energy at resonance (VASER). One portion of the lipoaspirates was implanted into the subcutaneous layer of nu mice for 4 and 12 weeks. ASCs were isolated from the other portion of the lipoaspirate and subjected to proliferation and differentiation assays.

RESULTS

Although in vivo fat grafting presented similar adipose tissue survival for the 2 different liposuction methods, more angiogenesis and less fibrosis was observed in the VASER group based on histologic evaluation. Furthermore, VASER-derived ASCs presented better quality in terms of cell differentiation capacity.

CONCLUSIONS

The in vivo study confirmed better graft angiogenesis with less inflammation, apoptosis, and scar formation in the VASER group. ASCs harvested with VASER exhibited increased differentiation capacity compared with those obtained by TSAL, and represent an excellent source for fat grafting and regenerative medicine.

The Effect of Lipoaspirate Processing Technique on Complications in Autologous Fat Grafting for Breast Reconstruction: A Propensity Score Analysis Study

BACKGROUND

The use of autologous fat grafting (AFG) is becoming increasingly common as an adjunct to breast reconstruction. However, there is a paucity of data comparing the varying processing devices.

OBJECTIVES

The goal of this study was to compare the outcomes of 2 commercially available AFG processing devices.

METHODS

A retrospective review was conducted of patients who underwent AFG with dual-filter (Puregraft) or single-filter (Revolve) processing systems between 2016 and 2019. Propensity score matching was utilized to adjust for confounding. A total of 38 breasts from the Puregraft group were matched with 38 breasts from the Revolve group.

RESULTS

Matching was successful in achieving a similar distribution of baseline characteristics between the 2 groups. The mean number of AFG sessions was comparable between the 2 groups (P = 0.37) with a similar median total volume (Puregraft, 159 mL vs Revolve, 130 mL; P = 0.23). Complication rates were similar between the 2 devices (Puregraft, 26%; Revolve, 18%; P = 0.47). Patients with at least 1 complication had higher overall AFG volume (median, 200 mL vs 130 mL; P = 0.03) and number of sessions (mean, 2.4 vs 1.8, P = 0.009) compared with those without any postoperative complication.

CONCLUSIONS

Overall complication rates were comparable between 2 commonly used, commercially available AFG processing systems, and therefore the choice of which to use should be based on surgeon preference. Future studies are underway to decipher whether either system offers superior graft retention, cosmetic, or patient-reported outcomes.

LEVEL OF EVIDENCE: 3

Phenotypic and Cellular Characteristics of a Stromal Vascular Fraction/Extracellular Matrix Gel Prepared Using Mechanical Shear Force on Human Fat

The retention of fat-derived grafts remains a challenge for regenerative medicine. Fat aspirates from patients undergoing liposuction were prepared into standard Coleman fat grafts or further isolated using mechanical shear force to prepare a stromal vascular fraction (SVF)/extracellular matrix (ECM) gel. The retention rate of the SVF/ECM gel was significantly higher than that of the Coleman fat at 3, 14, 28, and 60 days following transplantation on the backs of nude mice. The viscosity of the fat was directly proportional to the shearing force. Although the mechanical isolation did not affect the total number of cells, it significantly decreased the number of living cells. Flow cytometry showed a greater number of mesenchymal stem cells, supra-adventitial (SA)-adipose stromal cells (ASCs), and adipose-derived stem cells but a lower number of endothelial progenitor cells in the SVF/ECM gel than in the Coleman fat. Thus, mechanical isolation of fat can increase the pluripotency of adipocytes, which can improve graft retention in cell therapy.

Rhinoplasty with Fillers and Fat Grafting

Nonsurgical rhinoplasty is one choice for cases in which open surgery may be harmful, the deformity is not indicated to correct with open surgery, or in patients who have phobia of general anesthesia or any type of surgery. Autologous fat injection or fillers are most common materials currently available in the market. In this article, we explain the indications, contraindications, methods, and complications of this treatment.

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 Effects of Facial Lipografting on Skin Quality: A Systematic Review

BACKGROUND

Autologous lipografting for improvement of facial skin quality was first described by Coleman in 2006. The current dogma dictates that adipose tissue-derived stromal cells that reside in the stromal vascular fraction of lipograft contribute to skin rejuvenation (e.g., increased skin elasticity), a more homogenous skin color, and softening of skin texture. Nowadays, many studies have been reported on this "skin rejuvenation" effect of autologous fat grafting. This systematic review was undertaken to assess the efficacy of autologous lipografting on skin quality.

METHODS

The MEDLINE, Embase, Cochrane Central, Web of Science, and Google Scholar databases were searched for studies evaluating the effect of autologous lipografting on facial skin quality (May 11, 2018). Outcomes of interest were skin texture, color, and elasticity in addition to histologic outcomes and number of complications.

RESULTS

Nine studies were included, with 301 patients treated in total. No meta-analysis could be performed because of heterogeneity of the metrics and outcomes. Eight studies reported increased skin elasticity; improvement in skin texture; and a more homogeneous skin color after treatment with lipografting, cellular stromal vascular fraction, or nanofat. One study reported no increased skin elasticity after lipografting. Histologic improvement was seen after lipografting and adipose tissue-derived stromal cell injections. However, in general, the level of evidence of the included studies was low. No serious complications were reported.

CONCLUSION

Autologous facial lipografting and cellular stromal vascular fraction and adipose tissue-derived stromal cell injections hardly seem to improve facial skin quality but can be considered a safe procedure.

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

Importance

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

Objective

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

Design, Setting, and Participants

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

Intervention

Autologous fat grafting to correct facial asymmetry.

Main Outcomes and Measures

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

Results

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

Conclusions and Relevance

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

Trial Registration

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

Level of Evidence

1.

From liposuction to adipose-derived stem cells: indications and technique

Background and aim of the work:

Adipose tissue is an organ of energy storage, an endocrine organ, a soft tissue filler and a cosmetically unnecessary tissue discarded by liposuction. Liposuction was designed to correct unaesthetic deposits of subcutaneous fat; it produces satisfactory silhouette contouring when performed by appropriately trained operators using properly selected technologies. However, from lipoaspirate it is possible to obtain autologous fat graft and adipose-derived stem cells (ASCs) for reconstructive surgery and regenerative medicine. Autologous fat transplantation uses include the correction of body contour, malformations and post-surgical outcomes. The regenerative properties of ASCs allow treating damaged tissues such as wounds, burns, scars and radiodermatitis. The aim of this study was to perform a literature review highlighting the crucial role of adipose tissue in plastic and reconstructive surgery, from liposuction to lipofilling and ASCs, exposing the indications, procedures and complications of these surgical techniques.

Methods:

Literature review of publications concerning liposuction, lipofilling and adipose-derived stem cells (ASCS).

Results:

The introduction of liposuction allowed the use of adipose tissue for many clinical uses. The adipose tissue filling properties have been highlighted by the advent of lipofilling. The regenerative properties evidence of autologous fat transplantation encouraged the research on the clinical use of ASCs.

Conclusions:

Adipose tissue is not only the main energy storage of our body but also an important source of stem cells that can be used in various fields of regenerative medicine and tissue engineering with encouraging results for the future. (www.actabiomedica.it)

The role of fat grafting in prepectoral breast reconstruction

Prepectoral breast reconstruction has reemerged as a promising alternative to submuscular implants, as they place the patient at lower risk for pain, muscular impairment, and animation deformity. However, the thinner amount of overlying tissue in prepectoral reconstruction presents its own unique set of challenges. A "rippling" deformity is seen in some prepectoral patients, which is typically corrected with fat grafting. This report details our recommended technique for fat grafting in the prepectorally implanted patient.

Autologous fat grafting: Harvesting techniques

Autologous fat grafting is widely used for soft-tissue augmentation and replacement in reconstructive and aesthetic surgery providing a biocompatible, natural and inexpensive method. Multiple approaches have been developed in the past years, varying in the location of adipose tissue donor-sites, use of wetting solutions, harvesting, processing and placing techniques. Despite many advances in this subject, the lack of standardization in the protocols and the unpredictability of the resorption of the grafted tissue pose a significant limitation for graft retention and subsequent filling. In this review, we discuss several approaches and methods described over the last years concerning the harvesting of autologous fat grafts. We focus on contents such as the best donor-site, differences between existing harvesting techniques (namely tissue resection, hand aspiration or liposuction techniques), recommended harvesting cannula diameters, pressure application and volume of wetting solution injected prior aspiration. Results and comparisons between methods tend to vary according to the outcome measured, thus posing a limitation to pinpoint the most efficient methods to apply in fat grafting. Additionally, the lack of a standard assay to determine viability or volume augmentation of fat grafting remains another limitation to obtain universally accepted grafting procedures and protocols.

•

Distinct harvesting procedures associate with different outcomes of fat graft take.

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Flank, abdomen, thigh and knee are the more consistently used donor-sites for fat.

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Higher vacuum pressures in liposuction are more traumatic for the tissue.

•

The tumescent technique is a safer procedure with improved aesthetic results.

•

Comparing harvesting techniques is a big challenge given the multiple variables.

A Non-Enzymatic Method to Obtain a Fat Tissue Derivative Highly Enriched in Adipose Stem Cells (ASCs) from Human Lipoaspirates: Preliminary Results

Adipose tissue possesses phenotypic gene expression characteristics that are similar to human mesenchymal stem cells (hMSCs). Nevertheless, the multilineage potential may be inhibited, and cells may not expand adequately to satisfy the requirements of Good Manufacturing Practice (cGMP). An autologous hMSC-enriched fat product would fulfil the void from a biomedical and clinical perspective. In this study, we suggest a novel mechanism using a closed system without enzymes, additives or other modifications, which will produce non-expanded, accessible material. This decentralized fat product, unlike unprocessed lipoaspirates, adequately encloses the vascular stroma with adipocytes and stromal stalks along with their vascular channels and lumina. This fat product contained hASCs and fewer hematopoietic elements such as lipoaspirates, which were digested enzymatically according to flow cytometric investigations, and molecular analysis also showed significant hASC uniformity within the cells of the stromal vascular tissue. Moreover, the fat product produced a higher quantity of hASCs similar to hMSCs in isolation with the typical characteristics of an osteogenic, chondrogenic and adipogenic lineage. Interestingly, these properties were evident in the non-enzymatic derived adipose tissue, as opposed to hASCs in isolation from the enzymatically digested lipoaspirates, suggesting that the aforementioned procedure may be an adequate alternative to regenerate and engineer tissue for the treatment of various medical conditions and promote efficient patient recovery.

The Reliability of Free Buccal Fat Graft for Treatment of Severe Gingival Recessions at Mandibular and Maxillary Exposed Roots

INTRODUCTION

The occurrence of gingival recessions (GRs) is multifactorial, mainly due to trauma induced by traumatic toothbrushing, orthodontic tooth movement, as well as anatomical factors such as bone dehiscence, teeth malposition, and muscle pull. Fat tissue in the oral cavity is widely available and easily accessed. The use of pedicled buccal fat pad (BFP) graft is well known in maxillofacial surgery and has been shown promising results, becoming safe and effective graft for several clinical applications. However the use of fat tissue harvested from the buccal fat pad as a free graft (BFFP) is less common, but recently, it has been described by the author for different intraoral clinical applications. The aim of this study is to present additional application using the BFFG for coverage of severe muco-GRs and to discuss the promising outcomes of this procedure.

PATIENTS AND METHODS

A technique for harvesting intraoral BFFG for the use in mucogingival surgery is presented. A total of 10 patients (age: 38.3 ± 6.8 years) with 17 teeth presenting severe GRs (4.8 ± 1.8 mm) were included in the study. Recessions treated using BFFGs were recorded at baseline and 12 months after surgery.

RESULTS

A total of 17 GRs were treated using BFFG. At 12 months, significant reduction of recession occurred. Initial recession was reduced from 4.8 ± 1.8 mm to 1.7 ± 0.9 mm. A mean of 3.1-mm reduction in GR was achieved compared to baseline.

CONCLUSIONS

The new, simple, technique for treatment of severe GRs using BFFG resulted in significant reduction of GRs.

Extracorporeal shock wave therapy in situ - novel approach to obtain an activated fat graft

One of the mainstays of facial rejuvenation strategies is volume restoration, which can be achieved by autologous fat grafting. In our novel approach, we treated the adipose tissue harvest site with extracorporeal shock wave therapy (ESWT) in order to improve the quality of the regenerative cells in situ. The latter was demonstrated by characterizing the cells of the stromal vascular fraction (SVF) in the harvested liposuction material regarding cell yield, adenosine triphosphate (ATP) content, proliferative capacity, surface marker profile, differentiation potential and secretory protein profile. Although the SVF cell yield was only slightly enhanced, viability and ATP concentration of freshly isolated cells as well as proliferation doublings after 3 weeks in culture were significantly increased in the ESWT compared with the untreated group. Likewise, cells expressing mesenchymal and endothelial/pericytic markers were significantly elevated concomitant with an improved differentiation capacity towards the adipogenic lineage and enhancement in specific angiogenic proteins. Hence, in situ ESWT might be applied in the future to promote cell fitness, adipogenesis and angiogenesis within the fat graft for successful facial rejuvenation strategies with potential long-term graft survival.

Procedure, applications, and outcomes of autologous fat grafting

OBJECTIVE

To systematically review the procedure, applications, and outcomes of autologous fat grafting, a promising technique with various clinical applications.

PATIENTS AND METHODS

Literature review of publications concerning autologous fat grafting.

RESULTS

Since its introduction, lipofilling has become increasingly popular; however, its results are variable and unpredictable. Several modifications have been made to the procedures of fat harvesting, processing, and injecting. Surgical excision and low negative-pressure aspiration with large-bore cannulas minimize adipocyte damage during fat harvesting. The "wet" method of fat harvesting involves fluid injection at the donor site and facilitates lipoaspiration while minimizing pain and ecchymosis. For fat processing, centrifugation at a low speed is preferable to high-speed centrifugation, gravity separation or filtration. Fat injection at the recipient site should be performed using small-gauge cannulas in a fanning out pattern over multiple sessions, rather than a single session. Fat grafts exhibit not only dermal filler properties but also regenerative potential owing to the presence of stem cells in fat tissue. Thus, the clinical applications of autologous fat grafting include correction of secondary contour defects after breast reconstruction, release of painful scar contractures, and treatment of burn scars and radiodermatitis. Lipofilling is also used in aesthetic surgery, such as facial and hand rejuvenation, augmentation rhinoplasty, and breast and gluteal augmentation. The complications of lipofilling are minimal and include bruising, swelling, pain, infection, necrosis, and calcification.

CONCLUSIONS

Lipofilling is a low-risk procedure that can be used to correct soft-tissue defects in the face, trunk, and extremities, with minimal discomfort for patients.

Improvement of adipose tissue-derived cells by low-energy extracorporeal shock wave therapy

BACKGROUND

Cell-based therapies with autologous adipose tissue-derived cells have shown great potential in several clinical studies in the last decades. The majority of these studies have been using the stromal vascular fraction (SVF), a heterogeneous mixture of fibroblasts, lymphocytes, monocytes/macrophages, endothelial cells, endothelial progenitor cells, pericytes and adipose-derived stromal/stem cells (ASC) among others. Although possible clinical applications of autologous adipose tissue-derived cells are manifold, they are limited by insufficient uniformity in cell identity and regenerative potency.

METHODS

In our experimental set-up, low-energy extracorporeal shock wave therapy (ESWT) was performed on freshly obtained human adipose tissue and isolated adipose tissue SVF cells aiming to equalize and enhance stem cell properties and functionality.

RESULTS

After ESWT on adipose tissue we could achieve higher cellular adenosine triphosphate (ATP) levels compared with ESWT on the isolated SVF as well as the control. ESWT on adipose tissue resulted in a significantly higher expression of single mesenchymal and vascular marker compared with untreated control. Analysis of SVF protein secretome revealed a significant enhancement in insulin-like growth factor (IGF)-1 and placental growth factor (PLGF) after ESWT on adipose tissue.

DISCUSSION

Summarizing we could show that ESWT on adipose tissue enhanced the cellular ATP content and modified the expression of single mesenchymal and vascular marker, and thus potentially provides a more regenerative cell population. Because the effectiveness of autologous cell therapy is dependent on the therapeutic potency of the patient's cells, this technology might raise the number of patients eligible for autologous cell transplantation.

Comparison of intraoperative procedures for isolation of clinical grade stromal vascular fraction for regenerative purposes: a systematic review

Intraoperative application of the stromal vascular fraction (SVF) of adipose tissue requires a fast and efficient isolation procedure of adipose tissue. This review was performed to systematically assess and compare procedures currently used for the intraoperative isolation of cellular SVF (cSVF) and tissue SVF (tSVF) that still contain the extracellular matrix. Pubmed, EMBASE and the Cochrane central register of controlled trials databases were searched for studies that compare procedures for intraoperative isolation of SVF (searched 28 September 2016). Outcomes of interest were cell yield, viability of cells, composition of SVF, duration, cost and procedure characteristics. Procedures were subdivided into procedures resulting in a cSVF or tSVF. Thirteen out of 3038 studies, evaluating 18 intraoperative isolation procedures, were considered eligible. In general, cSVF and tSVF intraoperative isolation procedures had similar cell yield, cell viability and SVF composition compared to a nonintraoperative (i.e. culture laboratory-based collagenase protocol) control group within the same studies. The majority of intraoperative isolation procedures are less time consuming than nonintraoperative control groups, however. Intraoperative isolation procedures are less time-consuming than nonintraoperative control groups with similar cell yield, viability of cells and composition of SVF, and therefore more suitable for use in the clinic. Nevertheless, none of the intraoperative isolation procedures could be designated as the preferred procedure to isolate SVF. Copyright © 2017 John Wiley & Sons, Ltd.

A Comprehensive In Vitro Comparison of Preparation Techniques for Fat Grafting

BACKGROUND

Lipomodeling is a technique that uses the patient's own fat for tissue regeneration and augmentation. The extent of regenerative effect is reported to be determined by the numbers of adipose-derived stem cells and the viability of cells in processed adipose tissue which, together with other factors, influence the degree of graft retention. This study addresses whether differences exist in properties of fat graft obtained by three commonly used techniques.

METHODS

Adipose tissue harvested from the hypogastric regions of 14 patients was processed by decantation, centrifugation, and membrane-based tissue filtration. The morphology of each preparation was assessed by electron microscopy and overall cell viability was assessed by live/dead assay. The number of adipose-derived stem cells was determined and their stem cell character was assessed by the presence of cell surface molecules (i.e., CD105, CD90, CD31, and CD45) and by their capacity to differentiate into adipogenic and osteogenic lineages.

RESULTS

First, morphologies of processed fat samples obtained by individual procedures differed, but no preparation caused obvious damage to cellular or acellular components. Second, although the highest numbers of adipose-derived stem cells were contained in the upper fraction of centrifuged lipoaspirates, the difference between preparations was marginal. Third, the maximal concentration of adipose fraction (removal of watery component) of lipoaspirate was achieved by membrane-based tissue filtration. Finally, no significant differences in overall viability were detected.

CONCLUSIONS

Properties of processed lipoaspirate were influenced by the preparation procedure. However, the differences were not dramatic; both centrifugation and membrane-based filtration are methods of choice whose selection depends on other criteria (e.g., practicality) for individual surgical settings.

The power of fat and its adipose-derived stromal cells: emerging concepts for fibrotic scar treatment

Lipofilling or lipografting is a novel and promising treatment method for reduction or prevention of dermal scars after injury. Ample anecdotal evidence from case reports supports the scar‐reducing properties of adipose tissue grafts. However, only a few properly controlled and designed clinical trials have been conducted thus far on this topic. Also, the underlying mechanism by which lipofilling improves scar aspect and reduces neuropathic scar pain remains largely undiscovered. Adipose‐derived stromal or stem cells (ADSC) are often described to be responsible for this therapeutic effect of lipofilling. We review the recent literature and discuss anticipated mechanisms that govern anti‐scarring capacity of adipose tissue and its ADSC. Both clinical and animal studies clearly demonstrated that lipofilling and ADSC influence processes associated with wound healing, including extracellular matrix remodelling, angiogenesis and modulation of inflammation in dermal scars. However, randomized clinical trials, providing sufficient level of evidence for lipofilling and/or ADSC as an anti‐scarring treatment, are lacking yet warranted in the near future. © 2017 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons Ltd