Quantitative and qualitative dermal change with microfat grafting of facial scars

Micronized cellular adipose matrix purified with a bladed connector contains abundant functional adipose stem cells

INTRODUCTION

A specialized device equipped with a sharp blade filter has been developed to enable more efficient purification of a micronized cellular adipose matrix (MCAM) containing stem cells. The aim of this study is to compare the characteristics and functions of the population of stromal cells (mSVF) and cultured cells (mASCs) purified using this device with those of cSVF and cASCs obtained through conventional enzymatic purification.

METHODS

Cell viability, proliferation capacity and yield were assessed. Characterization of stem cell potency was performed by analyzing cell surface markers including CD34, a marker of activated adipose-derived stem cells. The trilineage differentiation potential was evaluated using RT-PCR and histology.

RESULTS

The yield rate of mSVF obtained from MCAM was significantly higher than that with the conventional method, although use of the device resulted in a slight decrease in cell viability. After culture, mASCs exhibited a remarkable clonogenic potential and significantly higher cell proliferation potential than cASCs. The mASCs also displayed a distinct pattern of ASC cell surface markers, increased expression of genes related to CD34, high pluripotency, and a high trilineage differentiation ability.

CONCLUSION

The specialized device enhanced the yield of SVF and produced cells with high proliferation rates and characteristics that include expression of stem cell markers.

Effectiveness of Autologous Fat Grafting in the Treatment of Scars: A Systematic Review and Meta-Analysis

BACKGROUND

Autologous fat transfer (AFT) has been proposed as a possible treatment for scar tissue and its associated symptoms. Its effectiveness's evidence is yet unidentified though. The aim of this meta-analysis is to evaluate the currently available evidence on the efficacy and safety of autologous fat transfer in treating post-burn and post-traumatic scars using a validated scar measurement tool.

METHODS

This study performed a systematic literature review in November 2023 using the following electronic databases: MEDLINE, SCOPUS, Directory of Open Access Journals (DOAJ), PUBMED, and Google Scholar. The following key terms were included: (Fat grafting OR Autologous fat transfer) AND (body scars OR body burns OR body wounds) AND (Efficacy OR Safety OR satisfaction). We evaluated articles according to predefined quality criteria. The following data were included during the extraction period: patient demographics, indications for AFT, the number of AFT sessions, follow-up periods, and changes in the Patient and Observer Scar Assessment Scale (POSAS) scores, which contain both the patient and observer components.

RESULTS

This study included 1326 patients and 23 published articles. A total of 14 prospective studies, 7 retrospective studies, and 2 Randomized clinical trials studies were evaluated. These 23 articles came from diverse global locations; the earliest was published in 1992, and the most recently published in 2022.

CONCLUSION

Our findings demonstrated significant enhancements in scar characteristics from both patient and observer perspectives. Overall, AFT holds promise as a valuable treatment option for scar-related conditions as it enhances scar quality ,contributing to improved patient outcomes and satisfaction.

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 Table of Contents or the online Instructions to Authors www.springer.com/00266.

Camouflage of Postburn Scarring Alopecia Using Nanofat Grafting and Follicular Unit Hair Transplantation

BACKGROUND

Postburn scarring alopecia on hair-bearing aesthetic subunits causes cosmetic disfiguring and psychological problems. Follicular unit extraction (FUE) hair transplantation is an effective technique for camouflaging postburn scarring alopecia. However, poorly vascularized and fibrotic scar tissue limits the viability of grafts. The mechanical and vascular characteristics of scar tissue can be improved by nanofat grafting. This study aimed to present the results of postburn scarring alopecia treatment using nanofat-assisted FUE hair transplantation.

METHODS

Eighteen patients who had postburn scarring alopecia in and around the beard were enrolled. Patients underwent single-session nanofat grafting and FUE hair transplantation at 6-month intervals. Twelve months after hair transplantation, the survival rate of transplanted follicular graft, scar improvement, and patient satisfaction were assessed by counting each transplanted follicle individually, using the Patient and Observer Scar Assessment Scale, and using a 5-point Likert satisfaction scale, respectively.

RESULTS

Nanofat grafting and hair transplantation were successfully performed without complication. All scars significantly improved in mature characteristics ( P < 0.00001 for patients; P < 0.00001 for observers). The survival and density rates of transplanted follicular units ranged from 77.4% to 87.9% (mean, 83.2% ± 2.5%) and 10.7% to 19.6% (mean, 15.2% ± 2.46%), respectively. All patients reported significantly satisfying cosmetic results ( P < 0.00001).

CONCLUSIONS

Scarring alopecia is an inevitable and challenging late complication of deep burned hair-bearing units. Combining nanofat injection and FUE hair transplantation is among the most innovative and effective treatments for postburn scarring alopecia.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

The Effect of Fat Grafting on Scars Hyperpigmentation: A Systematic Review and Meta-Analysis

BACKGROUND

Hyperpigmented scars, particularly in exposed body areas, can be difficult to conceal and may evoke psychological distress. While the precise causes of scar dyschromia are not fully understood, alterations in melanogenic activity appear to hold more significance than changes in melanocyte quantity. Current treatments encompass laser interventions. However, it is essential to consider their costs and potential complications in relation to their limited proven effectiveness. Fat grafting has gained interest as a scar modulation technique due to its regenerative properties, and its efficacy in reducing scar hyperpigmentation is currently under investigation.

METHODS

A systematic review and meta-analysis was reported according to PRISMA guidelines. PubMed, Embase, and Cochrane Library databases were accessed. PROSPERO registration number is CRD42023457778. The primary outcome was a change in scar pigmentation after fat grafting. Pigmentation changes after fat grafting were calculated using the standardized mean difference (SMD) between baseline and postoperative scores according to POSAS and VSS scales. Bias assessment was conducted according to the National Institute for Health and Clinical Excellence quality assessment tool.

RESULTS

A total of 8 articles meeting inclusion and exclusion criteria were identified, involving 323 patients with hyperpigmented scars treated with fat grafting. A significant difference in scar pigmentation was noted after treatment with fat grafting according to observers' ratings, with a SMD of - 1.09 [95% CI: - 1.32; - 0.85], p<0.01. The SMD for patient-reported scar pigmentation after treatment with fat grafting was - 0.99 [96% CI: - 1.31; - 0.66], p<0.01. Four studies provided objective measurements of melanin changes after fat grafting and revealed inconsistent findings compared to subjective observations.

CONCLUSIONS

Fat grafting shows promise in ameliorating hyperpigmented scars based on subjective assessments, but further corroborating evidence from objective measures is required.

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 .

Microfat exerts an anti-fibrotic effect on human hypertrophic scar via fetuin-A/ETV4 axis

BACKGROUND

Hypertrophic scar is a fibrotic disease following wound healing and is characterized by excessive extracellular matrix deposition. Autologous microfat grafting proves an effective strategy for the treatment thereof as it could improve the texture of scars and relieve relevant symptoms. This study aims to explore the potential mechanisms underlying the anti-fibrotic effect of microfat on hypertrophic scars.

METHODS

In this study, we injected microfat into transplanted hypertrophic scars in mouse models and investigated the subsequent histological changes and differential expression of mRNAs therein. As for in vitro studies, we co-cultured microfat and hypertrophic scar fibroblasts (HSFs) and analyzed molecular profile changes in HSFs co-cultured with microfat by RNA sequencing. Moreover, to identify the key transcription factors (TFs) which might be responsible for the anti-fibrotic function of microfat, we screened the differentially expressed TFs and transfected HSFs with lentivirus to overexpress or knockdown certain differentially expressed TFs. Furthermore, comparative secretome analyses were conducted to investigate the proteins secreted by co-cultured microfat; changes in gene expression of HSFs were examined after the administration of the potential anti-fibrotic protein. Finally, the relationship between the key TF in HSFs and the microfat-secreted anti-fibrotic adipokine was analyzed.

RESULTS

The anti-fibrotic effect of microfat was confirmed by in vivo transplanted hypertrophic scar models, as the number of α-SMA-positive myofibroblasts was decreased and the expression of fibrosis-related genes downregulated. Co-cultured microfat suppressed the extracellular matrix production of HSFs in in vitro experiment, and the transcription factor ETV4 was primarily differentially expressed in HSFs when compared with normal skin fibroblasts. Overexpression of ETV4 significantly decreased the expression of fibrosis-related genes in HSFs at both mRNA and protein levels. Fetuin-A secreted by microfat could also downregulate the expression of fibrosis-related genes in HSFs, partially through upregulating ETV4 expression.

CONCLUSIONS

Our results demonstrated that transcription factor ETV4 is essential for the anti-fibrotic effect of microfat on hypertrophic scars, and that fetuin-A secreted by microfat could suppress the fibrotic characteristic of HSFs through upregulating ETV4 expression. Microfat wields an alleviative influence over hypertrophic scars via fetuin-A/ETV4 axis.

Fat Graft Retention: Adipose Tissue, Adipose-Derived Stem Cells, and Aging

SUMMARY

Over the past 30 years, there has been a dramatic increase in the use of autologous fat grafting for soft-tissue augmentation and to improve facial skin quality. Several studies have highlighted the impact of aging on adipose tissue, leading to a decrease of adipose tissue volume and preadipocyte proliferation and increase of fibrosis. Recently, there has been a rising interest in adipose tissue components, including adipose-derived stem/stromal cells (ASCs) because of their regenerative potential, including inflammation, fibrosis, and vascularization modulation. Because of their differentiation potential and paracrine function, ASCs have been largely used for fat grafting procedures, as they are described to be a key component in fat graft survival. However, many parameters as surgical procedures or adipose tissue biology could change clinical outcomes. Variation on fat grafting methods have led to numerous inconsistent clinical outcomes. Donor-to-donor variation could also be imputed to ASCs, tissue inflammatory state, or tissue origin. In this review, the authors aim to analyze (1) the parameters involved in graft survival, and (2) the effect of aging on adipose tissue components, especially ASCs, that could lead to a decrease of skin regeneration and fat graft retention.

CLINICAL RELEVANCE STATEMENT

This review aims to enlighten surgeons about known parameters that could play a role in fat graft survival. ASCs and their potential mechanism of action in regenerative medicine are more specifically described.

Stromal vascular fraction-enriched fat grafting as treatment of adherent scars: study design of a non-randomized early phase trial

Background

In the last decades, autologous fat grafting has been used to treat adherent dermal scars. The observed regenerative and scar-reducing properties have been mainly ascribed to the tissue-derived stromal vascular fraction (tSVF) in adipose tissue. Adipose tissue’s components augment local angiogenesis and mitosis in resident tissue cells. Moreover, it promotes collagen remodeling. We hypothesize that tSVF potentiates fat grafting-based treatment of adherent scars. Therefore, this study aims to investigate the effect of tSVF-enriched fat grafting on scar pliability over a 12-month period.

Methods and design

A clinical multicenter non-randomized early phase trial will be conducted in two dedicated Dutch Burn Centers (Red Cross Hospital, Beverwijk, and Martini Hospital, Groningen). After informed consent, 46 patients (≥18 years) with adherent scars caused by burns, necrotic fasciitis, or degloving injury who have an indication for fat grafting will receive a sub-cicatricic tSVF-enriched fat graft. The primary outcome is the change in scar pliability measured by the Cutometer between pre- and 12 months post-grafting. Secondary outcomes are scar pliability (after 3 months), scar erythema, and melanin measured by the DSM II Colormeter; scar quality assessed by the patient and observer scales of the Patient and Observer Scar Assessment Scale (POSAS) 2.0; and histological analysis of scar biopsies (voluntary) and tSVF quality and composition. This study has been approved by the Dutch Central Committee for Clinical Research (CCMO), NL72094.000.20.

Conclusion

This study will test the clinical efficacy of tSVF-enriched fat grafting to treat dermal scars while the underlying working mechanism will be probed into too.

Trial registration

Dutch Trial Register NL 8461. Registered on 16 March 2020

Effectiveness of Autologous Fat Transfer in the Treatment of Scar-Related Conditions: A Systematic Review and Meta-analysis

BACKGROUND AND AIM

Autologous fat transfer (AFT) has been introduced as a potential treatment option for scar-tissue and its related symptoms. However, the scientific evidence for its effectiveness remains unclear. This meta-analysis aims to evaluate the available evidence regarding the effectiveness of autologous fat transfer for the treatment of scar-tissue and its related conditions.

METHODS

PubMed/Medline database was queried from its inception till the end of November 2021. All the relevant studies assessing the effect of autologous fat transfer in the treatment of scar-related conditions were pooled in using a random-effects model.

RESULTS

9 studies (n=179) were included in the meta-analysis. Pooled analysis demonstrates significant improvement in all subscales of the POSAS patient score with most prominent in color 2.4 points (95% CI 1.78-3.041), stiffness 2.9 points (95% CI 2.33-3.45), irregularity 2.2 points (95% CI 1.093-3.297) and thickness 1.8 points (95% CI 0.804-2.719), respectively. Pain and itch improved relatively lesser, 1.3 points (95% CI 0.958-1.674) and 0.6 points (95% CI 0.169-1.215), respectively. The POSAS observer scale showed a relatively lower improvement with the least in vascularity 0.5 points (95% CI 0.098-0.96), pigmentation 0.8 points (95% CI 0.391-1.276) and surface area 0.8 points (95% CI 0.34-1.25). Thickness improved by 1.4 points (95% CI 0.582-2.3), relief 1.0 points (95% CI 0.461-1.545) and pliability 1.5 points (95% CI 1.039-2.036).

CONCLUSION

Our findings demonstrate that autologous fat transfer (AFT) is a promising treatment for scar-related conditions as it provides beneficial results in the scar quality. Future research should focus on the long-term effects of AFT and high-level evidence studies such as, randomized controlled trials (RCTs) and cohort studies are required.

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 .

Histological analysis of the effect of nanofat grafting in scar rejuvenation

Introduction:

Aims:

Materials and Methods:

Results:

Conclusion:

Immediate fat and nanofat-enriched fat grafting in breast reduction for scar management

BACKGROUND

Reduction mammoplasty can be successful but surgical scars may continue to be a most undesirable and unavoidable outcome. Various medical and non-invasive methods are available to minimize scar formation but as yet no methods have been discovered to eliminate them. We hypothesize that immediate fat and nanofat-enriched fat graft transfer may improve the scar quality and optimize results.

MATERIALS AND METHODS

This prospective study comprised 45 superomedial pedicle wise-pattern breast reduction patients divided into three groups of 15 in a randomized fashion. The control group had no additional injections whereas the other two groups received injections of fat and nanofat-enriched fat grafts immediately under their surgery scars, respectively. Surgical scar formation was evaluated at six months and scars were scored using the Vancouver scar scale and a visual analogue scale.

RESULTS

Fat and nanofat-enriched fat graft-injected groups scored significantly better on all items of the Vancouver scar scale, except for scar height, compared to the control group (p < 0.05). Visual analogue scores were significantly lower in the fat and nanofat-enriched fat graft-injected groups compared to the control group (p < 0.05).

CONCLUSIONS

In breast reduction patients, simultaneous fat and nanofat-enriched fat grafting appears to be a safe and promising strategy for scar management.

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 .

Autologous Fat Transfer for Scar Prevention and Remodeling: A Randomized, Blinded, Placebo-controlled Trial

Autologous fat transfer—also referred to as fat grafting—has been reported to provide beneficial effects to overlying scar and skin. Despite procedural frequency, there is a paucity of high-level evidence guiding the surgeon in technique, patient selection, and efficacy.

Autologous fat transfer to treat fibrosis and scar-related conditions: A systematic review and meta-analysis

BACKGROUND

Autologous fat transfer (AFT), also known as lipofilling, has been demonstrated to be more than just a filler. Through both mechanical dissection and local tissue remodelling mediated by stem cells, it is thought to improve scar quality, function and even pain. This paper aims to investigate the evidence regarding its safety and effectiveness for treating fibrosis and scar-related conditions.

METHODS

A literature search was performed in PubMed, Embase and the Cochrane Library to identify relevant studies. Extensive data extraction and standardization allowed conducting a meta-analysis.

RESULTS

Forty-five studies (3033 patients) provided sufficient data for meta-analysis. The AFT treatment resulted in significant increase in satisfaction scores of both patient and surgeon (p  =  0.001). Furthermore, a significant overall scar improvement was also found in the evaluation using the Patient and Observer Scar Assessment Scale, with the most notable effect in the scar stiffness (p<0.001) and pliability (p  =  0.004). In patients with severe pain, AFT resulted in a significant pain reduction of 3.7 points on the Visual Analogue Scale (p<0.001). Last, but not the least, the evidence suggests a significant recovery of radiotherapy-induced tissue damage (p  =  0.003) and function (p  =  0.012). On average, 1.4 procedures were required to achieve the desired result. Minor complications occurred in 4.8% of the procedures.

CONCLUSIONS

AFT is a promising treatment for fibrosis and scar-related conditions. Future research should focus on determining the long-term effects of AFT on fibrosis, pain and function. In addition, it would be crucial to quantify the mechanical and regenerative properties of fat as well as the effect of added supplements or stem cells.

Autologous fat grafting for the treatment of sclerotic lesions and scars

INTRODUCTION

Microfat grafting is a well-known technique that is underutilized in dermatology. Instead of removing sclerotic tissue, microfat grafting preserves the tissue and uses stem cells for remodeling its structure into normal tissue. We performed a retrospective study of patients treated with microfat grafting for sclerotic and atrophic skin lesions and scars.

PATIENTS AND METHODS

Seventy-two microfat grafts were performed using the Magalon technique under general anaesthesia for the treatment of sclerotic and atrophic skin lesions. We performed grafts for different indications, such as scars (n=55) and sclerotic and atrophic skin lesions (n=17: Parry-Romberg syndrome, morphea). The main outcome was assessed for satisfaction during follow-up. In addition, an independent committee judged the results based on photographs.

RESULTS

Satisfaction levels (e.g. results were judged to be "good") were almost 91% (n=50/55) for scars and 100% (n=17/17) for atrophic and sclerotic skin lesions. Satisfaction levels according to the independent committee were 94.1% for sclerotic and atrophic lesions and nearly 51% for scars.

CONCLUSION

Satisfaction was high after microfat grafting for atrophic and sclerotic skin lesions. Microfat grafting enabled restoration of the skin texture by exploiting stem cell properties. It is an efficient dermatological therapy for sclerotic and atrophic lesions, for which there are few alternative treatments.

Histological Evaluation of the Skin After Fat Grafting: A Blinded, Randomized, Controlled Clinical Study

BACKGROUND

Autologous fat graft is often employed to treat body contour defects. There is currently increased interest in the regenerative properties of fat grafting.

OBJECTIVES

The authors evaluated the histological changes of fat grafting in a blinded randomized controlled trial of staged fat grafting-abdominoplasty.

METHODS

Ten women between 24 and 55 years of age with a body mass index <30 kg/m2 and previous cesarean scar were submitted to fat grafting followed by staged abdominoplasty. The C-section scar served as a landmark for standardization of fat grafting site and control. One side of the abdomen was fat grafted and the other was left intact (control). At the time of abdominoplasty, 4 months later, a full-thickness skin sample from each hemi abdomen (fat-grafted area and control) was collected and sent to histological analysis.

RESULTS

All of the fat-grafted samples showed extracellular lipids and signs of fat graft viability, whereas no such changes occurred in the control group. There were no statistically significant differences in fat-grafted vs control samples regarding skin inflammatory infiltrate (P = 0.582), dermis thickness (P = 0.973), vascular density (P = 0.326), and amount of elastic fibers (P = 1).

CONCLUSIONS

The histological evaluation of women's abdominoplasty surgical site skin after 4 months of fat grafting showed signs of fat graft in 100% of the grafted sides but no change in skin inflammatory infiltrate, dermis thickness, vascularity density, or elastic fiber quantity.

Efficacy and Safety of Autologous Fat Transfer in Facial Reconstructive Surgery: A Systematic Review and Meta-analysis

Importance

The use of autologous fat transfer (AFT) or lipofilling for correcting contour deformities is seen as one of the major breakthroughs in reconstructive plastic surgery. Its applications in facial reconstructive surgery have been of particular interest owing to the prospect of achieving autologous reconstruction by a minimally invasive approach. However, its unpredictability and variable degree of resorption have limited its utility and much skepticism still exists regarding its efficacy. Furthermore, more than 2 decades of clinical research have produced a highly fragmented body of evidence that has not been able to provide definite answers.

Objective

To investigate the safety and efficacy of AFT in facial reconstruction through a systematic review and meta-analysis.

Data Sources

A literature search was performed in PubMed, Embase, and the Cochrane Library from inception to October 11, 2017.

Study Selection

All published studies investigating the efficacy and safety of AFT in facial reconstructive surgery.

Data Extraction and Synthesis

Two independent reviewers performed data extraction systematically, adhering to the PRISMA guidelines. Summary measures were pooled in a random-effects model meta-analysis.

Main Outcomes and Measures

The patient and surgeon satisfaction, graft survival, number of AFT sessions, and the incidence of AFT-related complications were the main outcomes of interest in this meta-analysis.

Results

This systematic review resulted in the inclusion 52 relevant studies consisting of 1568 unique patients. These included 4 randomized clinical trials, 11 cohort studies, and 37 case series. The overall follow-up averaged 1.3 years after AFT. Meta-analysis revealed a very high overall patient satisfaction rate of 91.1% (95% CI, 85.1%-94.8%) and overall surgeon satisfaction rate of 88.6% (95% CI, 83.4%-92.4%). The number of AFT sessions required to achieve the desired result was 1.5 (95% CI, 1.3-1.7) and 50% to 60% of the injected volume was retained at 1 year. Only 4.8% (95% CI, 3.3%-6.9%) of procedures resulted in clinical complications.

Conclusions and Relevance

To our knowledge, this study provides the first overview of the current knowledge about AFT in facial reconstructive surgery. Our results confirm that AFT is an effective technique for treating soft-tissue deformities in the head and neck, with low rate of minor complications.

Level of Evidence

NA.

Autologous adipose tissue grafting for the management of the painful scar

BACKGROUND AIMS

There is currently no definitive treatment for the painful scar. Autologous adipose tissue grafting (AATG) as a treatment option for scars has become increasingly popular and there is now an abundance of evidence in the literature that supports its application. Some studies suggest that human adipose tissue is a rich source of multipotent mesenchymal stromal cells. To our knowledge, there is currently no systematic literature review to date that examines the effectiveness of AATG for reducing pain in scars. Our novel systematic review aims to examine clinical studies on the use of AATG in the treatment of the painful scar.

METHODS

A literature search was performed using the following databases: PubMed, Cumulative Index to Nursing and Allied Health Literature, Web of Science, Medline, Cochrane library and Embase. The following key words and search terms were used: adipose stem cells, scar, pain, autologous fat grafting, scar management and neuropathic pain. Human interventional studies using autologous adipose tissue grafting for the treatment of painful scars including case series, case-control, cohort studies and randomized controlled trials were reviewed.

RESULTS

A total of 387 studies were found and 18 studies from January 1990 to January 2019 were identified as relevant for the purpose of this systematic review. Two studies were evidence level V, seven were evidence level IV, six were evidence level III, two were evidence level II and one was level I. A total of 337 scars were assessed in 288 patients for improvement in pain after scar treatment using adipose tissue grafting. An improvement in the analgesic effect was recorded in 12 of the 18 studies with adipose tissue grafting. A total of 233 of the 288 treated subjects responded with reduction in pain, whereas the rest did not. We carried out a pooled analysis of the studies and observed an odds ratio of 3.94 (P = 0.00001) when comparing pain reduction to no change in pain.

CONCLUSIONS

We conclude that AATG is a promising and safe modality for the treatment of the painful scar. There is an abundance of low-level evidence to support its use as an alternative treatment but there is a lack of high-level evidence at present to support its standard use. Future long-term randomized controlled trials with analgesic scores as the primary outcome measures are required to assess long-term efficacy.

Role of Fractionated Fat in Blending the Lid-Cheek Junction

BACKGROUND

Fat grafting has been used extensively in plastic surgery in the past two decades. Here, the authors report the retrospective comparison of patients who underwent fractionated fat injection to blend the lid-cheek junction with those who had regular fat injection.

METHODS

After obtaining institutional review board approval, a retrospective review of patients who underwent lower blepharoplasty with fractionated fat injection for blending the lid-cheek junction from January of 2014 through October of 2015 was performed. The results were compared to those of lower blepharoplasty patients who did not have fractionated fat injected before January of 2014. Twelve prospectively selected patients underwent histopathologic and gene expression comparisons.

RESULTS

A comparison of complications between the two groups revealed no significant differences. Furthermore, there was no significant difference between the two groups for sequelae of fractionated fat injection and regular fat injection. The gene expression analysis of the fractionated and regular fat did not show any difference between undifferentiated and differentiated cells. In addition, Oil Red O staining of the fractionated and regular fat after differentiation showed that cells from both fat groups differentiated equally well.

CONCLUSIONS

Fractionated fat injection appears to be a safe addition in blending the lid-cheek junction in the five-step lower blepharoplasty. There is no fat nodule formation with injection of fractionated fat injection compared with injection of regular fat performed superficially in the tear trough area. Contrary to what has previously been shown, the presence of viable cells in fractionated fat was noted.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Utility of Adipocyte Fractions in Fat Grafting in an Athymic Rat Model

BACKGROUND

Multiple processing and handling methods of autologous fat yield to variations in graft retention and viability, which results in unpredictable clinical outcomes.

OBJECTIVES

This study aims to understand the skin effects of fat graft preparations that contain a varying ratio of free-lipid and stem-cell-bearing stromal vascular fractions (SVF).

METHODS

Lipoaspirates from consenting patients were processed into emulsified fat and then SVF and adipocyte fractions (free-lipid). SVF enriched with 0%, 5%, and 15% free-lipid were grafted along the dorsum of athymic rats. The xenografts were collected 45 days after grafting and then prepped for immunostaining.

RESULTS

Xenografts resulted in viable tissue mass under the panniculus carnosus of rats as confirmed with human specific markers. A low percentage of human cells was also detected in the lower reticular dermis. Although grafts with SVF formed adipocytes of normal architecture, grafts formed with free-lipid alone resulted in large lipid vacuoles in varying sizes. Among graft preparations, SVF with 10% free-lipid resulted in much-developed adipocyte architecture with collagen and elastin. Compared with SVF alone grafts, SVF with free-lipid had higher CD44 expression, suggesting a localized immune response of adipocytes.

CONCLUSIONS

Current studies suggest that SVF enriched with approximately 10% free-lipid provides the best conditions for fat graft differentiation into viable fat tissue formation as well as collagen and elastin production to provide mechanical support for overlaying skin in an athymic rat model. Additionally, application of this therapeutic modality in a simple clinical setting may offer a practical way to concentrate SVF with free-lipid in a small volume for the improvement of clinical defects.

LEVEL OF EVIDENCE 5

Comparing different nanofat procedures on scars: role of the stromal vascular fraction and its clinical implications

AIM

Recently, a new fat grafting technique termed 'nanofat grafting' was proposed which improved tissue repair by the stem cells contained in the stromal vascular fraction (SVF) of nanofat. Here, we reported the clinical outcomes of different nanofat procedures in the treatment of scars in relation with SVF cell yield.

METHODS

Three different modified nanofat grafting procedures (supercharged-, evo- and centrifuged-modified nanofat) were compared with the classic nanofat method, and histological analysis was performed to assess skin regeneration. Residual nanofat samples were analyzed to determine SVF immunophenotype and yield from each procedure.

RESULTS

Supercharged-modified nanofat gave the best results in terms of clinical outcome and SVF yield. Histological analysis revealed similar skin regeneration in all treatments.

CONCLUSION

This work suggested a positive correlation between SVF yield and clinical outcomes in the nanofat treatment of scars.

Autologous Tissue Graft in Revision Medial Epicanthoplasty Using Subciliary Fat and Orbicularis Oculi Muscle

The medial epicanthal fold is one of the racial anatomic characteristics of Asians. As medial epicanthoplasty has become one of the most common cosmetic surgeries among Asians, the need for revision of overcorrected medial epicanthus also increased. In revision medial epicanthoplasty, an autologous tissue graft to the subcutaneous plane is used to reduce postoperative scar. Medial epicanthoplasty, using V-Y advancement and rotation flap, was performed in 93 patients (revision medial epicanthoplasty with autologous tissue graft, 60 patients; revision medial epicanthoplasty only, 33 patients). A V-Y and rotation flap was designed to cover the overexposed lacrimal lake. A small amount of fat tissue and orbicularis oculi muscle were harvested from the upper eyelid through the double-fold line and grafted to the subcutaneous space of the medial epicanthal area. We evaluated the patients' satisfaction with the overall outcome and scar. The mean intercanthal distance increased from 32.3 mm before surgery to 34.6 mm after surgery. Satisfaction with the scar and overall outcome was higher in the patient group who underwent medial epicanthoplasty with autologous tissue graft. No complication was observed in the autologous tissue graft group, whereas 1 patient who underwent medial epicanthoplasty without autologous tissue graft showed recurrence of the medial epicanthal fold, 5 months after surgery. Medial epicanthoplasty with autologous tissue graft is a simple and reliable method to repair the overcorrected medial epicanthus that can efficiently increase the intercanthal distance and prevent scar contracture.

Fat Grafting for Burn, Traumatic, and Surgical Scars

Fat grafting provides a reliable modality with expanding usefulness in reconstructive plastic surgery. Owing to its mechanical and theorized regenerative properties, adipose tissue can improve scar qualities and scar related symptoms when grafted adjacent to or within a scar. In this article, the literature describing the effect of fat grafting on various types of scars, current scientific understanding of fat grafting for scars, and our current approach to the management of problematic burn scars are reviewed.

Effectiveness of Autologous Fat Grafting in Adherent Scars: Results Obtained by a Comprehensive Scar Evaluation Protocol

BACKGROUND

Nowadays, patients normally survive severe traumas such as burn injuries and necrotizing fasciitis. Large skin defects can be closed but the scars remain. Scars may become adherent to underlying structures when the subcutical fat layer is damaged. Autologous fat grafting provides the possibility of reconstructing a functional sliding layer underneath the scar. Autologous fat grafting is becoming increasingly popular for scar treatment, although large studies using validated evaluation tools are lacking. The authors therefore objectified the effectiveness of single-treatment autologous fat grafting on scar pliability using validated scar measurement tools.

METHODS

Forty patients with adherent scars receiving single-treatment autologous fat grafting were measured preoperatively and at 3-month follow-up. The primary outcome parameter was scar pliability, measured using the Cutometer. Scar quality was also evaluated by the Patient and Observer Scar Assessment Scale and the DSM II ColorMeter. To prevent selection bias, measurements were performed following a standardized algorithm.

RESULTS

The Cutometer parameters elasticity and maximal extension improved 22.5 percent (p < 0.001) and 15.6 percent (p = 0.001), respectively. Total Patient and Observer Scar Assessment Scale scores improved from 3.6 to 2.9 on the observer scale, and from 5.1 to 3.8 on the patient scale (both p < 0.001). Color differences between the scar and normal skin remained unaltered.

CONCLUSIONS

For the first time, the effect of autologous fat grafting on functional scar parameters was ascertained using a comprehensive scar evaluation protocol. The improved scar pliability supports the authors' hypothesis that the function of the subcutis can be restored to a certain extent by single-treatment autologous fat grafting.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

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

Structural Fat Grafting to Improve Reconstructive Outcomes in Secondary Cleft Lip Deformity

Objective

To describe the technique and results of structural fat grafting in cleft lip revision, including patient satisfaction and aesthetic outcome.

Design

Retrospective case series

Setting

Multidisciplinary cleft care center.

Patients

All patients who underwent structural fat grafting between June 2006 and September 2012 for cleft lip revision, with appropriate photographic follow-up included. Twenty-two cases were reviewed; 18 had sufficient data to be included.

Interventions

Patients underwent structural fat grafting for cleft lip revision, most commonly injecting fat under deficient philtral columns, the nostril base, and upper lip.

Main Outcome Measures

Blinded observers rated outcomes using the Asher-McDade nasolabial appearance rating scale. Patients completed questionnaires assessing their satisfaction. A paired Student's t-test was used to test outcomes for significance (alpha = 0.05).

Results

Patients were an average of 16 years old (range 6-43); average length of follow up was 11.7 months. Overall symmetry and aesthetics were improved based on the nasal form ( P = 0.006) and vermillion border (P - 0.04) when rated using the Asher-McDade scale. No complications were recorded. Patients were significantly happier with their appearance after fat grafting (P < 0.001) and were uniformly positive when questioned about the ease of the surgery and rate of recovery.

Conclusions

Structural fat grafting is a safe and effective way to improve symmetry and enhance facial proportions in patients with cleft lip. Given the high degree of patient satisfaction, few complications, and durable results, fat grafting offers many advantages in cleft lip revision.

The Use of Autologous Fat Grafting for Treatment of Scar Tissue and Scar-Related Conditions: A Systematic Review

BACKGROUND

Scar tissue can cause cosmetic impairments, functional limitations, pain, and itch. It may also cause emotional, social, and behavioral problems, especially when it is located in exposed areas. To date, no gold standard exists for the treatment of scar tissue. Autologous fat grafting has been introduced as a promising treatment option for scar tissue-related symptoms. However, the scientific evidence for its effectiveness remains unclear. This systematic review aims to evaluate the available evidence regarding the effectiveness of autologous fat grafting for the treatment of scar tissue and scar-related conditions.

METHODS

A systematic literature review was performed using MEDLINE, Cochrane Library, EMBASE, and Web of Science. No language restrictions were imposed.

RESULTS

Twenty-six clinical articles were included, reporting on 905 patients in total. Meta-analysis was not performed because of the heterogeneous methodology demonstrated among the articles. Main outcome measures were scar appearance and skin characteristics, restoration of volume and/or (three-dimensional) contour, itch, and pain. All publications report a beneficial effect of autologous fat grafting on scar tissue. There is statistical significant improvement of the scar appearance, skin characteristics, and pain. Itch and restoration of volume and three-dimensional contour also improved.

CONCLUSIONS

Autologous fat grafting is used to improve a variety of symptoms related to scar tissue. This systematic review suggests that autologous fat grafting provides beneficial effects with limited side effects. However, the level of evidence and methodological quality are quite low. Future randomized controlled trials with a methodologically strong design are necessary to confirm the effects of autologous fat grafting on scar tissue and scar-related conditions.

The Immunomodulatory Effects of Mesenchymal Stem Cells in Prevention or Treatment of Excessive Scars

Excessive scars, including keloids and hypertrophic scars, result from aberrations in the process of physiologic wound healing. An exaggerated inflammatory process is one of the main pathophysiological contributors. Scars may cause pain, and pruritis, limit joint mobility, and cause a range of cosmetic deformities that affect the patient's quality of life. Extensive research has been done on hypertrophic scar and keloid formation that has resulted in the plethora of treatment and prevention methods practiced today. Mesenchymal stem cells, among their multifunctional roles, are known regulators of inflammation and have been receiving attention as a major candidate for cell therapy to treat or prevent excessive scars. This paper extensively reviews the body of research examining the mechanism and potential of stem cell therapy in the treatment of excessive scars.

Nanofat grafting: basic research and clinical applications

BACKGROUND

The indications for fat grafting are increasing steadily. In microfat grafting, thin injection cannulas are used. The authors describe their experience of fat injection with even thinner injection needles up to 27 gauge. The fat used for this purpose is processed into "nanofat." Clinical applications are described. Preliminary results of a study, set up to determine the cellular contents of nanofat, are presented.

METHODS

Nanofat grafting was performed in 67 cases to correct superficial rhytides, scars, and dark lower eyelids. Three clinical cases are described. In the research study, three fat samples were analyzed. The first sample was a classic lipoaspirate (macrofat). The second sample was microfat, harvested with a multiport small-hole cannula. The third was microfat processed into nanofat. Processing consisted of emulsification and filtering of the lipoaspirate. Fat samples were analyzed for adipocyte viability. Cells from the stromal vascular fraction and the CD34+ subfraction were quantified. The stem cell quality was investigated by culturing the cells in standard and adipogenic media.

RESULTS

No viable adipocytes were observed in the nanofat sample. Adipose-derived stem cells were still richly present in the nanofat sample. Cell cultures showed an equal proliferation and differentiation capacity of the stem cells from the three samples. Clinical applications showed remarkable improvements in skin quality 6 months postoperatively. No infections, fat cysts, granulomas, or other unwanted side effects were observed.

CONCLUSIONS

Nanofat injections might become a new concept in the lipofilling area. In clinical situations, nanofat seems to be suitable for skin rejuvenation purposes.

Effect of human adipose derived stem cells on scar formation and remodeling in a pig model: a pilot study

BACKGROUND

Adipose-derived stem cells (ASCs) have positive effects in the wound healing process.

OBJECTIVE

To clarify whether ASCs positively mitigate scar formation in the wound remodeling process.

MATERIALS AND METHODS

Full-thickness skin defects were created on the dorsal skin of Yorkshire pigs. After the defects were transformed into early scars, ASCs were injected, and the same amount of phosphate buffered saline (PBS) was injected in the control group. Clinical and histologic examinations were performed.

RESULTS

In the experimental group, the areas of scars were smaller than those of control groups. The color of scars was more similar to that of the surrounding normal tissue, and scar pliability was better. The number of mast cells decreased, and more-mature collagen arrangement was noted. In the early period of scar remodeling, the expression of transforming growth factor beta (TGF-β)3 and matrix metalloproteinase 1 (MMP1) was greater in the experimental group than in control group. In the late period, the level of alpha smooth muscle actin and tissue inhibitor of metalloproteinase 1 were dramatically less, although the level of MMP1 was lower in the experimental group than in control group.

CONCLUSIONS

Local injection of ASCs decreases scar size and provides better color quality and scar pliability. It decreases the activity of mast cells and inhibits the action of TGF-β against fibroblasts and positively stimulates scar remodeling through greater expression of MMP molecules.

Rasch analysis of the Patient and Observer Scar Assessment Scale (POSAS) in burn scars

PURPOSE

The Patient and Observer Scar Assessment Scale (POSAS) is a questionnaire that was developed to assess scar quality. It consists of two separate six-item scales (Observer Scale and Patient Scale), both of which are scored on a 10-point rating scale. After many years of experience with this scale in burn scar assessment, it is appropriate to examine its psychometric properties using Rasch analysis.

METHODS

Cross-sectional data collection from seven clinical trials resulted in a data set of 1,629 observer scores and 1,427 patient scores of burn scars. We examined the person-item map, item fit statistics, reliability, response category ordering, and dimensionality of the POSAS.

RESULTS

The POSAS showed an adequate fit to the Rasch model, except for the item surface area. Person reliability of the Observer Scale and Patient Scale was 0.82 and 0.77, respectively. Dimensionality analysis revealed that the unexplained variance by the first contrast of both scales was 1.7 units. Spearman correlation between the Observer Scale Rasch measure and the overall opinion of the clinician was 0.75.

CONCLUSION

The Rasch model demonstrated that the POSAS is a reliable and valid scale that measures the single-construct scar quality.

Current applications and safety of autologous fat grafts: a report of the ASPS fat graft task force

TASK FORCE STATEMENT: In 2007, the American Society of Plastic Surgeons formed a task force to conduct an assessment regarding the safety and efficacy of autologous fat grafting, specifically to the breast, and to make recommendations for future research. The task force formulated specific issues regarding fat grafting and then compiled them to focus on five broad-based questions: 1. What are the current and potential applications of fat grafting (specifically breast indications, and if data are available, other cosmetic and reconstructive applications)? 2. What risks and complications are associated with fat grafting? 3. How does technique affect outcomes, including safety and efficacy, of fat grafting? 4. What risk factors need to be considered for patient selection at this level of invasiveness? 5. What advancements in bench research/molecular biology potentially impact current or future methods of fat grafting? To answer these questions, the task force reviewed the scientific literature, critically appraised the information available, and developed evidence-based practice recommendations. Although the primary issue of interest was fat grafting to the breast, other aspects of fat grafting were evaluated.