A Comprehensive In Vitro Comparison of Preparation Techniques for Fat Grafting

Secondary Trigger Point Deactivation Surgery for Nerve Compression Headaches: A Scoping Review

Background

Primary trigger point deactivation surgery has been successful in reducing or eliminating nerve compression headaches between 79% and 90% of the time. The aim of this review article was to discuss the factors that contribute to index trigger point deactivation surgery failure, the importance of reevaluating trigger points following failure, and the options for secondary surgery.

Methods

A literature search was performed using a combination of keywords involving "chronic headache" and "nerve deactivation surgery," in databases until February 2023.

Results

Data of 1071 patients were evaluated and included (11 articles). The failure rate after index trigger point deactivation surgery occurs is approximately 12%, primarily due to incomplete primary trigger point deactivation. Secondary trigger points may not appear until the primary trigger is eliminated, which occurs in 17.8% of patients. Reevaluation of previously diagnosed trigger points as well as uncovered trigger points and additional preoperative testing is indicated to help determine candidacy for further surgical deactivation. To address scarring that could contribute to failure, corticosteroid injection, acellular dermal matrix, adipofascial fat, or expanded polytetrafluoroethylene sleeves have been described with beneficial effects. For neuroma management, regenerative peripheral nerve interface, targeted muscle reinnervation, a combination of both, relocation nerve grafting, or nerve capping have also been described. Neurectomy can be performed when patients prefer anesthesia and/or paresthesia over current pain symptoms.

Conclusion

Secondary trigger point deactivation surgery is indicated when there is suspicion of incomplete deactivation, internal scarring, neuroma, or newly-diagnosed trigger points.

The composition of cell-based therapies obtained from point-of-care devices/systems which mechanically dissociate lipoaspirate: a scoping review of the literature

Purpose

Cell-based therapies using lipoaspirate are gaining popularity in orthopaedics due to their hypothesised regenerative potential. Several ‘point-of-care’ lipoaspirate-processing devices/systems have become available to isolate cells for therapeutic use, with published evidence reporting their clinical relevance. However, few studies have analysed the composition of their ‘minimally-manipulated’ cellular products in parallel, information that is vital to understand the mechanisms by which these therapies may be efficacious. This scoping review aimed to identify devices/systems using mechanical-only processing of lipoaspirate, the constituents of their cell-based therapies and where available, clinical outcomes.

Methods

PRISMA extension for scoping reviews guidelines were followed. MEDLINE, Embase and PubMed databases were systematically searched to identify relevant articles until 21^st April 2022. Information relating to cellular composition and clinical outcomes for devices/systems was extracted. Further information was also obtained by individually searching the devices/systems in the PubMed database, Google search engine and contacting manufacturers.

Results

2895 studies were screened and a total of 15 articles (11 = Level 5 evidence) fulfilled the inclusion criteria. 13 unique devices/systems were identified from included studies. All the studies reported cell concentration (cell number regardless of phenotype per millilitre of lipoaspirate) for their devices/systems (range 0.005–21 × 10⁶). Ten reported cell viability (the measure of live cells- range 60–98%), 11 performed immuno-phenotypic analysis of the cell-subtypes and four investigated clinical outcomes of their cellular products. Only two studies reported all four of these parameters.

Conclusion

When focussing on cell concentration, cell viability and MSC immuno-phenotypic analysis alone, the most effective manual devices/systems were ones using filtration and cutting/mincing. However, it was unclear whether high performance in these categories would translate to improved clinical outcomes. Due to the lack of standardisation and heterogeneity of the data, it was also not possible to draw any reliable conclusions and determine the role of these devices/systems in clinical practice at present.

Level of Evidence

Level V Therapeutic.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40634-022-00537-0.

A Retrospective Study of SVF-gel Compared With Nanofat Combined With High-density Fat in the Treatment of Early Periorbital Aging

PURPOSE

To compare the effectiveness of transplantation with stromal vascular fraction (SVF)-gel or nanofat combined with high-density fat prepared with the Coleman technique (nanofat+high-density fat) to restore volume in the periorbital region or for periorbital rejuvenation in early periorbital aging.

METHODS

This retrospective study included 103 patients who received a transplant of SVF-gel (n = 58) or nanofat+high-density fat (n = 45) to restore volume in the periorbital region (n = 85) or for periorbital rejuvenation (n = 18) in our hospital between January 2016 and January 2020. Patient satisfaction and the reoperation rate were evaluated.

RESULTS

All patients had improved periorbital contouring and augmentation. Among the patients that received treatment to restore volume in the periorbital region, 17% and 65.9% of patients administered SVF-gel were very satisfied or satisfied, and 5.3% and 44.7% of patients administered nanofat+high-density fat were very satisfied or satisfied.

PATIENTS

administered SVF-gel were significantly more satisfied than patients administered nanofat+high-density fat with improvements in periorbital contouring (p < 0.05). Among the patients that received treatment for periorbital rejuvenation, 54.5% and 27.3% of patients administered SVF-gel were very satisfied or satisfied, and 28.6% and 42.8% of patients administered nanofat+high-density fat were very satisfied or satisfied. There was no significant difference between groups (p > 0.05). Some patients underwent a second operation after 3 to 8 months. Patients administered SVF-gel to restore volume in the periorbital region had a significantly lower reoperation rate than patients administered nanofat+high-density fat (12.7% [6/47] vs. 34.2% [13/38]; p < 0.05). There was no significant difference in the reoperation rate in patients treated for periorbital rejuvenation (9.1% [1/11] vs. 14.3% [1/7]; p > 0.05).

CONCLUSION

SVF-gel and nanofat+high-density fat are effective for restoring volume in the periorbital region and for periorbital rejuvenation in early periorbital aging. The reoperation rate was significantly lower and patient satisfaction scores were significantly higher in patients administered SVF-gel to restore volume in the periorbital region compared with patients administered nanofat+high-density fat.

Modern Fat Grafting Techniques to the Face and Neck

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Understand age-related changes to the face and neck and pertinent anatomy and discuss important aspects of fat graft harvesting, processing, and infiltration. 2. Recognize key differences between common techniques for fat processing and infiltration and develop a plan for patients based on site-specific facial anatomical zones. 3. Appreciate the utility of fat grafting as an adjunct to other facial rejuvenating procedures such as face lift and blepharoplasty procedures and list the potential complications from fat grafting to the face and neck.

SUMMARY

Fat grafting to the face and neck aids in volume restoration, thereby addressing soft-tissue atrophy associated with the aging face, acquired conditions, or congenital malformations. Often, fat grafting may sufficiently restore facial volume alone or in conjunction with other facial rejuvenation procedures. Facial/neck fat grafting requires a systematic and thoughtful approach, with special care to atraumatic technique. This CME article covers the principles and techniques for modern facial fat grafting to the face and neck. Increasing data support the ability of autologous fat to produce significant and sustainable appearance-related changes. The authors follow the general principles of the Coleman technique for facial fat grafting and have observed tremendous success over the years. Other techniques for facial fat grafting are also discussed including microfat and nanofat processing. As the understanding of facial fat compartments continues to evolve, the authors may better predict fat grafting outcomes following augmentation. Finally, the technique described as "lipotumescence" has been successfully used in the breast and other regions of the body that have radiation damage and is discussed in this article specifically for the face and neck.

Assessment of the Causes of Differences in Centrifugation Protocols as a Fat-Processing Technique: A Systematic Literature Review

BACKGROUND

Centrifugation has been widely used for fat graft processing. However, numerous different centrifugation protocols have been proposed in different studies. Investigation of these major differences is needed to clarify ambiguities and to achieve standardization. This review aimed to assess the causes of differences in centrifugation protocols as a fat-processing technique.

METHODS

Full-text and English-language articles between 1990 and 2020 were included in this study. Articles that assess the effect of centrifugation on fat graft survival with the following research purposes were selected: determination of the effect of centrifugation force/speed, determination of the effect of centrifugation time/duration, and comparison with other fat-processing techniques.

RESULTS

Fifty-four full-text, English-language articles were included. The number of articles that assessed centrifugation force/speed was 17 and centrifugation duration/time was 4, and the number of articles that compared centrifugation with other fat-processing techniques was 29 and centrifugation with noncentrifugation techniques was 4. Based on the study design, 25 experiments were performed in vivo, and 41 were performed in vitro.

CONCLUSION

Misuse of force (g) and speed (rpm) for defining the centrifugation protocol, differences in selected techniques for the graft harvest and graft transfer steps and differences in the analysis methods for fat graft survival are the main causes of these substantial variations among studies.

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.

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.

Obesity-induced nucleosome release predicts poor cardio-metabolic health

OBJECTIVE

While circulating nucleosome levels are high in obese mouse models, it is unknown where these nucleosomes originate from and whether they are a marker of cardio-metabolic health in humans. Here, we aimed to determine whether an association exists between circulating nucleosomes and the risk of developing obesity, metabolic syndrome (MetS) and/or a dysfunctional cardiovascular performance.

METHODS

We randomly selected 120 participants of the Kardiovize Brno 2030 study across three BMI strata: BMI 18-25, 25-30, and > 30. We assessed the association between circulating nucleosome levels and the risk of obesity, MetS, and poor cardiovascular health. We then cultured human neutrophils, adipocytes, and hepatoma cells to study nucleosome origins in a fat-rich environment.

RESULTS

Circulating nucleosome levels positively correlated with BMI (R = 0.602, p < 0.05), fatty liver index (R = 0.622, p < 0.05), left ventricular mass (R = 0.457, p < 0.05), and associated with MetS (p < 0.001) and poor cardiovascular health (p < 0.001). Incubating neutrophils with 1-10 μM free fatty acids triggered nucleosome production without concomitant cell death. Nucleosomes were not produced during pre-adipocyte differentiation or upon incubation of hepatic cells with palmitic acid.

CONCLUSIONS

Neutrophils are a bona fide source of circulating nucleosomes in an obesogenic environment and in overweight/obese patients. High nucleosome levels are associated with MetS and cardiovascular performance, and might represent novel candidate biomarkers for cardio-metabolic health.

A Comparison of Fat Graft Processing Techniques: Outcomes in 1,158 Procedures in Prosthetic Breast Reconstructions

As fat grafting in breast reconstruction evolves, questions of technique and outcomes persist. We compared 2 common fat processing techniques—decantation (DEC) versus closed wash and filtration (CWF)—with regard to outcomes and efficacy.

An Overview of Principles and New Techniques for Facial Fat Grafting

Facial fat grafting is a small-volume procedure and is primarily performed for facial rejuvenation, contouring, or regenerative surgery. The unsatisfying retention rate after fat grafting, however, led to unpredictable outcomes, subsequent multiple procedures, and even some complications. A variety of methods have been proposed to enhance the results of facial fat grafting, including several established surgical principles and many possible new techniques. Adding stem cells, fat preparations, and platelet concentrates may improve the survival after fat grafting but randomized controlled clinical studies are needed to determine their safety and efficacy as well as clinical indications for each technique.

Adipose Stromal Vascular Fraction Gel Grafting: A New Method for Tissue Volumization and Rejuvenation

BACKGROUND

The clinical outcomes of fat grafting vary and are technique-dependent. Stromal vascular fraction (SVF) gel is a novel, mechanically processed fat product with high concentrations of adipose tissue-derived stem cells and other SVF cells. This study evaluated the volumization and rejuvenation effects of SVF-gel.

OBJECTIVE

This study evaluated the volumization and rejuvenation effects of SVF-gel.

METHODS

This retrospective, single-center study included 126 patients who underwent SVF-gel grafting and 78 who underwent conventional lipoinjection for various indications from March 2015 to February 2017. Patient satisfaction and secondary surgery rates were evaluated. Samples of transferred SVF-gel were harvested and examined histologically.

RESULTS

All patients showed improvements in facial augmentation and contour. Patients in the SVF-gel group experienced mild postoperative swelling and a low secondary surgery rate (10.9%). Assessment of patient-rated satisfaction on a 5-point Likert scale found that 77.3% of patients in the SVF-gel group were satisfied (54.5%) or very satisfied (22.8%) with their outcomes. By comparison, 53.8% of patients who underwent conventional lipoinjection were satisfied (48.7%) or very satisfied (5.1%). Moreover, SVF-gel showed effective antiwrinkle and skin rejuvenation effects. Hematoxylin-eosin staining showed a normal adipose tissue structure in transferred SVF-gel.

CONCLUSION

Stromal vascular fraction gel is effective for both volumization and rejuvenation, and may be superior to conventional lipoinjection for facial recontouring.

European Survey Study Among Plastic/Breast Surgeons on the Use of and Opinion Toward Autologous Fat Transfer: With Emphasis on Breast Surgery

Objective. The aim of this study is to examine the experience of European surgeons on autologous fat transfer (AFT) and highlight differences between countries and levels of experience. Background Data. The popularity of AFT causes an increase in sophisticated scientific research and clinical implementation. While results from the former are well-documented, important aspects of the latter are far less recognized. Methods. An international survey study about surgeon background, besides AFT familiarity, technique, and opinion, was distributed among surgeons from 10 European countries. The differences between countries and levels of experience were analyzed using a logistic regression model. Results. The mean respondent age, out of the 358 completed questionnaires, was 46 years. Ninety-seven percent of the respondents were plastic surgeons, who practiced AFT mostly in breast surgery and considered themselves experienced with the technique. The thigh and abdomen were less favored harvest locations by the Belgium and French respondents, respectively, and both the French and Austrian respondents preferred manual aspiration over liposuction in harvesting the fat. Despite minor differences between countries and experience, the intraglandular space was injected in all subgroups. Conclusions. The expanding use of AFT in Europe will lead to more experience and heterogeneity regarding the technique. However, despite an obvious adherence to Coleman's method, deviations thereof become more apparent. An important example of such a deviation is the ongoing practice of intraglandular AFT despite being a contraindication in various European guidelines. These unsafe practices should be avoided until scientific clarification regarding oncological safety is obtained and should therefore be the focus of surgeon education in Europe.

Biphasic calcium phosphate scaffolds with controlled pore size distribution prepared by in-situ foaming

In this study, a reproducible method of fabricating hierarchically 3D porous scaffolds with high porosity and pore interconnectivity is reported. The method is based on in-situ foaming of a dispersion of diisocyanate, polyol, water and hydroxyapatite (HA) to form a hard foamed HA/polyurethane composite which after heat treatment provided a bi-phase calcium phosphate scaffold. This technique, combining the advantages of polymer sponge and direct foaming methods, provides a better control over the macrostructure of the scaffold. A modification of the multi-scaled porous macrostructure of scaffolds produced by changing the ratio of input reactants and by sintering temperature was studied. The pore morphology, size, and distribution were characterized using a scanning electron microscope and mercury porosimetry. The pores were open and interconnected with multi-scale (from several nanometres to millimetres) sizes convenient for using in tissue engineering applications. The bioactivity was confirmed by growing an apatite layer on the surfaces after immersion in simulated body fluid. The material was biocompatible, as shown by using normal human adipose tissue-derived stem cells (ASC). When seeded onto the scaffolds, the ASC adhered and remained healthy while maintaining their typical morphology.

Complications in Gluteal Augmentation

Gluteal augmentation is rapidly gaining in popularity and this is driving aesthetic surgeons to gain experience and develop techniques to meet patient expectations. Currently, the 2 main techniques - gluteal fat grafting and gluteal implant for augmentation have significant limitations. Autologous fat grafting seems to have a mortality rate significantly higher than other aesthetic procedures. Implant based gluteal augmentation is equally difficult. This is a broad review of all the complications associated with both types and autologous gluteal augmentation. Society and individual surgeons are developing guidelines for the procedure based on theoretic etiologies. Gluteal implant augmentation is also fraught with problems.

Autologous Fat Transfer for Facial Rejuvenation: A Systematic Review on Technique, Efficacy, and Satisfaction

Background

Parallel to the steady decline in surgical aesthetic procedures to the face, dermal fillers seem to have gained a more prominent place in facial rejuvenation over the last couple of years. As a dermal, facial filler, autologous fat transfer (AFT) seems to have real potential because of the biocompatibility of adipose tissue besides being a procedure with few and primarily minor complications. This systematic review aims to evaluate the available evidence regarding the safety and effectiveness of AFT for facial rejuvenation.

Method

A systematic review after the Preferred-Reporting-Items-for-Systematic-Reviews-and-Meta-Analysis (PRISMA) statement was conducted. MEDLINE, Embase, and Cochrane Library were searched up to December 2016, with no language restrictions imposed. Case series, cohort studies, and randomized controlled trials (RCTs) reporting on relevant outcomes were included.

Results

Eighteen clinical articles were included, reporting on 3,073 patients in total over a mean follow-up period of 13.9 months. Meta-analysis showed an overall complication rate of 6% (95% CI 3.0-14.0), with hematoma/ecchymosis (5%), fat necrosis/oil cysts (2%), and irregular fat distribution and scars (both 2%) being among the most reported. No major complications were reported, and the overall patient satisfaction rate was 81%.

Conclusion

Although the evidence in this systematic review is still limited and plagued by heterogeneity between studies, AFT seems to be a promising method in facial rejuvenation with fewer complications than other fillers and high patient satisfaction rates. Further large-cohort, preferably multicenter, RCTs should substantiate these results through quantifiable volumetric assessment tools and validated patient questionnaires, while adhering to predetermined nomenclature in terms of complications.

Mesenchymal Stem Cells from Adipose Tissue in Clinical Applications for Dermatological Indications and Skin Aging

Operating at multiple levels of control, mesenchymal stem cells from adipose tissue (ADSCs) communicate with organ systems to adjust immune response, provide signals for differentiation, migration, enzymatic reactions, and to equilibrate the regenerative demands of balanced tissue homeostasis. The identification of the mechanisms by which ADSCs accomplish these functions for dermatological rejuvenation and wound healing has great potential to identify novel targets for the treatment of disorders and combat aging. Herein, we review new insights into the role of adipose-derived stem cells in the maintenance of dermal and epidermal homeostasis, and recent advances in clinical applications of ADSCs related to dermatology.