Comparison of Telfa Rolling and a Closed Washing System for Autologous Fat Processing Techniques in Postmastectomy Breast Reconstruction

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

Background

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

Methods

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

Results

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

Conclusion

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

Streamlining the Fat: A Systematic Review of Active Closed Wash and Filtration in Autologous Fat Grafting After Breast Reconstruction

Although fat grafting in breast reconstruction continues to grow in popularity, the optimal technique remains elusive and outcomes are varied. This systematic review of available controlled studies utilizing active closed wash and filtration (ACWF) systems sought to examine differences in fat processing efficiency, aesthetic outcomes, and revision rates. A literature search was performed from inception to February 2022 following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) in Ovid MEDLINE (Wolters Kluwer, Alphen aan den Rijn, the Netherlands), Ovid Embase (Wolters Kluwer), and Cochrane Library (Wiley, Hoboken, NJ). Two independent reviewers screened the studies for eligibility with Covidence software. Bibliographies and citing references from selected articles were screened from Scopus (Elsevier, Amsterdam, the Netherlands). The search identified 3476 citations, with 6 studies included. Three studies demonstrated a significantly higher volume of graftable fat harvested in a significantly lower mean grafting time with ACWF than with their respective controls. With respect to adverse events, 3 studies reported significantly lower incidences of nodule or cyst formation with ACWF with respect to control. Two studies reported a significantly lower incidence of fat necrosis with ACWF vs control, with this trend upheld in 2 additional studies. Three studies reported significantly lower revision rates with ACWF with respect to control. No study reported inferiority with ACWF for any outcome of interest. These data suggest that ACWF systems yield higher fat volumes in less time than other common techniques, with decreased rates of suboptimal outcomes and revisions, thereby supporting active filtration as a safe and efficacious means of fat processing that may reduce operative times. Further large-scale, randomized trials are needed to definitively demonstrate the above trends.

LEVEL OF EVIDENCE: 4

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

Background

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

Methods

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

Results

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

Conclusions

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

Strategies to Improve AFT Volume Retention After Fat Grafting

BACKGROUND

Autologous fat grafting has gained increasing popularity used in plastic surgery as a strategy to improve functional and aesthetic outcome. However, variable augmentation results have concerned surgeons in that volume loss of grafted fat reported fluctuates unsteadily.

AIM

An optimal technique that clinically maximizes the long-term survival rate of transplantation is in urgent need to be identified.

METHOD

The PubMed/MEDLINE database was queried to search for animal and human studies published through March of 2022 with search terms related to adipose grafting encompassing liposuction, adipose graft viability, processing technique, adipose-derived stem cell, SVF and others.

RESULTS

45 in vivo studies met inclusion criteria. The principal of ideal processing technique is effective purification of fat and protection of tissue viability, such as gauze rolling and washing-filtration devices. Cell-assisted lipotransfer including SVF, SVF-gel and ADSCs significantly promotes graft retention via differentiation potential and paracrine manner. ADSCs induce polarization of macrophages to regulate inflammatory response, mediate extracellular matrix remodeling and promote endothelial cell migration and sprouting, and differentiate into adipocytes to replace necrotic cells, providing powerful evidence for the benefits and efficacy of cell-assisted lipotransfer.

CONCLUSION

Based on the current evidence, the best strategy can not be decided. Cell-assisted lipotransfer has great potential for use in regenerative medicine. But so far mechanically prepared SVF-gel is conducive to clinical promotion. PRP as endogenous growth factor sustained-release material shows great feasibility.

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 Grafting With CO2 Tissue Preparation (Carbo-pneumodissection): A Safe Method for Expanding and Enhancing Recipient Site Capacity and Aesthetic Outcomes

BACKGROUND

Autologous fat grafting (AFG) is commonly used as part of aesthetic and reconstruction procedures, but expanding and enhancing the recipient site capacity remains a major challenge.

OBJECTIVES

The aim of this study was to describe and assess an innovative intraoperative carbon dioxide (CO2) pneumodissection (CPD) recipient site preconditioning procedure intended to improve recipient site capacity and AFG outcomes.

METHODS

From June 2019 to August 2021, 53 patients after mastectomy or lumpectomy (76 breasts) underwent 96 AFG procedures as a separate stage immediately following tissue preconditioning with CPD.

RESULTS

There were no systemic or major local complications. The mean number of AFG procedures required to complete the reconstruction was 1.3 per breast. The vast majority of patients achieved a final satisfactory aesthetic outcome with either 1 or 2 procedures (77.6% and 18.4%, respectively). The volume of fat graft delivered into the recipient site per session following CPD was higher than previous literature reports for all study groups. Furthermore, the CPD procedure was associated with a reduced need for subsequent AFG to complete the reconstruction. The positive effect of CPD, in terms of AFG volume delivered, was even more prominent among scarred irradiated breasts. Despite the large fat graft volumes delivered in our study, only 5.3% of breasts experienced fat necrosis following the procedure.

CONCLUSIONS

CPD constitutes a safe, innovative, intraoperative method to expand and enhance recipient site capacity and fat grafting outcome. CPD allows cavernous expansion alongside preservation of the microcirculation. CPD works for both healthy and compromised tissues, in either reconstructive or aesthetic procedures.

LEVEL OF EVIDENCE: 4

“Achieving Optimal Clinical Outcomes in Autologous Fat Grafting: A Systematic Review of Processing Techniques”

BACKGROUND

Autologous fat grafting (AFG) is a versatile technique in reconstructive and cosmetic surgery. Graft processing is a key source of variability resulting in unreliable clinical outcomes, with no consensus on the optimal methodology. This systematic review identifies the evidence base supporting different processing paradigms.

METHODS

A systematic literature search was conducted using the PubMed, Scopus and The Cochrane Foundation databases. Studies comparing AFG processing methods and reporting long-term patient outcomes were identified.

RESULTS

Twenty-four studies (2413 patients) were identified. Processing techniques evaluated included centrifugation, decantation, washing, filtration, gauze rolling, as well as commercial devices and adipose-derived stem/stromal cell (ASC) enrichment methods. Objective volumetric and subjective patient-reported outcomes were discussed. There was a variable reporting of complications and volume retention rates. Complications were infrequent; palpable cysts (0-20%), surgical-site infections (0-8%) and fat necrosis (0-58.4%) were the most reported. No significant differences in long-term volume retention between techniques were found in AFG in the breast. In head and neck patients, greater volume retention was documented in ASC enrichment (64.8-95%) and commercial devices (41.2%) compared to centrifugation (31.8-76%).

CONCLUSIONS

Graft processing through washing and filtration, including when incorporated into commercial devices, results in superior long-term outcomes compared to centrifugation and decantation methods. ASC enrichment methods and commercial devices seem to have superior long-term volume retention in facial fat grafting.

Autologous Fat Grafting in Reconstructive Breast Surgery: Clinically Relevant Factors Affecting the Graft Take

BACKGROUND

Autologous fat grafting is an effective tool for soft tissue augmentation in reconstructive breast surgery. Despite the major advantages of this minimally invasive approach, the unpredictability of graft survival presents challenges.

OBJECTIVES

No clear consensus on the optimal technique has yet been published and well-defined prospective studies investigating impairing factors are lacking. This aim of this study was to generate valuable fundamental data.

METHODS

Ten female patients undergoing elective autologous fat grafting after nipple-sparing mastectomy were enrolled. Punch biopsies and lipoaspirates were collected from the harvest site for histologic, gene expression, and scanning electron microscopic analysis. Noninvasive Lipometer measurements determining the subcutaneous adipose tissue thickness at the graft site were used to calculate the respective take rate. Patient- and surgery-related data were acquired and correlated with the take rate.

RESULTS

A statistically relevant correlation between the take rate and the existing mean subcutaneous adipose tissue thickness at the grafted breast prior to surgery was observed. An approximate correlation was identified regarding the number of previous grafting sessions, body weight, and BMI. No statistically significant correlation was demonstrated for age, harvest site, or the mean adipocyte size. A lower level of cell damage was observed in scanning electron microscopic samples of washed lipoaspirates; and a strong indirect correlation with the expression of the adipocyte markers FABP4 and PLIN1 was apparent.

CONCLUSIONS

Factors correlating to the take rate were identified. Future studies investigating the clinical relevance of each impairing factor are essential to contribute to the optimization of this valuable method.

LEVEL OF EVIDENCE: 4

Preoperative Risk Factors and Complication Rates of Breast Augmentation With Fat Grafting

BACKGROUND

The current literature on the complications and risk factors of autologous fat grafting (AFG) for breast augmentation is scant and inconclusive.

OBJECTIVES

The aim of this study was to use a large, multicenter database to determine the major complications and risk factors of patients undergoing breast augmentation with AFG in comparison to breast augmentation with implants.

METHODS

Patients undergoing breast augmentation with AFG as well as with implants between January 2, 2017 and July 31, 2019 were identified from the CosmetAssure database (Birmingham, AL). The primary outcome was the occurrence of major complication(s) requiring emergency department visit, hospital admission, or reoperation within 45 days postoperatively. Age, gender, BMI, smoking, diabetes, facility, ASA class, and anesthetic type were evaluated as risk factors.

RESULTS

Among the 76,128 patients enrolled in CosmetAssure, 789 (1.0%) underwent breast augmentation with AFG, in comparison to 18,544 (24.3%) patients with implants. The incidence of any major complication in the AFG cohort and implant cohort was 3.2% and 2.3%, respectively. Infection was significantly higher in the AFG cohort (1.1% vs 0.5%). Tobacco users were more likely to have any complication, infection, and pulmonary dysfunction/hypoxia on univariate analysis. ASA Class III/IV was more likely to have any complication and infection. On multivariate analysis, smoking was an independent risk factor for any complication (relative risk = 17.1) and infection (relative risk = 20.2).

CONCLUSIONS

Infection and hematoma are the most common major complications in breast augmentation with AFG. Tobacco use is the only independent risk factor for overall complications and infection. Breast augmentation with AFG has a higher infection rate than augmentation with implants.

LEVEL OF EVIDENCE: 4

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 .