Fat Processing Techniques Research Articles

“SAVE” - Shock Assisted Viable Extraction: A Minimally Manipulative Method of Processing Regenerative Cells for Clinical Use

Abstract Background Extraction of adipose derived stem cells (ASC) from the stromal vascular fraction (SVF) has gained significant attention lately in the realm of regenerative medicine. However, finding highly efficient methods of extraction that also comply with United States regulations has prevented widespread clinical use. Objectives The objective of this study was to evaluate a novel ASC extraction device to quantify viable ASC extraction and processing efficiency. Methods SVF extracted from abdominal fat samples and processed using a novel shock-assisted viable extraction (SAVE) device was tested for stem cell count and viability. Additionally, time required for processing was recorded. Results Twelve adipose samples were utilized for this study. After a mean time of three minutes, cell count yield ranged of 47,400 to 189,400 of viable regenerative cells per cc, with an average of 122,464 viable regenerative cells per cc. Conclusions SAVE is a novel fat processing technique with high stem cell extraction that shows promise from a regulatory, yield, time efficiency, and cost perspective.

Mechanical force promotes tissue and molecular changes in adipose tissue regeneration post-transplantation.

Fat grafting often yields inconsistent and suboptimal results, necessitating improved fat processing techniques. A stromal vascular fraction (SVF) gel created using mechanical emulsification demonstrates superior retention rates to conventional Coleman fat grafts. This study investigated the mechanisms at play by transplanting fat aspirates from liposuction patients-either processed as Coleman fat grafts or further refined into an SVF gel via mechanical shear force-onto the backs of nude mice. The retention rate of the SVF gel after transplantation surpassed that observed for Coleman fat. Hematoxylin and eosin (HE) staining and immunofluorescence results demonstrated that the SVF gel group could form new adipose tissue characterized by well-organized mature fat structures. Mechanical shear force application induced increased mesenchymal stem cell abundance. Rather than merely surviving regeneration, fat was regenerated after transplantation, and the regenerated cells were mainly from mice, which was supported by microarray analysis. RNA-seq highlighted 601 genes expressed between SVF gel and Coleman fat groups, with 164 genes upregulated (cell cycle processes), and 437 genes downregulated (lipid metabolism). The application of mechanical shear force reduces the risk of complications and fosters cell proliferation and division, thereby enhancing the retention and regeneration of transplanted fat.

What Patient-related Factors Most Strongly Influence Autologous Fat Grafting Volume Retention in Breast Augmentation?

Background: Regarding autologous fat grafting for breast augmentation, the factors influencing volume retention are unclear. Few studies have assessed which factors, particularly patient-related variables, could affect volume retention and to what extent, without performing multivariate analysis. In this study, we performed three-dimensional breast volume measurements before and after autologous fat grafting, calculated the volume and volume retention, and investigated factors that may affect volume retention. Methods: A total of 204 breasts that underwent autologous fat grafting by the same surgeon at our hospital between May 25 and December 25, 2021 were included. Volumetric measurements were taken preoperatively and at 1, 3, and 6 months postoperatively using a three-dimensional camera; volume retention was calculated. Linear mixed model analysis was performed to examine the effects of age, body mass index, number of total autologous fat grafting procedures, pregnancy and lactation history, smoking status, fat processing techniques (sedimentation versus centrifugation), preoperative volume, and weight change at the 3- and 6-month postoperative volume retention analyses. Results: Using multivariate analysis, the preoperative volume was found to be a significant factor at 3 and 6 months. The preoperative volume affected fat volume retention rate by 0.004 (P = 0.001) and 0.008 (P = 0.011) per 10 mL at 3 and 6 months, respectively. Conclusions: The preoperative volume likely affected fat volume retention. Specifically, a 100-mL increase in the preoperative breast volume might increase the volume retention by 4%–8%. Preoperative volume is an important confounding factor for future studies.

Long-term volume retention after fat processing with cotton gauze rolling and centrifugation: A comparative study in nude mice.

Autologous fat grafting for correcting soft-tissue defects in cosmetic and reconstructive procedures has grown in popularity. Fat processing is implicated as a variable affecting quality, viability, and subsequent graft retention. This study aimed to identify a better fat processing technique for optimal outcomes. Fresh human aspirated fat was processed with cotton gauze rolling or centrifugation and named rolled fat (RF) and centrifuged fat (CF), respectively. Processed fat grafts were analyzed in vitro to determine yield, stromal vascular fraction (SVF) content, and viability. Then, RF and CF were transplanted subcutaneously to different flanks of every nude mouse. Fat samples were weighed to evaluate the volume retention 3 months post-transplantation. Tissue structure, densities of vessels, and CD68-positive macrophages were examined by histological staining. The compression rate of lipoaspirate by cotton gauze rolling was 25%, which was more effective than the rate of 50% by centrifugation. The numbers of SVF cells per gram of RF and CF were (1.02 ± 0.14) ×106 and (0.65 ± 0.26)×106, respectively (P < 0.05). Long-term graft retention was significantly higher in the RF group than in the CF group. Histological analysis of all implants revealed intact adipose tissue and equivalent vascularity. The number of CD68-positive macrophages in the RF group was much less than in the CF group on day 7. The results of this animal experiment showed that, compared with centrifugation, processing with cotton gauze rolling produces more condensed fat, higher SVF content, and decreased inflammatory response, thereby improving long-term volume retention. Further explorations are required to verify the superiority of cotton gauze rolling in clinical settings.

Evaluation of Adipose Cell-Based Therapies for the Treatment of Thumb Carpometacarpal Joint Osteoarthritis

Adipose tissue and its regenerative products which are isolated with enzymatic or mechanical processing of the harvested fat have been studied in a wide range of degenerative diseases, including osteoarthritis of the knee and hip. Intra-articular injection of these products can provide symptomatic relief of pain and postpone surgery. However, their use in the treatment of thumb carpometacarpal joint (CMCJ) osteoarthritis is limited and just a few studies have been published on that topic. For this reason, a review of the literature was performed by a thorough search of eight terms using the Pubmed database. In total, seven human studies met the selection criteria, including case-control studies, case-series and one case report. In all studies, intra-articular injection of autologous fat in osteoarthritic thumb CMCJ provided reduction in pain and improvement in hand function. Grip and pinch strength showed variable results, from no change to significant improvement. Fat-processing techniques were based on centrifugation and mechanical homogenization but biological characterization of the injected cells was not performed in any study. Although the results are encouraging, a uniformly standardized method of fat processing and the conduction of randomized controlled trials in the future could better evaluate the effectiveness of this procedure for thumb CMCJ osteoarthritis.

Washing Lipoaspirate Improves Fat Graft Survival in Nude Mice

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. 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. 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. 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. 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. 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 .

Fat Processing Techniques: A Narrative Review.

This study reviewed the literature regarding different fat processing techniques, in order to update the information for healthcare personnel and provide the latest evidence in selecting purification methods. PubMed (MEDLINE), EMBASE, the Cochrane Library, and the Cochrane Central Register of Controlled Trials were comprehensively searched to identify studies that compared different fat purification methods for animal and human studies published through July 2020. Papers were screened using inclusion and exclusion criteria, and relative data were collected for review. A total of 3292 studies were identified, of which 30 were included for review. The findings of existing clinical studies showed that the filtration and washing filtration methods performed better in the volume retention rate of adipose tissue. In terms of postoperative complications (fat necrosis, nodules, cysts, etc.), the incidence of complications of centrifugation is generally higher than that of other purification methods, while Telfa gauze and washing filtration system show better safety. More comparative studies are needed to draw conclusions about clinical efficacy and satisfaction. The existing basic science studies generally believe that centrifugation has no advantage in the integrity and metabolic activity of adipose tissue. However, there is no definite conclusion about the volume retention rate of grafts in animal experiments. In recent years, studies on the cost-effectiveness of various purification methods have emerged, and the efficiency advantages of commercial systems have also been gradually reflected. In the future, the purification efficiency will be improved based on ensuring clinical efficacy, which will be translated into cost savings. 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 .

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

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. 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. 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. 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. 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.

Evaluation of a new adipose tissue processing method for breast and buttock fat grafting procedures

BackgroundThere is still some debate about the best adipose processing method for autologous fat transfer procedures. This article reports a series of 66 fat grafting procedures using a novel fat processing technique that involves washing, “micronization,” and decantation.MethodsWe retrospectively reviewed the files of all patients operated on over a 2-year period by the two investigators. They underwent breast or buttock surgery that employed the novel fat processing technique for fat transfer. Complications and patient satisfaction were recorded, and fat resorption was qualitatively assessed based on clinical examination and photographs.ResultsData were retrieved from a total of 66 procedures performed on 43 patients: 17 breast augmentations, 8 buttock augmentations, and 41 breast reconstructions. Five patients also underwent concomitant facial fat grafting. The complications were one case of transient liponecrotic cyst in the breast, one case of transient areolar sensitivity reduction, and two cases of infection. The infections were reported in patients from the breast reconstruction cohort who had a history of radiotherapy. There was no complication associated with facial fat grafting. Patient satisfaction was achieved in 82.4 to 92.5% of cases depending on the study cohort. Fat resorption was graded as minimal to moderate in 95% of all cases.ConclusionsThis retrospective study supports the safety and effectiveness of this novel fat processing method in breast and buttock surgeries. Further controlled studies are needed to compare its performance with that of other techniques.Level of evidence: Level III, therapeutic study

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

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

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

Background: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.Methods:Chart review of a single surgeon experience with breast fat grafting was performed. Data extracted included demographics, technique, complications, graft volume, and revision rates. Secondarily, the timeline of complication profiles was analyzed. Lastly, subgroup analysis of radiated versus nonradiated breast outcomes was performed.Results:One thousand one hundred fifty-eight fat grafting procedures were performed on 775 breasts (654 DEC, 504 CWF). Time-to-event analysis for all complications showed no difference between groups. Independent risk factors for fat necrosis included DEC technique, body mass index >30 kg/m2, and fat injection >75 mL. The majority of cases of fat necrosis, cyst/nodule formation, ultrasounds, and biopsies occurred more than 6 months after grafting. Average graft volume was lower in DEC compared with CWF breasts (50.6 versus 105.0 mL, P < 0.01), and more DEC breasts required repeat fat grafting procedures (39.9% versus 29.6%, P < 0.01). Radiated breasts received larger fat graft volume (89.9 versus 72.4 mL, P < 0.01) and required more fat graft procedures (average 1.62 versus 1.47, P < 0.01).Conclusions:This study represents the largest series of breast reconstruction fat grafting to date. DEC harvest technique may be a risk factor for fat necrosis, which results in less fat injection and greater need for repeat procedures. Similarly, radiated breasts require larger graft volume and more repeat procedures.

Safety Profiles of Fat Processing Techniques in Autologous Fat Transfer for Breast Reconstruction.

Autologous fat transfer is common in breast reconstruction because of its versatility for use in contour deformities. The authors examined three different fat grafting processing techniques for complications and safety profile using their institutional database. Retrospective review was performed of patients from a single institution who had undergone autologous fat transfer following breast reconstruction from 2012 to 2016. Individuals were separated into three cohorts according to fat harvest technique: (1) centrifugation, (2) Telfa gauze, or (3) Revolve. Complications between the groups were assessed. A total of 267 cases of autologous fat transfer were identified (centrifugation, n = 168; Telfa, n = 44; and Revolve, n = 55). Grafting by means of centrifugation was associated with the greatest incidence of oil cysts (12.5 percent; p = 0.034), postoperative adverse events observed in the clinic (13.7 percent; p = 0.002), and total complications (25.6 percent; p = 0.001). The use of Telfa resulted in the lowest rates of oil cyst formation (0 percent; p = 0.002) and total complications (2.3 percent; p = 0.001). Grafting by means of centrifugation was also associated with the highest frequency of repeated injections among the three techniques after initial grafting (19.6 percent; p = 0.029). In contrast, Revolve demonstrated a repeated injection rate of just 5.45 percent, significantly lower when independently compared with centrifugation (p = 0.011). Multivariate analysis demonstrated that higher total graft volume (p = 0.002) and the use of centrifugation (p = 0.002) were significant risk factors for adverse events seen in the clinic postoperatively. Significant differences in postoperative outcomes exist between varying fat transfer techniques. Autologous fat transfer by means of centrifugation harbored the highest rates of complication, whereas Telfa and Revolve exhibited similar safety profiles. Therapeutic, III.

Facial aesthetic fat graft retention rates after filtration, centrifugation, or sedimentation processing techniques measured using three-dimensional surface imaging devices.

Objective:How to increase the long-term retention rate of autologous fat grafting has been widely discussed. This study aimed to evaluate long-term fat graft retention rates for the most widely used fat processing methods in the area of facial esthetic surgery, including centrifugation, filtration, and sedimentation, using three-dimensional (3D) imaging.Data Sources:PubMed, Embase, Wiley/Cochrane Library, and Web of Science databases were comprehensively searched from inception to July 2018 according to the guidelines of the American Society of Plastic Surgeons Fat Graft Task Force Assessment Methodology.Study Selection:Articles were screened using predetermined inclusion and exclusion criteria. Data collected included patient characteristics, follow-up devices, fat grafting techniques, and clinical outcomes. Patient cohorts were pooled, and fat graft retention rates were calculated. Complications were summarized according to different clinical characteristics.Results:Of 77 articles, 10 clinical studies met the inclusion criteria and reported quantified measurement outcomes with 3D imaging which provide precise volumetric data with approximately 2% standard deviation compared to real volumes. Data of 515 patients were included. Fat grafting retention varied from 21% to 82%. We found filtration and centrifugation techniques could result in better retention outcomes. However, retention varied within each processing technique, with no significant difference among the 3 techniques. Twenty-two complications were reported among 515 patients, including donor-site hematoma (1 case), mild post-operative erythema (2 cases), mild volumetric asymmetries (2 cases), chronic edema (2 cases), overcorrection (2 cases), skin irregularity (6 cases), and headache or dysesthesia (7 cases).Conclusions:Filtration and centrifugation techniques may result in better fat grafting retention outcomes than gravity sedimentation; however, more accurate statistical evidence is needed. Controversies continue to exist with respect to the performance of the different fat-processing techniques in fat graft retention.

A prospective randomized study comparing centrifugation and sedimentation for fat grafting in breast reconstruction

Fat grafting is an efficient method to correct large volumetric defects after mastectomy. There is an ongoing debate regarding the best method of processing the harvested fat before fat grafting. This study aimed to introduce a new MRI model and to compare two fat processing techniques measuring the gain in soft tissue thickness after fat grafting to the chest wall. Fifty-one mastectomy patients (one double sided), who required delayed implant reconstruction, with poor skin conditions were proposed fat grafting prior to implant reconstruction. At the time of fat grafting, patients were randomly assigned to centrifugation or sedimentation of the aspirated fat. The trial was undertaken in a single-center private practice setting. The gain in soft tissue thickness of the chest wall was measured using an MRI model, with 12 predefined points for measurement. Two MRIs were performed, one prior to fat grafting and one 8 weeks thereafter. The radiologist was blinded to the fat graft processing method used. Seven cases were excluded because they did not complete their second MRI. The analyses were thus based on 44 patients (one double sided). Centrifugation was performed in 21 cases and sedimentation in 24 cases. The mean gain in soft tissue thickness was +7.0mm in the centrifugation group and +8.8mm in the sedimentation group (p=.268). The mean operative time was 88min in the centrifugation group and 78min in the sedimentation group (p=.11). There were no adverse events for any of the patients. We developed a simple and reproducible MRI model to objectively measure and evaluate different fat processing techniques prior to fat grafting. At a median time of 8 weeks after one session of fat grafting, there was no benefit of centrifugation over sedimentation.

Sustained Overcorrection After Autologous Facial Fat Grafting in the Pediatric Population: A Case Series.

Autologous fat grafting is a valuable tool in the correction of facial soft tissue asymmetry and volume deficits. Pubertal growth and fluctuations in body mass present unique challenges to achieving satisfactory results after autologous fat transfer in the pediatric population. Few studies exist describing the outcomes and complications of pediatric facial fat grafting. The objective of this study is to identify the complication profile and outcomes after autologous fat grafting for the correction of facial asymmetry and volume deficits in the pediatric population. Retrospective chart review was performed identifying 19 patients having undergone autologous fat grafting to the face for correction of facial volume deficits or asymmetry. Intraoperative variables were analyzed including blood loss, tumescent volume, lipoaspirate volume, graft volume transferred, donor fat processing technique, and donor site. Patient growth parameters were evaluated using body mass index (BMI) at the time of grafting and most recent follow up. Outcomes were evaluated based on adequacy of the graft, number of revisions or corrections, and complications. A total of 19 patients were identified. The median age at the time of primary fat graft was 17 years. The average change in BMI from preoperative to the latest recorded date was +0.60 ± 1.90. The average time from primary procedure to most recent follow up was 1.7 years. Abdomen was the most common donor site utilized. Adequate correction was achieved with an average of 1.4 graftings. Complications included contour irregularity (n = 1) and persistent overcorrection (n = 3). One patient required lipoaspiration for treatment of overcorrection. An unpaired t test demonstrated no significant difference in preoperative BMI (P = 0.58), postoperative BMI (P = 0.28), or change in BMI after grafting (P = 0.56) between adequately corrected and overcorrected patients. Fat transfer is a safe and viable method for the correction of facial asymmetry in the pediatric population. Repeat fat grafting procedures may be required to achieve adequate correction; however, postoperative overcorrection is unlikely to resolve spontaneously in the pediatric population and is unrelated to changes in BMI. Care should be taken to minimize the degree of primary overcorrection when treating facial asymmetry in the pediatric population.

Schonende Aufbereitung von Fett für den Lipotransfer

Background With a growing interest in autologous fat grafting, this method is now widely used for soft tissue filling in aesthetic and reconstructive surgery. The technique can provide good clinical outcomes, provided that it is well mastered. However, many parameters can influence adipose graft survival, including fat harvesting, the fat processing technique and fat injection into the recipient site. While protocols differ between surgeons, there is a real will to refine the technique, in order to limit fat resorption after grafting and improve long-term clinical outcomes.

Processing Technique for Lipofilling Influences Adipose-Derived Stem Cell Concentration and Cell Viability in Lipoaspirate

Autologous fat grafting is a highly used technique in plastic and reconstructive surgery. Several fat-processing techniques have been described, with centrifugation frequently touted as the optimal method. Processing is one factor important for maximizing cell viability and adipose-derived mesenchymal stem cell (ADSC) concentrations. This study compared two methods of fat preparation (centrifugation vs Telfa-rolling) to determine which technique results in the greatest degree of cell viability and ADSC concentration. Abdominal fat was harvested from five patients. Equal aliquots were divided and processed by both centrifugation and Telfa-rolling. Samples were analyzed for ADSC proportions via flow cytometry and cell viability using methylene blue-based cell counting. Paired t tests were performed on all samples, and a P value lower than 0.05 was considered statistically significant. Telfa-rolling processing resulted in a higher percentage of isolated ADSCs (P<0.5 for 3 of 4 parameters) and a significantly higher number of viable cells (P<0.05). Telfa-rolling results in a higher proportion of ADSCs and greater cell viability than centrifugation for donor adipose graft preparation. Further studies are necessary to confirm whether optimal preparation translates to improved augmentation and cell take at the recipient site. 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 .

Long-term clinical outcomes of fat grafting by low-pressure aspiration and slow centrifugation (Lopasce technique) for different indications

Autologous fat grafts have been used successfully for structural fat grafting in facial, lip, and hand rejuvenation, body contour improvement, and traumatic defect restoration. The purposes of this study were to define a new fat graft harvesting and processing technique, which is named the “Lopasce technique” (low-pressure aspiration and slow centrifugation technique), and to evaluate the late clinical outcomes of fat grafting by this technique for different indications. A retrospective study was performed using the medical records of 21 patients (17 women and four men). The mean injected fat volume was 33.2 ± 34 cc (range 6–125 cc). The mean follow-up period was 13.2 ± 5.6 months (range 6–26 months). Postoperative results were evaluated by subjective and objective methods. In the subjective evaluation, 19 patients stated that there had been little resorption and that it was not necessary to repeat the fat grafting, one patient reported that the fat was resorbed in part, and one patient reported that the fat was resorbed completely. In the objective evaluation, the amount of fat graft taken in the recipient sites was between 60%–80% (average 70%) when compared with preoperative and late postoperative photographs of the patients at the 6- and 26-month follow-ups. Fat grafting is a simple, effective, and reproducible technique with a high satisfaction rate and few disadvantages or complications. We consider that structural fat grafting with the lopasce technique is an easy, effective, and long-lasting treatment for correction of congenital or acquired defects associated with various medical conditions.

Comparison of 3 Techniques of Fat Grafting and Cell-Supplemented Lipotransfer in Athymic Rats

Given the wide application of autologous fat grafting, a new emphasis on fat processing techniques has emerged in an effort to limit unpredictable degrees of resorption often seen with this procedure. With the growing interest in regenerative medicine, approaches to supplement fat grafts with adipose-derived stem cells are evolving in hopes of promoting vascularization and neoadipogenesis. The authors evaluated the outcomes of the most common processing techniques for fat grafting--decantation, washing, high-speed centrifugation--and stromal vascular cell-supplemented lipotransfer to determine which method yields a higher percentage of retention and better quality graft. A total of 32 subcutaneous injections of processed human lipoaspirate were carried out in 8 athymic rats. Each animal received all 4 processing conditions, with end points at 4, 8, and 12 weeks postinjection. Evaluation of graft survival included serial measurements of volume retention and histologic analysis. At 12 weeks postinjection, cell-supplemented and centrifuged grafts showed the most consistent volume maintenance. Based on histologic analysis, cell-supplemented and washed grafts had higher scores of viability and vascularity, with the former presenting the least cystic necrosis and calcification as well as minimal inflammation. Cell-supplemented lipotransfer had optimal outcomes for graft retention, viability, and vascularity, while washing resulted in high viability with a less intensive process. High-speed centrifugation resulted in consistent volume retention but lower viability. Each of these approaches is ideal under different circumstances and contributes to the versatility and reliability of fat grafting.

A Clinical Trial in Facial Fat Grafting: Filtered and Washed versus Centrifuged Fat

Although the increasing trend is to rebuild facial soft-tissue volume with autologous fat transfer, there is no agreement concerning the best way of processing the harvested fat before reinjecting it. Among all the reported fat graft processing techniques, in the present study, the authors compared the clinical results obtained using simple filtered and washed fat with those achieved by means of pure centrifuged fat. A prospective double-blind study was conducted on 25 healthy patients undergoing facial fat transplantation from January of 2006 to June of 2006. During the same session, half the face was injected with simple filtered and washed fat, and the other half was instead treated with centrifuged fat. Subjective and objective methods were used to evaluate the results. The subjective methods included a questionnaire, sent to all patients, accompanied by an explanatory letter. The objective method involved the evaluation of preoperative and postoperative photographs by a three-member jury. The average follow-up period was 12 months. The authors' experimental work demonstrates that there was no significant difference between the two fat-processing techniques. In the long term, the implanted hemifacial regions produced comparable results. The authors, following their personal experience based on the reported data, went back to using the simple filtered fat after some years of use of centrifuged fat.