Autologous fat grafting in breast reconstruction: implications for follow-up and surveillance

Preconditioning Strategies for Improving the Outcome of Fat Grafting

Autologous fat grafting is a common procedure in plastic, reconstructive, and aesthetic surgery. However, it is frequently associated with an unpredictable resorption rate of the graft depending on the engraftment kinetics. This, in turn, is determined by the interaction of the grafted adipose tissue with the tissue at the recipient site. Accordingly, preconditioning strategies have been developed following the principle of exposing these tissues in the pretransplantation phase to stimuli inducing endogenous protective and regenerative cellular adaptations, such as the upregulation of stress-response genes or the release of cytokines and growth factors. As summarized in the present review, these stimuli include hypoxia, dietary restriction, local mechanical stress, heat, and exposure to fractional carbon dioxide laser. Preclinical studies show that they promote cell viability, adipogenesis, and angiogenesis, while reducing inflammation, fibrosis, and cyst formation, resulting in a higher survival rate and quality of fat grafts in different experimental settings. Hence, preconditioning represents a promising approach to improve the outcome of fat grafting in future clinical practice. For this purpose, it is necessary to establish standardized preconditioning protocols for specific clinical applications that are efficient, safe, and easy to implement into routine procedures.

Analysis of Factors Affecting the Choice of Implant-based or Autologous Fat Grafting Breast Augmentation: A Retrospective Study

BACKGROUND

Breast augmentation mainly includes implant-based and autologous fat grafting augmentation. Choosing the right surgical method for the patient is particularly important. However, an analysis of the factors that may affect the choice of surgical methods among patients has not yet been performed. In this study, the authors sought to identify the factors that influence the choice of surgical methods for women who receive implant or autologous fat grafting breast augmentation.

METHODS

A total of 192 female patients with micromastia who were hospitalized for breast augmentation from June 2018 to June 2021 were included in the study. The enrolled patients were divided into the implant group (n=92) and the fat group (n=100). Univariate and multivariate analyses were then performed on the data.

RESULTS

In the univariate analysis, there were statistical differences between the implant and fat group in weight, BMI, marital status, occupation, bilateral midsternal line-nipple distance difference, bilateral nipple-inframammary fold distance difference in the natural state, and others (P<0.05). In the final logistic binary regression analysis, the statistically different factors included the acceptable number of operations, chest circumference through the armpit, and chest circumference through the inframammary fold (P<0.05).

CONCLUSION

There were several factors, such as acceptable numbers of operations, chest circumference through the armpit, and chest circumference through the inframammary fold, may affect the choice of breast augmentation surgery method for Chinese female patients.

LEVEL OF EVIDENCE

Level-III, retrospective cohort study.

Autologous fat grafting and adipose-derived stem cells therapy for acute burns and burn-related scar: A systematic review

Objectives

The objective of this study was to analyze all available research on the application of autologous fat grafting (AFG) and adipose-derived stem cells (ADSC) to present evidence-based recommendations, particularly in the clinical treatment of acute burns and burn-related scars.

Materials and Methods

We conducted a systematic search of PubMed, COCHRANE, and EMBASE, as well as a manual search of previous reviews' reference lists up. The risk of bias (RoB) was assessed using RoB 2.0 and ROBINS-I, where appropriate.

Results

Six eligible studies were selected (2 randomized clinical trials [RCT], 1 retrospective cohort, and 3 experimental studies) with subjects ranging from 3 to 100. Only one study evaluated the use of AFG for acute burns. Improvements in wound healing, vascularization, scar characteristics, and tissue architecture were generally observed in some studies, supported by molecular markers, while one study reported nonsignificant results. Subjective patient satisfaction was reported to have improved. Functional outcomes improvement in the treated regions was minimal. However, study heterogeneity arose mainly from treatment protocols. Cautious results interpretation due to potential bias, especially in selection and confounding domains, and limited clinical trials are important to note. More studies are needed to evaluate.

Conclusion

AFG and ADSC hold potential as valuable treatment options for burn-related scars, supported by a body of evidence, but further well-designed RCT are needed. The efficacy of acute burn settings is yet to be further evaluated since evidence is limited.

Autogenous breast reconstruction for total mastectomies: a narrative review

Background and Objective

Mastectomies have a significant socio-psychological impact, motivating patients to undergo breast reconstruction. Initially, silicone implants were used to reconstruct the breast. However, breast implants have been the subject of successive crises throughout the years. Indeed, rupture, silicone bleeding, and capsular contracture remain topical. In 2019, the BIOCELL textured breast implants was banned and recalled due to the discovery of the breast implant-associated anaplastic large cell lymphoma (BIA-ALCL). More recently, the breast implant illness has been depicted in the media. To cope with these issues and to respond to some patients' expectations for a natural reconstruction, plastic surgeons have developed autogenous solutions for breast reconstruction. Since Taylor's research on angiosomes, the development of the microsurgery and more recently fat grafting, autogenous breast reconstruction has known a tremendous expansion. Autologous breast reconstruction allows a more natural feeling and texture. This narrative review aims to provide to the readers a comprehensive and updated evidence-based overview of state of the art about autologous breast reconstruction after total mastectomy.

Methods

We conducted a narrative review of the literature searching for papers published between January 2010 and December 2022. The MeSH terms with different combinations were used to identify articles for inclusion. After screening article titles and abstracts independently by three authors, 66 papers were included in this review.

Key Content and Findings

In this review, the authors describe and discuss the different autogenous techniques in breast reconstruction.

Conclusions

Autologous reconstructions provide very satisfactory, durable, and reliable results with relatively low complication rates. Deep inferior epigastric perforator (DIEP) flaps, latissimus dorsi flaps and autologous fat grafting are the most common type of autogenous breast reconstructions.

CCNB1 may as a biomarker for the adipogenic differentiation of adipose-derived stem cells in the postoperative fat transplantation of breast cancer

Background

Adipose-derived stem cells (ADSCs) are closely associated with the survival rate of transplanted fat in breast reconstruction after breast cancer surgery. Nevertheless, the intrinsic mechanisms regulating ADSCs adipogenic differentiation remain ambiguous. The aim of our study was to explore the relevant genes and pathways to elucidate the potential mechanisms of adipogenic differentiation in ADSCs.

Methods

The Gene Expression Omnibus (GEO) dataset GSE61302 was downloaded and analyzed to identify differentially expressed genes (DEGs). Key genes and signaling pathways were obtained through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional and enrichment analysis. Protein-protein interaction (PPI) network and hub gene analyses were performed with the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database and Cytoscape software. Finally, the transcription levels of hub genes in the adipogenic differentiated group and undifferentiated group of ADSCs were compared via real-time quantitative polymerase chain reaction (RT-qPCR).

Results

In total, 1,091 DEGs were identified through bioinformatics analysis of the adipogenic differentiated group and undifferentiated group. If was then found that the 10 downregulated key genes, CCNB1, NUSAP1, DLGAP5, TTK, CCNB2, KIF23, BUB1B, CDC20, CDCA8, and KIF11 may play important roles in the adipogenic differentiation of ADSCs. Subsequent in vitro experimental verification also revealed that the messenger RNA (mRNA) expression levels of cyclin B1 in adipogenic differentiated cells and undifferentiated cells were significantly different at the early stage (P<0.05), but there was no significant difference at the late stage (P>0.05).

Conclusions

As a key gene, CCNB1 might be a potential biomarker in the adipogenic differentiation of ADSCs at the early stage.

Fatter Is Better: Boosting the Vascularization of Adipose Tissue Grafts

Adipose tissue resorption after fat grafting is a major drawback in plastic and reconstructive surgery, which is primarily caused by the insufficient blood perfusion of the grafts in the initial phase after transplantation. To overcome this problem, several promising strategies to boost the vascularization and, thus, increase survival rates of fat grafts have been developed in preclinical studies in recent years. These include the angiogenic stimulation of the grafts by growth factors and botulinum neurotoxin A, biologically active gels, and cellular enrichment, as well as the physical and pharmacological stimulation of the transplantation site. To transfer these approaches into future clinical practice, it will be necessary to establish standardized procedures for their safe application in humans. If this succeeds, the surgical outcomes of fat grafting may be markedly improved, resulting in a significant reduction of the physical and psychological stress for the patients.

[Update and Trends in Breast Reconstruction After Mastectomy]

Due to refinements in operating techniques, autologous breast reconstruction has become part of standard care. It has become more difficult to advise patients due to the expansion of oncologic options for mastectomy, radiation therapy and the variety of reconstructive techniques. The goal of reconstruction is to achieve oncologically clear margins and a long-term aesthetically satisfactory result with a high quality of life. Immediate reconstruction preserves the skin of the breast and its natural form and prevents the psychological trauma associated with mastectomy. However, secondary reconstructions often have a higher satisfaction, since here no restitutio ad integrum is assumed. Alloplastic, i. e., implant-based, breast reconstruction and autologous breast reconstruction are complementary techniques. This article provides an overview of current options for breast reconstruction including patients' satisfaction and quality of life following breast reconstruction. Although immediate reconstruction is still the preferred choice of most patients and surgeons, delayed reconstruction does not appear to compromise clinical or patient-reported outcomes. Recent refinements in surgical techniques and autologous breast reconstruction include stacked-flaps, as well as microsurgical nerve coaptation to restore sensitivity, which lead to improved outcomes and quality of life. Nowadays Skin-sparing and nipple-sparing mastectomy, accompanied by improved implant quality, allows immediate prosthetic breast reconstruction as well as reemergence of the prepectoral implantation. The choice of breast reconstruction depends on the type of mastectomy, necessary radiation, individual risk factors, as well as the patient's habitus and wishes. Overall, recent developments in breast reconstruction led to an increase in patient satisfaction, quality of life and aesthetic outcome with oncological safety.

Characterization of Human Subcutaneous Adipose Tissue and Validation of the Banking Procedure for Autologous Transplantation

Adipose tissue (AT) is composed of a heterogeneous population which comprises both progenitor and differentiated cells. This heterogeneity allows a variety of roles for the AT, including regenerative functions. In fact, autologous AT is commonly used to repair soft tissue defects, and its cryopreservation could be a useful strategy to reduce the patient discomfort caused by multiple harvesting procedures. Our work aimed to characterize the cryopreserved AT and to validate its storage for up to three years for clinical applications. AT components (stromal vascular fraction-SVF and mature adipocytes) were isolated in fresh and cryopreserved samples using enzymatic digestion, and cell viability was assessed by immunofluorescence (IF) staining. Live, apoptotic and necrotic cells were quantified using cytometry by evaluating phosphatidylserine binding to fluorescent-labeled Annexin V. A multiparametric cytometry was also used to measure adipogenic (CD34+CD90+CD31-CD45-) and endothelial (CD34+CD31+CD45-) precursors and endothelial mature cells (CD34-CD31+CD45-). The maintenance of adipogenic abilities was evaluated using in vitro differentiation of SVF cultures and fluorescent lipid staining. We demonstrated that AT that is cryopreserved for up to three years maintains its differentiation potential and cellular composition. Given our results, a clinical study was started, and two patients had successful transplants without any complications using autologous cryopreserved AT.

Postoperative Antibiotics Confer No Protective Association After Fat Grafting for Breast Reconstruction

INTRODUCTION

Autologous fat grafting after breast reconstruction is a commonly used technique to address asymmetry and irregularities in breast contour. While many studies have attempted to optimize patient outcomes after fat grafting, a key postoperative protocol that lacks consensus is the optimal use of perioperative and postoperative antibiotics. Reports suggest that complication rates for fat grafting are low relative to rates after reconstruction and have been shown to not be correlated to antibiotic protocol. Studies have additionally demonstrated that the use of prolonged prophylactic antibiotics do not lower the complication rates, stressing the need for a more conservative, standardized antibiotic protocol. This study aims to identify the optimal use of perioperative and postoperative antibiotics that optimizes patient outcomes.

METHODS

Patients in the Optum Clinformatics Data Mart who underwent all billable forms of breast reconstruction followed by fat grafting were identified via Current Procedural Terminology codes. Patients meeting inclusion criteria had an index reconstructive procedure at least 90 days before fat grafting. Data concerning these patient's demographics, comorbidities, breast reconstructions, perioperative and postoperative antibiotics, and outcomes were collected via querying relevant reports of Current Procedural Terminology; International Classification of Diseases, Ninth Revision; International Classification of Diseases, Tenth Revision; National Drug Code Directory, and Healthcare Common Procedure Coding System codes. Antibiotics were classified by type and temporal delivery: perioperatively or postoperatively. If a patient received postoperative antibiotics, the duration of antibiotic exposure was recorded. Outcomes analysis was limited to the 90-day postoperative period. Multivariable logistic regression was performed to ascertain the effects of age, coexisting conditions, reconstruction type (autologous or implant-based), perioperative antibiotic class, postoperative antibiotic class, and postoperative antibiotic duration on the likelihood of any common postoperative complication occurring. All statistical assumptions made by logistic regression were met successfully. Odds ratios and corresponding 95% confidence intervals were calculated.

RESULTS

From more than 86 million longitudinal patient records between March 2004 and June 2019, our study population included 7456 unique records of reconstruction-fat grafting pairs, with 4661 of those pairs receiving some form of prophylactic antibiotics. Age, prior radiation, and perioperative antibiotic administration were consistent independent predictors of increased all-cause complication likelihood. However, administration of perioperative antibiotics approached a statistically significant protective association against infection likelihood. No postoperative antibiotics of any duration or class conferred a protective association against infections or all-cause complications.

CONCLUSIONS

This study provides national, claims-level support for antibiotic stewardship during and after fat grafting procedures. Postoperative antibiotics did not confer a protective benefit association against infection or all-cause complication likelihood, while administering perioperative antibiotics conferred a statistically significant increase in the likelihood that a patient experienced postoperative complication. However, perioperative antibiotics approach a significant protective association against postoperative infection likelihood, in line with current guidelines for infection prevention. These findings may encourage the adoption of more conservative postoperative prescription practices for clinicians who perform breast reconstruction, followed by fat grafting, reducing the nonindicated use of antibiotics.

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

Oncological Safety of Autologous Fat Grafting in Breast Reconstruction: A Meta-analysis Based on Matched Cohort Studies

BACKGROUND

Autologous fat grafting has become a commonly used procedure for breast reconstruction after breast cancer surgical treatment. Nevertheless, oncological considerations remain concerning autologous fat grafting after breast cancer surgery.

OBJECTIVE

This meta-analysis aimed to summarize the current matched cohort studies and provide high-quality evidence-based conclusions on the oncological safety of fat grafting in breast reconstruction.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines were followed. A literature search was performed on August 1, 2021, using PubMed. All relevant matched cohort studies of patients undergoing autologous fat grafting after breast cancer surgery were included. After independently screening the studies and extracting the data, pooled estimates for local and regional recurrence as well as distant metastases were conducted using Review Manager software (RevMan, version 5.3). Outcomes were expressed as odds ratios and 95% confidence intervals.

RESULTS

Seventeen studies involving 7494 patients were included. The observed outcomes indicated that no significant differences existed in the risks of local and regional recurrence or distant metastases between autologous fat grafting and control groups. Also, there was no significant heterogeneity among the studies.

CONCLUSION

This study provided evidence-based conclusions that support the use of autologous fat grafting in breast reconstruction.

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 .

Autologous Fat Grafting to the Breast: An Educational Review

Autologous fat grafting (AFG) is a technique that is increasingly utilized in breast cosmetic and reconstructive surgery. In this procedure, fat is aspirated by liposuction from one area of the body and injected into the breast. The procedure and process of AFG has evolved over the last few decades, leading to more widespread use, though there is no standard method. Autologous fat grafting is generally considered a safe procedure but may result in higher utilization of diagnostic imaging due to development of palpable lumps related to fat necrosis. Imaging findings depend on surgical technique but typically include bilateral, symmetric, retromammary oil cysts and scattered dystrophic and/or coarse calcifications when AFG is used for primary breast augmentation. More focal findings occur when AFG is used to improve specific areas of cosmetic deformity, scarring, or pain following breast cancer surgery. As with any cause of fat necrosis, imaging features tend to appear more benign over time, with development of rim calcifications associated with oil cysts and a shift in echogenicity of oil cyst contents on ultrasound towards anechoic in some cases. This article reviews the AFG procedure, uses, complications, and imaging findings.

Autologous Fat Grafting for Oncologic Patients: A Literature Review

Autologous fat grafting (AFG) serves as an effective method to address volume defects, contour irregularities, and asymmetry in both aesthetic and reconstructive procedures. In recent years, there has been growing concern about the potential of cancer recurrence and interference with cancer surveillance in oncologic patients receiving AFG. The adipose tissue contains adipose-derived stem cells (ASCs), a specific type of mesenchymal stem cells, that facilitate secretion of numerous growth factors which in turn stimulate tissue regeneration and angiogenesis. As such, it has been theorized that ASCs may also have the potential to stimulate cancer cell proliferation and growth when used in oncologic patients. Multiple research studies have demonstrated the ability of ACSs to facilitate tumor proliferation in animal models. However, clinical research in oncologic patients has yielded contradictory findings. Although the literature pertaining to oncologic safety in head and neck, as well as sarcoma, cancer patients remains limited, studies demonstrate no increased risk of tumor recurrence in these patient populations receiving AFG. Similarly, both the efficacy and safety of AFG have been well established in breast cancer patients through numerous clinical studies. More recently, preclinical research in animal models has shown that AFG has the potential to facilitate tissue regeneration and improve joint contracture following irradiation. Ultimately, further research is needed to elucidate the safety of AFG in a variety of oncologic patients, as well as explore its use in tissue regeneration, particularly in the setting of radiotherapy. Level of Evidence: 4.

The Future of Fat Grafting

One of the earliest reported cases of autologous fat grafting (AFG) was by Neuber in 1893 and consisted of the transfer of small lobules of fat from the upper arm for cicatrical depression of the face. He advocated the use of smaller grafts, noting that pieces larger than the size of a bean would form cysts. In 1895, Czerny excised a lumbar lipoma and transplanted it to the chest for breast reconstruction. Since these early reports, the knowledge base around AFG has expanded exponentially, as illustrated by the other papers within this special topic. As we embark on the next phase of AFG in the clinical setting, there are several directions which are near-clinical translation. This paper discusses future directions in fat grafting that build on optimization of our current techniques as clinical indications expand, such as supplementing purified lipoaspirate and the associated regulatory burden, or deconstructing adipose tissue to selectively use adipose graft components for a variety of regenerative indications.

Oncologic Safety of Autologous Fat Grafting in Breast Reconstruction

Autologous fat grafting is a useful adjunct to breast reconstruction to address contour changes, volume loss, and deformity. More recent benefits observed include mitigation of pain and inflammation. Although there is no clinical evidence to suggest an increased risk in recurrence or new cancer development in fat grafting for breast reconstruction, the oncologic safety of grafting has come into question. Adipose tissue grafts contain progenitor cells and immunomodulatory cytokines, which may induce vasculogenesis or tumor progression or recurrence at the site. Although these are all theoretical concerns, there is a discrepancy between basic science research and clinical outcomes studies. In this review, the authors summarize available literature regarding three important controversies in fat grafting for oncologic breast reconstruction: the interaction of graft component cells, such as adipose-derived stem cells, with cancer cells; the concern of fat grafting interference with breast cancer screening and detection; and clinical evidence regarding the oncologic safety of fat grafting following breast cancer treatment.