Surgical Decision Making in Autologous Fat Grafting: An Evidence-Based Review of Techniques to Maximize Fat Survival

Differential Secretomes of Processed Adipose Grafts, the Stromal Vascular Fraction, and Adipose-Derived Stem Cells

There are multiple methods to prepare lipoaspirate for autologous fat transfer; however, graft retention remains unpredictable. The purpose of this study was to compare the cellular and protein composition of adipose grafts and the stromal vascular fraction (SVF) resulting from three common techniques to prepare adipose grafts. Adipose grafts were harvested from healthy donors and processed via three techniques: centrifugation (C), a single-filter (SF) device, and a double-filtration (DF) system. Part of each graft was analyzed or further processed to isolate the SVF. Cell viability, surface markers, cytokine, and growth factors were compared between the graft and SVF as well as adipose-derived stem cells (ASCs). Overall, we found variations across the three processing techniques and among the graft components (ASCs, SVF, and fat). Cell viability within the grafts was similar (94.6%, 92.3%, and 93.6%; P = 0.93). The trend was a greater percentage of ASCs from SF versus DF or centrifugation (6.95%, 4.63%, and 1.93%, respectively, P = 0.06). Adipogenic markers (adiponectin and leptin) were similar among all three grafts (P = 0.45). Markers of tissue remodeling were greatest in the SVF compared with fat and ASCs, regardless of processing technique. There was higher relative expression of MMP-9 (2×), Extracellular matrix metalloproteinase inducer (EMMPRIN) (2.5×), endoglin (5×), and IL-8 (1.5×) in the SVF (P < 0.005). Our study identified differences in cytokine expression in adipose grafts and the SVF, particularly in cytokines important in inflammation and wound healing. These secretomes may impact graft retention and fat necrosis and have the potential implications in cell-assisted lipotransfer. There were no significant differences between the final products of any of the processing techniques.

Breast Lipofilling: Is the Bra Really Full? Clinical Bra Pressure Measurement and In Vitro Testing of Processed and Unprocessed Fat Cells

BACKGROUND

Breast lipofilling, a popular cosmetic and reconstructive procedure, involves the transplantation of autologous fat to enhance breast volume and contour. Despite its widespread use, cell processing and the aftertreatment remain controversial. This study investigates the pressure applied by a compression bra and reports in vitro stress tests of processed and unprocessed fat cells.

METHODS

Clinical bra pressure measurements were conducted on a cohort of 45 patients following lipofilling, reduction mammoplasties and DIEP flaps. Laboratory analysis included cell vitality testing using Resazurin assays of processed and unprocessed fat cells after exposure to mechanical or hyperbaric pressure.

RESULTS

Our findings show a mean overall pressure value of the compression bra for all patients of 6.7 ± 5.7 mmHg (range 0-35). Cell processing is superior to sedimentation only regarding fat cell vitality. However, neither mechanical pressure within the specified range nor hyperbaric oxygen exposure significantly affected fat graft survival as measured by Resazurin assays.

CONCLUSION

The in vitro measurements showed that it was impossible to harm fat cells with external pressure during lipofilling procedures, regardless of their processing. In the clinical context, the compression bra applied pressure values deceeding the perfusion pressure and may therefore not diminish oxygen supply nor harm the transplanted cells. Therefore, we recommend the use of a compression bra for all lipofilling procedures around the breast.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to Table of Contents or online Instructions to Authors www.springer.com/00266.

Orbital fat graft retroseptal transconjunctival blepharoplasty for treatment of groove in the infraorbital region

PURPOSE

To investigate the efficacy of the retroseptal transconjunctival blepharoplasty together with tear trough ligament (TTL) and Orbicularis retaining ligament (ORL) release with orbital fat graft in the management of groove in the infraorbital region (GIR).

METHODS

A prospective study of 80 eyes of 40 patients that underwent retroseptal transconjunctival lower blepharoplasty together with TTL and ORL release and resected orbital fat grafting. An ophthalmic examination includes lower eyelid evaluation and Barton's Tear trough deformity grading was done at baseline, 2 weeks, 3 months, and 6 months after the surgery. Patient satisfaction was evaluated using Global aesthetic improvement scale (GAIS) and Blepharoplasty outcomes evaluation (BOE).

RESULTS

Baseline tear trough defects were graded into grade 1, 2, and 3 in 12 (15%), 39 (48.75%) and 29 (36.25%) eyes, respectively. While at 6 months follow-up, grade 0 was recorded in 63 (78.75%) eyes, and grade 1 was recorded in 17 (21.25%) eyes. The amount of fat removed was 0.52 ± 0.04 mL per eye, whereas the amount of injected fat graft was 0.24 ± 0.04. The mean operative time was 33.2 ± 4.1 min per eye. GAIS showed degree 1, 2, and 3 in 8 (20%), 29 (72.5%), and 3 (7.5%) patients at 6 months follow-up, respectively. The mean baseline BOE increased significantly from 36.5 ± 5.9 to 86.9 ± 5.5 at 6 months follow-up.

CONCLUSIONS

Our cohort highlights the beneficial effects of TTD/ORL release with resected orbital fat grafting in the management of GIR and infraorbital hollow.

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.

The Optimal Layer for Breast Augmentation in an Autologous Fat Grafting Murine Model

BACKGROUND

Fat grafting is an effective procedure for breast augmentation, but the variations in this technique result in unpredictable fat retention. Therefore, animal models are needed to simulate the operation and the optimal layer for fat retention.

OBJECTIVES

An autologous fat grafting murine model for breast augmentation was built to detect a new layer for fat grafting in the chest.

METHODS

The left side of the female rat inguinal fat flap was harvested, dissected into small pieces, and autotransplanted into 3 different layers of the breast. Retention rate and hematoxylin and eosin (H&E) staining were measured at 1, 4, 8 12, and 16 weeks. Immunofluorescence staining was utilized to detect adipocytes and endothelial cells, and immunohistochemistry was conducted to evaluate the expression of integrins β1 and α6.

RESULTS

The volume of fat grafts slightly grew in the intramuscular and submuscular layers at Week 4. Retention rates in the subcutaneous layer and submuscular layer were significantly higher than the intramuscular layer at Week 16. H&E staining showed that oil cysts existed in the subcutaneous layer throughout the 16 weeks. At the terminal time point, well-vascularized mature adipose structures were observed in intramuscular and submuscular layers, with smaller adipocytes in intramuscular layers. Immunohistochemistry analysis showed that integrin β1 was identically expressed in every adipocyte in all the layers, whereas integrin α6 selectively expressed in bigger adipocytes in the intramuscular layer. The expression intensities of integrin β1 and α6 were significantly higher in the intramuscular layer than in the subcutaneous and submuscular layers.

CONCLUSIONS

The angiogenic and moderate mechanical environment makes the submuscular layer the optimal layer for fat retention.

Deconstructing Fat to Reverse Radiation Induced Soft Tissue Fibrosis

Adipose tissue is composed of a collection of cells with valuable structural and regenerative function. Taken as an autologous graft, these cells can be used to address soft tissue defects and irregularities, while also providing a reparative effect on the surrounding tissues. Adipose-derived stem or stromal cells are primarily responsible for this regenerative effect through direct differentiation into native cells and via secretion of numerous growth factors and cytokines that stimulate angiogenesis and disrupt pro-inflammatory pathways. Separating adipose tissue into its component parts, i.e., cells, scaffolds and proteins, has provided new regenerative therapies for skin and soft tissue pathology, including that resulting from radiation. Recent studies in both animal models and clinical trials have demonstrated the ability of autologous fat grafting to reverse radiation induced skin fibrosis. An improved understanding of the complex pathologic mechanism of RIF has allowed researchers to harness the specific function of the ASCs to engineer enriched fat graft constructs to improve the therapeutic effect of AFG.

Therapeutic potential of adipose tissue-derivatives in modern dermatology

Stem cell-mediated therapies in combination with biomaterial and growth factor-based approaches in regenerative medicine are rapidly evolving with increasing application beyond the dermatologic field. Adipose-derived stem cells (ADSCs) are the more frequently used adult stem cells due to their abundance and easy access. In the case of volumetric defects, adipose tissue can take the shape of defects, restoring the volume and enhancing the regeneration of receiving tissue. When regenerative purposes prevail on volume restoration, the stromal vascular fraction (SVF) rich in staminal cells, purified mesenchymal stem cells (MSCs) or their cell-free derivatives grafting are favoured. The therapeutic efficacy of acellular approaches is explained by the fact that a significant part of the natural propensity of stem cells to repair damaged tissue is ascribable to their secretory activity that combines mitogenic factors, cytokines, chemokines and extracellular matrix components. Therefore, the secretome's ability to modulate multiple targets simultaneously demonstrated preclinical and clinical efficacy in reversing pathological mechanisms of complex conditions such atopic dermatitis (AD), vitiligo, psoriasis, acne and Lichen sclerosus (LS), non-resolving wounds and alopecia. This review analysing both in vivo and in vitro models gives an overview of the clinical relevance of adipose tissue-derivatives such as autologous fat graft, stromal vascular fraction, purified stem cells and secretome for skin disorders application. Finally, we highlighted the major disease-specific limitations and the future perspective in this field.

The Utilization Of Poly-L-Lactic Acid As A Safe And Reliable Method For Volume Maintenance After Facelift Surgery With Fat Grafting

Background

For age-related volume loss, fat grafting is now recognized as an integral adjunctive procedure with facelift surgery. However, when there is continued and unpredicted volume loss postoperatively, the surgeon has limited options for restoring this lost volume.

Objectives

Poly-l-lactic acid (PLLA) is a proven biostimulator that creates volumetric enhancement. This study is undertaken to demonstrate that PLLA is a safe and efficacious option for maintenance of post-facelift volume loss.

Methods

A retrospective review was conducted to identify all patients who underwent facelift surgery with fat grafting and postoperative PLLA injections from 2010 to 2018 by a single surgeon. Demographic and clinical data were collected and analyzed.

Results

This review identified a total of 241 patients who had undergone a facelift with fat grafting and PLLA injections. Of these, 190 patients were treated with PLLA after facelift and fat grafting, while 51 patients received PLLA injections before their operation. We identified 5 common indications for use of PLLA after facelift surgery and fat grafting. These included unexplained early fat graft loss, significant weight loss in the postoperative period, normal aging process, and patients who had a high perioperative lean body mass. Additionally, PLLA was found to be an effective volumizer for site-specific areas that did not undergo fat grafting during the initial operation. There were no complications reported from the PLLA injections related to nodule formation, papules, or granulomas.

Conclusions

The high degree of variability in the survival of fat grafts with facelift surgery is an accepted reality. PLLA represents a safe and highly effective solution to restore volume loss in patients who have undergone facelifts with fat grafting.

Research update of adipose tissue-based therapies in regenerative dermatology

Mesenchymal stromal/stem cells (MSCs) have a spontaneous propensity to support tissue homeostasis and regeneration. Among the several sources of MSCs, adipose-derived tissue stem cells (ADSCs) have received major interest due to the higher mesenchymal stem cells concentration, ease, and safety of access. However, since a significant part of the natural capacity of ADSCs to repair damaged tissue is ascribable to their secretory activity that combines mitogenic factors, cytokines, chemokines, lipids, and extracellular matrix components, several studies focused on cell-free strategies. Furthermore, adipose cell-free derivatives are becoming more attractive especially for non-volumizing purposes, such as most dermatological conditions. However, when keratinocytes, fibroblasts, melanocytes, adipocytes, and hair follicle cells might not be locally sourced, graft of materials containing concentrated ADSCs is preferred. The usage of extracellular elements of adipose tissue aims to promote a self-autonomous regenerative microenvironment in the receiving area restoring physiological homeostasis. Hence, ADSCs or their paracrine activity are currently being studied in several dermatological settings including wound healing, skin fibrosis, burn, and aging.The present work analyzing both preclinical and clinical experiences gives an overview of the efficacy of adipose tissue-derivatives like autologous fat, the stromal vascular fraction (SVF), purified ADSCs, secretome and extracellular matrix graft in the field of regenerative medicine for the skin.