Fat grafting's past, present, and future: why adipose tissue is emerging as a critical link to the advancement of regenerative medicine

Transplantation of Cold-Stimulated Subcutaneous Adipose Tissue Improves Fat Retention and Recipient Metabolism

BACKGROUND

Induction of beige fat for grafting is an emerging transplantation strategy. However, safety concerns associated with pharmaceutical interventions limit its wider application. Moreover, because beige fat is a special type of fat with strong metabolic functions, its effect on the metabolism of recipients after grafting has not been explored in the plastic surgery domain.

OBJECTIVES

The aim of this study was to explore whether cold-induced inguinal white adipose tissue (iWAT) transplantation has a higher retention rate and beneficial effects on recipient metabolism.

METHODS

C57/BL6 mice were subjected to cold stimulation for 48 hours to induce the browning of iWAT and harvested immediately. Subsequently, each mouse received a transplant of 0.2 mL cold-induced iWAT or normal iWAT. Fat grafts and recipients' iWAT, epididymal adipose tissue, and brown adipose tissue were harvested at 8 weeks after operation. Immunofluorescence staining, real-time polymerase chain reaction, and western blot were used for histological and molecular analysis.

RESULTS

Cold-induced iWAT grafting had a higher mean [standard error of the mean] retention rate (67.33% [1.74%] vs 55.83% [2.94%], P < .01) and more satisfactory structural integrity than normal iWAT. Histological changes identified improved adipose tissue homeostasis after cold challenge, including abundant smaller adipocytes, higher levels of adipogenesis, angiogenesis, and proliferation, but lower levels of fibrosis. More importantly, cold-induced iWAT grafting suppressed the inflammation of epididymal adipose tissue caused by conventional fat grafting, and activated the glucose metabolism and thermogenic activity of recipients' adipose tissues.

CONCLUSIONS

Cold-induced iWAT grafting is an effective nonpharmacological intervention strategy to improve the retention rate and homeostasis of grafts. Furthermore, it improves the adverse effects caused by traditional fat grafting, while also conferring metabolic benefits.

Preconditioning strategies for improving the outcome of fat grafting

Autologous fat grafting is a common procedure in plastic, reconstructive and esthetic 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 pre-transplantation phase to stimuli inducing endogenous protective and regenerative cellular adaptations, such as the up-regulation 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.

Comparative Efficacy and Safety of Cell-Assisted and Conventional Lipotransfer in Facial Filling: A Systematic Review and Meta-Analysis

PURPOSE

We aim to compare the efficacy and safety of cell-assisted lipotransfer (CAL) and conventional lipotransfer (CLT) in facial filling.

METHODS

The PubMed and Embase databases were searched for relevant publications until February 2023. All studies evaluating the efficacy and safety of cell-assisted and conventional lipotransfer in facial filling were included. We calculated pooled standardized mean difference (SMD) and 95% CIs for continuous outcomes and pooled risk ratio (RR) with 95% CIs for binary outcomes. The Cochrane's Risk of Bias Tool and the Newcastle-Ottawa Scale (NOS) were used to evaluate the quality of studies.

RESULTS

A total of 15 studies with 737 patients were included in this analysis. The fat survival rate and patient satisfaction rate were significantly higher in the CAL group compared to the CLT group (SMD: 3.04, 95% CI 2.09-3.99; RR: 1.34, 95% CI 1.08-1.67). However, no significant difference in complication rates (RR: 0.95, 95% CI 0.50-1.81) and a lower secondary operation rate in the CAL group (RR: 0.52, 95% CI 0.03-0.82) were observed. No obvious publication bias was observed in the funnel plot (Egger's P values = 0.084 and 0.403).

CONCLUSIONS

Based on the pooled results, we tentatively conclude that CAL may have superior fat survival rate and satisfaction rate compared to CLT in facial filling, without compromising patient safety. However, the majority of the included studies were observational studies with small sample sizes. Future research should focus on investigating the long-term efficacy and safety of these techniques.

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 these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Enhanced Fat Graft Viability and Remodeling Using a Helium-based Radiofrequency Device to Prepare the Recipient Site

BACKGROUND

Improvements to autologous fat grafting for soft tissue augmentation are needed to overcome the unpredictable volume retention. Approaches such as fat harvesting and processing, injection technique, preparation of the recipient site, and supplemental biologics are topics of ongoing research. Here, an energy-based device was investigated as a stimulatory tool for recipient site preparation for improving fat graft retention.

OBJECTIVE

The objective was to measure the stimulatory responses in fat grafts after 4 weeks when using a helium-based radiofrequency device to pretreat the recipient tissue.

METHODS

Using an autologous fat grafting mouse model, the inguinal fat pad was grafted in a small cranial pocket after either a saline injection alone (control) or a saline injection followed by pretreatment (treated). The fat pad was resected after 4 weeks, sectioned and stained with immunofluorescence markers to investigate tissue remodeling.

RESULTS

Pretreatment resulted in higher viability of adipocytes, a higher concentration of viable ASCs in areas of adipose tissue regeneration, and localized macrophages in the areas of regeneration when compared to the control. There was no observable difference in vascularity or angiogenesis. The staining for ASCs was higher in the pretreated group in comparison with the control group (5.0% vs. 3.3%, p=0.36) when using a pixel classifier in QuPath in the viable adipose tissue regions.

CONCLUSIONS

The use of a helium-based radiofrequency device as a pretreatment tool appears to increase the viability of the adipose tissue likely due to higher concentration of ASCs. The apparent increase in viable ASCs may be due to enhanced proliferation or paracrine recruitment of these cells in response to the helium-based radiofrequency treatment.

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 these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 . Bullet List of Important Points: Pretreatment of the fat graft recipient site increases the viability of the adipose tissue after 4 weeks in comparison with the control grafts. The increased viability is likely due to the observed increase in adipose-derived stem cells in the pretreated group. Pretreatment enhanced the adipose tissue remodeling as colocalization of adipose-derived stem cells and macrophages showed an active remodeling, whereas the control group exhibited more necrotic and fibrotic tissue.

Intramuscular Posterior Thigh Volumization: An Aesthetic and Harmonious Transition to the Gluteal Region (Hv-FAT)

The gluteal region remains the preferred site for fat grafting. However, the transition from the gluteal region to the thighs has not been well studied. This study aimed to describe an echographic guidance hamstring volumization procedure (Hv-FAT) as a complement to body contouring surgery.

The efficacy of cell-assisted versus conventional lipotransfer: A systematic review and meta-analysis

Autologous lipotransfer is an essential component of soft tissue reconstruction. However, it is not widely applied or accepted by surgeons due to its unstable survival rate and uncertain efficacy. The cell-assisted fat transfer (CAL) is a promising technique that increases the fat survival rate. However, it is controversial based on various clinical studies. Here, we assessed the fat survival and complication rates of CAL, compared to the conventional autologous lipotransfer. To conduct our research, two reviewers independently screened related articles published in Medicine (via PubMed), EMBASE, Cochrane Library, and Web of Science. The combined effect estimates for efficacy evaluation was performed by the Review Manager software (RevMan 5.4.1). In total, 14 articles were included in our analysis (n = 722). Based on our analysis, the survival rate of the fat graft in CAL was significantly higher than the conventional fat grafting group (non-CAL group) (SMD = 2.81, 95%CI [1.54, 4.08], P < 0.01). In the subgroup, the fat retention of CAL in the facial filling was higher than the conventional one (SMD = 3.01, 95%CI [1.68, 4.33], P < 0.01). After breast augmentation, however, the difference between the experimental and control group was not statistically significant (SMD = 1.80, 95%CI [-0.31, 3.91], P = 0.09). Moreover, the CAL group exhibited comparable complications as the non-CAL group. Based on our analysis, the CAL group was significantly better than the conventional lipotransfer in terms of fat survival, particularly, during facial filling. However, it failed to reduce the complication rate, compared to the non-CAL group.

Function-preserving fat grafting in the breast: Results based on 18 years of experience

BACKGROUND

Autologous fat transplantation has been used for breast nearly 40 years, but there are two main problems: the volume retention rate is unpredictable, leading to too many operations, and various complications, such as nodules, necrosis and calcification, occur.

OBJECTIVE

The author proposed "function-preserving fat grafting" (FPFG) and reviewed the clinical data of patients from October 2002 to December 2020.

METHODS

A total of 1218 patients underwent surgery, and 767 patients were followed up for more than half a year. Their ages ranged from 22 to 61 (31.9±10.1) years, and the BMI values ranged from 16.1 to 28.2 (20.6±2.73) kg/m2. Group I included 703 cases of breast aesthetic augmentation, group II included 38 cases of breast reconstruction after mastectomy (10 cases after radiotherapy and 7 cases after the Brava device was worn) and group III included 26 cases of simultaneous implant exchange with fat.

RESULTS

At 6 months after the operation, 89.8% of the patients were satisfied with the outcome. For these patients, aesthetic augmentation required 1.9±0.73 procedures, and the unilateral breast injection volume was 180-380 ml (265.5±46.6); breast reconstruction required an average of 3.4±0.71 procedures, and the unilateral injection volume was 140-370 ml (233.9±67.7). The simultaneous implant exchange volume with fat was 160-320 ml (241.3±35.8 ml). There were 9 cases (1.2%) of palpable nodules, 3 cases of infection (0.39%), and no other severe complications.

CONCLUSIONS

FPFG has the advantages of requiring few operations; leading to few necrosis, oil cysts and nodules; and leading to high postoperative satisfaction.

Translational products of adipose tissue-derived mesenchymal stem cells: Bench to bedside applications

With developments in the field of tissue engineering and regenerative medicine, the use of biological products for the treatment of various disorders has come into the limelight among researchers and clinicians. Among all the available biological tissues, research and exploration of adipose tissue have become more robust. Adipose tissue engineering aims to develop by-products and their substitutes for their regenerative and immunomodulatory potential. The use of biodegradable scaffolds along with adipose tissue products has a major role in cellular growth, proliferation, and differentiation. Adipose tissue, apart from being the powerhouse of energy storage, also functions as the largest endocrine organ, with the release of various adipokines. The progenitor cells among the heterogeneous population in the adipose tissue are of paramount importance as they determine the capacity of regeneration of these tissues. The results of adipose-derived stem-cell assisted fat grafting to provide numerous growth factors and adipokines that improve vasculogenesis, fat graft integration, and survival within the recipient tissue and promote the regeneration of tissue are promising. Adipose tissue gives rise to various by-products upon processing. This article highlights the significance and the usage of various adipose tissue by-products, their individual characteristics, and their clinical applications.

Modern Fat Grafting Techniques to the Face and Neck

LEARNING OBJECTIVES

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

SUMMARY

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

The Effects of Lipoaspirate-Derived Fibrous Tissue on Survival Quality and Mechanical Property of Fat Grafts

BACKGROUND

Fibrous connective tissue (referred to as fiber) in lipoaspirates would be discarded before lipotransfer in case of cannula blockage. However, the fiber contains extracellular matrix which provide structure support and is rich in stromal vascular fractions (SVFs). Removal of the fiber might theoretically affect the survival quality and mechanical properties of fat grafts. But there is few evidence in vivo and vitro about how the fiber affects the fat grafts.

OBJECTIVE

To assess the effect of fibers on the survival quality and mechanical property of fat grafts.

METHODS

The SVFs in both fat and fiber were obtained by collagenase digestion for cells counting and comparison. Three groups were designed according to the different proportions of fat and fiber: the fat group (100% fat), the mixed group (50% fat, 50% fiber in volume ratio), and the fiber group (100% fiber). Three groups of grafts were transplanted in vivo to evaluate the differences in volume retention rate, histological characteristics and mechanical properties.

RESULTS

The amount of SVF cells in fibers (3.47 ± 1.49 × 104 cells/mL) was significantly lower than that in fat (12.3 ± 4.95 × 104 cells/mL) (P < 0.05). Grafts in the mixed group and the fiber group showed an increase of volume retention at week 4, but the fiber content showed no significant effects on the volume retention of grafts in three groups at week 12. Elasticity modulus of grafts in the fat group was higher than that in the fiber group and the mixed group at week 4 and 8, the fiber content showed no significant effects on the elasticity modulus of grafts in three groups at week 12. The addition of the fiber reduced the inflammation, cysts, fibrosis, and capillaries density of the grafts.

CONCLUSIONS

There were few SVF cells in the fiber. When it was mixed with fat in different proportions and transplanted in vivo, the content of fiber showed no significantly different effects on the long-term volume retention and mechanical property of fat grafts. Due to the risk of blockage, it is recommended to discard the fiber in lipoaspirates.

Efficacy, safety and complications of autologous fat grafting to the eyelids and periorbital area: A systematic review and meta-analysis

Background

In recent years, autologous fat grafting (AFG), also known as fat transfer or lipofilling, has been widely performed for periorbital rejuvenation and defect correction, although the evidence regarding its efficacy and safety is still lacking. Besides, with respect to the periorbital region, it is invariably the earliest appearance area of the facial aging phenomenon. Therefore, a systematic review and meta-analysis is needed to evaluate the efficacy and safety of this technique.

Methods

A literature search was performed in PubMed, Embase, and the Cochrane library databases on November 20, 2020, adhering to the PRISMA guidelines, to identify all relevant articles. Then, a data extraction and standardization process was performed to assess all outcome data. Ultimately, the data were assessed using a random effects regression model with comprehensive meta-analysis software.

Results

Thirty-nine studies consisting of 3 cohorts and 36 case series with a total of 4046 cases were included. Meta-analysis revealed a relatively high satisfaction rate of 90.9% (95% CI, 86.4%–94.0%). Frequent complications in 4046 patients receiving AFG were edema, chemosis, and contour irregularity, with an overall complication rate of 7.9% (95% CI, 4.8%–12.8%).

Conclusion

This systematic review and meta-analysis showed that AFG for rejuvenation of eyelids and periorbital area provided a high satisfaction rate and did not result in severe complications. Therefore, AFG might be performed safely for periorbital rejuvenation and reconstruction.

Regenerative medicine approaches for the management of respiratory tract fistulas

Respiratory tract fistulas (or fistulae) are abnormal communications between the respiratory system and the digestive tract or the adjacent organs. The origin can be congenital or, more frequently, iatrogenic and the clinical presentation is heterogeneous. Respiratory tract fistulas can lead to severely reduced health-related quality of life and short survival. Therapy mainly relies on endoscopic surgical interventions but patients often require prolonged hospitalization and may develop complications. Therefore, more conservative regenerative medicine approaches, mainly based on lipotransfer, have also been investigated. Adipose tissue can be delivered either as unprocessed tissue, or after enzymatic treatment to derive the cellular stromal vascular fraction. In the current narrative review, we provide an overview of the main tissue/cell-based clinical studies for the management of various types of respiratory tract fistulas or injuries. Clinical experience is limited, as most of the studies were performed on a small number of patients. Albeit a conclusive proof of efficacy cannot be drawn, the reviewed studies suggest that grafting of adipose tissue-derived material may represent a minimally invasive and conservative treatment option, alternative to more aggressive surgical procedures. Knowledge on safety and tolerability acquired in prior studies can lead to the design of future, larger trials that may exploit innovative procedures for tissue processing to further improve the clinical outcome.

Radiographic Comparison of Superior and Inferior Gluteal Vessels in Jackknife versus Prone Position: A Prospective, Self-Controlled Trial

Mortality after gluteal augmentation with fat transfer techniques is extremely high. Placement of fat subcutaneously versus in the gluteal musculature, or both, is considerably debated. The purpose of this study was to radiographically show the anatomical difference in live subjects in different procedural positions: the flexed or "jackknife" versus prone position. A total of 10 women underwent computed tomographic scanning of the pelvis with venous phase run-off in both the jackknife and prone positions. A computed tomography-specialized radiologist then reviewed images and measured distances from the inferior and superior gluteal veins to the skin and muscle. Three-dimensional imaging and analysis were also performed. Measurements were significantly shorter with respect to distance from skin to muscle, skin to vessel, and vessel to muscle observed from inferior and superior gluteal veins in the jackknife versus the prone position. Three-dimensional modeling showed a significant reduction in the volume and inferior and superior gluteal vein diameters when in the jackknife position. When placed in the jackknife position for gluteal augmentation with fat transfer, extreme caution should be taken with the injecting cannula, as the underlying muscle is only 2 to 3 cm deep. Three-dimensional analysis showed narrowed and reduced volume of gluteal vasculature when in the jackknife position; this is a possible indication of torsion or stretch on the vessel around the pelvic rim that could cause vein avulsion injury from the pressurized fat within the piriform space.

Effect of Breast Cancer and Adjuvant Therapy on Adipose-Derived Stromal Cells: Implications for the Role of ADSCs in Regenerative Strategies for Breast Reconstruction

Tissue engineering using Adipose Derived Stromal Cells (ADSCs) has emerged as a novel regenerative medicine approach to replace and reconstruct soft tissue damaged or lost as a result of disease process or therapeutic surgical resection. ADSCs are an attractive cell source for soft tissue regeneration due to the fact that they are easily accessible, multipotent, non-immunogenic and pro-angiogenic. ADSC based regenerative strategies have been successfully translated to the clinical setting for the treatment of Crohn's fistulae, musculoskeletal pathologies, wound healing, and cosmetic breast augmentation (fat grafting). ADSCs are particularly attractive as a source for adipose tissue engineering as they exhibit preferential differentiation to adipocytes and support maintenance of mature adipose graft volume. The potential for reconstruction with an autologous tissue sources and a natural appearance and texture is particularly appealing in the setting of breast cancer; up to 40% of patients require mastectomy for locoregional control and current approaches to post-mastectomy breast reconstruction (PMBR) are limited by the potential for complications at the donor and reconstruction sites. Despite their potential, the use of ADSCs in breast cancer patients is controversial due to concerns regarding oncological safety. These concerns relate to the regeneration of tissue at a site where a malignancy has been treated and the impact this may have on stimulating local disease recurrence or dissemination. Pre-clinical data suggest that ADSCs exhibit pro-oncogenic characteristics and are involved in stimulating progression, and growth of tumour cells. However, there have been conflicting reports on the oncologic outcome, in terms of locoregional recurrence, for breast cancer patients in whom ADSC enhanced fat grafting was utilised as an alternative to reconstruction for small volume defects. A further consideration which may impact the successful translation of ADSC based regenerative strategies for post cancer reconstruction is the potential effects of cancer therapy. This review aims to address the effect of malignant cells, adjuvant therapies and patient-specific factors that may influence the success of regenerative strategies using ADSCs for post cancer tissue regeneration.

Three-dimensional Volumetric Analysis of 3 Fat-Processing Techniques for Facial Fat Grafting: A Randomized Clinical Trial

Importance

Autologous fat grafting has revolutionized the field of facial soft-tissue augmentation, despite a lack of standardization. Objective data are needed to arrive at consensus regarding the best technique for optimal volume retention.

Objective

To compare 3 fat-processing techniques with 3-dimensional (3-D) technology to explore the optimal fat-processing technique for improving the volume retention of grafted fat.

Design, Setting, and Participants

From September 2015 to December 2016, patients with facial asymmetry were treated by initial facial fat grafting at the Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College. Sixty-three patients (21 per group) were randomized to 1 of 3 fat-processing techniques: sedimentation, centrifugation, and cotton pad filtration. Patients underwent 3-D scanning preoperatively and at 1, 3, 6, and 12 months postoperatively. Patients who did not complete preoperative or postoperative follow-up and 3-D imaging were excluded from the analysis.

Intervention

Autologous fat grafting to correct facial asymmetry.

Main Outcomes and Measures

The percentage volume maintenance of each fat-processing technique was measured with 3-D software and analyzed with variance analysis.

Results

Of the 63 randomized patients, 30 (7 men, 23 women; mean [SD] age at surgery, 22.2 [8.0] years) completed follow-up. The mean (SD) percentage volume maintenance of the 3 groups at 1, 3, 6, and 12 months postoperatively was, respectively, 49% (4%), 45% (3%), 43% (3%), and 41% (3%) for the cotton pad filtration group; 41% (3%), 38% (4%), 36% (4%), and 34% (3%) for the centrifugation group; and 37% (4%), 34% (4%), 31% (3%), and 31% (3%) for sedimentation group. The variance analysis showed that the cotton pad filtration group demonstrated a statistically significant higher percentage volume maintenance in comparison with the centrifugation and sedimentation groups.

Conclusions and Relevance

The use of 3-D technology provides an objective and accurate way to evaluate different fat-processing techniques. Autologous fat processed by cotton pad filtration had a significant higher volume retention than did that processed by centrifugation and sedimentation technique.

Trial Registration

chictr.org.cn Identifier: ChiCTR-IOR-14005599.

Level of Evidence

1.

Adipose tissue-derived ECM hydrogels and their use as 3D culture scaffold

Adipose tissue has the therapeutic capacity in the form of a fat graft, for example, for treatment of irradiation-induced scars and difficult to heal dermal wounds. For large-scale clinical application, an off-the-shelf product is warranted. In recent years, ECM-derived hydrogels are postulated to harbour therapeutic capacity and might even replicate the beneficial effects of adipose tissue. In normal homeostasis, the natural ECM acts as a deposit of growth factors, that releases them over time. In the healing of lesions, this might promote cell accumulation and proliferation which in turn stimulates angiogenesis and repair. The decellularization of tissue and the generation of hydrogels may leave cytotoxic traces. Therefore, our research assessed the cytotoxic effect of human adipose tissue-derived ECM hydrogels on connective tissue cells i.e. fibroblasts. The results showed no cytotoxicity, meaning the hydrogels caused no cell death. Cell migration and survival were observed when cultured in ECM hydrogels and followed for 7 days. Cell survival in the hydrogel was confirmed with CFDA staining and also cells showed the ability to penetrate and migrate throughout the gel. We conclude that ECM hydrogels are promising to use as innovative therapy for wound healing.

Electrical stimulation promotes the angiogenic potential of adipose-derived stem cells

Autologous fat transfer (AFT) is limited by post-operative volume loss due to ischemia-induced cell death in the fat graft. Previous studies have demonstrated that electrical stimulation (ES) promotes angiogenesis in a variety of tissues and cell types. In this study we investigated the effects of ES on the angiogenic potential of adipose-derived stem cells (ASC), important progenitor cells in fat grafts with proven angiogenic potential. Cultured human ASC were electrically stimulated for 72 hours after which the medium of stimulated (ES) and non-stimulated (control) ASC was analysed for angiogenesis-related proteins by protein array and ELISA. The functional effect of ES on angiogenesis was then assessed in vitro and in vivo. Nine angiogenesis-related proteins were detected in the medium of electrically (non-)stimulated ASC and were quantified by ELISA. The pro-angiogenic proteins VEGF and MCP-1 were significantly increased following ES compared to controls, while the anti-angiogenic factor Serpin E1/PAI-1 was significantly decreased. Despite increased levels of anti-angiogenic TSP-1 and TIMP-1, medium of ES-treated ASC significantly increased vessel density, total vessel network length and branching points in chorio-allantoic membrane assays. In conclusion, our proof-of-concept study showed that ES increased the angiogenic potential of ASC both in vitro and in vivo.

Autologous Lipotransfer - Daily Therapeutic Practice in Breast Cancer: An Intergroup Analysis Encompassing NOGGO, WSG, GBG, AWO Gyn and DGPRÄC

Background

Autologous fat transfer in breast reconstruction has become increasingly important in breast reconstructive surgery. Although the indication to obtain fat, the various operative procedures, and the risks for the patient have been addressed in a large number of studies, detailed information on the everyday use of autologous lipotransfer in breast units in Germany is still lacking.

Methods

The objective of the study was to obtain primary data on the use of autologous lipotransfer to treat breast cancer patients in Germany and to determine measures for quality assurance in the daily practice. An online questionnaire concerning breast cancer and lipofilling was sent to specialists in gynecology and plastic surgery.

Results

Two-thirds of the specialists who responded to the questionnaire use autologous lipotransfer for breast reconstruction and did not report an increase of local recurrence following lipotransfer. There were only small differences between gynecologists and plastic surgeons regarding the procedure and indication for lipotransfer. The method is highly accepted by patients and physicians, and both gynecologists and plastic surgeons rated the improvement achieved through lipofilling as 'high'.

Conclusions

The lack of randomized controlled data, especially in high-risk patients, demonstrates the necessity for a registry study on this topic. Our survey describes, in detail, the indications for lipofilling as well as its appropriate application in breast cancer patients in Germany and may thereby reduce the present therapeutic uncertainties.

Regenerative Potential and Inflammation-Induced Secretion Profile of Human Adipose-Derived Stromal Vascular Cells Are Influenced by Donor Variability and Prior Breast Cancer Diagnosis

Adipose tissue contains a heterogeneous population of stromal vascular fraction (SVF) cells that work synergistically with resident cell types to enhance tissue healing. Ease of access and processing paired with therapeutic promise make SVF cells an attractive option for autologous applications in regenerative medicine. However, inherent variability in SVF cell therapeutic potential from one patient to another hinders prognosis determination for any one person. This study investigated the regenerative properties and inflammation responses of thirteen, medically diverse human donors. Using non-expanded primary lipoaspirate samples, SVF cells were assessed for robustness of several parameters integral to tissue regeneration, including yield, viability, self-renewal capacity, proliferation, differentiation potential, and immunomodulatory cytokine secretion. Each parameter was selected either for its role in regenerative potential, defined here as the ability to heal tissues through stem cell repopulation and subsequent multipotent differentiation, or for its potential role in wound healing through trophic immunomodulatory activity. These data were then analyzed for consistent and predictable patterns between and across measurements, while also investigating the influence of the donors' relevant medical histories, particularly if the donor was in remission following breast cancer treatment. Analyses identified positive correlations among the expression of three cytokines: interleukin (IL)-6, IL-8, and monocyte chemoattractant protein (MCP)-1. The expression of these cytokines also positively related to self-renewal capacity. These results are potentially relevant for establishing expectations in both preclinical experiments and targeted clinical treatment strategies that use stem cells from patients with diverse medical histories.

Revisiting the Advances in Isolation, Characterization and Secretome of Adipose-Derived Stromal/Stem Cells

Adipose-derived stromal/stem cells (ASCs) seems to be a promising regenerative therapeutic agent due to the minimally invasive approach of their harvest and multi-lineage differentiation potential. The harvested adipose tissues are further digested to extract stromal vascular fraction (SVF), which is cultured, and the anchorage-dependent cells are isolated in order to characterize their stemness, surface markers, and multi-differentiation potential. The differentiation potential of ASCs is directed through manipulating culture medium composition with an introduction of growth factors to obtain the desired cell type. ASCs have been widely studied for its regenerative therapeutic solution to neurologic, skin, wound, muscle, bone, and other disorders. These therapeutic outcomes of ASCs are achieved possibly via autocrine and paracrine effects of their secretome comprising of cytokines, extracellular proteins and RNAs. Therefore, secretome-derivatives might offer huge advantages over cells through their synthesis and storage for long-term use. When considering the therapeutic significance and future prospects of ASCs, this review summarizes the recent developments made in harvesting, isolation, and characterization. Furthermore, this article also provides a deeper insight into secretome of ASCs mediating regenerative efficacy.

Facial skin rejuvenation by autologous dermal microfat transfer in photoaged patients: Clinical evaluation and skin surface digital profilometry analysis

Cumulative long-term exposure to solar ultraviolet radiation promotes premature skin aging characterized by wrinkle formation and reduced skin elasticity. In this study, we assessed whether microfat transfer could improve dermal and subcutaneous tissue thickness loss associated with photoaging. Twenty-one patients affected by facial photoaging (photodamage grade II-IV; age range 35-62 years; 19 females, 2 males; all of Caucasian origin) were treated using minimally invasive autologous dermal white fat transfer harvested with a recently designed microcannula. The results were determined by clinical assessment and patient self-evaluation and quantified by the Antera 3D^® dermal digital device for noninvasive, objective, reliable, and accurate assessment of facial skin texture, color, and wrinkle characteristics. Compared with the pretreatment condition, the increment in soft tissue volume and improvement in skin quality and texture were assessed by a dermatologist after treatment. In addition, instrumental evaluation by digital skin profilometry of the treated areas revealed a 41% reduction in average wrinkle depth (7.29 ± 1.04 × 10^-2 mm pretreatment vs. 4.31 ± 1.16 × 10^-2 mm at 90 days posttreatment; p < 0.001), improved skin texture, more homogeneous and uniform skin color, and declined facial hemoglobin and melanin concentrations. The majority of patients (above 90%) reported improvements in self-perception. No significant complications were reported throughout the study. In conclusion, by using digital profilometry analysis as an objective and innovative tool to determine the outcome of treatment, we demonstrated that autologous microfat transfer is a safe and well-tolerated procedure with measurable beneficial effects on facial skin aging.

Autologous fat grafting in keloids and hypertrophic scars: a review

Keloid and hypertrophic scars are unique human dermal fibroproliferative disorders of the injured skin and are associated with pain, itch and can cause functional limitations. A number of genetic, systemic and local factors have been identified in the formation of keloids and hypertrophic scars. Studies have shown that adipose-derived stem cells have angiogenic and antiapoptotic properties which has effects on wound healing, soft-tissue restoration and scar remodelling, and thus may have a role in managing keloid scaring. However, this role is not well described in the literature. A systemic review of available literature was thus undertaken, regarding the use of fat grafting in treatment of keloids and hypertrophic scarring. In total, 858 articles were identified, with ten studies ultimately fulfilling inclusion criteria. There were no studies specifically isolating the keloids and hypertrophic group of patients, and thus quantitative data were completely lacking from the literature. There were, however, individual cases described, and qualitatively encouraging clinical results were reported for the use of fat grafting on keloids and hypertrophic scars. Combined with the current theoretical and immunohistochemical understanding through other laboratory and animal studies, fat grafting may play a role in the treatment of keloids and hypertrophic scaring; however, specific evidence is currently lacking. The role for further research is clear.

Keloid and hypertrophic scars are difficult to treat conditions. Some studies have suggested that fat cells may have a role in managing these scars although this role is not well described in the literature. We perform a systematic review of available literature, examining the evidence for this.

Modern trends in lipomodeling

Lipomodeling is the process of relocating autologous fat to change the shape, volume, consistency, and profile of tissues, with the aim of reconstructing, rejuvenating, and regenerating body features. There have been several important advancements in lipomodeling procedures during the last thirty years. Four clinical steps are important for the success of engraftment: fat harvesting, fat processing, fat reinjection, and preconditioning of the recipient site. With the discovery of adipose derived stem cells and dedifferentiated cells, fat cells become a major tool of regenerative medicine. This article reviews recent trends in lipomodeling trying to understand most of the issues in this field.

Transcriptional and Cell Cycle Alterations Mark Aging of Primary Human Adipose-Derived Stem Cells

Adult stem cells play a critical role in the maintenance of tissue homeostasis and prevention of aging. While the regenerative potential of stem cells with low cellular turnover, such as adipose-derived stem cells (ASCs), is increasingly recognized, the study of chronological aging in ASCs is technically difficult and remains poorly understood. Here, we use our model of chronological aging in primary human ASCs to examine genome-wide transcriptional networks. We demonstrate first that the transcriptome of aging ASCs is distinctly more stable than that of age-matched fibroblasts, and further, that age-dependent modifications in cell cycle progression and translation initiation specifically characterize aging ASCs in conjunction with increased nascent protein synthesis and a distinctly shortened G1 phase. Our results reveal novel chronological aging mechanisms in ASCs that are inherently different from differentiated cells and that may reflect an organismal attempt to meet the increased demands of tissue and organ homeostasis during aging. Stem Cells 2017;35:1392-1401.

Receptor for hyaluronan mediated motility (RHAMM/HMMR) is a novel target for promoting subcutaneous adipogenesis

Hyaluronan, CD44 and the Receptor for Hyaluronan-Mediated Motility (RHAMM, gene name HMMR) regulate stem cell differentiation including mesenchymal progenitor differentiation. Here, we show that CD44 expression is required for subcutaneous adipogenesis, whereas RHAMM expression suppresses this process. We designed RHAMM function blocking peptides to promote subcutaneous adipogenesis as a clinical and tissue engineering tool. Adipogenic RHAMM peptides were identified by screening for their ability to promote adipogenesis in culture assays using rat bone marrow mesenchymal stem cells, mouse pre-adipocyte cell lines and primary human subcutaneous pre-adipocytes. Oil red O uptake into fat droplets and adiponectin production were used as biomarkers of adipogenesis. Positive peptides were formulated in either collagen I or hyaluronan (Orthovisc) gels then assessed for their adipogenic potential in vivo following injection into dorsal rat skin and mammary fat pads. Fat content was quantified and characterized using micro CT imaging, morphometry, histology, RT-PCR and ELISA analyses of adipogenic gene expression. Injection of screened peptides increased dorsal back subcutaneous fat pad area (208.3 ± 10.4 mm²versus control 84.11 ± 4.2 mm²; p < 0.05) and mammary fat pad size (45 ± 11 mg above control background, p = 0.002) in female rats. This effect lasted >5 weeks as detected by micro CT imaging and perilipin 1 mRNA expression. RHAMM expression suppresses while blocking peptides promote expression of PPARγ, C/EBP and their target genes. Blocking RHAMM function by peptide injection or topical application is a novel and minimally invasive method for potentially promoting subcutaneous adipogenesis in lipodystrophic diseases and a complementary tool to subcutaneous fat augmentation techniques.

Method for selective quantification of adipose-derived stromal/stem cells in tissue

Fat grafts are valuable for soft-tissue regeneration and augmentation. However, fat graft systems require further improvement for the prediction of graft retention. The concentration of adipose-derived stromal/stem cells (ASCs) is one of the most important factors that affect graft retention; however, current cell quantification techniques have not been applied to adipose tissue. Here we developed a method for the selective quantification of ASCs in tissue (SQAT). We identified a characteristic methylated site in the CD31 promoter after searching for specific markers of ASCs. This DNA methylation was not detected in any cell type other than ASCs in adipose tissue. Therefore, analyzing this methylation may be a suitable approach for quantifying ASCs in tissues because DNA is readily extracted from tissues. SQAT is based on quantifying this methylation by quantitative polymerase chain reaction using methylation-sensitive HapII-treated DNA as the template. SQAT was validated based on the numbers of ASCs determined by CD31⁻/CD34⁺-based flow cytometry. The results obtained by both methods were perfectly correlated, thereby demonstrating that SQAT is a useful tool for quantifying ASCs. SQAT analysis using ASCs isolated from suctioned fat according to the standard protocol (i.e., collagenase treatment) showed that the yield of ASCs was 59% ± 21%, which suggests that the ASC isolation technique requires further improvement. Furthermore, SQAT is an excellent method for quantifying ASCs in arbitrary samples (particularly tissue), which could dramatically improve ASC isolation technologies and fat graft systems, thereby facilitating the prediction of graft retention.

Microautologous Fat Transplantation for Primary Augmentation Rhinoplasty: Long-Term Monitoring of 198 Asian Patients

Background

Numerous techniques and materials are available for increasing the dorsal height and length of the nose. Microautologous fat transplantation (MAFT) may be an appropriate strategy for augmentation rhinoplasty.

Objectives

The authors sought to determine the long-term results of MAFT with the so-called one-third maneuver in Asian patients who underwent augmentation rhinoplasty.

Methods

A total of 198 patients who underwent primary augmentation rhinoplasty with MAFT were evaluated in a retrospective study. Fat was harvested by liposuction and was processed and refined by centrifugation. Minute parcels of purified fat were transplanted to the nasal dorsum with a MAFT-Gun. Patient satisfaction was scored with a 5-point Likert scale, and aesthetic outcomes were validated with pre- and postoperative photographs.

Results

The mean age of the patients was 45.5 years. The mean operating time for MAFT was 25 minutes, and patients underwent 1-3 MAFT sessions. The mean volume of fat delivered per session was 3.4 mL (range, 2.0-5.5 mL). Patients received follow-up for an average of 19 months (range, 6-42 months). Overall, 125 of 198 patients (63.1%) indicated that they were satisfied with the results of 1-3 sessions of MAFT. There were no major complications.

Conclusions

The results of this study support MAFT as an appropriate fat-transfer strategy for Asian patients undergoing primary augmentation rhinoplasty.

Level of Evidence: 4

Therapeutic

Isolation and differentiation potential of human mesenchymal stem cells from adipose tissue harvested by water jet-assisted liposuction

BACKGROUND

In recent years the therapeutic application of extracted adipose tissue for autologous fat grafting and the application of adipose tissue-derived mesenchymal stem cells (adMSC) isolated thereof has progressed. Water-jet assisted liposuction (WAL) is 1 procedure for harvesting adipose tissue and provides a favorable aesthetic outcome combined with high tissue protection. Tissue aspirated by WAL has been successfully applied in grafting procedures.

OBJECTIVES

The aims of this study were to confirm the tissue viability and to understand the abundance and mesenchymal differentiation capacity of stem cells within the tissue.

METHODS

We analyzed tissue integrity of WAL tissue particles via fluorescence microscopy. The adMSC content was determined by isolating the cells from the tissue. The mesenchymal differentiation capacity was confirmed with cytochemical staining methods.

RESULTS

The stromal vascular fraction of WAL tissue showed high viability and contained an average of 2.6 × 105 CD34-positive cells per milliliter of tissue. Thus WAL tissue contains a high number of stem cells. Furthermore adMSC isolated from WAL tissue showed typical mesenchymal differentiation potential.

CONCLUSIONS

WAL of adipose tissue is well suited for autologous fat grafting because it retains tissue viability. Furthermore it is a valid source for the subsequent isolation of adMSC with multipotent differentiation potential.

LEVEL OF EVIDENCE

3 Therapeutic.

Cryopreserved Subcutaneous Adipose Tissue for Fat Graft

Cryopreservation of subcutaneous white adipose tissue (sWAT) avoids multiple surgeries in patients subjected to reconstructive procedure. Fat grafts were performed subcutaneously on 26 mice treated with fresh (13 mice) or cryopreserved (13 mice) human sWAT. Cytofluorometry for CD marker expression of stem cells, differentiation capability, and in vivo survival of fat grafts were evaluated. In vitro analysis evidenced that cryopreservation did not affect the stem potential of samples. In vivo MRI showed that grafts were well preserved in 13 mice treated with fresh sWAT, whereas in 13 animals treated with thawed fat, graft volumes were strongly reduced after 1 week. Ultrastructural studies performed both on fresh and thawed specimens demonstrated that grafts performed with thawed sWAT are able to store lipids more slowly with respect to grafts performed with fresh sWAT and adipocytes maintained a multilocular appearance. Collected data demonstrated that the protocol of cryopreservation could maintain the regenerative capability of the sWAT, but the rate of reabsorption after fat grafting is higher using cryopreserved sWAT. Maintaining the stem potential of sWAT after cryopreservation is a very important aspect for reconstructive and regenerative medicine. The employment of cryopreserved sWAT represents an interesting goal for surgeons. Surely there is the necessity to improve the protocol of cryopreservation.

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 these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors http://www.springer.com/00266 .

Autologous fat grafting in the treatment of fibrotic perioral changes in patients with systemic sclerosis

Autologous fat tissue grafting (AFTG) has been successfully used in the treatment of different sclerotic conditions, including localized scleroderma. Patients with advanced systemic sclerosis (SSc)-related perioral thickening and mouth opening limitation are candidates for this therapeutic approach. AFTG of the lips was performed to improve mouth opening in patients with SSc. We enrolled in the study 20 female patients with diffuse SSc (median age 35 ± 15 years and 11 ± 10 years of disease duration). Two-milliliter fractions of autologous fat drawn from trochanteric or periumbilical areas were injected in eight different sites around the mouth. Baseline and after-treatment mouth opening changes were assessed by measuring interincisal distance and oral perimeter, while skin hardness was tested by digital durometer. Pre- and posttreatment modifications of microvascular architecture were assessed by counting capillaries in the inferior lip videocapillaroscopy (VC) images and by scoring the microvascular density (MVD) in anti-CD34/CD31 immunohistochemical (IH) stained perioral skin biopsy sections. Similarly, histological sections were examined to evaluate dermoepidermic junction (DEJ) modifications. Three months after treatment, both the interincisal distance and oral perimeter significantly increased (p < 0.001). At the same time, a significant skin neovascularization became evident, both considering the VC images (p < 0.001) and MVD scores in IH sections (p < 0.0001). Finally, some skin histological aspects also improved, as shown by the significant changes in DEJ flattening scores (p < 0.0001). The present study suggests that, in patients with SSc, AFTG can improve mouth opening and function, induce a neovascularization, and partially restore the skin structure.

Deaths Caused by Gluteal Lipoinjection: What Are We Doing Wrong?

BACKGROUND

Intramuscular gluteal lipoinjection has become one of the most commonly used surgical procedures for achieving improvement in the gluteal contour; however, there are few studies that report and analyze the causes of secondary death from this surgical procedure.

METHODS

An analysis of secondary deaths from gluteal lipoinjection procedures was performed in Mexico and Colombia over periods of 10 and 15 years, respectively. In Mexico, the study was performed through a survey of all members of the Mexican Association of Reconstructive, Plastic and Aesthetic Surgery. In Colombia, the study was performed through an analysis of deaths and autopsies documented by the National Institute of Legal Medicine and Forensic Sciences Regional Bogotá.

RESULTS

A total of 413 Mexican plastic surgeons reported 64 deaths related to liposuction, with 13 deaths caused by gluteal lipoinjection. In Colombia, nine deaths were documented. Of the 13 deaths in Mexico, eight (61.6 percent) occurred during lipoinjection, whereas the remaining five (38.4 percent) occurred within the first 24 hours. In Colombia, six deaths (77.7 percent) occurred during surgery and three occurred (22.2 percent) immediately after surgery. In the Colombian autopsy results, seven cases of macroscopic fat embolism and two cases with a microscopic embolism were reported, with abundant fatty tissue in the infiltrated gluteal muscles.

CONCLUSIONS

In this study, the authors found that intramuscular gluteal lipoinjection is associated with mortality caused by gluteal blood vessel damage allowing macroscopic and microscopic fat embolism; therefore, buttocks lipoinjection should be performed very carefully, avoiding injections into deep muscle planes.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Development of a System and Method for Automated Isolation of Stromal Vascular Fraction from Adipose Tissue Lipoaspirate

Autologous fat grafting for soft tissue reconstruction is challenged by unpredictable long-term graft survival. Fat derived stromal vascular fraction (SVF) is gaining popularity in tissue reconstruction as SVF-enriched fat grafts demonstrate improved engraftment. SVF also has potential in regenerative medicine for remodeling of ischemic tissues by promoting angiogenesis. Since SVF cells do not require culture expansion, attempts are being made to develop automated devices to isolate SVF at the point of care. We report development of a closed, automated system to process up to 500 mL lipoaspirate using cell size-dependent filtration technology. The yield of SVF obtained by automated tissue digestion and filtration (1.17 ± 0.5 × 10⁵ cells/gram) was equivalent to that obtained by manual isolation (1.15 ± 0.3 × 10⁵; p = 0.8), and the viability of the cells isolated by both methods was greater than 90%. Cell composition included CD34+CD31− adipose stromal cells, CD34+CD31+ endothelial progenitor cells, and CD34−CD31+ endothelial cells, and their relative percentages were equivalent to SVF isolated by the manual method. CFU-F capacity and expression of angiogenic factors were also comparable with the manual method, establishing proof-of-concept for fully automated SVF isolation, suitable for use in reconstructive surgeries and regenerative medicine applications.

Magnetic Resonance Imaging of Human Tissue-Engineered Adipose Substitutes

Adipose tissue (AT) substitutes are being developed to answer the strong demand in reconstructive surgery. To facilitate the validation of their functional performance in vivo, and to avoid resorting to excessive number of animals, it is crucial at this stage to develop biomedical imaging methodologies, enabling the follow-up of reconstructed AT substitutes. Until now, biomedical imaging of AT substitutes has scarcely been reported in the literature. Therefore, the optimal parameters enabling good resolution, appropriate contrast, and graft delineation, as well as blood perfusion validation, must be studied and reported. In this study, human adipose substitutes produced from adipose-derived stem/stromal cells using the self-assembly approach of tissue engineering were implanted into athymic mice. The fate of the reconstructed AT substitutes implanted in vivo was successfully followed by magnetic resonance imaging (MRI), which is the imaging modality of choice for visualizing soft ATs. T1-weighted images allowed clear delineation of the grafts, followed by volume integration. The magnetic resonance (MR) signal of reconstructed AT was studied in vitro by proton nuclear magnetic resonance ((1)H-NMR). This confirmed the presence of a strong triglyceride peak of short longitudinal proton relaxation time (T1) values (200 ± 53 ms) in reconstructed AT substitutes (total T1=813 ± 76 ms), which establishes a clear signal difference between adjacent muscle, connective tissue, and native fat (total T1 ~300 ms). Graft volume retention was followed up to 6 weeks after implantation, revealing a gradual resorption rate averaging at 44% of initial substitute's volume. In addition, vascular perfusion measured by dynamic contrast-enhanced-MRI confirmed the graft's vascularization postimplantation (14 and 21 days after grafting). Histological analysis of the grafted tissues revealed the persistence of numerous adipocytes without evidence of cysts or tissue necrosis. This study describes the in vivo grafting of human adipose substitutes devoid of exogenous matrix components, and for the first time, the optimal parameters necessary to achieve efficient MRI visualization of grafted tissue-engineered adipose substitutes.

Volumizing viaducts of the midface: defining the Beut techniques

BACKGROUND

In nonsurgical facial rejuvenation, autologous fat and dermal fillers have become an effective method to achieve symmetry and balance of the midface. Nonsurgical techniques that target the dynamic anatomical relationships existing in the midface can improve rejuvenation outcomes in this commonly augmented region.

OBJECTIVES

The authors described techniques for fat compartment and potential space volumization of the midface via a standardized and reproducible technique. They placed emphasis on access to anatomical spaces and compartments within the midface.

METHODS

In 11 hemifacial cadavers, hyaluronic acid filler homogenized with red dye was injected via 3 midfacial ports that were anatomically designed to access the superficial fat compartments, deep fat compartments, or traverse the prezygomatic space. Specimens were dissected in a layered fashion to analyze relationships between the injected filler and midfacial anatomy. We have described 4 site-specific procedural techniques and created a video containing anatomical renderings of each targeted viaduct accompanied by technique demonstrations.

RESULTS

We found that Beut techniques 1 through 4 can be performed through 3 midfacial viaducts. Port placement 1.5 cm inferolateral to the alar base in the nasolabial crease created a medial midface viaduct, suitable for access to the deep medial cheek fat, medial superficial fat compartment, premaxillary space, and adjacent superior nasolabial cheek compartment. Port placement within the nasojugal groove provided a middle midface viaduct to access the middle superficial fat compartment and medial suborbicularis oculi fat (SOOF). Port placement 1.5 cm inferolateral to the lateral canthus created a lateral midface viaduct to approach the pre-periosteal fat, prezygomatic space, lateral SOOF, and infraorbital fat compartment.

CONCLUSIONS

Our findings indicate that anterior and lateral cheek projection, V-deformity correction, rhytid softening, and tear trough effacement can be achieved through the midfacial viaducts. Systematic assessment and site-specific nonsurgical rejuvenation of the midface may lead to increased safety, accuracy, and technique reproducibility in this commonly injected region.

Novel treatment for recalcitrant rectovaginal fistulas: fat injection

INTRODUCTION AND HYPOTHESIS

The treatment of recurrent rectovaginal fistula (RVF) is a challenge for the surgeon. Within plastic surgery fat harvesting and subsequent transplantation by injection is an established method for soft tissue augmentation. We hypothesized whether soft tissue augmentation by transperineal injection of autologous fat could stimulate fistula healing in women with recalcitrant RVF.

MATERIALS AND METHODS

Six patients with a recalcitrant RVF, 4 due to obstetric injury and 2 associated with Crohn's disease, were included in the pilot study. The fat graft from the lower abdomen was injected transperineally around the fistula tract. At the end of the injection procedure the fistula tract was transected transversely.

RESULTS

In 1 patient the fistula healed after a single treatment, while the other 5 required two treatments with a 6-week interval. In the patients with an RVF due to obstetric injury no recurrence occurred during follow-up, mean 41 months (range 4-53). In the 2 patients with Crohn's disease a new fistula developed after 23 and 25 months respectively.

CONCLUSION

We describe fat injection as a new and promising method for the treatment of a recalcitrant RVF where previous attempts had failed to heal the fistula. This method does not include wide dissection, thereby reducing the risk of injury to important neurovascular structures. The method is minimally invasive and causes minimal donor site morbidity. More advanced techniques can still be used in cases of recurrence.

Trigeminal neuralgia: a new therapy?

Trigeminal neuralgia (TN) is a rare form of neuropathic pain that results in sudden, unilateral and recurrent pains in the distribution of one or more branches of the trigeminal nerve. The aetiology of TN remains unclear and several theories have been proposed. Many medical and surgical methods have been applied with only partial effectiveness and several side effects. New hypotheses and therapeutic methods are urgently needed. Using evidence presented in a literature review and in our own case report, we hypothesize that pain resulting from trigeminal neuralgia can be caused by demyelinating lesions in the trigger zone. These lesions can be repaired through the injection of fat containing Adipose-Derived Stem Cells (ADSC).

Human adipose-derived stem cell adipogenesis induces paracrine regulation of the invasive ability of MCF-7 human breast cancer cells in vitro

The aim of this study was to determine the effects of paracrine regulation on the invasive ability of MCF-7 human breast cancer cells through human adipose-derived stem cell (hADSC) adipogenesis. hADSC differentiation of the third and fourth passages of cells was induced in different induction media: osteogenic, adipogenic and chondrogenic. Transwell migration assays in the differently conditioned media, flow cytometry, enzyme-linked immunosorbent assay and western blot analysis for selected cytokines were performed. The flow cytometric analysis demonstrated positive expression of CD29, CD44 and CD105, while expression of CD34 and CD45 was not identified. The transwell migration assay showed that the invasive ability of MCF-7 cells was significantly enhanced during hADSC adipogenesis. hADSCs exerted a significantly positive effect on the invasive activity of MCF-7 cells during adipo-genesis. The results indicate that the high expression levels of activating protein 2 (aP2) in MCF-7 and adipocytes induced for 12 days may be associated with cell growth, invasion and metastasis. Peroxisome proliferator-activated receptor γ may be involved in fatty syntheses during adipogenic initiation and following adipogenic differentiation, possibly acting as a protection factor resulting in cell maturation and differentiation. This study also demonstrated that the expression of vascular endothelial growth factor was repressed by hADSCs, while that of matrix metalloproteinase-2 and urokinase-type plasminogen activator was increased to a significant level.