Immediate SVF-Gel Injection Reduced Incision Scar Formation: A Prospective, Double-Blind, Randomized, Self-control Trial.

BACKGROUND: Skin incision scars are cosmetically displeasing; the effects of current treatments are limited, and new methods to reduce scar formation need to be found. OBJECTIVE: We sought to determine whether immediate postoperative injection of stromal vascular fraction gel (SVF-gel) could reduce scar formation at skin incision sites. METHODS: A prospective, randomized, double-blind, self-controlled trial was conducted in patients who underwent breast reduction. SVF-gel was intradermally injected into the surgical incision on one randomly selected side, with the other side receiving saline as a control. At the 6-month follow-up, the incision scars were evaluated using the Vancouver scar scale (VSS) and visual analog scale (VAS). Antera 3D camera was used for objective evaluation. RESULTS: The VSS score and VAS score were significantly different between the SVF-gel-treated side (3.80 ± 1.37, 3.37±1.25) and the control side (5.25 ± 1.18, 4.94 ± 1.28). Moreover, the SVF-gel-treated side showed statistically significant improvements in scar appearance, based on evidences from Antera 3D camera. LIMITATIONS: This was a single-center, single-race, and single-gender study. Furthermore, the results were available only for the 6-month interim follow-up period. CONCLUSION: Postoperative immediate SVF-gel injection in surgical incisions can reduce scar formation, and exert a preventive effect on scars. LEVEL OF EVIDENCE I: Evidence obtained from at least one properly designed randomized controlled trial. 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 .

Dual Network Hydrogels Based on PRP and SA Promote the Retention Rate and Vascularization of Transplanted Fat.

BACKGROUND: Autologous adipose tissue often experiences ischemia and hypoxia after transplantation, leading to low retention rates and unstable operative impacts due to necrotic absorption. Platelet-rich plasma (PRP) can enhance fat regeneration and increase the fat retention rate after transplantation. However, the quick release of growth factors (GFs) in PRP decreases therapeutic efficiency. This study aimed to achieve a slow release of PRP to promote fat retention. METHODS: We prepared a dual-network hydrogel (DN gel) based on FDA-approved PRP and sodium alginate (SA) through a simple "one-step" activation process. In vivo study, adipose tissue with saline (control group), SA gel (SA gel group), PRP gel (PRP gel group), and DN gel (DN gel group) was injected subcutaneously into the dorsum of nude mice. At 4 and 12 weeks after injection, tissues were assessed for volume and weight. Hematoxylin and eosin staining (HE) and immunofluorescence staining were performed for histological assessment. RESULTS: DN gel exhibits long-lasting growth factor effects, surpassing conventional clinical PRP gel regarding vascularization potential. In fat transplantation experiments, DN gel demonstrated improved vascularization of transplanted fat and increased retention rates, showing promise for clinical applications. CONCLUSIONS: DN gel-assisted lipofilling can significantly improve the retention rate and quality of transplanted fat. DN gel-assisted lipofilling, which is considered convenient, is a promising technique to improve neovascularization and fat survival. 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.

Particles of Different Sizes Affect the Retention Pattern of the Fat Grafts in a Mouse Model.

BACKGROUND: Autologous fat grafting is an effective form of soft tissue regeneration. However, the optimal fat particle size and graft retention pattern need more research. METHODS: The mouse inguinal fat pad was harvested and cut into fat particles of different diameters: ≥ 5 mm, 3-4 mm, 2-3 mm, 1-2 mm and 1 mm (micro-fat). A volume of 0.2 ml fat was transplanted into another mouse dorsum. Volume and retention rate were measured at 1, 4, 8 and 12 weeks. Histology analysis was performed. Immunofluorescence staining was used to evaluate M1 and M2 macrophage infiltration and graft angiogenesis. RESULTS: Fat retention was highest in the "> 5 mm" group and lowest in the "micro-fat" group. Large vacuoles were more common in larger-diametered fat particles. There was less collagen accumulation in the well-vascularized connective tissue in the "1-2 mm" group. The infiltrated nucleated cells peak at week 4 in groups of fat particles under 3 mm and at week 8 in in groups with fat particles above 3 mm. The number of M1 macrophages peaked at week 1 and then declined in all groups except for the "5 mm" group. The number of M2 macrophages peaked at week 4 and gradually decreased through 12 weeks in the groups below 3 mm, but increased through 12 weeks in the groups above 3 mm. Vascular intensity was similar to M2 macrophage prevalence. CONCLUSIONS: Fat particles of different sizes may posses different retention patterns. Larger grafts have higher retention rate but worse quality. Meanwhile, smaller grafts have better quality with lower retention rate. 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 .

Effects of Melatonin on Fat Graft Retention Through Browning of Adipose Tissue and Alternative Macrophage Polarization.

BACKGROUND: Melatonin is a widely used drug that can affect adipocyte inflammation, resulting in adipose tissue browning. Inducing the browning of white fat and changing the inflammatory microenvironment of early transplanted fat have positive effects on the retention rate of fat grafts. This study aimed to evaluate the effects of melatonin on fat graft retention, determine whether it is related to adipose tissue browning and the inflammatory microenvironment, and explore the underlying mechanisms. METHODS: A C57BL/6 mice fat transplantation model was established. The mice were divided into a control group (ethanol), a high-dose group (40 mg/kg/day melatonin), a medium-dose group (20 mg/kg/day melatonin), and a low-dose group (10 mg/kg/day melatonin). They were also given oral gavage treatment for 2 weeks. The grafted fat was collected 2, 4, and 12 weeks after treatment. RESULTS: The medium-dose and high-dose melatonin groups had significantly higher fat graft retention rates than the control group at 12 weeks. The medium-dose melatonin group had smaller multilocular adipocytes, which enhanced the expression of uncoupling protein 1 and increased neovascularization in the grafted fat. The medium-dose group also had a higher distribution of M2 macrophages. CONCLUSIONS: These findings suggest that melatonin administration can improve the retention of fat grafts through polarization of macrophages toward the anti-inflammatory type and induction of adipose tissue browning. 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 .

Meta-Analysis of the Oncological Safety of Autologous Fat Grafting After Breast Cancer on Basic Science and Clinical Studies.

BACKGROUND: The purpose of the present study was to comprehensively evaluate the oncological safety of autologous fat grafting after breast cancer by combining experimental and clinical studies. METHODS: All studies published before August 2021 were collected by searching PubMed, Cochrane, Embase, Web of Science, SINOMED, and China National Knowledge Infrastructure. After screening the research and extracting the data, RevMan was used to perform the meta-analysis. RESULTS: Five basic science studies and 26 clinical studies, involving a total of 10,125 patients, were eventually included. In the basic science studies, adipose-derived stem cells promoted breast cancer growth, but fat grafting and adipose-derived stem cells plus fat grafting were not associated with breast cancer growth. An overall analysis of clinical studies showed that autologous fat grafting does not increase the risk of breast cancer recurrence. Subgroup analyses indicated that autologous fat grafting did not increase the risk of breast cancer recurrence in Asian or Caucasian patients, in patients undergoing breast-conserving surgery or modified radical mastectomy, in patients with in situ carcinomas or invasive carcinomas, or in patients undergoing postoperative radiotherapy. CONCLUSION: This study combined experimental and clinical studies to conclude that autologous fat grafting does not increase the risk of breast cancer recurrence. However, the experimental results suggest that adipose-derived stem cells should be used with caution after breast cancer surgery. 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 .

Use of platelet-rich fibrin in fat grafts during facial lipostructure.

Background: This review was designed to discuss the safety and efficacy of using platelet-rich fibrin (PRF) in fat grafts during facial lipostructure. Methods: From January 2018 to December 2021, 650 fat grafts for facial lipostructure were performed in the authors' department. According to their wishes, we divided the patients into two groups: 498 patients were treated with autologous fat injection (control group), and 152 patients were treated with autologous fat injection combined with PRF. All of the patients were monitored for at least six months. The effects were evaluated via physician assessment and patient satisfaction rates, and the incidences of complications were compared. Results: All the cases had a degree of improvement after treatment. The patient satisfaction rate was 55.3% in the PRF group and 43.4% in the control group. In all, 68.4% of the patients in the PRF group and 58.2% in the control group indicated that one-stage surgery was sufficient to achieve the desired effect. According to the evaluation conducted by the plastic surgeon, 59.2% of patients in the PRF group and 47.0% in the control group achieved a perfect effect. A total of 76.3% of patients in the PRF group and 63.9% in the control group reported that one surgery achieved satisfactory results. The difference between the PRF and control groups was statistically significant. Conclusion: Using an autologous fat graft during facial lipostructure is beneficial and safe when combined with PRF. The combination may enhance the effect and satisfaction rate. Further research and prospective clinical studies are needed to understand the role of PRF in fat grafting.

Innovative Application of Three-Dimensional-Printed Breast Model-Aided Reduction Mammaplasty.

Symptomatic macromastia places a severe physical and psychological burden on patients. Reduction mammaplasty is the primary treatment; however, conventional surgery may lead to postoperative nipple-areolar complex necrosis due to damage to the dominant supplying arteries. In this study, we designed and fabricated an innovative, three-dimensional-printed breast vascular model to provide surgical guidance for reduction mammaplasty. Preoperative computed tomography angiography scanning data of patients were collected. The data were then processed and reconstructed using the E3D digital medical modeling software (version 17.06); the reconstructions were then printed into a personalized model using stereolithography. The three-dimensional-printed breast vascular model was thus developed for individualized preoperative surgical design. This individualized model could be used to intuitively visualize the dominant supplying arteries' spatial location in the breasts, thereby allowing effective surgical planning for reduction mammaplasty. The three-dimensional-printed breast vascular model can therefore provide an individualized preoperative design and patient education, avoid necrosis of the nipple-areolar complex, shorten operation duration, and ensure safe and effective surgery in patients.

Platelet-Rich Fibrin in Fat Grafts for Facial Lipofilling: A Randomized, Controlled Split-Face Clinical Trial.

Objective: Previous studies have reported that platelet-rich fibrin (PRF) may enhance the efficacy of fat grafts in facial lipofilling. However, these studies either lacked objective data or were not randomized, controlled trials. Thus, we aimed to objectively evaluate the efficacy of PRF in facial lipofilling. Methods: A controlled, split-face, randomized trial (January 2018 to May 2019) based on 18 patients who underwent fat grafts for bilateral temple lipofilling was performed. Each patient received a combination of an autologous fat graft and PRF on one side and a fat graft combined with an equal volume of saline on the other side. The effects of PRF were evaluated by comparing the remaining bilateral fat graft volumes through a digital three-dimensional reconstruction technique. Improvements in the appearance and recovery time of each temple were assessed by both a surgeon and patients who were blinded to the treatment assignment. Complications were also recorded. Results: Bilateral temple lipofilling showed no evidence of fat embolism, vascular/nerve injury, infection, massive edema, or prolonged bruising. Three-dimensional reconstruction data and the assessments from both the surgeon and patients revealed no significant differences in fat graft retention volume between the PRF-positive and PRF-negative lipofilling groups. However, recovery time in the PRF-positive lipofilling sites was significantly shortened compared with that of the PRF-negative lipofilling sites. Conclusion: Facial filling with autologous fat grafts is effective and safe. Our results show that PRF does not markedly improve fat graft volume retention in the temple but significantly reduces postoperative recovery time. Trial Registration Number: ChiCTR2100053663.

Bone marrow mesenchymal stem cells enhance angiogenesis and promote fat retention in fat grafting via polarized macrophages.

BACKGROUND: Fat grafting is one of the most common soft tissue filling methods in plastic surgery. Bone marrow mesenchymal stem cell (BM-MSC) transplantation is an effective method for improving graft retention. However, the role of BM-MSCs in fat transplantation is not completely clear. METHODS: Human fat particles, together with BM-MSCs or PBS as a control, were subcutaneously transplanted into the backs of nude mice. Samples were taken on days 14, 30 and 90 post-grafting to calculate the fat graft retention rate, and tissue staining was evaluated. Furthermore, macrophages were treated with BM-MSC conditioned medium (BM-MSC-CM) to identify the beneficial component secreted by these stem cells. RESULTS: In this study, we found that BM-MSCs improved retention by enhancing angiogenesis in fat grafting. Further analysis revealed that BM-MSCs could significantly inhibit the expression of the proinflammatory M1 macrophage markers interleukin (IL)-1ß, tumor necrosis factor-α (TNF-α) and IL-6 in the early stages of fat grafting and promote the expression of the anti-inflammatory M2 macrophage markers Arg1, IL-10 and VEGF. Furthermore, our results showed that IL-10 secreted by BM-MSCs induced M2 macrophage polarization in vitro. CONCLUSIONS: BM-MSC transplantation can improve the fat retention rate and promote angiogenesis, which may be related to M2 macrophages. These results help elucidate the role of BM-MSCs in fat grafting.

Severe Vascular Complications Caused by Facial Autologous Fat Grafting: A Critical Review.

BACKGROUND: Vascular embolism is the most severe complication after autologous fat grafting. With a worldwide increase in fat grafting, there has been a rise in severe vascular complications, such as ophthalmic artery embolism, cerebral artery embolism, and even death. This article aims to review the role of fat in causing severe vascular complications and the association between fat grafting and severe vascular complications. METHODS: A critical review was conducted by appraising the cases of severe vascular complications associated with facial fat grafting reported globally. Repeated cases that were reported in multiple publications were further screened. RESULTS: The final search yielded 50 publications in English that met the inclusion criteria for review. A total of 113 cases of fat-induced severe vascular complications in the literature were identified. The number of cases reported yearly has increased over time, with even more significant increases since 2010. The glabella and temple are the most common sites of severe vascular complications described in the literature. In addition, only one case of ophthalmic artery embolism and one case of cerebral artery embolism have been treated successfully. CONCLUSIONS: Given the increase in reported cases of severe vascular complications, both doctors and patients should pay careful attention to the risks of facial fat grafting. Because of the unclear mechanism of vascular embolism and the lack of guidelines for prevention and treatment, the effective cure rate is unsatisfactory. We propose that preventing vascular embolism is a priority in fat grafting and that timely, multidisciplinary treatment should be performed when severe vascular complications occur. It is necessary in future studies to explore the mechanisms of vascular embolism and effective treatment strategies to promote the development of fat grafting.

An Overview of Principles and New Techniques for Facial Fat Grafting.

Facial fat grafting is a small-volume procedure and is primarily performed for facial rejuvenation, contouring, or regenerative surgery. The unsatisfying retention rate after fat grafting, however, led to unpredictable outcomes, subsequent multiple procedures, and even some complications. A variety of methods have been proposed to enhance the results of facial fat grafting, including several established surgical principles and many possible new techniques. Adding stem cells, fat preparations, and platelet concentrates may improve the survival after fat grafting but randomized controlled clinical studies are needed to determine their safety and efficacy as well as clinical indications for each technique.

Platelet-Rich Plasma and Platelet-Rich Fibrin Enhance the Outcomes of Fat Grafting: A Comparative Study.

BACKGROUND: Autologous fat grafting is an efficient procedure in plastic surgery. However, its long-term tissue absorption is variable and technique-dependent. Platelet-rich plasma positively affects fat-grafting outcomes but still has shortcomings, and platelet-rich fibrin has been reported to have efficacy in fat transplantation. Here, we compared the effects of platelet-rich fibrin and platelet-rich plasma in fat grafting using histologic analysis. METHODS: Twenty rabbits were divided randomly into two groups. In each group, the groin region fat pads were cut into 1-mm granules. Platelet-rich fibrin-treated or platelet-rich plasma-treated fat granules were transplanted into one ear, whereas the contralateral ear was transplanted with normal saline-treated fat granules. Histologic characteristics and capillary density of grafted tissue were analyzed 12 weeks after fat grafting. RESULTS: The grafted fat in the platelet-rich fibrin-treated group showed higher tissue retention than that in the control group [weight retention, 19.57 percent (interquartile range, 13.87 to 29.93 percent) versus 9.04 percent (interquartile range, 6.16 to 16.80 percent), p < 0.05; and volume retention, 18.00 percent (interquartile range, 10.50 to 26.50 percent) versus 8.00 percent (interquartile range, 5.75 to 13.25 percent), p < 0.05] and higher neovascularized capillary density than that in the platelet-rich plasma-treated and control groups. The platelet-rich plasma-treated group showed higher vessel density without superior tissue retention compared with the control group. CONCLUSION: Platelet-rich fibrin increased tissue retention, quality, and vascularization of grafted fat compared with the control group and showed effects similar to those of platelet-rich plasma on tissue retention and histologic graft improvement.

Conventional Nanofat and SVF/ADSC-Concentrated Nanofat: A Comparative Study on Improving Photoaging of Nude Mice Skin.

BACKGROUND: Nanofats could improve photoaging. Stromal vascular fraction (SVF) and adipose-derived stem cells (ADSCs) may play pivotal roles. However, SVFs and ADSCs in nanofats processed by conventional methods cannot be enriched. Some researchers have found that after centrifugation, the SVF/ADSC density increases from top to bottom. OBJECTIVES: The authors hypothesized that centrifugation can be used to obtain SVF/ADSC-concentrated nanofats that are superior to conventional nanofats in improving the photoaging of skin. METHODS: After a photoaging model was successfully established in nude mice, the back of each mouse was divided into 4 areas and randomly injected with conventional nanofat, centrifuged nanofat (either the middle or lower layer of centrifuged nanofat), or normal saline. Wrinkles, dermis thickness, dermal collagen content, and elastic fiber morphology were measured and compared at weeks 4 and 8. RESULTS: Compared with the wrinkles in the physiological saline injection areas, the wrinkles in the areas injected with the 3 nanofats (lower and middle layers of centrifuged nanofat and conventional nanofat) were significantly reduced. All 3 nanofat groups showed increased dermal thickness, increased collagen content, and a more regular distribution of elastic fibers compared with the saline injection areas. CONCLUSIONS: The study established the efficacy of nanofats in improving photoaging by reducing wrinkles and increasing the thickness of dermal collagen, making nanofats a promising novel treatment for photoaging. The SVF/ADSC-concentrated nanofats exhibited the most improvement.

Improving the Retention Rate of Fat Grafts in Recipient Areas via Botulinum Toxin A Treatment.

BACKGROUND: Improving the retention rate of transplanted fat is, currently, of great concern. Partial immobilization, angiogenesis, and adipose tissue-derived stem cells, all proven to be influenced by botulinum toxin A (BTX-A), are significant in fat graft retention. OBJECTIVES: The authors sought to determine the impact of BTX-A on fat grafts. METHODS: Our study included 12 Sprague Dawley rats and each rat's hind limbs were randomly designated as the BTX-A side and control side. We injected 0.2 mL of BTX-A-treated fat into the quadriceps femoris and subcutaneous space of the BTX-A sides. This was also done for the control sides but with untreated fat. We performed electroneuromyography of recipient muscles at 1 week post-operation. The rats were euthanized at 12 weeks post-operation and we observed the fat retention rate, the fat's histologic characteristics, and the density of vessels and mature adipocytes. RESULTS: The amplitudes of electroneuromyography were smaller for the BTX-A sides than the control sides. For intramuscularly injected fat, the BTX-A sides had better retention rates and histologic characteristics and a higher density of vessels and mature adipocytes than the control sides. For subcutaneously injected fat, the BTX-A sides had better histologic characteristics and a higher density of vessels and mature adipocytes than the control sides, but the retention rates were not significantly different between the 2 sides. CONCLUSIONS: Injecting BTX-A-treated fat grafts can immobilize the surrounding muscles. BTX-A can improve the density of vessels and mature adipocytes, histologic characteristics of fat grafts, and retention rate of fat grafts transplanted into muscles.

Association of Autologous Fat Injection in Facial Artery With Ophthalmological Complications: An Experimental Animal Study.

IMPORTANCE: Complications caused by autologous fat filling have been reported. Comprehensive knowledge of the possible adverse effects of autologous fat filling is needed. OBJECTIVE: To determine the association of autologous fat filling with ophthalmic function complications. DESIGN, SETTING, AND PARTICIPANTS: Four adult New Zealand white rabbits were killed for a facial anatomy study. Sixty-four adult New Zealand white rabbits underwent fat harvest using the Coleman technique. Autologous fat was minced or digested with collagenase 1 and centrifuged to separate fat lipid and fat granules. Either 0.2 mL or 0.4 mL of minced fat, fat granules, fat lipid, or saline (control) was retrogradely injected into the facial artery of rabbit models. Electroretinography and ophthalmic fundoscopy were performed to measure the retina and fundus artery occlusions 2 weeks after surgery. MAIN OUTCOMES AND MEASURES: Visual impairment, blindness, and death. RESULTS: Injection of 0.2 mL of fat granules, fat lipid, and saline resulted in 100% (8 of 8), 62.5% (5 of 8), and 0 ophthalmic complications, respectively; and 0.4 mL resulted in 87.5% (7 of 8), 12.5% (1 of 8), and 0 ophthalmic complications, respectively. Injection of 0.2 mL and 0.4 mL minced fat led to 100% (8 of 8) ophthalmic complications and death, respectively. The mortality rates were 37.5% (3 of 8), 12.5% (1 of 8), and 0 for 0.2 mL emboli injection, and 100% (8 of 8), 50% (4 of 8), and 0 for 0.4 mL, respectively. CONCLUSIONS AND RELEVANCE: In this study, minced fat injection was associated with more ophthalmic complications than injection of fat granules and fat lipid. Increasing the injection volume of fat tissues could raise the incidence of morbidity and mortality. LEVEL OF EVIDENCE: NA.

Improvement in the Retention Rate of Transplanted Fat in Muscle by Denervation.

BACKGROUND: Improvement in the retention rate of transplanted fat is currently a topic of interest. The retention of transplanted fat relies heavily on the reestablishment of blood supply and the function of the adipose-derived stem cells (ADSCs), which may both be impeded by mechanical force. However, the effect of mechanical force on the retention of adipose implants remains unclear. OBJECTIVES: This study aimed to evaluate the effectiveness of immobilization on fat retention rate. METHODS: Immobilization was carried out by denervation of the hind limb of rats to reduce the mechanical force. Sprague-Dawley (SD) rats were used, and the two hind limbs were assigned at random to the immobilization side and the control side. On average, 0.4 mL of fat was injected into the bilateral muscle and subcutaneous space of the hind limb, and 6 rats were sacrificed at each time point. The outcome measures included the retention rate, the histologic evaluation, and the density of new vessels and proliferative ADSCs. RESULTS: For the muscle fat, the retention rate improved, and more proliferative ADSCs and new vessels were found in the immobilization group. The histologic evaluation between the two sides was of no statistical significance. For the fat in the subcutaneous space, no statistical difference was observed in all the outcome measures between the two sides. CONCLUSIONS: Regional immobilization of the recipient site by denervation can improve the retention of the fat graft in muscles owing to improved density of the new vessels and proliferative ADSCs.

The Role of Platelet Concentrates in Facial Fat Grafting.

Autologous fat grafting is increasingly being used as a method for the repair of facial soft tissue defects and facial rejuvenation, given its low risk of adverse effects and high efficacy. However, the unpredictability of graft retention is a limitation of this procedure. In addition, there is no standard procedure to date for autologous fat grafting. Different methods have been developed to increase the retention of grafted fat. For instance, platelet concentrates have been used to directly deliver bioactive factors to grafted fat. Platelet concentrates also provide incidental therapeutic benefits by enhancing the persistence of fat grafted in the face via the release of growth factors and cytokines. In this review, we describe current strategies for improving the survival of facial fat grafts, mainly focusing on the application of growth factors/cytokines and platelet concentrates to fat grafting.

Browning of Human Subcutaneous Adipose Tissue after Its Transplantation in Nude Mice.

BACKGROUND: The clinical unpredictability of autologous fat grafting originates partially from the unique characteristics of adipose tissue. Evidence of adipose remodeling toward browning (developing of brown-like adipocytes in white adipose tissue) in response to trauma has been emerging. With regard to fat grafting surgery by which adipose tissue depots are directly and ubiquitously traumatized, whether it affects adipose phenotype change toward browning has not been previously reported. METHODS: Human subcutaneous adipose tissues were harvested from the abdominal region of female patients by means of liposuction and were then injected into the dorsal flanks of athymic nude mice. After 12 weeks, fat grafts were harvested and subjected to histologic analysis. RESULTS: Hematoxylin and eosin staining showed the appearance of small multilocular adipocytes in the peripheral region of the grafts. These adipocytes exhibited higher staining for uncoupling protein 1 (a fat browning-specific marker), mitochondrial protein, and CD31 compared with the central ones, indicating the presence of brown-like adipocytes (i.e., beige adipocytes) in this area. Furthermore, immunofluorescence staining demonstrated that these beige adipocytes might be derived from de novo adipogenesis from progenitors of graft origin. CONCLUSION: Results of this study suggest that browning of subcutaneous white adipose tissue participates in adaptive tissue remodeling following grafting and contributes to adipose tissue repair.

Transfusion of ethylene carbodiimide-fixed donor splenocytes prolongs survival of vascularized skin allografts.

BACKGROUND: Allograft rejection is a major obstacle to the widespread clinical application of vascularized composite allotransplantation. Recent studies revealed a noncytoreductive strategy to protect allografts by the transfusion of ethylene carbodiimide-fixed donor splenocytes (ECDI-SPs). To determine whether this approach offers advantages in protecting skin allografts, we examined the immunological protection of infusing ECDI-SPs with a 30-d administration of rapamycin on the skin allografts of mice. MATERIALS AND METHODS: C57BL/6 recipient mice received BALB/c donor full-thickness skin or vascularized skin transplants at day 0, along with the infusion of donor ECDI-SPs 7 d before and 1 d after allotransplantation and a 30-d course of rapamycin. Recipients received ECDI-untreated splenocytes or C3H allografts as controls. In vitro allostimulatory activity of ECDI-SPs and donor-specific ex vivo hyporesponsiveness were tested. Production of related cytokines (TGF-ß, IL-10, IL-1ß, and TNF-α) and expression of CD4+Foxp3+ regulatory T cells (Tregs) were also examined. RESULTS: Transfusion of ECDI-SPs combined with rapamycin significantly prolonged survival of full-thickness skin (median survival time [MST]: 28 d) and full-thickness skin allografts (MST: 71 d) compared with untreated splenocytes (MSTs: 11 d and 30 d) or C3H allografts (MSTs: 11 d and 38 d). This effect was accompanied by increased production of IL-10 and TGF-ß, decreased production of IL-1ß and TNF-α, and expansion of Tregs in vitro and in vivo. CONCLUSIONS: ECDI-SP infusion combined with short-term rapamycin administration provides a promising approach to prolong the skin allograft survival.

Reconstruction of Large Postburn Facial-Scalp Scars by Expanded Pedicled Deltopectoral Flap and Random Scalp Flap: Technique Improvements to Enlarge the Reconstructive Territory.

The scars of face and scalp caused by burning often show as 1 large facial-scalp scar. The deltopectoral flap was recognized as one of the first choices for the facial scar reconstruction. However, this flap cannot cross the level of zygomatic arch traditionally when it was transferred with pedicle. When the flap reconstructed the facial-scalp scars with expanded random scalp flap, another flap was often needed to reconstruct the remaining temple and forehead scars. The authors reviewed 24 patients of large facial-scalp scars reconstructed by expanded pedicled deltopectoral flap and scalp flap with several technique improvements. The seaming scar between the deltopectoral flap and scalp flap in the temple region formed the new hairline. The technique improvements included ligation of the perforating branches of the transverse cervical artery and thoracoacromial artery when dissecting the pocket, the partial bolster compressive dressing to the distal part of the flap and dividing the pedicle partly as a delaying procedure before dividing the pedicle completely. Good skin compliance, normal contours, and emotional expression were noted. There were complications including expander exposure in 3 patients, stretch marks in 5 patients, flap tip necrosis in 2 patients, and mild postoperative hypertrophic scars in 3 patients. In conclusion, the expanded pedicled deltopectoral flap can enlarge the reconstructive territory in face successfully with the technique improvements. The combination of the expanded pedicled deltopectoral flap and scalp flap is a reliable and excellent reconstructive option for large postburn facial-scalp scars.