Fat grafting in trauma and reconstructive surgery

Injectable Pectin-Alginate Hydrogels for Improving Vascularization and Adipogenesis of Human Fat Graft

Autologous fat grafting (AFG) is the most prevailing tool for soft tissue regeneration in clinics, although efficiency is limited to unpredictable volume resorption due to poor vascularization and eventual necrosis. This study sought to improve the AFG efficiency using a hydrogel as a carrier for human fat graft (F) with and without platelet-rich plasma (PRP). PRP is clinically well known for the local release of several endogenous growth factors and has been in clinical use already. A human-fat-graft-encapsulated pectin-alginate hydrogel (FG) was developed and characterized. PRP was added to F to develop a human fat graft with PRP (FP). FP was admixed with a pectin-alginate hydrogel to develop FGP. FG and FGP showed the smooth injectable, elastic, and shear-thinning properties. FG and FGP groups showed enhanced cell viability and proliferation compared to the control F in vitro. We also investigated the in vivo angiogenesis and neo-adipogenesis ability of F, FG, FGP, and FP in nude mice after subcutaneous injection. After 2 and 4 weeks, an MRI of the mice was conducted, followed by graft explantation. The explanted grafts were also assessed histologically and with immunohistochemistry (IHC) studies. MRI and histology results revealed better vascularity of the FG and FGP system compared to fat graft alone. Further, the IHC studies, CD 31, and perilipin staining also revealed better vasculature and adipogenesis of FG and FGP systems. These results indicate the enhanced angiogenesis and adipogenesis of FG and FGP. Thus, developed pectin-alginate hydrogel-based fat graft systems FG and FGP replenish the native microenvironment by mediating angiogenesis and adipogenesis, thereby maximizing the clinical outcomes of autologous fat grafting.

The Selective Centrifugation Ensures a Better In Vitro Isolation of ASCs and Restores a Soft Tissue Regeneration In Vivo

Autologous fat grafting procedures in plastic surgery have been extensively used to reinforce soft tissue in congenital or acquired tissue impairments. With this background, the aim of this study is firstly to examine the impact of a selective centrifugation on existing adipose stem cells (ASCs) in terms of stemness profile maintenance and, secondly, to investigate the effect of restoring volume in reconstruction on patients affected by soft tissue damage. After centrifugation, the fat graft products were separated into two layers and subsequently examined in vitro for the expression of CD34, CD90, CD117, CD105, CD29, CD31, CD44, CD73, CD133, CD14 and CD45 markers by flow cytometry and gene expression analyses were performed for Sox2, WNT3A, END, CD44, FUT4, COLL1, CTNNB1, hbEGF, KRTLG, MMP2 and VIM genes. The results showed that in the middle-high density (MHD) layer there was a peak concentration of ASCs, compared to another layer obtained after centrifugation. Research carried out on patients under treatment for soft tissue regeneration using cells obtained from MHD layer selection will be fundamental in comparative analysis. These studies will lead to an adequate standardization of outcomes, provided that treatment is performed through cell selection. Therefore, a unique procedure in tissue reconstruction and regeneration through fat grafting is presented here.

Exosomes derived from human adipose mensenchymal stem cells accelerates cutaneous wound healing via optimizing the characteristics of fibroblasts

Prolonged healing and scar formation are two major challenges in the treatment of soft tissue trauma. Adipose mesenchymal stem cells (ASCs) play an important role in tissue regeneration, and recent studies have suggested that exosomes secreted by stem cells may contribute to paracrine signaling. In this study, we investigated the roles of ASCs-derived exosomes (ASCs-Exos) in cutaneous wound healing. We found that ASCs-Exos could be taken up and internalized by fibroblasts to stimulate cell migration, proliferation and collagen synthesis in a dose-dependent manner, with increased genes expression of N-cadherin, cyclin-1, PCNA and collagen I, III. In vivo tracing experiments demonstrated that ASCs-Exos can be recruited to soft tissue wound area in a mouse skin incision model and significantly accelerated cutaneous wound healing. Histological analysis showed increased collagen I and III production by systemic administration of exosomes in the early stage of wound healing, while in the late stage, exosomes might inhibit collagen expression to reduce scar formation. Collectively, our findings indicate that ASCs-Exos can facilitate cutaneous wound healing via optimizing the characteristics of fibroblasts. Our results provide a new perspective and therapeutic strategy for the use of ASCs-Exos in soft tissue repair.

Adipocytes Viability After Suction-Assisted Lipoplasty: Does the Technique Matter?

BACKGROUND

Suction-assisted lipoplasty (SAL; liposuction) is an established aesthetic procedure in plastic surgery. The main parameters differentiating one method of lipoplasty from another are safety, consistency of results, and other more technical parameters. Due to the recent popularity of lipotransfer, the quality of extracted fat has become a relevant parameter. We compare the viability of extracted adipocytes after dry SAL, hyper-tumescent PAL (power-assisted lipoplasty), and water-assisted lipoplasty (WAL).

METHODS

We used fluorescent microscopy to differentiate viable from necrotic/apoptotic cells after liposuction using each of the mentioned methods.

RESULTS

The ratio of living cells between the three methods was significantly different with dry liposuction yielding inferior ratios (p = 0.011). When omitting extreme results, we found that the body-jet technique (WAL) yielded higher ratios of living cells than the hyper-tumescent technique (p < 0.001). The total number of cells was highest in the hyper-tumescent method (p = 0.013).

CONCLUSIONS

Our results indicate that the hyper-tumescent technique yields the highest number of cells, whereas the body-jet technique yields the highest living cells ratio. The dry technique is clearly inferior to both.

NO LEVEL ASSIGNED

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Late revision or correction of facial trauma-related soft-tissue deformities

Surgical approaches used in accessing the facial skeleton for fracture repair are often the same as or similar to those used for cosmetic enhancement of the face. Rarely does facial trauma result in injuries that do not in some way affect the facial soft-tissue envelope either directly or as sequelae of the surgical repair. Knowledge of both skeletal and facial soft-tissue anatomy is paramount to successful clinical outcomes. Facial soft-tissue deformities can arise that require specific evaluation and management for correction. This article focuses on revision and correction of these soft-tissue-related injuries secondary to facial trauma.

The role of fat grafting in the treatment of posttraumatic maxillofacial deformities

Purpose The first autologous adipose tissue grafting was performed by Neuber in 1893 with an open approach. In the early 1980s, Illouz and Fournier introduced closed liposuction. In the 1990s, Coleman published a new method of atraumatic fat transplantation. Recently, immunohistochemical studies of the extracellular matrix of the lipoaspirate showed the presence of adipose-derived stem cells. The purpose of this study is to describe the role of fat grafting in the management of posttraumatic facial deformities. Methods The study population was composed of all patients who underwent facial fat grafting between March 2008 and November 2010 as a secondary reconstructive procedure after an initial unsatisfactory treatment of the skeletal fractures. We analyzed the postoperative morphological changes by comparing the grafted side of the face to the contralateral side with the aid of a software package. Results Nineteen patients were surgically treated with fat transplantation for facial asymmetry due to a pathological postoperative healing of the soft tissue. Clinical examination and software analysis showed adequate postoperative facial balance without major complications. Conclusion Fat grafting is a very powerful tool to correct posttraumatic maxillofacial deformities and to ensure a long-term follow-up. Although we have achieved excellent clinical results in our reconstructive clinical cases, we are convinced that more complex prospective studies, enriched by long-term radiological controls, are needed to fully understand the biological behavior of the transplanted fat in the posttraumatic face.

[Postoperative complications in plastic surgery]

Plastic surgery covers a broad spectrum of diseases and conditions in the areas of reconstructive surgery, hand, burn and aesthetic surgery. Besides acquired defects or malformations an increasing number of patients are being treated for surgical or multimodal complications. In a considerable number of patients plastic and reconstructive surgery remains the only therapeutic alternative after other therapy has failed. Therefore complication management in plastic surgery is of utmost importance for a successful outcome. In addition patient expectations in the results of plastic surgery as a discipline of invention and problem solving are steadily increasing. This challenge is reflected in clinical patient management by intensive research in tissue engineering and regenerative medicine. Patients in plastic surgery are recruited from all age groups of either gender, involving traumatic and oncologic as well as congenital and aesthetic disorders. The demographics of aging, multimorbidity and obesity pose new challenges to plastic surgery. Although age over 70 years is not an independent risk factor per se for complications in plastic surgery, e.g. for complex free flap transfer, medical problems are present at a higher rate, which is to be expected in this age group. Risk factors such as alcoholism and coronary heart diseases seem to be independent predictors of perioperative complications. Therefore older patients can also benefit from plastic surgery and recurrent operations by the corresponding risk and complication management. Complication management necessitates careful patient selection, estimation of operative risks and patient-adapted selection of procedures. In addition to expertise in plastic surgery a thorough knowledge of non-surgical and surgical back-up procedures for technical incidents as well as vascular circulatory and wound healing disorders is required to deal successfully with complications in plastic surgery. This article presents these specific aspects of postoperative complication management in plastic surgery.