Eyelid fat grafting: indications, operative technique and complications; a systematic review

International audienceIntroduction - Many recent studies concerning autologous fat grafting in the eyelids have been published, mostly consisting of case reports and retrospective case series. However, no study on the overall complication or satisfaction rate associated with the various grafting techniques exists. We performed a comprehensive literature review to determine the outcomes and complications of eyelid fat grafting, as well as patient satisfaction.Methods - A systematic review of the literature using the PRISMA criteria was conducted. This protocol was registered at the Prospective Register of Systematic Reviews at the National Institute for Health Research.Results - Sixteen studies, representing 1,159 patients and published between June 2004 and December 2014, were included. Satisfactory results, judged by clinical examination, were observed in all studies. Few postoperative complications were reported.Conclusions - We demonstrated that the procedures were easy to perform, and achieved satisfactory and sustainable results with few complications in both reconstructive and cosmetic surgery. However, a wide disparity exists in the various fat harvesting, fat purification, and reinjection techniques. Further studies are required to assess the long-term outcomes. Our conclusions should be accepted cautiously due to the small number of articles and the lack of evidence in published studies.<br

KDM6B drives epigenetic reprogramming associated with lymphoid stromal cell early commitment and immune properties

Mature lymphoid stromal cells (LSCs) are key organizers of immune responses within secondary lymphoid organs. Similarly, inflammation-driven tertiary lymphoid structures depend on immunofibroblasts producing lymphoid cytokines and chemokines. Recent studies have explored the origin and heterogeneity of LSC/immunofibroblasts, yet the molecular and epigenetic mechanisms involved in their commitment are still unknown. This study explored the transcriptomic and epigenetic reprogramming underlying LSC/immunofibroblast commitment. We identified the induction of lysine demethylase 6B (KDM6B) as the primary epigenetic driver of early immunofibroblast differentiation. In addition, we observed an enrichment for KDM6B gene signature in murine inflammatory fibroblasts and pathogenic stroma of patients with autoimmune diseases. Last, KDM6B was required for the acquisition of LSC/immunofibroblast functional properties, including the up-regulation of CCL2 and the resulting recruitment of monocytes. Overall, our results reveal epigenetic mechanisms that participate in the early commitment and immune properties of immunofibroblasts and support the use of epigenetic modifiers as fibroblast-targeting strategies in chronic inflammation

KDM6B drives epigenetic reprogramming associated with lymphoid stromal cell early commitment and immune properties

Mature lymphoid stromal cells (LSCs) are key organizers of immune responses within secondary lymphoid organs. Similarly, inflammation-driven tertiary lymphoid structures depend on immunofibroblasts producing lymphoid cytokines and chemokines. Recent studies have explored the origin and heterogeneity of LSC/immunofibroblasts, yet the molecular and epigenetic mechanisms involved in their commitment are still unknown. This study explored the transcriptomic and epigenetic reprogramming underlying LSC/immunofibroblast commitment. We identified the induction of lysine demethylase 6B (KDM6B) as the primary epigenetic driver of early immunofibroblast differentiation. In addition, we observed an enrichment for KDM6B gene signature in murine inflammatory fibroblasts and pathogenic stroma of patients with autoimmune diseases. Last, KDM6B was required for the acquisition of LSC/immunofibroblast functional properties, including the up-regulation of CCL2 and the resulting recruitment of monocytes. Overall, our results reveal epigenetic mechanisms that participate in the early commitment and immune properties of immunofibroblasts and support the use of epigenetic modifiers as fibroblast-targeting strategies in chronic inflammation

VCA supercooling in a swine partial hindlimb model

Vascularized composite allotransplantations are complex procedures with substantial functional impact on patients. Extended preservation of VCAs is of major importance in advancing this field. It would result in improved donor-recipient matching as well as the potential for ex vivo manipulation with gene and cell therapies. Moreover, it would make logistically feasible immune tolerance induction protocols through mixed chimerism. Supercooling techniques have shown promising results in multi-day liver preservation. It consists of reaching sub-zero temperatures while preventing ice formation within the graft by using various cryoprotective agents. By drastically decreasing the cell metabolism and need for oxygen and nutrients, supercooling allows extended preservation and recovery with lower ischemia–reperfusion injuries. This study is the first to demonstrate the supercooling of a large animal model of VCA. Porcine hindlimbs underwent 48 h of preservation at − 5 °C followed by recovery and normothermic machine perfusion assessment, with no issues in ice formation and favorable levels of injury markers. Our findings provide valuable preliminary results, suggesting a promising future for extended VCA preservation

Machine Perfusion Enables 24-h Preservation of Vascularized Composite Allografts in a Swine Model of Allotransplantation

The current gold standard for preserving vascularized composite allografts (VCA) is 4°C static cold storage (SCS), albeit muscle vulnerability to ischemia can be described as early as after 2 h of SCS. Alternatively, machine perfusion (MP) is growing in the world of organ preservation. Herein, we investigated the outcomes of oxygenated acellular subnormothermic machine perfusion (SNMP) for 24-h VCA preservation before allotransplantation in a swine model. Six partial hindlimbs were procured on adult pigs and preserved ex vivo for 24 h with either SNMP (n = 3) or SCS (n = 3) before heterotopic allotransplantation. Recipient animals received immunosuppression and were followed up for 14 days. Clinical monitoring was carried out twice daily, and graft biopsies and blood samples were regularly collected. Two blinded pathologists assessed skin and muscle samples. Overall survival was higher in the SNMP group. Early euthanasia of 2 animals in the SCS group was linked to significant graft degeneration. Analyses of the grafts showed massive muscle degeneration in the SCS group and a normal aspect in the SNMP group 2 weeks after allotransplantation. Therefore, this 24-h SNMP protocol using a modified Steen solution generated better clinical and histological outcomes in allotransplantation when compared to time-matched SCS

Adipose tissu : improvement of knowledge of adipose tissu and stromal vascular fraction, advantage in the field of plastic surgery

L’objectif de cette thèse était d’améliorer les connaissances fondamentales sur le tissu adipeux, organe qui est au cœur de la pratique des chirurgiens plasticiens. En effet, ce tissu peut être transplanté de façon autologue afin de combler une perte de substance (rôle volumateur des adipocytes) mais également servir à des fins de régénération tissulaire en lien avec les cellules de la fraction vasculaire stromale (FVS) et tout particulièrement des cellules stromales mésenchymateuses (CSM). Ces cellules s’obtiennent après lipoaspiration du tissu par une digestion enzymatique de la graisse obtenue. Il s’avère que les connaissances disponibles sur ces CSM sont essentiellement issues d’études in vitro après une phase de culture cellulaire plus ou moins longue et ainsi les propriétés in vivo sont mal connues. Ce travail a donc consisté à caractériser l’hétérogénéité du compartiment stromal natif du tissu adipeux obtenu après digestion enzymatique. Nous avons isolé deux populations stromales natives distinctes : les ASC (CD34+), en grande majorité, et des cellules péricytaires (CD146+). Ces 2 types cellulaires différaient dans leurs phénotypes, leurs potentiels de clonogénécité et leurs propriétés immunomodulatrices in vitro et in vivo. Nous avons ensuite comparé la digestion enzymatique du tissu aux techniques de digestion mécanique utilisable au sein de nos blocs opératoires. Nous avons démontré que ces nouvelles techniques permettaient bien de produite les cellules de la FVS dont des CSM, cellules particulièrement intéressante pour des gestes de régénération tissulaire. De plus, l’ensemble des techniques de laboratoire acquise au cours de ce travail nous ont permis d’investiguer le rôle des techniques de lipoaspiration utilisé en chirurgie plastique sur le tissu adipeux. Nous avons démontré par cytométrie de flux et par immunofluorescence in situ qu’une partie de la trame microvasculaire était conservée. L’ensemble de ces résultats viennent s’ajouter aux données cliniques démontrant que la lipoaspiration du tissu est un geste permettant d’être plus conservateur pour le tissu et pourrait expliquer des taux de complications moindre après chirurgie de contour de la silhouette.The aim of this work was to improve the knowledge on adipose tissue, organ that is at the heart of the practice of plastic surgeons. Indeed, this tissue can be transplanted autologously in order to fill a defect (volumizing role of the adipocytes) but also to be used for tissue regeneration in connection with the cells of the stromal vascular fraction (SVF) and especially the mesenchymal stromal cells (MSCs). These cells are obtained after liposuction of the tissue by enzymatic digestion of the extracellular matrix. It turns out that the knowledge available on these CSM is essentially derived from in vitro studies after a cell culture phase and thus the in vivo properties are poorly known. This work consisted in characterizing the heterogeneity of the native stromal compartment of adipose tissue obtained after enzymatic digestion. We isolated two distinct native stromal populations: the ASC (CD34 +), for the most part, and the pericyte cells (CD146 +). These 2 cell types differed in their phenotypes, their clonogenecity potentials and their immunomodulatory properties in vitro and in vivo. We then compared the enzymatic digestion of the tissue with the techniques of mechanical digestion usable within our operating room. We have demonstrated that these new techniques made it possible to produce the cells of the FVS including MSC, cells particularly interesting for regenerative surgery. In addition, all the laboratory techniques acquired during this work allowed us to investigate the role of liposuction techniques used in plastic surgery on adipose tissue. We have demonstrated by flow cytometry and confocal microscopy, that part of the microvasculature framework is conserved after liposuction. All of these results are in addition to clinical data demonstrating that liposuction of the tissue is a gesture to be more conservative for the tissue and could explain lower rates of complications after contour surgery

Les cellules stromales natives du tissu adipeux (isolement, caractérisation phénotypique et propriétés immunomodulatrices)

Le traitement conservateur du cancer du sein peut aboutir à des séquelles morphologiques importantes. Actuellement, le transfert de tissu adipeux utilisé comme produit de comblement représente souvent la seule possibilité de correction chirurgicale de ces déformations. Ce traitement pose aujourd'hui question du fait de la présence de cellules stromales mésenchymateuses au sein du tissu nommées adipose-derived stromal cells (ADSC). Ces cellules connues pour leurs propriétés immunosuppressives ont montré dans plusieurs études réalisées chez l'animal qu'elles peuvent favoriser la croissance tumorale, sans qu'un lien entre les 2 phénomènes n'ait été formellement démontré. En effet, il s'avère que les connaissances disponibles sur ces ADSC sont essentiellement issues d'études in vitro après une phase de culture cellulaire plus ou moins longue et ainsi les propriétés des cellules stromales mésenchymateuses du tissu adipeux in vivo sont mal connues. Ce travail a donc consisté à caractériser l'hétérogénéité phénotypique du compartiment stromal natif du tissu adipeux en comparaison avec des ADSC cultivées standard. Grâce à une analyse par cytométrie en flux multi-couleurs du tissu adipeux, nous avons isolé deux populations stromales natives distinctes: les ADSC, en grande majorité, mas aussi une autre présentant un phénotype de cellules péricytaires. Ces 2 types cellulaires différaient dans leur expression de marqueurs stromaux mais aussi de molécules permettant les interactions avec les cellules immunitaires. De même, en culture, ces cellules avaient aussi une morphologie différente et les ADSC natives possédaient un potentiel d'autorenouvellement supérieur attesté par des tests de clonogénicité. Enfin, grâce à des tests d'inhibition de la prolifération de lymphocytes T activés en présence de ces cellules, il est apparu que les ADSC natives montraient un pouvoir immunosuppresseur puissant, supérieur à celui des péricytes. Cette inhibition de prolifération dépendait de l'activité de l'enzyme immunosuppressive indoléamine-2,3 dioxygénase dont la synthèse était déclenchée par la présence d'une cytokine inflammatoire, l'interféron gamma. Le tissu adipeux à l'état natif contient donc 2 types de cellules stromales aux propriétés biologiques différentes, en particulier envers le système immunitaire. Leur capacité immunosupressive vis-à-vis des lymphocytes T, qui sont des acteurs majeurs de la surveillance immunitaire cellulaire anti-tumorale les rend potentiellement dangereuses en reconstruction mammaire après cancer, ce qui renforce les recommandations de prudence sur les indications opératoires. Il est donc nécessaire de poursuivre l'amélioration des connaissances sur les cellules stromales natives du tissu adipeux afin de mieux définir la balance bénéfices/risques des transferts graisseux en reconstruction mammaires.RENNES1-BU Santé (352382103) / SudocSudocFranceF

Comment on &quot;Augmentation mammaplasty by superolateral thoracic flap: a case report&quot;

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Vertical Body Lift: Surgical Technique and Comparison with the Inferior Body Lift Technique

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