The treatment of wounds using the body's own resources is a promising approach to support the physiological regenerative process. To advance this concept, we evaluated the effect of nanofat (NF) on ...wound healing. For this purpose, full-thickness skin defects were created in dorsal skinfold chambers of wild-type mice. These defects were filled with NF generated from the inguinal subcutaneous adipose tissue of green fluorescent protein (GFP)
donor mice, which was stabilized using platelet-rich plasma (PRP). Empty wounds and wounds solely filled with PRP served as controls. Wound closure, vascularization and formation of granulation tissue were repeatedly analyzed using stereomicroscopy, intravital fluorescence microscopy, histology and immunohistochemistry over an observation period of 14 days. PRP + NF-treated wounds exhibited accelerated vascularization and wound closure when compared to controls. This was primarily due to the fact that the grafted NF contained a substantial fraction of viable GFP
vascular and lymph vessel fragments, which interconnected with the GFP
vessels of the host tissue. Moreover, the switch from inflammatory M1- to regenerative M2-polarized macrophages was promoted in PRP + NF-treated wounds. These findings indicate that NF markedly accelerates and improves the wound healing process and, thus, represents a promising autologous product for future wound management.
Over the last years, prepectoral implant-based breast reconstruction has undergone a renaissance due to several technical advancements regarding mastectomy techniques and surgical approaches for the ...placement and soft tissue coverage of silicone implants. Initially abandoned due to the high incidence of complications, such as capsular contraction, implant extrusion, and poor aesthetic outcome, the effective prevention of these types of complications led to the prepectoral technique coming back in style for the ease of implant placement and the conservation of the pectoralis muscle function. Additional advantages such as a decrease of postoperative pain, animation deformity, and operative time contribute to the steady gain in popularity. This review aims to summarize the factors influencing the trend towards prepectoral implant-based breast reconstruction and to discuss the challenges and prospects related to this operative approach.
BACKGROUND:Several methods to prepare the recipient site in fat grafting have been proposed in recent decades. However, to date, these procedures have never been reviewed exhaustively. The purpose of ...the present study is to provide a comprehensive overview of the different techniques to prepare the recipient site for fat grafting as they were investigated in preclinical studies, with resulting outcomes and underlying mechanisms of action.
METHODS:The PubMed/MEDLINE database was queried to search for preclinical investigations on the preparation of the recipient site in fat grafting using the following algorithm((recipient site) AND (fat grafting) OR (lipofilling) OR (lipograft)). A priori criteria were applied to review the resulting articles.
RESULTS:Thirteen animal studies met inclusion criteria. Overall, five techniques were identifiedexternal volume expansion, implantation of alloplastic material (silicone sheets), administration of cell-proliferation factors (i.e., vascular endothelial growth factor, adipose tissue–derived stromal vascular fraction, and interleukin-8), ischemia, and microneedling. A positive effect on cellular activity (cell proliferation and angiogenesis) was demonstrated by all studies and achieved with all techniques. Seven of the eight authors who examined this aspect reported enhancement of fat graft survival.
CONCLUSIONS:Improvement of fat grafting surgical outcomes is documented preclinically using different recipient-site preparation techniques, particularly through enhancement of vascularization and soft-tissue expansion. This understanding will lead to further clinical research, especially for those cases where improvement of the recipient site is recommended, such as contracted scars or preirradiated tissues.
Summary Background Fat grafting for primary breast augmentation is growing in popularity due to its autologous properties and its side benefit of removing unwanted fat from other areas, although ...volume gain is unpredictable and patient safety remains unclear. Objective The aim of this study was to provide an evidence-based overview of autologous fat grafting to healthy breast tissue with focus on volume gain, safety and complications. Design A systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Data sources The MEDLINE, Cochrane Library and EMBASE databases were searched for clinical studies on autologous fat grafting to healthy breast tissue within the last 30 years. Data extraction Clinical articles were evaluated for indication, pre- and postoperative work-up, surgical technique, volume gain (efficacy), complications, radiographic changes and oncological safety. The level of evidence was assessed according to the Oxford Centre for Evidence-based Medicine 2011. Results A total of 36 articles involving 1453 patients with a mean follow-up period of 16.3 months (1–156 months) were included. No randomised controlled studies were found. Six percent of the patients undergoing fat grafting to healthy breast tissue experienced major complications requiring a surgical intervention or hospitalisation. Two patients with breast cancer (0.1%) after fat grafting for cosmetic purposes were reported. Average breast volume gain ranged from 55% to 82% relative to the grafted fat volume. Conclusions The prevalence of complications and re-operations in fat grafting to healthy breast tissue compared favourably to implant-based breast augmentation. Although no increased incidence of breast cancer was found, long-term breast cancer screening and the implementation of publicly accessible registries are critically important to proving the safety of fat grafting.
Caloric restriction (CR) is a cost-effective and easy-to-perform approach to counteracting surgical stress. The present study therefore evaluates the tissue-protective effects of a 30% CR in ...musculocutaneous flaps undergoing ischemia. For this purpose, a well-established murine dorsal skinfold chamber model, in combination with random pattern musculocutaneous flaps, was used. C57BL/6N mice were divided at random into a CR group (n = 8) and a control group with unrestricted access to standard chow (n = 8). The CR animals were subjected to a 30% reduction in caloric intake for 10 days before flap elevation. Intravital fluorescence microscopy was carried out on days 1, 3, 5, 7 and 10 after flap elevation to assess the nutritive blood perfusion, angiogenesis and flap necrosis. Subsequently, the flap tissue was harvested for additional histological and immunohistochemical analyses. The CR-treated animals exhibited a significantly higher functional capillary density and more newly formed microvessels within the flap tissue when compared to the controls; this was associated with a significantly higher flap survival rate. Immunohistochemical analyses showed a decreased invasion of myeloperoxidase-positive neutrophilic granulocytes into the flap tissue of the CR-treated mice. Moreover, the detection of cleaved caspase-3 revealed fewer cells undergoing apoptosis in the transition zone between the vital and necrotic tissue in the flaps of the CR-treated mice. These results demonstrate that a CR of 30% effectively prevents flap necrosis by maintaining microperfusion on a capillary level and inhibiting inflammation under ischemic stress. Hence, CR represents a promising novel conditioning strategy for improving the survival of musculocutaneous flaps with random pattern perfusion.
Nowadays, multimodal cancer therapy results in very high survival rates of early-stage breast cancer and microsurgical flap-based breast reconstruction has become safe and reliable, with gradually ...increasing demand because of its durable and aesthetically pleasing results. This study aimed to explore the impact of different flap shaping and inset techniques on patient-reported outcome measures (PROMs) with regard to the aesthetic result in abdominal flap-based breast reconstruction.
A systematic review was performed screening Pubmed, Cochrane Library and Web of Science for original articles reporting flap inset strategies, concomitantly providing PROMs on the aesthetic result.
Of 319 studies identified, six met the inclusion criteria. The studies described different flap rotation options according to the patient's morphology, different inset planes, and avoidance of the monitoring skin paddle, and suggested that a higher flap-to-mastectomy mass ratio was associated with better aesthetic results. In two comparative studies, according to the PROMs (BREAST-Q, Likert scale) and independent observer judgement, both higher patient satisfaction and superior aesthetic results were observed with the newly described techniques.
Emphasis on the aesthetic outcome in terms of breast shape and symmetry, providing an individualized approach of flap inset, considering the contralateral breast's shape and volume, results in higher satisfaction scores.
Vascularized lymph node (VLN) transfer is an emerging strategy to re-establish lymphatic drainage in chronic lymphedema. However, the biological processes underlying lymph node integration remain ...elusive. This study introduces an experimental approach facilitating the analysis of short-term molecular and cellular effects of ischemia/reperfusion on VLN flaps. Lymph node flaps were dissected pedicled on the lateral thoracic vessels in 44 Lewis rats. VLN flaps were exposed to 45 or 120 minutes ischemia by in situ clamping of the vascular pedicle with subsequent reperfusion for 24 hours. Flaps not exposed to ischemia/reperfusion served as controls. Lymph nodes and the perinodal adipose tissue were separately analyzed by Western blot for the expression of lymphangiogenic and angiogenic growth factors. Moreover, morphology, microvessel density, proliferation, apoptosis and immune cell infiltration of VLN flaps were further assessed by histology and immunohistochemistry. Ischemia for 120 minutes was associated with a markedly reduced cellularity of lymph nodes but not of the perinodal adipose tissue. In line with this, ischemic lymph nodes exhibited a significantly lower microvessel density and an increased expression of VEGF-D and VEGF-A. However, VEGF-C expression was not upregulated. In contrast, analyses of the perinodal adipose tissue revealed a more subtle decrease of microvessel density, while only the expression of VEGF-D was increased. Moreover, after 120 minutes ischemia, lymph nodes but not the perinodal adipose tissue exhibited significantly higher numbers of proliferating and apoptotic cells as well as infiltrated macrophages and neutrophilic granulocytes compared with non-ischemic flaps. Taken together, lymph nodes of VLN flaps are highly susceptible to ischemia/reperfusion injury. In contrast, the perinodal adipose tissue is less prone to ischemia/reperfusion injury.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In the murine model system of adipogenesis, the CD24 cell surface protein represents a valuable marker to label undifferentiated adipose progenitor cells. Indeed, when injected into the residual fat ...pads of lipodystrophic mice, these CD24 positive cells reconstitute a normal white adipose tissue (WAT) depot. Unluckily, similar studies in humans are rare and incomplete. This is because it is impossible to obtain large numbers of primary CD24 positive human adipose stem cells (hASCs). This study shows that primary hASCs start to express the glycosylphosphatidylinositol (GPI)-anchored CD24 protein when cultured with a chemically defined medium supplemented with molecules that activate the Hedgehog (Hh) signaling pathway. Therefore, this in vitro system may help understand the biology and role in adipogenesis of the CD24-positive hASCs. The induced cells’ phenotype was studied by flow cytometry, Real-Time Quantitative Polymerase Chain Reaction (RT-qPCR) techniques, and their secretion profile. The results show that CD24 positive cells are early undifferentiated progenitors expressing molecules related to the angiogenic pathway.
After a burn injury, superficial partial-thickness burn wounds may progress to deep partial-thickness or full-thickness burn wounds, if kept untreated. This phenomenon is called secondary burn wound ...progression or conversion. Burn wound depth is an important determinant of patient morbidity and mortality. Therefore, reduction or even the prevention of secondary burn wound progression is one goal of the acute care of burned patients. The objective of this study was to review preclinical approaches evaluating therapies to reduce burn wound progression. A systematic review of experimental approaches in animals that aim at reducing or preventing secondary burn wound progression was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta Analysis (PRISMA) guidelines. The selected references consist of all the peer-reviewed studies performed in vivo in animals and review articles published in English, German, Italian, Spanish, or French language relevant to the topic of secondary burn wound progression. We searched MEDLINE, Cochrane Library, and Google Scholar including all the articles published from the beginning of notations to the present. The search was conducted between May 3, 2012 and December 26, 2013. We included 29 experimental studies in this review, investigating agents that maintain or increase local perfusion conditions, as well as agents that exhibit an anti-coagulatory, an anti-inflammatory, or an anti-apoptotic property. Warm water, simvastatin, EPO, or cerium nitrate may represent particularly promising approaches for the translation into clinical use in the near future. This review demonstrates promising experimental approaches that might reduce secondary burn wound progression. Nevertheless, a translation into clinical application needs to confirm the results compiled in experimental animal studies.
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