[Microvascular effects of burn plasma transfer and therapeutic options in a rat model]. / Mikrovaskuläre Effekte des Verbrennungsplasma-transfers und therapeutische Optionen im Tiermodell.

INTRODUCTION: Thermal injuries with more than 20% of burned body surface area (BSA) lead to systemic shock with generalised oedema in addition to local tissue destruction. This condition, known as burn injury, is caused by immunmodulative mediators whose individual significance is not known in detail. We present an experimental model where plasma of burned animals (burn plasma) is transmitted to healthy animals, to trigger burn iniury without performing direct burn trauma. MATERIAL AND METHODS: The systemic oedema is measured by extravasation of fluorescent albumin in mesenterial venules of Wistar rats. In addition, leukocyte-endothelial interactions ("leukocyte rolling and sticking") is examined. RESULTS: The systemic capillary leak is induced by both direct thermal trauma as well as by infusion of burn plasma. This is evident even after plasma dilution (1% in Ringer's lactate) of the burn plasma. In addition, topical therapy for burned animals (donors) with cerium nitrate led to a significant reduction of plasma extravasation in receiver animals. In addition, systemic antioxidant therapy with high-dose vitamin C of receiver animals, led to a significant reduction of the capillary leak. Leukocyte-endothelial interactions are not significantly affected in either case. CONCLUSION: In summary, for the first time a reliable model of burn injury has been established, which eliminates mediator-independent effects. In addition, our studies show that antioxidant therapy with high doses of vitamin C and topical treatment with cerium nitrate both reduce the systemic capillary leak in receiver animals. Their positive influence could therefore soon be integrated in clinical treatment algorithms.

[Microsurgical techniques for breast reconstruction]. / Mikrochirurgische Brustrekonstruktion.

The results of a survey show that less then 10% of affected women are aware of the various options for breast reconstruction. However, in modern medicine the correlation between emotional well-being and physical health has been established as an important factor. The first successful autologous breast reconstruction was performed by Czerny in 1895. After introduction of silicon implants for breast augmentation this method was also increasingly used for breast reconstruction. Worldwide most reconstructions are implant based, however the symptomatic rate of capsular contracture is up to 38% and the reoperation rate for implant-based reconstruction and radiotherapy up to 35%. Autologous reconstruction procedures have a significantly lower complication rate. This article describes the modern microsurgical techniques for breast reconstruction and discusses the indications and achievable results.

The antimicrobial effect of acetic acid--an alternative to common local antiseptics?

Acetic acid has been commonly used in medicine for more than 6000 years for the disinfection of wounds and especially as an antiseptic agent in the treatment and prophylaxis of the plague. The main goal of this study was to prove the suitability of acetic acid, in low concentration of 3%, as a local antiseptic agent, especially for use in salvage procedures in problematic infections caused by organisms such as Proteus vulgaris, Acinetobacter baumannii or Pseudomonas aeruginosa. This study was designed to compare the in vitro antimicrobial effect of acetic acid with those of common local antiseptics such as povidone-iodine 11% (Betaisodona), polyhexanide 0.04% (Lavasept), mafenide 5% and chlohexidine gluconate 1.5% cetrimide 15% (Hibicet). Former studies suggest the bactericidal effect of acetic acid, but these data are very heterogeneous; therefore, a standardised in vitro study was conducted. To cover the typical bacterial spectrum of a burn unit, the following Gram-negative and Gram-positive bacterial strains were tested: Escherichia coli, P. vulgaris, P. aeruginosa, A. baumannii, Enterococcus faecalis, Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus (MRSA) and beta-haemolytic Streptococcus group A and B. The tests showed excellent bactericidal effect of acetic acid, particularly with problematic Gram-negative bacteria such as P. vulgaris, P. aeruginosa and A. baumannii. The microbiological spectrum of acetic acid is wide, even when tested at a low concentration of 3%. In comparison to our currently used antiseptic solutions, it showed similar - in some bacteria, even better - bactericidal properties. An evaluation of the clinical value of topical application of acetic acid is currently underway. It can be concluded that acetic acid in a concentration of 3% has excellent bactericidal effect and, therefore, seems to be suitable as a local antiseptic agent, but further clinical studies are necessary.

[New concepts in local burn wound therapy]. / Neue Konzepte in der Oberflächentherapie bei Verbrennungswunden.

Local burn wound care represents an integral part in the treatment of burn victims. A primary treatment goal is to prevent superficial infections, which can lead to life-threatening bacteraemia and sepsis. Secondary goals include improvement of functional and aesthetic outcome of the regenerating skin or scar tissue. Within the last few years numerous innovations have been evolved and some have already been incorporated into the clinical routine. In line with this, the first mid-term studies can be found in the literature. For instance, a hydrosurgical system can now be used for debridement and novel skin substitutes like Suprathel and Matriderm are commercially available. This review article summarises the most recent innovations in local burn wound care and puts them into a scientific perspective.

An old dream revitalised: preconditioning strategies to protect surgical flaps from critical ischaemia and ischaemia-reperfusion injury.

The prevention of ischaemia and the adequate restitution of blood flow to ischaemic tissue are pivotal to halt the progression of cellular injury associated with decreased oxygen and nutrient supply. Accordingly, the search for novel strategies which aim at preventing ischaemia-reperfusion-induced tissue damage is still of major interest in flap surgery. Preconditioning represents an elegant approach to render the tissue more resistant against deleterious ischaemic insults. For many decades, 'surgical delay' has been the standard method of tissue preconditioning. During the last 10 years, ischaemic preconditioning was added to the repertoire of plastic surgeons to protect flaps from ischaemic necrosis. The invasiveness and expenditure of time of these procedures, however, have always been major drawbacks, hindering a wide distribution in clinical practice. Consequently, the motivation has all along been to further refine and simplify protective strategies. Recent experimental studies have now shown that efficient protection from ischaemic necrosis can also be achieved by remote preconditioning or pretreatment with chemical agents and growth factors, which mimic the action of surgical delay and ischaemic preconditioning. In addition, the local application of unspecific stressors, including both heating and cooling, have been shown to effectively improve flap microcirculation and, thus, tissue survival. In view of successful translational research, it is now time that the efficacy of these novel preconditioning procedures is proven in prospective randomised clinical trials.

Consensus meeting on "Relevance of parenteral vitamin C in acute endothelial dependent pathophysiological conditions (EDPC)".

The 22 supersetnd Hohenheim Consensus Workshop took place in at the University of Stuttgart-Hohenheim. The subject of this conference was vitamin C and its role in the treatment of endothelial dysfunction. Scientists, who had published and reviewed scientific and regulatory papers on that topic were invited, among them basic researchers, toxicologists, clinicians and nutritionists. The participants were presented with eleven questions, which were discussed and answered at the workshop, with the aim of summarising the current state of knowledge. The explicatory text accompanying the short answers was produced and agreed on after the conference and was backed up by corresponding references. The therapeutic relevance of administration of the physiological antioxidant vitamin C in high parenteral doses in Endothelial Dependent Pathophysiological Conditions (EDPC) was discussed. Endothelial dysfunction is defined as including disturbed endothelial dependant relaxation of resistance vessels, breakdown of the microvascular endothelial barrier and/or loss of anti-adhesive function. It occurs in severe burn injury, intoxications, acute hyperglycemia, sepsis, trauma, and ischemic-reperfusion tissue injury and is induced by oxidative stress. Reduced plasma ascorbate levels are a hallmark of oxidative stress and occur in severe burns, sepsis, severe trauma, intoxication, chemotherapy/radiotherapy and organ transplantation. Vitamin C directly enhances the activity of nitric oxide synthase, the acyl CoA oxidase system and inhibits the actions of proinflammatory lipids. There is experimental evidence that parenteral high-dose vitamin C restores endothelial function in sepsis. In vitro, supraphysiological concentrations (> 1mM) of ascorbate restore nitric oxide bioavailability and endothelial function. Only parenterally, can enough vitamin C be administered to combat oxidative stress. There is no evidence that parenteral vitamin C exerts prooxidant effects in humans. Theoretical concerns in relation to competitive interactions between vitamin C and glucose cellular uptake are probably only relevant for oxidised vitamin C (dehydroascorbate).