[Reconstruction in polytraumatized burn patients]. / Rekonstruktion beim polytraumatisierten Brandverletzten.

BACKGROUND: Polytraumatized burn patients represent a rare patient collective and necessitate an individualized treatment concept due to the particular combination of injuries. OBJECTIVE: Against the background of this special injury pattern, especially with deep burns overlying the fracture zone, the question of a specific and interdisciplinary treatment algorithm arises. MATERIAL AND METHODS: This article is based on a PubMed database search and experiences of a trauma center for severely injured burn patients at a university hospital, with presentation of the special therapeutic requirements and goals exemplified by a case report. RESULTS: The evaluation of the literature search and own treatment results comes to the conclusion that the rate and extent of amputations and infections can be reduced by an early and interdisciplinary involvement of the plastic surgeon by early combined fracture stabilization, excision of necrotic tissue and immediate skin grafting. Furthermore, plastic reconstructive procedures enable a functional and esthetic reconstruction with optimized prosthesis fitting. CONCLUSION: Polytraumatized severely burned patients necessitate an interdisciplinary treatment approach, whereby preservation of length, functionality and esthetic appearance of the affected extremities and concurrent avoidance of bone and soft tissue infections have utmost priority.

[Soft tissue plastic surgery for complications in the skull region]. / Weichteilplastische Maßnahmen bei Komplikationen im Schädelbereich.

Tumor resection and trauma may leave devastating defects in the head and neck area complicating and preventing patient rehabilitation; therefore, plastic surgery methods are required which are able to prevent further complications and provide efficient functional and aesthetic reconstruction. In this review article typical cases and the interdisciplinary management of plastic surgery are presented.

The cost of post-burn scarring.

Deep burns lead to scarring and contractures for which there is little or no published data on treatment costs. The purpose of this study was to fill this gap by analysing treatment costs for burn sequelae. To do this, German-DRG for in-patient treatment was collected from the Burn Centre Lower Saxony. DRG-related T95.-coding served as a tool for burn-associated sequelae. Data on scar occurrence, plastic-reconstructive surgery and sick leave were collected by a questionnaire. The findings showed that 44.6% patients reported post-burn scarring and 31% needed surgical intervention. The expected risk for readmission was significantly higher (p=0.0002) with scars compared to without. Significantly higher costs for pressure garments were noted for scarred patients (p=0.04). No differences were found for ointments, silicone dressings or pain medication. Treatment costs for patients with scars were 5.6 times higher compared with no scar assessed by G-DRG. No differences were stated subsuming multiple readmissions for post-burn treatment per individual. Significantly higher costs (p=0.03) were noted for patients with burn sequelae other than scars with regard to individual readmissions. It has been revealed that treatment of scars causes higher costs than for other burn sequelae because of multiple surgical interventions. To reduce post-burn scarring and costs, specialized burn centres provide optimal and state-of-the-art treatment. As well as this, more emphasis should be laid on promoting research for the development of novel anti-scarring therapies.

Les brûlures profondes entraînent des cicatrices et des contractures pour lesquels il n'existe pas de données publiées dés coûts de traitement. Le but de cette étude était de combler cette lacune en analysant les coûts de traitement des séquelles de brûlures. Nous avons recueillies les données sur les séquelles de brûlure du Centre de Brûlés de Basse-Saxe en utilisant un questionnaire. Toutes les informations sur les cicatrices, la chirurgie plastique reconstructive et les congés de maladie ont été recueillies. Les résultats ont montré que 44.6% des patients avaient des cicatrices et 31% ont eu besoin d'une intervention chirurgicale. Le risque de réadmission était significativement plus élevé (p = 0,0002) parmi les patients avec des cicatrices. Pour ces patients les coûts étaient considérablement plus élevés pour les vêtements de compression (p = 0,04) mais, en ce qui concerne les pommades, les pansements siliconés ou les médicaments contre la douleur aucune différence n'a été trouvée. Les coûts de traitement pour les patients porteurs de cicatrices étaient 5,6 fois plus élevés par rapport aux patients sans aucune cicatrice. Les coûts plus élevés (p = 0,03) ont été observés chez les patients avec des séquelles de brûlures autre que cicatrices dues aux réadmissions individuelles. Nous avons noté aussi que le traitement des cicatrices entraîne des coûts plus élevés par rapport aux autres séquelles à cause des interventions chirurgicales multiples. Pour réduire les cicatrices post-brûlures, et donc les coûts, les centres spécialisés fournissent un meilleur traitement. De plus, l'accent devrait être mis sur la recherche pour le développement de nouvelles thérapeutiques anti-cicatrices.

[One-stage defect closure of deperiosted bone and exposed tendons with MATRIDERM® and skin transplantation. Possibilities and limitations]. / Einzeitige Defektdeckung von denudiertem Knochen und freiliegenden Sehnen mittels MATRIDERM® und Spalthaut. Möglichkeiten und Grenzen.

BACKGROUND: Full-thickness skin defects over functional structures (tendons, vessels) or deperiosted bones of the extremities usually require extensive soft tissue reconstruction to cover the defect. A new option for coverage of the defect is the application of MATRIDERM®, a bovine matrix consisting of collagen and elastin, as a neodermis underneath skin transplants. Can this combined one-stage surgical intervention successfully cover deperiosted bone or tendon? PATIENTS AND METHODS: We performed this one-stage procedure in ten patients instead of soft tissue reconstruction. The success of wound coverage with the one-stage method and in combination with skin transplantation for defects generally associated with considerable loss of transplants (deperiosted bones and tendons without paratenons) was determined. RESULTS: In nine of ten patients, complete defect coverage could be achieved. A one-stage wound closure in extensive defects with exposed tendons in four of five locations could be achieved. In deperiosted bone defects the one-stage coverage was only successful in two of six patients. However, complete wound closure could be achieved with a second skin transplantation in a patient with exposed tendon and bone in three of the four locations. CONCLUSION: As a one- or two-stage procedure, MATRIDERM® application with skin transplantation resulted in an effective defect closure without the need for a complex plastic reconstructive procedure. With regard to its functionality it cannot be considered as a substitute for skin flaps. In selected cases MATRIDERM® is an interesting and successful method in plastic reconstructive surgery.

[Stem cells from fatty tissue : A new resource for regenerative medicine?]. / Stammzellen aus dem Fettgewebe : Eine neue Ressource für die regenerative Medizin?

While stem cells derived from the bone marrow are well-known in clinical medicine, fatty tissue as a source of mesenchymal stem cells is still the subject of recent research. However, adipose-derived stem cells (ASC) are not only harvested less invasively, i.e. via minimally invasive liposuction, but also yield higher numbers of multipotent stem cells.Due to cell-cell interactions and also because of the very favorable secretion profile of growth factors and cytokines ASCs displayed an extraordinary regenerative potential in recent preclinical and clinical applications and achieved a significantly better healing in ischemic muscle, heart, and brain insults and in impaired wound healing. ASCs enhanced regeneration in skeletal tissues such as cartilage or bone. They also revealed immunomodulatory effects and improved the clinical status in immunological diseases.In conclusion ASCs are comparable to bone marrow-derived stem cells concerning possible applications in clinical medicine.

Fluid dynamics in bioreactor design: considerations for the theoretical and practical approach.

The following chapter summarizes principles of fluid dynamics in bioreactor design with a focus on mammalian cell-culture systems.

Skin tissue engineering.

The coverage of extensive wounds with viable autologous keratinocytes remains the only option of treatment if autologous donor skin is not obtainable. There is evidence that proliferating keratinocytes, as suspended cells or as a single layer, are adequate for wound closure. Understanding keratinocyte-matrix interactions not only allows us to influence keratinocyte outgrowth, adhesion, and migration, but may also guide us to modify matrix molecules for enhancing keratinocyte take. Further approaches may include the generation of genetically manipulated keratinocytes, which allow the use of an off-the-shelf epidermal replacement. As surgeons, our goal is to help burn patients with the best quality of skin in the shortest time possible. As tissue engineers, we have not achieved the goal of a universal skin product. By continually reviewing the options and using them, we can at least use the proper material in the adequate situation. Because of the limited resources, the need for comparisons of clinical effectiveness and cost are ever more important. As anatomy and physiology of engineered skin substitutes improve, they will become more similar to native skin autografts. Improvement of skin substitutes will result from inclusion of additional cell types (eg, melanocytes) and from modifications of culture media and scaffolds. Skin-substitute materials may be able to stimulate regeneration rather than repair, and tissue-engineered skin may match the quality of split-skin autografts, our present gold standard.

[Skin tissue engineering]. / Gewebeersatz (tissue engineering) von Dermis und Epidermis.

Cultivated epithelial autografts as multilayered, thin sheets represent a common standard in clinically applied tissue engineering substitutes, outnumbering all experimental alternatives. However, the unsatisfying short- and long-term results concerning mechanical stability and scarring require alternatives. The cultivation and transplantation of cultured autologous keratinocytes as a single cell suspension in a fibrin matrix, combined with allogenic skin grafting, has been investigated extensively in athymic nude mice. Wounds can be reliably reepithelialized after a cultivation period of only 14 days. Moreover, the successful combination of keratinocyte fibrin suspension and acellular dermis in an attempt to regenerate full thickness skin defects in a pig model has been demonstrated. The usefulness of subconfluently cultured keratinocytes-which can be harvested very early and are easy to handle-is enhanced by cotransplantation with decellularized dermis.

A quantitative analysis of the effect of insulin-like growth factor-1 infusion during mandibular distraction osteogenesis in rabbits.

AIM: To quantify, by histomorphometry, the effects of local insulin-like growth factor-1 (IGF-1) during mandibular distraction at various rates. METHODOLOGY: Mature rabbits underwent bilateral mandibular corticotomy and distraction lengthening. Recombinant IGF-1 was administered to two groups of rabbits via osmotic infusion pumps. Distraction regimes were as follows: Group A, 1 mm/day for 15 days; Group B, as for A plus IGF-1; Group C, 3 mm/day for 5 days; Group D, as for C plus IGF-1; and Group E, sham-operated controls. After a 28-day consolidation period, rabbits were sacrificed and bone deposition quantified using DEXA scanning, three-point bending, histological examination and sampled for histomorphometric analysis. RESULTS: DEXA scanning and three-point bending failed to detect any effect of distraction rate or of IGF-1 infusion. Histological and histomorphometric analysis suggested 1 mm/day to be the ideal distraction rate, as this was associated with greater osteoblastic activity and consistent bony union. However, IGF-1 infusion significantly enhanced osteoblastic activity at both distraction rates and resulted in bony union when distraction was performed at 3 mm/day. CONCLUSIONS: Distraction osteogenesis at a rate of 1 mm/day provides greater osteogenic stimulus than 3 mm/day. Exogenous IGF-1 has a positive influence on osteoblastic activity during distraction. Its effect is probably minimised by high levels of endogenous IGF-1.

Hypertonic cell shrinkage reduces the K+ conductance of rat colonic crypts.

It has previously been shown in studies of a renal epithelial cell line that nonselective cation (NSC) channels are activated by exposure to hypertonic solution. We have also found such channels in excised patches of colonic crypt cells. They require high Ca2+ activities on the cytosolic side and a low ATP concentration for their activation and have not been recorded from cell-attached patches of colonic crypts. We examine here whether this type of channel is activated by hypertonic cell shrinkage. Bath osmolality was increased by addition of 25, 50 or 100 mmol/l mannitol. Cell-attached and whole-cell patch recordings were obtained from rat base and mid-crypt cells. In whole-cell recordings we found that addition of 50 or 100 mmol/l mannitol depolarized these cells significantly from -78+/-2.0 to -66+/-3.8 mV (n=22) and from -78+/-1. 3 to -56+/-2.6 mV (n=61), respectively, and reduced the whole-cell conductance from 20+/-8.0 to 14+/-6.6 nS (n=7) and from 20+/-3.0 to 9.8+/-1.6 nS (n=19), respectively. In cell-attached patches K+ channels with a single-channel conductance of approximately 16 pS were found in most recordings. The activity of these channels (NxPo, N=number, Po=open channel probability) was reduced from 2.08+/-0.37 to 0.98+/-0.23 (n=15) by the addition of 50 mmol/l mannitol and from 1.75+/-0.26 to 0.77+/-0.20 (n=12) by 100 mmol/l mannitol. No NSC channel activity was apparent in any of these recordings. Previously we have shown that the 16-pS K+ channel is controlled by cytosolic Ca2+ ([Ca2+]i). Therefore we measured [Ca2+]i by the fura-2 method and found that hypertonic solution reduced [Ca2+]i significantly (n=16). These data indicate that exposure of rat colonic crypts to hypertonic solutions does not activate NSC channels; [Ca2+]i falls in hypertonic solution leading to a reduction in the value of K+ channel NxPo, a reduced whole-cell conductance and depolarization of mid-crypt cells. These processes probably assist volume regulation inasmuch as they reduce KCl losses from the cell.

The basolateral Ca2+-dependent K+ channel in rat colonic crypt cells.

Previous studies have indicated that a 16-pS K+ channel (KCca) in the basolateral membrane is responsible for the acetylcholine-induced whole-cell K+ conductance in these cells. In the present study we have examined this channel in excised inside-out patches of the basolateral membrane. Over a wide voltage range this channel showed inward rectification. The Ca2+ sensitivity was very marked, with a Hill coefficient of three and with half-maximal activation at 330 nmol/l. After several minutes most channels showed a slow run-down. Channel activity could be refreshed by addition of ATP (1 mmol/l) to the bath solution. The non-metabolizable derivative 5'-adenylylimidodiphosphate (AMP-PNP) had no such effect. In contrast, it inhibited channel activity by some 50%. ATP and its derivatives had no effect on the Ca2+ sensitivity. Channels activated by ATP were subsequently studied in the presence of alkaline (10 kU/l) or acidic (1 kU/l) phosphatase. Both phosphatases reduced channel activity significantly. These data suggest that the 16-pS K+ channel is directly controlled by cytosolic Ca2+. This regulatory step is probably distal to an activation produced by protein-kinase-C-dependent phosphorylation. As is the case for several other K+ channels, high concentrations of non-metabolizable ATP analogues inhibit this channel.