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Dive into the research topics where A. Groger is active.

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Featured researches published by A. Groger.


Burns | 2008

Retrospective analysis of tissue expansion in reconstructive burn surgery: Evaluation of complication rates

Ahmet Bozkurt; A. Groger; D. O’Dey; F. Vogeler; Andrzej Piatkowski; P.Ch. Fuchs; Norbert Pallua

Tissue expansion is a widespread and accepted concept in reconstructive surgery, but is also afflicted with a variety of complications. In burn patients, this technique allows large areas of burn scar to be replaced by tissue of similar texture and colour to the defect. We retrospectively reviewed our results with tissue expanders in 57 burn patients over a period of 8 years including 102 expanders. Statistical analyses revealed a significant influence of the anatomical region (p=0.0156; Chi-square=15.6811) and of the expander volume (p=0.0417; Chi-square=18.8918) on the failure rate outcome. Factors such as age, gender, number of expanders per patient and shape of expander showed no statistical correlation in relation to the failure rate (p-values >0.05). Furthermore, we present a short review of the recent literature of complications after tissue expansion. The presented study may help to draw attention on different aspects in tissue expansion and critically focus on each step of the tissue expansion procedure from implantation over inflation to explantation.


Shock | 2007

Cortisol in severely burned patients: investigations on disturbance of the hypothalamic-pituitary-adrenal axis.

P.C. Fuchs; A. Groger; Ahmet Bozkurt; Daniel Johnen; Timm P. Wolter; Norbert Pallua

Thermal injuries of more than 20% of body surface area lead to conditions resembling a severe systemic inflammatory response syndrome, such as in septic shock. It has been shown that septic shock may lead to disturbances in cortisol metabolism and balance of the hypothalamic-pituitary-adrenal axis. To investigate whether such a disturbance also occurs in the very early stages of systemic inflammatory response syndrome in burned patients, we performed 20 corticotropin-releasing hormone tests on day 1 after admission to our unit. In 7 of 20 patients, a disturbance of cortisol secretion could be demonstrated. Four patients developed adrenal insufficiency. The correlation between the abbreviated burn severity index and the risk of developing adrenal insufficiency was significant (P = 0.008). We observed a higher mortality rate in adrenally insufficient patients; however, because of the small patient number, we were not able to prove this observation with a statistical significant correlation (P = 0.11). Our findings indicate that temporary adrenal insufficiency occurs in the early stages of severe injury. Further investigations will have to be performed to clarify whether such patients benefit from cortisol replacement.


Inhalation Toxicology | 2008

The diversity of carbon monoxide intoxication: medical courses can differ extremely-a case report.

Gerrit Grieb; A. Groger; Ahmet Bozkurt; Ingo Stoffels; Andrzej Piatkowski; Norbert Pallua

Intoxications of carbon monoxide are frequent and may affect systems of lung, heart, and brain, leading to coma or death in severe cases. In this case report, we present two adults who were exposed to the same source of carbon monoxide for a nearly equal period of time. The first patient, a 28-yr-old female, developed massive symptoms including loss of consciousness, respiratory insufficiency, and lung complications resulting in severe lung edema. She was intubated and ventilated for 43 h before she recovered and could be extubated. The other patient, a 22-yr-old male, recovered immediately and was fully orientated after applying an oxygen mask at the scene of incident. After admission to the intensive care unit, both patients showed an equally high serum level of COHb and received hyperbaric oxygen therapy. The male patient was discharged from hospital the following day, whereas the female remained in intensive care for 4 days. A satisfactory explanation could not be found for the difference in the clinical progression in these two cases. However, this case report shows that, in spite of almost equal serum levels of carboxyhemoglobin (COHb), the individual symptoms can vary extremely. Therefore, a detailed medical history, physical examination, supporting diagnostic measures, and the continuous monitoring of vital parameters in a specialized clinic are essential.


Burns | 2010

The mobilisation of mononuclear cells and endothelial progenitor cells after burn injury in a porcine model.

A. Groger; Andrzej Piatkowski; Gerrit Grieb; Timm P. Wolter; P.C. Fuchs; Norbert Pallua

BACKGROUND Mononuclear blood cells (MNCs) consist of heterogeneous cell populations, for example, CD34+ cells and endothelial progenitor cells (EPCs). EPCs are involved in vasculogenesis, but little is known about their role during burn trauma. AIM This study investigates the role of MNCs and their subpopulations during and after burn injury in an experimental porcine setting. METHODS Eighteen 8-week-old German land pigs were scalded by immersion in 70 degrees C hot water for 3 min, resulting in a 30% total body surface area (TBSA) full-thickness burn. Vascular endothelial growth factor (VEGF) serum concentrations and MNC, EPC and CD34+ cell counts were measured at eight different time points up to 48 h following trauma. RESULTS The experimental porcine setting made it possible to determine the cell counts of MNCs, EPCs and CD34+ cells directly during burn trauma, which has not been described before. The data revealed a fulminant drop in MNC and EPC during burn trauma, whereas the CD34+ cell fraction rose. Besides significant changes in the VEGF serum concentration, a correlation between VEGF and EPC was also observed. CONCLUSION The results show that MNCs and their subpopulations are significantly affected by burn trauma and underpin their potential diagnostic and therapeutic importance during and after burn injury.


Burns | 2009

The extent of thermal injury affects fractions of mononuclear cells

Andrzej Piatkowski; A. Groger; Mira Pantel; Ahmet Bozkurt; Paul Fuchs; Norbert Pallua

BACKGROUND The mononuclear cell (MNC) fraction contains a variety of cell types, including stem cells such as endothelial progenitor cells (EPCs). EPC can rapidly revascularise ischaemic areas, but their role in burns is unclear. AIM This study investigates how thermal injury to the skin might influence mononuclear cells, CD34(+) cells and circulating EPC. METHODS The study group comprised 17 people with burns and 17 age-matched controls. Blood samples were collected at five different time points during the first 5 days of hospitalisation. Clinical parameters and scores were documented as well as cell counts for MNC, CD34(+) cells and EPC. Counts were quantified by fluorescence-activated cell sorting. Serum was tested for vascular endothelial growth factor VEGF(165) by ELISA. RESULTS All cell populations displayed significant, differing changes in counts and percentages after burn. These effects varied markedly over time and expressed different patterns if clinical scores were subjected to significance testing. EPC counts were significantly lowered in cases with fatal outcome. CONCLUSION Burn affects the numbers of circulating MNC, CD34(+) and EPC. These time-dependent changes imply involvement of these cell groups in the trauma. EPC counts seem to be a predictive factor for outcome of cases of severe burn.


Scandinavian Journal of Plastic and Reconstructive Surgery and Hand Surgery | 2007

Fibromatosis-like myofibroblastic tumour of forearm: case report and interdisciplinary management.

A. Groger; Ahmet Bozkurt; Andrzej Piatkowski; Alberto Perez-Bouza; Paul Fuchs; Norbert Pallua

We present a rare case of a fibromatosis-like myofibroblastic tumour of the forearm with infiltration of muscular, neural, and vascular structures. This is a rare and transitional type of myofibroblastic tumour, and we emphasise important aspects of diagnosis, clinical features, interdisciplinary management, and differential diagnoses.


Archive | 2004

Eigenschaften und biologische Wirkung von modifizierten Kollagen-Matrizes zur Verbesserung der Angiogenese

A. Groger; Gerrit Grieb; Guy Steffens; Ernst Magnus Noah; Norbert Pallua

Soft tissue defects represent a challenge in plastic surgery. Therefore many research efforts have focused onto materials that support tissue formation and especially angiogenesis. But still most of the commercially available products can serve only as temporary coverage due to the small angiogenic potency.


Biomaterials | 2008

Assessment of stem cell/biomaterial combinations for stem cell-based tissue engineering.

Sabine Neuss; Christian Apel; Patricia Buttler; Bernd Denecke; Anandhan Dhanasingh; Xiaolei Ding; Dirk Grafahrend; A. Groger; Karsten Hemmrich; Alexander Herr; Willi Jahnen-Dechent; Svetlana Mastitskaya; Alberto Perez-Bouza; Stephanie Rosewick; Jochen Salber; Michael Wöltje; Martin Zenke


Differentiation | 2007

Plasticity of human adipose stem cells to perform adipogenic and endothelial differentiation

M. Wosnitza; Karsten Hemmrich; A. Groger; Steffen Gräber; Norbert Pallua


Journal of Neuroscience Methods | 2008

Evaluation of functional nerve recovery with Visual-SSI—A novel computerized approach for the assessment of the static sciatic index (SSI)

Ahmet Bozkurt; Sacha Tholl; Sarah Wehner; Julian Tank; Miriam M. Cortese; Dan mon O'Dey; Ronald Deumens; Franz Lassner; Frank Schügner; A. Groger; Ralf Smeets; Gary Brook; Norbert Pallua

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P.C. Fuchs

RWTH Aachen University

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Paul Fuchs

RWTH Aachen University

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