Force distribution of a cylindrical grip differs between dominant and nondominant hand in healthy subjects.

INTRODUCTION: Grip strength and load distribution of the hand are important parameters for evaluating hand function. The purpose of this study was to analyze and compare grip force and load distribution of dominant and nondominant hands in right-handed healthy subjects. METHODS: Gripping measurements were performed on 40 healthy right-handed subjects using a cylindrical gripping device. Two different cylinders with circumferences of 150 mm (small cylinder) and 200 mm (large cylinder), respectively, were used for the measurements. Subjects were assigned to either the small or the large cylinder with respect to their hand size. Maximum and mean force applied during three intervals of gripping as well as the percent contribution of each digit, thenar, and hypothenar in relation to the total load applied were acquired. Values of dominant and nondominant hands were compared. RESULTS: Percent contribution of mean grip strength differed for the thumb (p = 0.007), ring finger (p < 0.001), little finger (p = 0.047), and palm (p < 0.001). Comparing the dominant and nondominant side, the dominant hand showed a lower contribution of the thumb, ring finger, and little finger, but a higher contribution of the palm. When analyzing maximum grip, percent contribution of the small fingers was equal between dominant and nondominant side (p = 0.1). Differences between dominant and nondominant thumb, ring finger, and palm persisted (p = 0.007, p = 0.001, p = 0.005, respectively). No differences could be shown for the index finger, middle finger, thenar, and hypothenar when analyzing both mean and maximum force. DISCUSSION AND CONCLUSION: Percent contribution of the thumb and the fingers to total grip strength differed between dominant and nondominant hands with a change in distribution when assessing maximum grip force. In right-handed subjects, thumb and ring finger have important roles during gripping.

Mesenchymal stem cells and myoblast differentiation under HGF and IGF-1 stimulation for 3D skeletal muscle tissue engineering.

BACKGROUND: Volumetric muscle loss caused by trauma or after tumour surgery exceeds the natural regeneration capacity of skeletal muscle. Hence, the future goal of tissue engineering (TE) is the replacement and repair of lost muscle tissue by newly generating skeletal muscle combining different cell sources, such as myoblasts and mesenchymal stem cells (MSCs), within a three-dimensional matrix. Latest research showed that seeding skeletal muscle cells on aligned constructs enhance the formation of myotubes as well as cell alignment and may provide a further step towards the clinical application of engineered skeletal muscle. In this study the myogenic differentiation potential of MSCs upon co-cultivation with myoblasts and under stimulation with hepatocyte growth factor (HGF) and insulin-like growth factor-1 (IGF-1) was evaluated. We further analysed the behaviour of MSC-myoblast co-cultures in different 3D matrices. RESULTS: Primary rat myoblasts and rat MSCs were mono- and co-cultivated for 2, 7 or 14 days. The effect of different concentrations of HGF and IGF-1 alone, as well as in combination, on myogenic differentiation was analysed using microscopy, multicolour flow cytometry and real-time PCR. Furthermore, the influence of different three-dimensional culture models, such as fibrin, fibrin-collagen-I gels and parallel aligned electrospun poly-ε-caprolacton collagen-I nanofibers, on myogenic differentiation was analysed. MSCs could be successfully differentiated into the myogenic lineage both in mono- and in co-cultures independent of HGF and IGF-1 stimulation by expressing desmin, myocyte enhancer factor 2, myosin heavy chain 2 and alpha-sarcomeric actinin. An increased expression of different myogenic key markers could be observed under HGF and IGF-1 stimulation. Even though, stimulation with HGF/IGF-1 does not seem essential for sufficient myogenic differentiation. Three-dimensional cultivation in fibrin-collagen-I gels induced higher levels of myogenic differentiation compared with two-dimensional experiments. Cultivation on poly-ε-caprolacton-collagen-I nanofibers induced parallel alignment of cells and positive expression of desmin. CONCLUSIONS: In this study, we were able to myogenically differentiate MSC upon mono- and co-cultivation with myoblasts. The addition of HGF/IGF-1 might not be essential for achieving successful myogenic differentiation. Furthermore, with the development of a biocompatible nanofiber scaffold we established the basis for further experiments aiming at the generation of functional muscle tissue.

[Surgical treatment of burns : Special aspects of pediatric burns]. / Chirurgische Behandlung von Verbrennungen : Besonderheiten bei Kindern.

BACKGROUND: Treatment of pediatric burn patients is very important because of the sheer frequency of burn wounds and the possible long-term ramifications. Extensive burns need special care and are treated in specialized burn centers. OBJECTIVES: The goal of this work is to present current standards in burn therapy and important innovations in the treatment of burns in children so that the common and small area burn wounds and scalds in pediatric patients in day-to-day dermatological practice can be adequately treated. MATERIALS AND METHODS: Analysis of current literature, discussion of reviews, incorporation of current guidelines. RESULTS: Burns in pediatric patients are common. Improvement of survival can be achieved by treatment in burn centers. The assessment of burn depth and area is an important factor for proper treatment. We give an overview for outpatient treatment of partial thickness burns. New methods may result in better long-term outcome. CONCLUSIONS: Adequate treatment of burn injuries considering current literature and guidelines improves patient outcome. Rational implementation of new methods is recommended.

A hundred patients with vertical rectus abdominis myocutaneous (VRAM) flap for pelvic reconstruction after total pelvic exenteration.

PURPOSE: We analysed the outcomes of a series of 100 consecutive patients with anorectal cancer with neoadjuvant radiochemotherapy and abdominoperineal exstirpation or total pelvic exenteration, who received a transpelvic vertical rectus abdominis myocutaneous (VRAM) flap for pelvic, vaginal and/or perineal reconstruction and compare a cohort to patients without VRAM flaps. METHODS: Within a 10-year period (2003-2013) in our institution 924 patients with rectal cancer stage y0 to y IV were surgically treated. Data of those 100 consecutive patients who received a transpelvic VRAM flap were collected and compared to patients without flaps. RESULTS: In 100 consecutive patients with transpelvic VRAM flaps, major donor site complications occurred in 6 %, VRAM-specific perineal wound complications were observed in 11 % of the patients and overall 30-day mortality was 2 %. CONCLUSIONS: The VRAM flap is a reliable and safe method for pelvic reconstruction in patients with advanced disease requiring pelvic exenteration and irradiation, with a relatively low rate of donor and recipient site complications. In this first study, to compare a large number of patients with VRAM flap reconstruction to patients without pelvic VRAM flap reconstruction, a clear advantage of simultaneous pelvic reconstruction is demonstrated.

[Extended skin and soft tissue defects after vascular wounds: plastic surgical concepts]. / Ausgedehnte Gewebedefekte bei vaskulären Wunden--Möglichkeiten der plastischen Chirurgie.

INTRODUCTION: Skin and soft-tissue defects at the ischaemic lower extremity represent a challenging condition. Major amputations can be prevented by optimised surgical therapy. The aim of any intervention is the revascularisation and defect reconstruction of the extremity. METHODS: This article aims to provide a structured overview on up-to-date therapeutic strategies and differentiated indications for certain surgical flaps in combination with bypass surgery for the treatment of chronic "vascular" wounds. RESULTS: Optimised conservative wound therapy, skin grafts, pedicled or microsurgical free flaps in combination with vascular bypasses can be applied to salvage ischaemic extremities. These operations require an interdisciplinary cooperation between vascular surgeons and plastic surgeons. DISCUSSION: These procedures should accordingly only be performed in specialised high-volume centres with significant vascular surgical and microsurgical expertise.

[Registry Research Funding of the German Society of Plastic, Reconstructive and Aesthetic Surgery (DGPRÄC) and Research Funding Report 2021/2022]. / Register Forschungsförderung der Deutschen Gesellschaft für Plastische, Rekonstruktive und Ästhetische Chirurgie (DGPRÄC) und Forschungsförderungs-Bericht 2021/2022.

BACKGROUND: Research is an integral part of academic medicine. In plastic surgery, it sets the course for innovations in the specialty. The purpose of this study is to present the research performance of plastic surgeons in Germany for the period 2021/2022 and to compare it with previous periods. MATERIALS AND METHODS: The directors of plastic surgical academic institutions reported all requested/approved and rejected research applications to public, non-public and industrial funding organizations. Data was gathered within an established online database. In addition, the DFG´s public database GEPRIS was screened for plastic surgical research grants. Data was also collected regarding research infrastructure and organization at the participating centers. RESULTS: 105 applications were reported to 54 different funding agencies from 20 plastic surgery centers. 37 funding applications were submitted to the major public funding agencies DFG, BMBF, BMWi, BMG, BMVg, G-BA and EU. Of these, 59,5% (22/37) were DFG, 13,5% (5/37) each BMBF and EU, 5,4% (2/37) BMWi, and 2,7% (1/37) each BMG, BMVg, and G-BA applications. The average funding volume of these proposals was 401,515 euros. Approved DFG proposals were most frequently assigned to the review board 205-27 Orthopedics, Trauma Surgery, Reconstructive Surgery (n=10/16, 62,5%). Over time, the research registry shows an increase in the number of proposals in general and those granted. 70,0% (14/20) of participating sites had their own experimental research laboratory, while only 40,0% (8/20) had their own clinical trial center. CONCLUSION: The 2021/2022 Research Funding Report once again highlights the impressive research accomplishments of the plastic surgery community.

Axially vascularized bone substitutes: a systematic review of literature and presentation of a novel model.

INTRODUCTION: The creation of axially vascularized bone substitutes (AVBS) has been successfully demonstrated in several animal models. One prototypical indication is bone replacement in patients with previously irradiated defect sites, such as in the mandibular region. The downside of current clinical practice, when free fibular or scapular grafts are used, is the creation of significant donor site morbidity. METHODS: Based on our previous experiments, we extended the creation of an arterio-venous loop to generate vascularized bone substitutes to a new defect model in the goat mandibula. In this report, we review the literature regarding different models for axially vascularized bone substitutes and present a novel model demonstrating the feasibility of combining this model with synthetic porous scaffold materials and biological tissue adhesives to grow cells and tissue. RESULTS: We were able to show the principal possibility to generate axially vascularized bony substitutes in vivo in goat mandibular defects harnessing the regenerative capacity of the living organism and completely avoiding donor site morbidity. CONCLUSION: From our findings, we conclude that this novel model may well offer new perspectives for orthopedic and traumatic bone defects that might benefit from the reduction of donor site morbidity.

Leaving the perfusion zones? Individualized flap design in 100 free DIEP and ms-TRAM flaps for autologous breast reconstruction using indocyanine green angiography.

BACKGROUND: There is still no consensus regarding the ideal zoning in abdominal-based autologous breast reconstruction using free DIEP or ms-TRAM flaps. In particular, the perfusion pattern of the flap according to the number of perforators used and their location remains controversial. In this study, the perfusion of free DIEP and ms-TRAM flaps is assessed intraoperatively and analyzed with regard to different perfusion patterns. METHODS: A retrospective analysis of 100 free flaps for breast reconstruction was performed. Following complete flap harvest, we used indocyanine green angiography for perfusion analysis. By applying two different contour levels, DIEP flaps with lateral or medial perforators and ms-TRAM flaps were assessed for their respective perfusion patterns. RESULTS: No statistically significant differences were found in the size of the perfusion area between the different flap types when applying the contour level of 20% (p >0.05). For the contour level of 30%, however, statistically significant differences were found between DIEP flaps with medially or laterally located perforators (p = 0.038). Laterally or medially located perforators in DIEP flaps showed no significant differences in their ability to cross the midline (contour level 20%, p = 0.068; contour level 30%, p = 0.058). CONCLUSION: Considering the variability of the perfusion of the abdominal wall and the high sensitivity of indocyanine green angiography for their detection, the abdominal zonings play a minor role. By using intraoperative indocyanine green angiography, a precise and patient-specific free flap surgery for autologous breast reconstruction is possible independent of perforator location.

The effect of hypergravity, hyperbaric pressure, and hypoxia on osteogenic differentiation of adipose stem cells.

Human adipose stem cells (ASCs) hold great potential for regenerative medicine approaches, including osteogenic regeneration of bone defects, that fail to heal autonomously. Osteogenic differentiation of stem cells is dependent on the stimulation of biophysical factors. In the present study, the effects of hypergravity, hypoxia, and hyperbaric treatment were investigated on adipose stem cell (ASC) metabolic activity, quantified by PrestoBlue conversion, and cell numbers, evaluated by crystal violet staining. Osteogenic differentiation was assessed by alkaline phosphatase (ALP) activity and cresolphthalein staining of calcium deposition. Differentiation was performed for 12 days, which was accompanied by periodical stimulation. Increasing gravity forces up to 50x g did not affect ASC viability, but it enhanced osteogenic markers with a strongest effect between 20 and 30x g. Hyperbaric stimulation at 3 bar decreased ASC cell numbers but increased ALP activity and calcium deposition. Hypoxia at 8 % atmospheric oxygen did not affect ASC proliferation, while cell numbers were reduced at 3 % oxygen. Furthermore, hypoxic conditions produced opposing results on osteogenic markers, as ALP activity increased whereas cresolphthalein staining decreased upon stimulation. These data demonstrated that intermittent short duration of basal physical or chemical impulses interfere with the osteogenic differentiation of ASCs. Our findings could be of specific relevance in ASC based therapies for regenerative medicine and bone tissue engineering approaches.

The impact of VEGF and bFGF on vascular stereomorphology in the context of angiogenic neo-arborisation after vascular induction.

The aim of this in vivo study was to gather quantitative information on the three-dimensional morphology of a new vascular network under the influence of angioactive growth factors. For this purpose, the arteriovenous loop model was used in 10 Lewis rats to generate a bioartificial vascular assembly by means of vascular induction. In this model, an isolated organoid is created in the medial thigh of the animal by methods of tissue engineering. A fibrin gel containing vascular endothelial growth factor (VEGF(165)) and basic fibroblastic growth factor (bFGF) was used as a matrix in the effect group (GF+). Fibrin matrices devoid of growth factors were used as controls (GF-). A microvascular replica of the organoid was created by means of corrosion casting and the network was investigated on stereo-paired images obtained by scanning electron microscopy. Vectors of intercapillary and interbranching distances as well as the diameter of the pores in the intussusceptive events diameter and the ratio of sprouting versus intussusceptive angiogenic events were compared in the two groups. The results were highly significant. In the GF+ group there were more profound three-dimensional morphological traits of angiogenesis, whereas advanced neovascularisation in the phase of remodelling was demonstrated by a higher incidence of intussusception, compared to control. These results illustrate the importance of morphological studies with focus on the generation of three-dimensional vascular networks.

De novo generation of an axially vascularized processed bovine cancellous-bone substitute in the sheep arteriovenous-loop model.

BACKGROUND/AIMS: The aim of this study was to generate an axially vascularized bone substitute. The arteriovenous (AV)-loop approach in a large-animal model was applied in order to induce axial vascularization in a clinically approved processed bovine cancellous bone (PBCB) matrix of significant volume with primary mechanical stability and to assess the course of increasing axial vascularization. METHODS: PBCB constructs were implanted into 13 merino sheep together with a microsurgically created AV loop in an isolation chamber. The vascularization process was monitored by sequential magnetic resonance imaging (MRI) scans. Explants were subjected to micro-computed tomography (micro-CT) analysis, histomorphometry and immunohistochemistry for CD31 and CD45. RESULTS: Increasing axial vascularization in PBCB constructs was quantified by histomorphometry and visualized by micro-CT scans. Intravital sequential MRI scans demonstrated a significant progressive increase in perfused volume within the matrices. Immunohistochemistry confirmed endothelial lining of newly formed vessels. CONCLUSION: This study demonstrates successful axial vascularization of a clinically approved, mechanically stable bone substitute with a significant volume by a microsurgical AV loop in a large-animal model. Thus microsurgical transplantation of a tissue-engineered, axially vascularized and mechanically stable bone substitute with clinically relevant dimensions may become clinically feasible in the future.

[Registry Research Funding of the German Society of Plastic, Reconstructive and Aesthetic Surgeons (DGPRÄC) and Research Funding Report 2019/2020]. / Register Forschungsförderung der Deutschen Gesellschaft der Plastischen, Rekonstruktiven und Ästhetischen Chirurgen (DGPRÄC) und Forschungsförderungsbericht 2019/2020.

BACKGROUND: Since 2015/16 the DGPRÄC collects, evaluates and publishes the research activities of academic sections, departments and clinics for plastic surgery at university hospitals in Germany, in order to raise the awareness of plastic surgical research performance. MATERIALS AND METHODS: The directors of plastic surgical academic institutions were contacted via the DGPRÄC and asked to report any requested/approved and rejected research applications to public, non-public and industrial funding organizations. Data was collected in our previously established online database: https://docs.google.com/forms/d/e/1FAIpQLSe6F5xmTyw-k7VKJx_2jkPA4LBXsA0sgBGMrC3rx_4bHj6uzQ/viewform?usp=sf_link. In addition, applications were identified via the DFG's public database GEPRIS. RESULTS: A total of 41 funding applications to the public funding institutes DFG, BMBF, BMWi, BMG and EU were identified. 75.6 % (31/41) of the applications had already been approved at the time of data collection, of which 77.4 % (24/31) were DFG, 9.7 % (3/31) were BMWi, 6.5 % (2/31) were EU and 3.2 % (1/31) were BMBF or BMG applications. The average funding amounted to 358 301 Euro. In 50.0 % (12/24) of the cases, the approved DFG proposals were assigned to the subject review board 205-27 Orthopedics, Trauma Surgery, Reconstructive Surgery. CONCLUSION: The continuous publication of plastic surgical research funding reports submitted by the convention of university plastic surgeons of the DGPRÄC portraits the excellent, collaborative research activity in the field of plastic surgery.

Foetal hepatocyte transplantation in a vascularized AV-Loop transplantation model in the rat.

The use of foetal liver cells (FLC) in the context of hepatic tissue engineering might permit efficient in vitro expansion and cryopreservation in a cell bank. A prerequisite for successful application of bioartificial liver tissue is sufficient initial vascularization. In this study, we evaluated the transplantation of fibrin gel-immobilized FLC in a vascularized arterio-veno-venous (AV)-loop model. FLC were isolated from embryonic/foetal (ED 16) rat livers and were enriched by using magnetic cell sorting (MACS). After cryopreservation, FLC were labelled by pkh-26. Cells were transplanted in a fibrin matrix into a subcutaneous chamber containing a microsurgically created AV-loop in the femoral region of the recipient rat. The chambers were explanted after 14 days. Subcutaneous implants without an AV-loop and cell-free implants served as controls. Fluorescence microscopy of the constructs was used to identify pkh-26(+)- donor cells. Characterization was performed by RT-PCR and immunhistology (IH) for CK-18 and CD31. Transplantation of FLC using the AV-loop permitted a neo-tissue formation in the fibrin matrix. A high-density vascularization was observed in the AV-loop constructs as shown by CD31 IH. Viable foetal donor cells were detected which expressed CK-18. FLC can be successfully used for heterotopic transplantation. Fibrin matrix permits rapid blood vessel ingrowth from the AV-loop and supports engraftment of FLC. It is therefore an appropriate environment for hepatocyte transplantation in combination with microsurgical vascularization strategies. Transplantation of fibrin gel-immobilized FLC may be a promising approach for the development of highly vascularized in vivo tissue-engineering-based liver support systems.

Evaluation of blood vessel ingrowth in fibrin gel subject to type and concentration of growth factors.

Our aim was to quantitatively assess the angiogenetic effects of VEGF and bFGF immobilized in a fibrin-based drug delivery system in a suitable subcutaneous rat model. After evaluation of a suitable implantation technique (6 rats), four teflon isolation chambers containing fibrin gel matrices were implanted subcutaneously in an upside-down fashion on the back of 30 Lewis rats. The matrices consisted of 500 microl fibrin gel with two different fibrinogen concentrations (10 mg/ml or 40 mg/ml fibrinogen) and 2 I.U./ml thrombin and contained VEGF and bFGF in five different concentrations (0 to 250 ng/ml each). At 3, 7 and 14 days after implantation, matrices were explanted and subjected to histological and morphometrical analysis. At 1 week, the volume of the fibrin clots was significantly smaller in the 100 and 250 ng/ml VEGF and bFGF groups in comparison to lower concentrated growth factors. At 1 and 2 weeks, the use of growth factors in low concentrations (25 ng/ml VEGF and bFGF) significantly increased the amount of fibrovascular tissue, average fraction of blood vessels and number of blood vessels at the matrix-host interface in comparison to growth factor-free controls. Higher concentrations were neither associated with further increase of tissue formation nor with increased sprouting of blood vessels in this model. This study demonstrates that fibrin gel-immobilized angioinductive growth factors efficiently stimulate generation of fibrovascular tissue and sprouting of blood vessels in a newly developed subcutaneous upside-down isolation chamber model with an optimum between 25 and 100 ng/ml.

Regression and persistence: remodelling in a tissue engineered axial vascular assembly.

In later stages of vasculoangiogenesis a vascular network is going through a metamorphosis for optimal perfusion and economy of energy. In this study we make a quantitative approach to phenomena of remodelling in a bioartificial neovascular network and suggest variance of calibre as a parameter of neovascular maturation. For this study, 18 male Lewis rats were subjected to the AV loop operation in combination with a hard porous biogenic matrix and an isolation chamber. The animals were allocated into three groups for different explantation intervals set to 2, 4 and 8 weeks, respectively. Collective attributes like vascular density, percent fractional area and variance of calibre were evaluated for a predefined region of interest (ROI). Late morphogenesis was evaluated by means of scanning electron microscopy. After the fourth week the absolute number of vessels within the ROI decreased (P < 0.03) whereas, on the contrary, the fractional area of all segments increased (P < 0.02). The variance in calibre was significantly increased in the 8-week group (P < 0.05). Lymphatic growth after week 4, early pericyte migration as well as intussusceptive angiogenesis were identified immunohistologically. Phenomena of remodelling were evaluated quantitatively in a neovascular network and variance could be proposed as a parameter of net vascular maturation.

[The "safe" flap - Preoperative perforator-mapping and intraoperative perfusion assessment to reduce flap-associated morbidity - Consensus statement of the German Speaking Working Group for Microsurgery of the Peripheral Nerves and Vessels]. / Der sichere Lappen ­ Präoperatives Gefäß-Mapping und intraoperative Perfusionsmessung zur Reduktion der lappenbedingten Morbidität.

Reconstructive microsurgery using free and pedicled flaps has become a reliable method with a high success rate. Preoperative perforator mapping and intraoperative assessment of perfusion might further reduce flap-associated morbidity.There are various techniques for perforator mapping and perfusion measurement, but no guidelines regarding their use. Therefore, an expert panel at the 40th Annual Meeting of the German-Speaking Working Group for Microsurgery of the Peripheral Nerves and Vessels (DAM) discussed and critically reviewed the current literature. The consensus statement represents the expert opinion based on the available literature and provides recommendations regarding the use of preoperative perforator mapping and intraoperative perfusion measurement.

[Registry Research Funding of the German Society of Plastic, Reconstructive and Aesthetic Surgeons (DGPRÄC) and Research Funding Report 2017/2018]. / Register Forschungsförderung der Deutschen Gesellschaft der Plastischen, Rekonstruktiven und Ästhetischen Chirurgen (DGPRÄC) und Forschungsförderungs-Bericht 2017/2018.

INTRODUCTION: This report serves to publicize the research of academic institutions for Plastic Surgery within our society DGPRÄC in 2017/2018 and sequels the funding report of 2015/2016. Applications to public, non-public, or industrial funding organizations were evaluated. At the same time, this paper analyses the number of approved DFG applications in Plastic, Thoracic and Vascular Surgery in the GEPRIS system. Contrary to these specialties, Plastic Surgery is not classified as an independent speciality in the subject structure of the DFG review board which results in a lack of transparency concerning Plastic Surgery research work. MATERIALS AND METHODS: Our previously established online database (https://docs.google.com/forms/d/1OaSnHyKTysawiI1ie7kfUxDf7nJP_RiTUJTsnb7Mq_E/edit) for reporting requested/ approved and rejected research applications to public, non-public and industrial funding organizations was continued and evaluated together with applications found in the DFG's public database GEPRIS. RESULTS: Compared to the previous year's report, the number of approved applications from public research organizations (DFG, BMBF, BMWi, EU) was increased from 23 to 27. We identified 19 approved DFG applications from Plastic Surgery, as compared to 9 and 8 applications by Thoracic and Vascular Surgery, respectively. SUMMARY: Taken together, this data emphasizes that our research is at least equal to that of other newly established surgical specialties within the framework of the DFG. Accordingly, we hope to provide further arguments for an adaptation of the DFG review boards subject structure to include Plastic Surgery as an independent specialty as it is for Vascular Surgery and Thoracic Surgery.

Scalp reconstruction: A 10-year retrospective study.

Scalp reconstruction is a challenging task for the reconstructive surgeon. In consideration of the anatomical and cosmetic characteristics, the defect depth and size, an armamentarium of reconstructive procedures ranging from skin grafts over local flaps to free tissue transfer has been described. In this 10-year retrospective study, 85 operative procedures for scalp reconstruction were performed at our department. The underlying entity, defect size/depth, reconstructive procedure, complications, and mean hospital stay were analyzed. In most cases, scalp reconstruction was necessary after oncologic resection (67%) or radiation therapy (16%). A total of 85 operative procedures were performed for scalp reconstruction including local flaps (n = 50), free tissue transfer (n = 18), and skin grafts (n = 17). Regarding the complication rate, we could detect an overall major complication rate of 16.5% with one free flap loss. Briefly, local flaps are an adequate and safe procedure for limited scalp defects. In the case of extensive scalp defects affecting the calvarium, prior multiple surgical interventions and/or radiation, we prefer free tissue transfer.

Reduction mammaplasty for benign phyllodes tumour in an adolescent female--a 13-year follow up.

Phyllodes tumours are rare neoplasms of the female breast, especially among adolescent women. We present the case of a 17-year old female patient with a large benign phyllodes tumour. The patient was treated by one-stage excision with reduction mammaplasty. Symmetry of breast contour and nipple-areola complex position could be restored. At follow-up after 13 years good cosmetic result was maintained and there was no evidence of local recurrence. Standard plastic surgical techniques like reduction mammaplasty might be applied in treating large benign tumours compromising the aesthetic aspect of the breast.

[Prevascularisation strategies in tissue engineering]. / Prävaskularisationsstrategien im Tissue Engineering.

INTRODUCTION: Experiments on animals have underlined the importance of vascularisation for biointegration and functionality of any given tissue engineering device. The aim of this investigation was to dissect the angiogenetic process in the frame of axial neovascularisation of a xenogenic solid matrix. The ultimate goal of this series of studies is the application of cells onto a prevascularised matrix, with the ambition to enhance cell survival after transplantation in vivo. MATERIALS AND METHODS: We performed a study in the rat with different vascular configurations in an isolation chamber. A disc-formed biogenic hard matrix (9 x 5 mm) was encased into an isolation chamber made of Teflon. In group 1, an arteriovenous fistula (AV loop) between the femoral vessels was microsurgically constructed and was placed around the matrix (n = 15). In group 2, the vascular carrier had the form of an arteriovenous ligated pedicle (n = 15). Evaluation intervals were two, four and eight weeks after implantation. The modes of evaluation included histology, scanning electron microscopy of corrosion casts as well as intravital micro-magnetic resonance imaging (MRI). RESULTS: The arteriovenous loop as vascular carrier revealed a higher capacity for angiogenesis over the bundle configuration. The neo-fibrovascular tissue displayed minimal inflammatory elements but dense vascularisation. Scanning electron microscopy demonstrated a vivid angiogenesis with rapid evolution of the vascular bead into mature, hierarchically organised network. Micro-MRI could be used for serial investigation in terms of flow measurements and detection of thrombosis. DISCUSSION: The presence of a vascular bed prior to cell transplantation might protect against hypoxia-induced cellular death, especially at central portions of the matrix, and therefore ensure physiological function of the device. The generation of vascularised bioartificial tissue substitutes might offer new modalities of surgical reconstruction for use in reparative medicine.