First Series of Free Flap Reconstruction Using a Dedicated Robotic System in a Multidisciplinary Microsurgical Center.

Robotic microsurgery is a novel technology for microsurgical free flap transplantation in reconstructive surgery. Recently, the first free flap transplantation using a dedicated robotic system for microsurgery (Symani Surgical System; Medical Microinstruments) was published for a single reconstructive case. For broader future application, evaluating its potential benefits in different anatomical regions, anastomotic configurations, and clinical scenarios is necessary. In this world-wide first free flap series using this robotic system, we describe our experience with this new technology in a multidisciplinary microsurgical center. The robotic system was used for different free flaps in a range of reconstructive applications in plastic surgery, oral and maxillofacial surgery, and head and neck surgery. A total of 23 flaps were performed, with all 23 arterial and a selection of two venous anastomoses being performed with the robotic system. Time for anastomoses was significantly longer than commonly. Five of the arterial robotic anastomoses had to be redone. All but one flap survived. We could show that this new dedicated microsurgical robotic system is feasible for carrying out robot-assisted anastomoses in end-to-end, as well as end-to-side fashion under varying clinical conditions and in different microsurgical subspecialties. However, some drawbacks still need to be overcome, which are partly related to individual and institutional learning curves, to finally estimate the potential benefit for robotic free flap surgery. Multidisciplinary application of the robotic system may accelerate this process by putting together different microsurgical backgrounds, while economic burden of establishing this new technology is spread among several departments.

[Settlement of the surgical treatment of lipoedema]. / Abrechnung der chirurgischen Therapie des Lipödems.

The billing of lipoedema treatment in Germany has come to be heterogeneous. This is due to the decision of the Federal Joint Committee ("Gemeinsamer Bundesausschuss", G-BA) to acknowledge lipoedema stage III as a treatment to be paid by the statutory health insurance funds ("Gesetzliche Krankenversicherung", GKV) until the completion of the trial study "LipLeg" at the end of 2024. Based on this decision, inpatient and outpatient surgical treatment of stage III lipoedema can be billed to the GKV, while the reimbursement of costs for surgical treatment of the other two stages remains a case-by-case decision of the GKV and is currently often rejected. Therefore, treatment costs are often paid by patients themselves. The question of the correct settlement of lipoedema treatment repeatedly arises in the context of legal disputes, which, in turn, repeatedly faces experts and courts with a major challenge. In the following article, the Task Force Lipoedema of the German Society for Plastic, Reconstructive and Aesthetic Surgery presents an overview of the various billing modalities and presents a proposal for the correct billing of lipoedema within the framework of the German medical fee schedule ("Gebührenordnung für Ärzte", GOÄ).

[Does it Always have to be the Abdomen? Alternative Flaps in Autologous Breast Reconstruction]. / Muss es immer das Abdomen sein? ­ Alternative Lappen zur mikrochirurgischen Brustrekonstruktion.

[English] Deep inferior epigastric artery perforator (DIEP) or muscle-sparing transverse rectus abdominis muscle (ms-TRAM) flaps remain the gold standard for autologous reconstruction in post-mastectomy patients, although many women may not be candidates for abdominally based free tissue transfer. In this scenario, there are several other donor site options based from the thigh (transverse and diagonal upper gracilis flaps, profunda artery perforator flap, lateral thigh flap), trunk (lumbar artery perforator flap), and buttock (superior and inferior gluteal artery perforator flaps). This article will provide insight into the history, relevant anatomy, surgical technique and novel applications (neurotization) for alternative flaps in autologous breast reconstruction.

Specific features of ex-obese patients significantly influence the functional cell properties of adipose-derived stromal cells.

Adipose-derived stromal cells (ADSC) are increasingly used in clinical applications due to their regenerative capabilities. However, ADSC therapies show variable results. This study analysed the effects of specific factors of ex-obese patients on ADSC functions. ADSC were harvested from abdominal tissues (N = 20) after massive weight loss. Patients were grouped according to age, sex, current and maximum body mass index (BMI), BMI difference, weight loss method, smoking and infection at the surgical site. ADSC surface markers, viability, migration, transmigration, sprouting, differentiation potential, cytokine secretion, telomere length and mtDNA copy number were analysed. All ADSC expressed CD73, CD90, CD105, while functional properties differed significantly among patients. A high BMI difference due to massive weight loss was negatively correlated with ADSC proliferation, migration and transmigration, while age, sex or weight loss method had a smaller effect. ADSC from female and younger donors and individuals after weight loss by increase of exercise and diet change had a higher activity. Telomere length, mtDNA copy number, differentiation potential and the secretome did not correlate with patient factors or cell function. Therefore, we suggest that factors such as age, sex, increase of exercise and especially weight loss should be considered for patient selection and planning of regenerative therapies.

An Innovative Arteriovenous (AV) Loop Breast Cancer Model Tailored for Cancer Research.

Animal models are important tools to investigate the pathogenesis and develop treatment strategies for breast cancer in humans. In this study, we developed a new three-dimensional in vivo arteriovenous loop model of human breast cancer with the aid of biodegradable materials, including fibrin, alginate, and polycaprolactone. We examined the in vivo effects of various matrices on the growth of breast cancer cells by imaging and immunohistochemistry evaluation. Our findings clearly demonstrate that vascularized breast cancer microtissues could be engineered and recapitulate the in vivo situation and tumor-stromal interaction within an isolated environment in an in vivo organism. Alginate-fibrin hybrid matrices were considered as a highly powerful material for breast tumor engineering based on its stability and biocompatibility. We propose that the novel tumor model may not only serve as an invaluable platform for analyzing and understanding the molecular mechanisms and pattern of oncologic diseases, but also be tailored for individual therapy via transplantation of breast cancer patient-derived tumors.

The Crosstalk Between Adipose-Derived Stem or Stromal Cells (ASC) and Cancer Cells and ASC-Mediated Effects on Cancer Formation and Progression-ASCs: Safety Hazard or Harmless Source of Tropism?

Adipose-derived stem or stromal cells (ASCs) possess promising potential in the fields of tissue engineering and regenerative medicine due to their secretory activity, their multilineage differentiation potential, their easy harvest, and their rich yield compared to other stem cell sources. After the first identification of ASCs in humans in 2001, the knowledge of their cell biology and cell characteristics have advanced, and respective therapeutic options were determined. Nowadays, ASC-based therapies are on the verge of translation into clinical practice. However, conflicting evidence emerged in recent years about the safety profile of ASC applications as they may induce tumor progression and invasion. Numerous in-vitro and in-vivo studies demonstrate a potential pro-oncogenic effect of ASCs on various cancer entities. This raises questions about the safety profile of ASCs and their broad handling and administration. However, these findings spark controversy as in clinical studies ASC application did not elevate tumor incidence rates, and other experimental studies reported an inhibitory effect of ASCs on different cancer cell types. This comprehensive review aims at providing up-to-date information about ASCs and cancer cell interactions, and their potential carcinogenesis and tumor tropism. The extracellular signaling activity of ASCs, the interaction of ASCs with the tumor microenvironment, and 3 major organ systems (the breast, the skin, and genitourinary system) will be presented with regard to cancer formation and progression.

Personalized medicine for reconstruction of critical-size bone defects - a translational approach with customizable vascularized bone tissue.

Tissue engineering principles allow the generation of functional tissues for biomedical applications. Reconstruction of large-scale bone defects with tissue-engineered bone has still not entered the clinical routine. In the present study, a bone substitute in combination with mesenchymal stem cells (MSC) and endothelial progenitor cells (EPC) with or without growth factors BMP-2 and VEGF-A was prevascularized by an arteriovenous (AV) loop and transplanted into a critical-size tibia defect in the sheep model. With 3D imaging and immunohistochemistry, we could show that this approach is a feasible and simple alternative to the current clinical therapeutic option. This study serves as proof of concept for using large-scale transplantable, vascularized, and customizable bone, generated in a living organism for the reconstruction of load-bearing bone defects, individually tailored to the patient's needs. With this approach in personalized medicine for the reconstruction of critical-size bone defects, regeneration of parts of the human body will become possible in the near future.

Tissue Engineering of Lymphatic Vasculature in the Arteriovenous Loop Model of the Rat.

Various therapeutic approaches, for example, in case of trauma or cancer require the transplantation of autologous tissue. Depending on the size and the origin of the harvested tissue, these therapies can lead to iatrogenic complications and donor-site morbidities. In future, these side effects could be avoided by transplanting artificially generated tissue consisting of different cell types and matrix components derived from the host body. Tissue that is grown in the patient could be advantageous compared with the more simply structured in vitro-grown alternatives. To overcome the limitations of graft vascularization, the arteriovenous (AV) loop technique has been established for different tissues in the last years and was adapted for lymphatic tissue engineering in the present study. We utilized the AV loop technique to grow human lymphatic vasculature in vivo in the Rowett nude (RNU) rat. A combination of human lymphatic endothelial cells (LECs) and bone marrow-derived mesenchymal stem cells was implanted in a fibrin matrix surrounding the AV loop. After 2 or 4 weeks of implantation, the animals were perfused and the tissue was harvested. It could be demonstrated by immunohistochemistry for human LYVE1, human CD31, and murine podoplanin that the implanted cells formed human lymphatic vasculature in the AV loop chamber. Beside development of murine podoplanin-positive vasculature in the AV loop tissue, vasculature positive for human marker proteins developed in comparable numbers. This suggests that implanted LECs are able to improve the lymphatic vascularization of the newly engineered tissue. Thus, we were able to establish an in vivo tissue engineering method to generate lymphatic vascularized soft tissue. An axially vascularized transplantable lymphatic vessel network was engineered without requiring advanced cell culture equipment, rendering the lymphatic AV loop highly suitable for applied regenerative medicine. Impact statement Various surgical procedures require the transplantation of autologous harvested tissue, for example, the vascularized lymph node transfer for the treatment of lymphedema. Tissue-engineered transplants could be used instead of autologous transplants and thereby help to reduce the side effects of those therapies. However, in vitro tissue engineering of large constructs requires a lot of know-how as well as advanced cell culture equipment, which might not be accessible in every hospital. In vivo tissue engineering approaches like the presented technique for the generation of transplantable networks of lymphatic vasculature could serve as an alternative for in vitro tissue engineering approaches in clinical settings.

Plastic Surgery Reconstruction of Chronic/Non-Healing Wounds.

In western countries, approximately 1 % of individuals are affected by chronic wounds during their lifetime. Due to changing demographics, this incidence will likely increase in the future. Additionally, the high prevalence is accompanied by substantial treatment expenditures. Therefore, it is of global interest to find effective treatment algorithms. In this article, we present up-to-date solutions for treating chronic / difficult to heal and complex wounds by means of plastic and reconstructive surgery. We outline the principles of chronic wounds and how to perform an appropriate diagnosis. Close cooperation and interdisciplinary exchange are important for optimizing treatment. We report the principles of wound debridement and the role of negative pressure wound therapy. Moreover, we discuss the state of the art of defect reconstruction by means of skin grafting, with or without acellular dermal matrices, local tissue transfers and free tissue transfers. In very complex cases, the local macrovascular blood flow is greatly reduced and there are few, if any, recipient vessels for free flap reconstruction. We discuss the role of arteriovenous loops to overcome this problem.

The Role of Plastic Reconstructive Surgery in Surgical Therapy of Soft Tissue Sarcomas.

BACKGROUND: Soft tissue sarcoma (STS) treatment is an interdisciplinary challenge. Along with radio(chemo)therapy, surgery plays the central role in STS treatment. Little is known about the impact of reconstructive surgery on STS, particularly whether reconstructive surgery enhances STS resection success with the usage of flaps. Here, we analyzed the 10-year experience at a university hospital's Comprehensive Cancer Center, focusing on the role of reconstructive surgery. METHODS: We performed a retrospective analysis of STS-patients over 10 years. We investigated patient demographics, diagnosis, surgical management, tissue/function reconstruction, complication rates, resection status, local recurrence and survival. RESULTS: Analysis of 290 patients showed an association between clear surgical margin (R0) resections and higher-grade sarcoma in patients with free flaps. Major complications were lower with primary wound closure than with flaps. Comparison of reconstruction techniques showed no significant differences in complication rates. Wound healing was impaired in STS recurrence. The local recurrence risk was over two times higher with primary wound closure than with flaps. CONCLUSION: Defect reconstructions in STS are reliable and safe. Plastic surgeons should have a permanent place in interdisciplinary surgical STS treatment, with the full armamentarium of reconstruction methods.

Human adipose-derived stem cells support lymphangiogenesis in vitro by secretion of lymphangiogenic factors.

Lymphedema is a chronic progressive disease ultimately resulting in severe, disfiguring swelling and permanent changes of the affected tissues. Presently, there is no causal treatment approach of lymphedema. Therefore, most therapies are purely symptomatic. However, the recent use of stem cell-based therapies has offered new prospects for alternative treatment options. The present study was performed to investigate the effects of human adipose-derived stem cells (ADSCs) on human dermal lymphatic endothelial cells (HDLECs) in terms of basic in vitro lymphangiogenic assays (WST-8 assay, scratch assay, transmigration assay, sprouting assay, tube formation assay). The influence of ADSC-conditioned medium (ADSC-CM) on HDLECs was compared to recombinant VEGF-C, bFGF and HGF. Further ADSC-CM was characterized by protein microarray and enzyme-linked immunosorbent assay (ELISA). Although key-lymphangiogenic growth factors - like VEGF-C - could only be detected in low concentrations within the conditioned medium (CM), HDLECs were potently stimulated to proliferate, migrate and to form tube like structures by ADSC-CM. Despite concentrations more than hundredfold higher than those found in the conditioned medium, stimulation with recombinant VEGF-C, bFGF and HGF was still weaker compared to ADSC-CM. These results highlight the effectiveness of growth factors secreted by ADSC to stimulate HDLEC, potentially providing a promising new therapeutic approach for the treatment of lymphedema.

Body Contouring Surgery Improves Physical Activity in Patients After Massive Weight Loss-a Retrospective Study.

BACKGROUND: The aim of the study was to compare physical activity (PA) in patients who had undergone massive weight loss (MWL), before and after body contouring procedures. METHODS: All patients undergoing body contouring surgery after MWL between 2007 and 2017 with a minimum follow-up of 6 months after the last procedure were included in this retrospective study. Excluded were those with a body mass index > 35 kg/m2 and those with comorbidities leading to impaired PA. Quality of life (QOL) was assessed using the Moorehead-Ardelt QOL Questionnaire II. Evaluation of PA was obtained with the International Physical Activity Questionnaire (IPAQ) short form and the Freiburg PA Questionnaire. Functional impairment during exercise was analyzed using a self-designed functional impairment score (FIS). RESULTS: In the 45 patients completing the survey (37 female, 8 male), an improvement in QOL (p < 0.001) and PA scored by the IPAQ (p = 0.017) was found. The Freiburg PA Questionnaire showed no difference in PA before and after body contouring surgery (p = 0,274). Furthermore, scores of the FIS indicated a decrease of functional impairment during physical activity after body contouring surgery (p < 0.001). CONCLUSION: Body contouring improves QOL and PA in patients after massive weight loss. The results of our study confirm the important role of plastic surgery in the treatment and maintenance of health of patients with former obesity.

Plasticity of patient-matched normal mammary epithelial cells is dependent on autologous adipose-derived stem cells.

Due to the increasing clinical application of adipose-derived stem cells (ADSC), e.g. lipotransfer for breast reconstruction, this study aimed to gain novel insights regarding ADSC influence on breast tissue remodeling and determine patient-dependent factors affecting lipotransfer as well as begin to address its oncological risks. The ADSC secretome was analyzed from five normal breast reduction patients and contained elevated levels of growth factors, cytokines and proteins mediating invasion. ADSC/ADSC secretomes were tested for their influence on the function of primary mammary epithelial cells, and tumor epithelial cells using cell culture assays. ADSC/ADSC secretomes significantly stimulated proliferation, transmigration and 3D-invasion of primary normal and tumor epithelial cells. IL-6 significantly induced an EMT and invasion. The ADSC secretome significantly upregulated normal epithelial cell gene expression including MMPs and ECM receptors. Our study supports that ADSC and its secretome promote favorable conditions for normal breast tissue remodeling by changing the microenvironment. and may also be important regarding residual breast cancer cells following surgery.

Tumor­type­dependent effects on the angiogenic abilities of endothelial cells in an in vitro rat cell model.

Adequate vascularization is pivotal for tumor progression and metastasis. Tumor angiogenesis is based on a sequence of interactions between the tumor and surrounding cells and the extracellular matrix. It is widely known that a tumor can influence and control its surroundings to create favorable conditions for further growth. To investigate the influence of various tumor types on endothelial cells (ECs), an in vitro rat cell model was used and rat liver EC52 cells were co­cultured with conditioned medium derived from breast cancer MCR86, osteosarcoma ROS­1, colon cancer CC531 and rhabdomyosarcoma R1H cell lines. In a distinct tumor­type­dependent manner, the EC52 cells exhibited changes in their function and gene expression. In all functional cell culture assays (proliferation, migration, transmigration, invasion and tube formation) the breast cancer cells exerted a significant effect on the angiogenic abilities of the ECs. When comparing the various tumor cell types, only the breast and colon cancer cells led to a significant stimulation of the EC migration and invasion. Proliferation, migration, invasion and tube formation were not or only hardly influenced by the osteosarcoma or rhabdomyosarcoma cells. Similarly, the breast and colon cancer cells exhibited the strongest influence on the upregulation of EC angiogenic genes, including the ones encoding vascular endothelial growth factor A, platelet and endothelial cell adhesion molecule 1, fibroblast growth factor 2, Von Willebrand factor, C­X­C motif chemokine ligand 12 and tyrosine kinase with immunoglobulin­like and EGF­like domains 1. Therefore, it is hypothesized that tumor cells enhance the angiogenic properties of ECs, including proliferation, migration, invasion and tube formation in a tumor­type­dependent manner. This is likely based on the upregulation of pro­angiogenic genes in ECs induced by varying cytokine secretion signatures of tumor cells.

Intra- and Postoperative Blood Flow Monitoring in a Sheep Model of Uterus Transplantation.

BACKGROUND: The introduction of the opportunity to transplant a viable uterus into women for fulfilling their desire to have a child has awakened high expectations worldwide. MATERIALS AND METHODS: A sheep model was used to evaluate tools for optimizing measurement of blood flow in uterine transplantation. Intraoperatively, blood flow was measured using unidirectional Doppler and indocyanine green (ICG) fluorescence imaging. Postoperatively, an implantable Doppler probe served as a tool for clinical monitoring the patency of anastomosed vessels. RESULTS: ICG imaging showed complete vascularization of the uterus before and in short-term evaluation after surgery. The implantable Doppler probe proved to be highly suitable for assessing patency of vessels in a non-invasive way. Results of histology, and real-time polymerase chain reaction demonstrated viability of the transplanted uterus. CONCLUSION: Different methods to monitor vasculature patency have proven to be advantageous in supporting both surgeons and researchers in ensuring successful implementation of uterine transplantation.

Changes of perfusion patterns of surgical wounds under application of closed incision negative pressure wound therapy in postbariatric patients1.

BACKGROUND: Negative pressure wound therapy applied over closed incisions (ciNPT) has been shown to influence wound healing. Therefore, the aim of this study was to examine the short-term effects of ciNPT on skin perfusion patterns in postbariatric wounds. METHODS: 17 patients were included. Patients from the study group received a ciNPT dressing with a continuous negative pressure of - 125 mmHg for five days. Two intra- and two postoperative measurements were performed using both a combined laser Doppler spectrophotometry and an ICG angiography system to determine oxygen saturation (sO2), hemoglobin content (rHb) and perfusion patterns. RESULTS: Three days postoperatively the sO2 was significantly higher in the study group compared to the control group and also compared to the end of the operation. Concerning the rHb, there was no statistical significant alteration in or between the groups, but a trend towards a correlated alteration of sO2 and rHb. ICG angiography showed an earlier and stronger enhancement of perfusion parameters in the study group. CONCLUSION: CiNPT has a positive effect on oxygen saturation and tissue perfusion, which are both associated with the wound healing process. The use of ciNPT could therefore possibly reduce the risk of wound healing complications in this high-risk patient group.

Operating on the Edge? Body Contouring Procedures in Patients with Body Mass Index Greater 35.

BACKGROUND: Body contouring surgery after massive weight loss was shown to ameliorate the patient's quality of life and to enhance physical and psychological well-being. However, numerous patients are still obese when presenting for body contouring surgery, not able to lose additional weight for various reasons. Data regarding general feasibility, outcome, and postoperative complications in obese patients is rare. The aim of this study was to investigate the outcome in body contouring procedures in obese patients. METHODS: A retrospective chart review of 65 cases in 42 patients was performed. Patients with a body mass index (BMI) > 35 kg/m2 at the time of operation were enrolled and all different types of body contouring surgery were included. Complications were classified as major (need for surgical intervention) and minor complications. RESULTS: The median BMI of all patients was 38 kg/m2 (range 35.1-65.1 kg/m2). The majority of performed types of body contouring was abdominal body contouring (panniculectomy n = 27 (42%), abdominoplasty n = 12 (18%)). Complications occurred in 27 cases (41.5%). Twenty-one cases (32.3%) were classified as minor complications, six (9.2%) as major complications. The most common major complications were hematoma and wound dehiscence; the most common minor complication was seroma. CONCLUSION: A reasonable risk for complications is well known in body contouring surgery especially in obese patients. It is imperative to discuss related risks and expected results. Taking several points into account concerning the perioperative management, reduction of major complications is possible even in still obese patients, making body contouring surgery a discussible option.

ADSCs and adipocytes are the main producers in the autotaxin-lysophosphatidic acid axis of breast cancer and healthy mammary tissue in vitro.

BACKGROUND: Breast cancer is the most common malignancy in women affecting one out of eight females throughout their lives. Autotaxin (ATX) is upregulated in breast cancer which results in increased lysophosphatidic acid (LPA) formation within the tumor. This study's aim was to identify the role of different mammary cell populations within the ATX-LPA axis. METHODS: Epithelial-cell-adhesion-molecule-positive (EpCAM) and -negative cells from breast tumors, adipose-derived stem cells (ADSCs) of tumor-adjacent and tumor-distant mammary fat were isolated and compared to healthy ADSCs, mammary epithelial cells (HMECs), and mesenchymal cells (MES) of healthy mammary tissue (n = 4 each) and further to well-established breast (cancer) cell lines. RESULTS: mRNA expression analyses revealed that ADSCs and MES largely expressed LPA receptor 1 (LPAR1) while epithelial cells mainly expressed LPAR6. LPA 18:1 activated all the cell populations and cell lines by rise in cytosolic free calcium concentrations. MES and ADSCs expressed ATX whereas epithelial cells did not. ADSCs revealed the highest expression in ATX with a significant decline after adipogenic differentiation in healthy ADSCs, whereas ATX expression increased in ADSCs from tumor patients. Breast (cancer) cell lines did not express ATX. Transmigration of MES was stimulated by LPA whereas an inhibitory effect was observed in epithelial cells with no differences between tumors and healthy cells. Triple-negative breast cancer (TNBC) cell lines were also stimulated and the transmigration partly inhibited using the LPA receptor antagonist Ki16425. CONCLUSIONS: We here show that each mammary cell population plays a different role in the ATX-LPA axis with ADSCs and adipocytes being the main source of ATX in tumor patients in our experimental setting. Inhibitors of this axis may therefore present a valuable target for pharmacological therapies.

Myogenic differentiation of primary myoblasts and mesenchymal stromal cells under serum-free conditions on PCL-collagen I-nanoscaffolds.

BACKGROUND: The creation of functional skeletal muscle via tissue engineering holds great promise without sacrificing healthy donor tissue. Different cell types have been investigated regarding their myogenic differentiation potential under the influence of various media supplemented with growth factors. Yet, most cell cultures include the use of animal sera, which raises safety concerns and might lead to variances in results. Electrospun nanoscaffolds represent suitable matrices for tissue engineering of skeletal muscle, combining both biocompatibility and stability. We therefore aimed to develop a serum-free myogenic differentiation medium for the co-culture of primary myoblasts (Mb) and mesenchymal stromal cells derived from the bone marrow (BMSC) and adipose tissue (ADSC) on electrospun poly-ε-caprolacton (PCL)-collagen I-nanofibers. RESULTS: Rat Mb were co-cultured with rat BMSC (BMSC/Mb) or ADSC (ADSC/Mb) two-dimensionally (2D) as monolayers or three-dimensionally (3D) on aligned PCL-collagen I-nanofibers. Differentiation media contained either AIM V, AIM V and Ultroser® G, DMEM/Ham's F12 and Ultroser® G, or donor horse serum (DHS) as a conventional differentiation medium. In 2D co-culture groups, highest upregulation of myogenic markers could be induced by serum-free medium containing DMEM/Ham's F12 and Ultroser® G (group 3) after 7 days. Alpha actinin skeletal muscle 2 (ACTN2) was upregulated 3.3-fold for ADSC/Mb and 1.7-fold for BMSC/Mb after myogenic induction by group 3 serum-free medium when compared to stimulation with DHS. Myogenin (MYOG) was upregulated 5.2-fold in ADSC/Mb and 2.1-fold in BMSC/Mb. On PCL-collagen I-nanoscaffolds, ADSC showed a higher cell viability compared to BMSC in co-culture with Mb. Myosin heavy chain 2, ACTN2, and MYOG as late myogenic markers, showed higher gene expression after long term stimulation with DHS compared to serum-free stimulation, especially in BMSC/Mb co-cultures. Immunocytochemical staining with myosin heavy chain verified the presence of a contractile apparatus under both serum free and standard differentiation conditions. CONCLUSIONS: In this study, we were able to myogenically differentiate mesenchymal stromal cells with myoblasts on PCL-collagen I-nanoscaffolds in a serum-free medium. Our results show that this setting can be used for skeletal muscle tissue engineering, applicable to future clinical applications since no xenogenous substances were used.

Reconstruction of composite defects of the scalp and neurocranium-a treatment algorithm from local flaps to combined AV loop free flap reconstruction.

BACKGROUND: Reconstruction of cranial composite defects, including all layers of the scalp and the neurocranium, poses an interdisciplinary challenge. Especially after multiple previous operations and/or radiation therapy, sufficient reconstruction is often only possible using microsurgical free flap transplantation. The aim of this study was to analyze the therapy of interdisciplinary cases with composite defects including the scalp and neurocranium. METHODS: From 2009 to 2017, 23 patients with 18 free flaps and 10 pedicled/local flaps were analyzed. First choices for free flaps were muscle flaps followed by fasciocutaneous flaps. RESULTS: Except for four patients, a stable coverage could be reached in the first operation. Three of these patients received a local scalp rotation flap in the first operation and needed an additional free flap because the local flap was no longer sufficient for coverage after wound healing deficiency or tumor relapse. The superficial temporal artery or external carotid artery served as recipient vessels. In special cases, venous grafts or an arteriovenous loop (AV loop) were used as extensions for the recipient vessels. CONCLUSIONS: In summary, an interdisciplinary approach with radical debridement of infected or necrotic tissue and the reconstruction of the dura mater are essential to reach a stable, long-lasting reconstructive result. Based on our experience, free flaps seem to be the first choice for patients after multiple previous operations and/or radiation therapy.