Background He use of mouse liver transplantation models remains crucial for answering questions regarding organ transplantation, tissue-resident immunity and tumor biology. The learning curve for this complex procedure involves use of animals without creating scientific output. We present a recipient mouse and donor liver model with realistic vessels for training in mouse liver transplantation, designed to reduce the number of animals needed during the training. Methods A 3D-model of the liver, skeleton and vessels (vena cava, hepatic artery and portal vein) was created using computed tomography images of a real mouse and 3D-printing to simulate orthotopic liver transplantation. Microsurgical experts from multiple research groups evaluated this model for usability, procedural details, and on how well the materials mimicked the real tissue. Results We successfully created an artificial model featuring the mouse body, organs, and vessels needed for initial training in mouse liver transplantation. The evaluation found it to realistically mimic the confined space of the surgical site and determined that it could be used for vessel anastomoses with suturing and the cuff-technique. Conclusions This simulation model enables a cost-effective approach for basic training in mouse liver transplantation that can easily be reproduced to reduce animal use in the training process.

Objective Evaluation of the benefits of a virtual reality (VR) environment with a head-mounted display (HMD) for decision-making in liver surgery. Background Training in liver surgery involves appraising radiologic images and considering the patient’s clinical information. Accurate assessment of 2D-tomography images is complex and requires considerable experience, and often the images are divorced from the clinical information. We present a comprehensive and interactive tool for visualizing operation planning data in a VR environment using a head-mounted-display and compare it to 3D visualization and 2D-tomography. Methods Ninety medical students were randomized into three groups (1:1:1 ratio). All participants analyzed three liver surgery patient cases with increasing difficulty. The cases were analyzed using 2D-tomography data (group “2D”), a 3D visualization on a 2D display (group “3D”) or within a VR environment (group “VR”). The VR environment was displayed using the “Oculus Rift ™” HMD technology. Participants answered 11 questions on anatomy, tumor involvement and surgical decision-making and 18 evaluative questions (Likert scale). Results Sum of correct answers were significantly higher in the 3D (7.1 ± 1.4, p < 0.001) and VR (7.1 ± 1.4, p < 0.001) groups than the 2D group (5.4 ± 1.4) while there was no difference between 3D and VR ( p = 0.987). Times to answer in the 3D (6:44 ± 02:22 min, p < 0.001) and VR (6:24 ± 02:43 min, p < 0.001) groups were significantly faster than the 2D group (09:13 ± 03:10 min) while there was no difference between 3D and VR ( p = 0.419). The VR environment was evaluated as most useful for identification of anatomic anomalies, risk and target structures and for the transfer of anatomical and pathological information to the intraoperative situation in the questionnaire. Conclusions A VR environment with 3D visualization using a HMD is useful as a surgical training tool to accurately and quickly determine liver anatomy and tumor involvement in surgery.

Die Chirurgie der Milz bei hämatologischen Erkrankungen erfordert eine gut abgewogene Indikationsstellung, da sich die Therapie aufgrund vieler neuer medikamentöser Ansätze in den letzten Jahren sehr verändert hat. Zusammenfassung der Indikationen, Operationsverfahren und perioperatives Management bei operativen Eingriffen an der Milz bei hämatologischen Erkrankungen. Selektive Literaturrecherche und Darstellung von Übersichtsarbeiten und Leitlinienempfehlungen. Bei hämatologischen Erkrankungen zählt die Chirurgie der Milz (Splenektomie und partielle Splenektomie) zum fundamentalen Repertoire der Therapie. In den letzten Jahren hat sich aufgrund neuer medikamentöser Therapien die Indikationsstellung weiter fokussiert; insbesondere bei der hereditären Sphärozytose, der Immunothrombozytopenie, bei symptomatischer Splenomegalie und Hypersplenismus hat sie ihren Stellenwert. Goldstandard ist die minimal-invasive Splenektomie. Aufgrund der Immun- und Sequestrierungsfunktion der Milz gilt es, prä- und postoperativ besonders auf infektiöse und thromboembolische Ereignisse zu achten und diesen vorzubeugen. Eine enge interdisziplinäre Zusammenarbeit mit der Hämatologie ist für das optimale Outcome der Patienten essenziell. Die minimal-invasive (partielle) Splenektomie gehört zum chirurgischen Repertoire in der Diagnostik und Therapie hämatologischer Erkrankungen. Aufgrund neuartiger medikamentöser Ansätze verändert sich die Therapie laufend. Eine enge Kooperation mit der Hämatologie ist für die optimale Indikationsstellung und das perioperative Management wichtig.

Background Image-guidance promises to make complex situations in liver interventions safer. Clinical success is limited by intraoperative organ motion due to ventilation and surgical manipulation. The aim was to assess influence of different ventilatory and operative states on liver motion in an experimental model. Methods Liver motion due to ventilation (expiration, middle, and full inspiration) and operative state (native, laparotomy, and pneumoperitoneum) was assessed in a live porcine model ( n = 10). Computed tomography (CT)-scans were taken for each pig for each possible combination of factors. Liver motion was measured by the vectors between predefined landmarks along the hepatic vein tree between CT scans after image segmentation. Results Liver position changed significantly with ventilation. Peripheral regions of the liver showed significantly higher motion (maximal Euclidean motion 17.9 ± 2.7 mm) than central regions (maximal Euclidean motion 12.6 ± 2.1 mm, p < 0.001) across all operative states. The total average motion measured 11.6 ± 0.7 mm ( p < 0.001). Between the operative states, the position of the liver changed the most from native state to pneumoperitoneum (14.6 ± 0.9 mm, p < 0.001). From native state to laparotomy comparatively, the displacement averaged 9.8 ± 1.2 mm ( p < 0.001). With pneumoperitoneum, the breath-dependent liver motion was significantly reduced when compared to other modalities. Liver motion due to ventilation was 7.7 ± 0.6 mm during pneumoperitoneum, 13.9 ± 1.1 mm with laparotomy, and 13.5 ± 1.4 mm in the native state ( p < 0.001 in all cases). Conclusions Ventilation and application of pneumoperitoneum caused significant changes in liver position. Liver motion was reduced but clearly measurable during pneumoperitoneum. Intraoperative guidance/navigation systems should therefore account for ventilation and intraoperative changes of liver position and peripheral deformation.

Hepatectomy, living donor liver transplantations and other major hepatic interventions rely on precise calculation of the total, remnant and graft liver volume. However, liver volume might differ between the pre- and intraoperative situation. To model liver volume changes and develop and validate such pre- and intraoperative assistance systems, exact information about the influence of lung ventilation and intraoperative surgical state on liver volume is essential. This study assessed the effects of respiratory phase, pneumoperitoneum for laparoscopy, and laparotomy on liver volume in a live porcine model. Nine CT scans were conducted per pig (N = 10), each for all possible combinations of the three operative (native, pneumoperitoneum and laparotomy) and respiratory states (expiration, middle inspiration and deep inspiration). Manual segmentations of the liver were generated and converted to a mesh model, and the corresponding liver volumes were calculated. With pneumoperitoneum the liver volume decreased on average by 13.2% (112.7 ml ± 63.8 ml, p < 0.0001) and after laparotomy by 7.3% (62.0 ml ± 65.7 ml, p = 0.0001) compared to native state. From expiration to middle inspiration the liver volume increased on average by 4.1% (31.1 ml ± 55.8 ml, p = 0.166) and from expiration to deep inspiration by 7.2% (54.7 ml ± 51.8 ml, p = 0.007). Considerable changes in liver volume change were caused by pneumoperitoneum, laparotomy and respiration. These findings provide knowledge for the refinement of available preoperative simulation and operation planning and help to adjust preoperative imaging parameters to best suit the intraoperative situation.

BACKGROUND:Virtual reality (VR) with head-mounted displays (HMD) may improve medical training and patient care by improving display and integration of different types of information. The aim of this study was to evaluate among different healthcare professions the potential of an interactive and immersive VR environment for liver surgery that integrates all relevant patient data from different sources needed for planning and training of procedures.METHODS:3D-models of the liver, other abdominal organs, vessels, and tumors of a sample patient with multiple hepatic masses were created. 3D-models, clinical patient data, and other imaging data were visualized in a dedicated VR environment with an HMD (IMHOTEP). Users could interact with the data using head movements and a computer mouse. Structures of interest could be selected and viewed individually or grouped. IMHOTEP was evaluated in the context of preoperative planning and training of liver surgery and for the potential of broader surgical application. A standardized questionnaire was voluntarily answered by four groups (students, nurses, resident and attending surgeons).RESULTS:In the evaluation by 158 participants (57 medical students, 35 resident surgeons, 13 attending surgeons and 53 nurses), 89.9% found the VR system agreeable to work with. Participants generally agreed that complex cases in particular could be assessed better (94.3%) and faster (84.8%) with VR than with traditional 2D display methods. The highest potential was seen in student training (87.3%), resident training (84.6%), and clinical routine use (80.3%). Least potential was seen in nursing training (54.8%).CONCLUSIONS:The present study demonstrates that using VR with HMD to integrate all available patient data for the preoperative planning of hepatic resections is a viable concept. VR with HMD promises great potential to improve medical training and operation planning and thereby to achieve improvement in patient care.

Augmented reality (AR) systems are currently being explored by a broad spectrum of industries, mainly for improving point-of-care access to data and images. Especially in surgery and especially for timely decisions in emergency cases, a fast and comprehensive access to images at the patient bedside is mandatory. Currently, imaging data are accessed at a distance from the patient both in time and space, i.e., at a specific workstation. Mobile technology and 3-dimensional (3D) visualization of radiological imaging data promise to overcome these restrictions by making bedside AR feasible.

There are no standards for optimal utilization of workplaces in laparoscopic training. This study aimed to define whether laparoscopy training should be done alone or in pairs (known as dyad training).

Purpose The data which is available to surgeons before, during and after surgery is steadily increasing in quantity as well as diversity. When planning a patient’s treatment, this large amount of information can be difficult to interpret. To aid in processing the information, new methods need to be found to present multimodal patient data, ideally combining textual, imagery, temporal and 3D data in a holistic and context-aware system. Methods We present an open-source framework which allows handling of patient data in a virtual reality (VR) environment. By using VR technology, the workspace available to the surgeon is maximized and 3D patient data is rendered in stereo, which increases depth perception. The framework organizes the data into workspaces and contains tools which allow users to control, manipulate and enhance the data. Due to the framework’s modular design, it can easily be adapted and extended for various clinical applications. Results The framework was evaluated by clinical personnel (77 participants). The majority of the group stated that a complex surgical situation is easier to comprehend by using the framework, and that it is very well suited for education. Furthermore, the application to various clinical scenarios—including the simulation of excitation propagation in the human atrium—demonstrated the framework’s adaptability. As a feasibility study, the framework was used during the planning phase of the surgical removal of a large central carcinoma from a patient’s liver. Conclusion The clinical evaluation showed a large potential and high acceptance for the VR environment in a medical context. The various applications confirmed that the framework is easily extended and can be used in real-time simulation as well as for the manipulation of complex anatomical structures.

Purpose The data which is available to surgeons before, during and after surgery is steadily increasing in quantity as well as diversity. When planning a patient’s treatment, this large amount of information can be difficult to interpret. To aid in processing the information, new methods need to be found to present multi-modal patient data, ideally combining textual, imagery, temporal and 3D data in a holistic and context-aware system. Methods We present an open-source framework which allows handling of patient data in a virtual reality (VR) environment. By using VR technology, the workspace available to the surgeon is maximized and 3D patient data is rendered in stereo, which increases depth perception. The framework organizes the data into workspaces and contains tools which allow users to control, manipulate and enhance the data. Due to the framework’s modular design, it can easily be adapted and extended for various clinical applications. Results The framework was evaluated by clinical personnel (77 participants). The majority of the group stated that a complex surgical situation is easier to comprehend by using the framework, and that it is very well suited for education. Furthermore, the application to various clinical scenarios including the simulation of excitation-propagation in the human atrium demonstrated the framework’s adaptability. As a feasibility study, the framework was used during the planning phase of the surgical removal of a large central carcinoma ? These authors contributed equally to this work. Micha Pfeiffer, Stefanie Speidel National Center for Tumor Diseases, Dresden, Germany E-mail: micha.pfeiffer@nct-dresden.de Matthias Huber Karlsruhe Institute of Technology, Institute for Anthropomatics and Robotics Hannes Kenngott, Anas Preukschas, Lisa Bettscheider, Beat Müller-Stich Heidelberg University Hospital, Department of General-, Visceraland Transplant Surgery ar X iv :1 80 3. 08 26 4v 1 [ cs .H C ] 2 2 M ar 2 01 8 2 Micha Pfeiffer et al. Fig. 1 Left: Traditionally, 2D slices of CT scans are used for planning. Right: In complex scenarios such as this one, where the tumor (yellow) and the various vessel trees (veins, arteries and bile ducts) lie close together, a 3D visualization could greatly benefit physicians in analyzing patient data (screenshot of the virtual reality application). from a patient’s liver. Conclusion The clinical evaluation showed a large potential and high acceptance for the VR environment in a medical context. The various applications confirmed that the framework is easily extended and can be used in real-time simulation as well as for the manipulation of complex anatomical structures.

BACKGROUND:Although minimally invasive surgery (MIS) has replaced many open procedures in visceral surgery, technical and psychomotor obstacles remain a constant challenge for surgeons and trainees. However, there are various training curricula enabling surgeons to acquire the visuospatial and psychomotor abilities additionally required when performing MIS. Currently accepted training modalities include box-trainers, organ and animal models as well as completely simulated training environments, realized in virtual reality (VR) trainers. All of these methods facilitate an adequate training prior to patient contact, so patient safety can benefit as well. This study aims to evaluate the benefit of a structured multi-modality laparoscopy training curriculum. METHODS:Junior and senior surgical residents are included (n = 60). Groups are stratified with concern to previous experience and training of participants. The training curriculum consists of a standardized sequence of available modalities and exercises on box- and VR-trainers. Specific consideration applies to the training effect during the repeated performance of a laparoscopic cholecystectomy (LC) between intervention (training in between LCs) and control group (no training in between LCs). Analysis of training effects is performed using a cadaveric model for LC and objectified using the validated scoring system Global Operative Assessment of Laparoscopic Skills (GOALS). DISCUSSION:This study assesses the value of a multimodal training platform in medical education and postgraduate training and aims at illustrating possible guidelines when establishing such a curriculum. Possible factors of influence, such as varying backgrounds, learning motivation and -success among participants are explored in the data analysis and add beneficially to further evaluating the efficacy of such training to more heterogeneous participant groups like medical students and other professionals.

In the last hundred years surgery has experienced a dramatic increase of scientific knowledge and innovation. The need to consider best available evidence and to apply technical innovations, such as minimally invasive approaches, challenges the surgeon both intellectually and manually. In order to overcome this challenge, computer scientists and surgeons within the interdisciplinary field of “cognitive surgery” explore and innovate new ways of data processing and management. This article gives a general overview of the topic and outlines selected pre-, intra- and postoperative applications. It explores the possibilities of new intelligent devices and software across the entire treatment process of patients ending in the consideration of an “Intelligent Hospital” or “Hospital 4.0”, in which the borders between IT infrastructures, medical devices, medical personnel and patients are bridged by technology. Thereby, the “Hospital 4.0” is an intelligent system, which gives the right information, at the right time, at the right place to the individual stakeholder and thereby helps to decrease complications and improve clinical processes as well as patient outcome.

Purpose: The validated Objective Structured Assessment of Technical Skills (OSATS) score is used for evaluating laparoscopic surgical performance. It consists of two subscores, a Global Rating Scale (GRS) and a Specific Technical Skills (STS) scale. The OSATS has accepted construct validity for direct observation ratings by experts to discriminate between trainees' levels of experience. Expert time is scarce. Endoscopic video recordings would facilitate assessment with the OSATS. We aimed to compare video OSATS with direct OSATS. Methods: We included 79 participants with different levels of experience [58 medical students, 15 junior residents (novices), and 6 experts]. Performance of a cadaveric porcine laparoscopic cholecystectomy (LC) was evaluated with OSATS by blinded expert raters by direct observation and then as an endoscopic video recording. Operative time was recorded. Results: Direct OSATS rating and video OSATS rating correlated significantly (ρ = 0.33, p = 0.005). Significant construct validity was found for direct OSATS in distinguishing between students or novices and experts. Students and novices were not different in direct OSATS or video OSATS. Mean operative times varied for students (73.4 ± 9.0 min), novices (65.2 ± 22.3 min), and experts (46.8 ± 19.9 min). Internal consistency was high between the GRS and STS subscores for both direct and video OSATS with Cronbach's α of 0.76 and 0.86, respectively. Video OSATS and operative time in combination was a better predictor of direct OSATS than each single parameter. Conclusion: Direct OSATS rating was better than endoscopic video rating for differentiating between students or novices and experts for LC and should remain the standard approach for the discrimination of experience levels. However, in the absence of experts for direct rating, video OSATS supplemented with operative time should be used instead of single parameters for predicting direct OSATS scores.

Background: Medical imaging is essential for the diagnosis and therapy of patients.Imaging data is required at the patient's bedside, but is usually accessed at desktop workstations.Advances in mobile technology makes real-time, point-of-care medical applications possible.Our aim was to evaluate such an augmented reality system for medical diagnosis and therapy with regard to feasibility and accuracy in a pilot study involving phantom, animal, and human models.Methods: After computed tomography imaging a tablet computer was positioned above the patient and a semi-transparent 3D-representation of structures of interest were superimposed on top of the patient's image.Live camera images and the 3D-Volume were registered by fiducial markers.Feasibility and accuracy were evaluated in a static model using the open source Heidelberg Laparoscopy Phantom.The system was further analyzed in a porcine animal study.Finally the setup was tested with a human volunteer.Results: In the phantom model of the 1380 analyzed AR-positions 83.9 % could be successfully realized.The reprojection error was 2.83 ± 2.68 mm.95 % of the measurements were below 6.71 mm.In the animal model 79.3 % of the 690 analyzed AR-positions could be successfully realized.In the animal study the reprojection error was 3.52 ± 3.00 mm.95 % of the measurements were below 9.49 mm.The reprojection error was significantly lower in the phantom model compared to the porcine model (P < 0.001).At last augmented reality was successfully realized in clinical case.Conclusion: Mobile, real-time and point-of-care augmented reality systems for clinical purposes are feasible and accurate in a realistic experimental setting.

Guest Editor Gabriele Schackert, Dresden The abstracts are available online, free of charge, under http://www.karger.com/Article/FullText/445224 Published online: April 20, 2016 www.karger.com/esr DOI: 10.1159/000445224 Basel • Freiburg • Paris • London • New York • Chennai • New Delhi • Bangkok • Beijing • Shanghai • Tokyo • Kuala Lumpur • Singapore • Sydney 35 Eur Surg Res 2016;57:34–80 DOI: 10.1159/000445224 Abstracts: 133rd Congress of the German Society of Surgery (DGCH) www.karger.com/esr © 2016 S. Karger AG, Basels: 133rd Congress of the German Society of Surgery (DGCH) www.karger.com/esr © 2016 S. Karger AG, Basel 1 Role of ENTPD2 in Liver Regeneration and Liver Fibrosis L. Feldbruegge1, S. Mitsuhashi1, E. Csizmadia1, M. Schmelzle2, S. Robson1 1Beth Israel Deaconess Medical Center, Boston, USA 2Charité, Berlin, Germany Background: Ecto-nucleoside triphosphate diphosphohydrolases (ENTPD) comprise a family of cell surface located transmembrane proteins that regulate purinergic signaling by catalyzing extracellular nucleotides, such as ATP and ADP. The prototype ENTPD1/CD39 is expressed on endothelium and sinusoidal immune cells, and is a regulator of liver regeneration. The closely related enzyme ENTPD2 is expressed on portal fibroblasts and perivascular cells. In vitro co-incubation studies show that this enzyme on fibroblasts regulates proliferation of cholangiocytes. Its role in liver function in vivo however, has not yet been determined. Herein, we examine pathophysiological functions of ENTPD2 in liver regeneration and liver fibrosis using a newly generated ENTPD2 deficient mouse line. Materials and Methods: Global ENTPD2 knockout mice and matched wild type mice were subjected to 2/3 hepatectomy as a model for liver regeneration, and to 6 weeks of carbon tetrachloride (CCl4) treatment to induce liver fibrosis. Outcomes were compared by studying serum liver function tests, liver histology and immunohistochemistry. Collagen content of liver tissue was determined biochemically by measuring relative hydroxyproline content. Results: ENTPD2 null mice develop normally on the C57BL6 background and do not show abnormalities in liver morphology at baseline. After partial hepatectomy, hepatic ENTPD2 mRNA expression in wild type mice decreased in the first 24 hours and then significantly increased to 3 times basal level at day 5. Serum ALT and other parameters of liver injury as well as the rate of hepatocellular proliferation were comparable in both groups, and there was no relevant difference in liver mass regeneration. However, when fibrosis was induced by CCl4 treatment, mice deficient for ENTPD2 showed significantly more collagen deposition as measured by hydroxyproline content. Histological analysis confirmed more severe fibrosis in the knockout mice while there was no significant difference in liver function tests. Conclusion: ENTPD2 null mice show no major hepatic developmental abnormalities and appear to maintain normal liver regeneration responses when subjected to the acute injury of partial hepatectomy in otherwise healthy livers. In the setting of chronic hepatocellular injury by CCl4 ingestion however, ENTPD2 deficient mice show significantly more fibrosis. As this ecto-enzyme is expressed by myofibroblastic cells surrounding bile ductules within portal triads, and deletion promotes fibrogenesis, we propose that ATP scavenging by ENTPD2 might represent a novel therapeutic target in fibrotic liver disease. 2 Platelets Promote CD133+BMSC Adhesion to Murine Micro and Hepatic Sinusoidal Endothelium Independent of ADP Stimulation Under Flow Condition J. Kirchner1, C. Duhme1, N. Lehwald1, K. Wieferich1, M. Schmelzle2, N.H. Stoecklein1, A. Krieg1, W.T. Knoefel1, J. Schulte am Esch1 1Universitätsklinikum der Heinrich Heine Universität Düsseldorf, Düsseldorf, 2Chirurgische Kliniken der Charité am Campus Virchow-Klinikum, Berlin, Germany Background: We previously demonstrated the therapeutic potential of hematopoetic CD133+ bone marrow stem cells (CD133+BMSC) to promote clinical liver regeneration and the potential of platelets for CD133+BMSC homing along human micro endothelium under shear stress. In this study, we have established a murine model to gain the option of investigation of null and overexpressing cells for homing relevant factors. Furthermore, we evaluated a putative adhesion promoting effect of platelets for CD133+BMSC-homing along hepatic sinusoidal vasculature. Materials and Methods: Commercially available mouse primary dermal micro vasculature endothelial cells (dMECC57BL/6) and mouse hepatic sinusoidal endothelial cells (mSEC) were cultured in capillaries in a live cell imaging system (Bioflux). Primary CD133+BMSC were purified from bone marrow flushed from murine tibiae and femori utilizing FACsorting. dMEC or mSEC were co-cultured under shear stress with CD133+BMSC and platelet rich plasma (PRP) or platelet poor plasma (PPP) as control prepared from murine BMSC donors. To test the effect of pre-stimulation of platelets for adhesion of CD133+BMSC, murine PRP was pre-stimulated with ADP monitored by aggregometry utilizing the Bohrlight-transmission method. Latter prevented over-stimulation with clot-formation. Results: Murine CD133+BMSC co-infused with PRP demonstrated mean adhesion rates of 144% (±17% StdDev; Abstracts 36 Eur Surg Res 2016;57:34–80 DOI: 10.1159/000445224 Abstracts: 133rd Congress of the German Society of Surgery (DGCH) www.karger.com/esr © 2016 S. Karger AG, Basels: 133rd Congress of the German Society of Surgery (DGCH) www.karger.com/esr © 2016 S. Karger AG, Basel p < 0.005) along dMEC under flow if contrasted to PPP co-incubation. Pre-stimulation of platelets with ADP demonstrated a further increase leading to improved adhesion of CD133+BMSC compared to unstimulated conditions. Analogue to micro endothelium a boost of mean adhesion rates of CD133+BMSC to 131% (±9% StdDev; p < 0.05) was observed subsequent to unstimulated PRP co-infusion along mSEC. Conclusion: Our data indicate platelets to trigger adhesion of CD133+BMSC to murine micro vasculature analogue to men in a stimulation independent manner. Further we demonstrate here for the first time that thrombocytes bear the capacity to promote BMSC-adhesion to hepatic vasculature. These data may add to the understanding of mechanisms by which platelets support hepatic generation and offer novel strategies to increase the efficacy of therapeutic BMSC-application in clinical liver disease. 3 Peptide XIB13 Reduces Capillary Leak in a Rodent Burn Model L. Von der Lohe1, K. Zhuravleva2, H. Lauer2, M. Lehnhardt2, J. Kolbenschlag1, K. Schossleitner3, P. Petzelbauer3, O. Goertz1 1Martin-Luther Krankenhaus, Berlin, 2Bergmannsheil Bochum, Bochum, Germany; 3Medical University Vienna, Wien, Austria Background: Edema due to capillary leak is a generalized and life threatening event in sepsis and major burns for which there is no causal treatment. Local burn wounds are an ideal model to investigate the impact of a new therapeutic agent on edema formation. We aimed to identify peptide sequences of cingulin that can attenuate stress-induced endothelial cytoskeleton disarrangement in vitro and which reduce burninduced edema in vivo. Materials and Methods: Cingulin-derived peptides were screened in high content cell culture assays monitoring actin displacement and endothelial cell/cell contacts. The ears of male hairless mice were inflicted with full thickness burns using a hot air jet. Mice with and without burn injuries were treated with Xib13 or solvent by continuous intraperitoneal application for 3 days. Edema, microcirculation, leukocyteendothelial interactions and angiogenesis – measured as nonperfused area – were investigated over a 12-day period using intravital fluorescence microscopy. Results: Xib13 reduced endothelial stress formation and stabilized endothelial tight junctions in cell-cultures. In the burn model, Xib13 improved angiogenesis compared to controls (non-perfused area on day 12: 5.7 ± 1.5% vs. 12.0 ± 2.1%; p b 0.05). Edema was significantly reduced at all observation points in Xib13-treated animals as compared to controls (day 12: 67.6 ± 2.6% vs. 83.2 ± 6.4%). Furthermore a dose dependent effect could be observed. Conclusion: Xib13 improved angiogenesis, reduced edema formation. Since edema formation is a serious parameter for burn conversion and is associated with survival it could provide a new treatment option for patients with burn injuries. 4 Horizontal Transfer of microRNA by Bone Marrow Derived Microparticles Modulates Inflammation after Experimental Liver Resection M. Schmelzle1, K. Splith2, I. Kämmerer2, C. Hegewald2, L. Feldbrügge3, J. Schulte am Esch4, J. Pratschke1, S. Robson3, S. Kuhn2 1Charité – Universitätsmedizin Berlin, Campus VirchowKlinikum, Berlin, 2Universität Leipzig, Leipzig, Germany; 3Beth Israel Deaconess Medical Center, Harvard University, Boston, USA; 4Universitätsklinikum Düsseldorf, Düsseldorf, Germany Background: Mechanisms involved in the communication between bone marrow stem cells and resident cells in the regenerating liver remain uncertain. We aimed to study implications of horizontal miRNA transfer by bone marrow (BM) derived plasma microparticles (MP) with regard to modulations of vascular inflammation and apoptosis of primary liver cells after partial hepatectomy. Materials and Methods: Partial hepatectomy was performed in C57Bl/6 wild type and Cd39 null mice, with latter being unable to phosphohydrolyze pro-inflammatory extracellular adenosine triphosphate (ATP) to adenosine. MP were isolated from the plasma and cell culture supernatant via two-step ultracentrifugation. Gene and miRNA expression was analyzed using qPCR. For fusion studies, MP were labeled with Cy3-labeled RNA oligonucleotides and stained with the PKH67. Fusion was imaged by FACS and confocal microscopy. Cell viability and apoptosis rate was measured using a commercial apoptosis assay. Results: After partial h

Apart from animal testing and clinical trials, surgical research and laparoscopic training mainly rely on phantoms. The aim of this project was to design a phantom with realistic anatomy and haptic characteristics, modular design and easy reproducibility. The phantom was named open-source Heidelberg laparoscopic phantom (OpenHELP) and serves as an open-source platform.

PURPOSE:Feature tracking and 3D surface reconstruction are key enabling techniques to computer-assisted minimally invasive surgery. One of the major bottlenecks related to training and validation of new algorithms is the lack of large amounts of annotated images that fully capture the wide range of anatomical/scene variance in clinical practice. To address this issue, we propose a novel approach to obtaining large numbers of high-quality reference image annotations at low cost in an extremely short period of time.METHODS:The concept is based on outsourcing the correspondence search to a crowd of anonymous users from an online community (crowdsourcing) and comprises four stages: (1) feature detection, (2) correspondence search via crowdsourcing, (3) merging multiple annotations per feature by fitting Gaussian finite mixture models, (4) outlier removal using the result of the clustering as input for a second annotation task.RESULTS:On average, 10,000 annotations were obtained within 24 h at a cost of $100. The annotation of the crowd after clustering and before outlier removal was of expert quality with a median distance of about 1 pixel to a publically available reference annotation. The threshold for the outlier removal task directly determines the maximum annotation error, but also the number of points removed.CONCLUSIONS:Our concept is a novel and effective method for fast, low-cost and highly accurate correspondence generation that could be adapted to various other applications related to large-scale data annotation in medical image computing and computer-assisted interventions.