43 results on '"Sündermann Simon"'
Search Results
2. Learning 3D aortic root assessment based on sparse annotations
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Chen, Weijie, Astley, Susan M., Brosig, Johanna, Krüger, Nina, Wamala, Isaac, Ivantsits, Matthias, Sündermann, Simon, Kempfert, Jörg, Heldmann, Stefan, and Hennemuth, Anja
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- 2024
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3. Preinterventional frailty assessment in patients scheduled for cardiac surgery or transcatheter aortic valve implantation: a consensus statement of the European Association for Cardio-Thoracic Surgery (EACTS) and the European Association of Preventive Cardiology (EAPC) of the European Society of Cardiology (ESC)
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Niebauer, Josef, Bäck, Caroline, Bischoff-Ferrari, Heike A, Dehbi, Hakim-Moulay, Szekely, Andrea, Völler, Heinz, and Sündermann, Simon H
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- 2024
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4. The 10 Commandments for Transaxillary TAVI
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Sündermann, Simon H., Dreger, Henryk, Hinkov, Hristian, and Kempfert, Jörg
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- 2023
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5. Minimally Invasive Extirpation of Benign Atrial Cardiac Tumors: Clinical Follow-Up and Survival
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Van Praet, Karel M., Kofler, Markus, Wilkens, Kristin, Sündermann, Simon H., Meyer, Alexander, Hommel, Matthias, Jacobs, Stephan, Falk, Volkmar, and Kempfert, Jörg
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Objective: Evidence determining the optimal treatment for cardiac tumors is rare. We report our midterm clinical outcome and patient characteristics of our series undergoing atrial tumor removal through a right lateral minithoracotomy (RLMT).Methods: From 2015 to 2021, 51 patients underwent RLMT for atrial tumor extirpation. Patients receiving concomitant atrioventricular valvular, cryoablation, and/or patent foramen ovale closure surgery were included. Follow-up was performed using standardized questionnaires (mean: 1,041 ± 666 days). Follow-up involved any tumor recurrence, clinical symptoms, and any recurrent arterial embolization. Survival analysis was successfully achieved in all patients.Results: Successful surgical resection was achieved in all patients. Mean cardiopulmonary bypass and cross-clamping times were 75 ± 36 and 41 ± 22 min, respectively. The most common tumor location was the left atrium (n= 42, 82.4%). Mean ventilation time was 12.74 ± 17.23 h, intensive care unit stay ranged from 1 to 1.9 days (median: 1 day). Nineteen patients (37.3%) received concomitant surgery. Histopathological analysis showed 38 myxoma (74.5%), 9 papillary fibroelastoma (17.6%), and 4 thrombus (7.8%). Thirty-day mortality was observed in 1 case (2%). One patient (2%) suffered a stroke postoperatively. No patient had a relapse of cardiac tumor. Three patients (9.7%) showed arterial embolization during follow-up. Thirteen follow-up patients (25.5%) were in New York Heart Association class ≤II. Overall survival was 90.2% at 2 years.Conclusions: A minimally invasive approach for benign atrial tumor resection is effective, safe, and reproducible. Of the atrial tumors, 74.5% were myxoma and 82% were located in the left atrium. A low 30-day mortality rate with no manifestation of recurrent intracardiac tumor was observed.
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- 2023
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6. A simulation-based phantom model for generating synthetic mitral valve image data–application to MRI acquisition planning
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Manini, Chiara, Nemchyna, Olena, Akansel, Serdar, Walczak, Lars, Tautz, Lennart, Kolbitsch, Christoph, Falk, Volkmar, Sündermann, Simon, Kühne, Titus, Schulz-Menger, Jeanette, and Hennemuth, Anja
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Purpose: Numerical phantom methods are widely used in the development of medical imaging methods. They enable quantitative evaluation and direct comparison with controlled and known ground truth information. Cardiac magnetic resonance has the potential for a comprehensive evaluation of the mitral valve (MV). The goal of this work is the development of a numerical simulation framework that supports the investigation of MRI imaging strategies for the mitral valve. Methods: We present a pipeline for synthetic image generation based on the combination of individual anatomical 3D models with a position-based dynamics simulation of the mitral valve closure. The corresponding images are generated using modality-specific intensity models and spatiotemporal sampling concepts. We test the applicability in the context of MRI imaging strategies for the assessment of the mitral valve. Synthetic images are generated with different strategies regarding image orientation (SAX and rLAX) and spatial sampling density. Results: The suitability of the imaging strategy is evaluated by comparing MV segmentations against ground truth annotations. The generated synthetic images were compared to ones acquired with similar parameters, and the result is promising. The quantitative analysis of annotation results suggests that the rLAX sampling strategy is preferable for MV assessment, reaching accuracy values that are comparable to or even outperform literature values. Conclusion: The proposed approach provides a valuable tool for the evaluation and optimization of cardiac valve image acquisition. Its application to the use case identifies the radial image sampling strategy as the most suitable for MV assessment through MRI.
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- 2023
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7. Single-Center Experience With a Self-Expandable Venous Cannula During Minimally Invasive Cardiac Surgery
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Van Praet, Karel M., Kofler, Markus, Meyer, Alexander, Sündermann, Simon H., Hommel, Matthias, Falk, Volkmar, and Kempfert, Jörg
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Objective: Venous drainage is often problematic in minimally invasive cardiac surgery (MICS). Here, we describe our experience with a self-expandable stent cannula designed to optimize venous drainage.Methods: The smart canula®was used in 58 consecutive patients undergoing MICS for mitral valve disease (n= 40), left atrial myxoma (n= 3), left ventricular outflow tract obstruction (n= 1), and aortic valve replacement via a right anterior minithoracotomy (n= 14) procedures. The venous cannula was placed under transesophageal echocardiography guidance to reach the superior vena cava. Vacuum-assisted venous drainage (between −20 and −35 mm Hg) was used to reach a target flow index of 2.2 L/min/m² at a core temperature of 34 °C using a goal-directed perfusion strategy aimed at a minimum DO2of 272 mL/min/m2. Cardiopulmonary bypass (CPB) parameters were recorded, and hemolysis-related parameters were analyzed on postoperative days 1 to 7.Results: Mean body surface area and median body mass index were 1.9 ± 0.2 m2and 25.2 (23.4, 30.2) kg/m2. Mean CPB and median cross-clamping times were 107.7 ± 24.4 min and 64.5 (53, 75.8) min, and median CPB flow during cardioplegic arrest was 4 (3.6, 4.2) L/min (median cardiac index 2.1 [2, 2.2] L/min/m²). Venous drainage was considered sufficient by the surgeon in all cases, and insertion and removal were uncomplicated. Mean SvO2during CPB was 80.2% ± 5.5%, and median peak lactate was 10 (8, 14) mg/dL, indicating sufficient perfusion. Mean venous negative drainage pressure during cross-clamping was 27.2 ± 12.3 mm Hg. Platelets dropped by 73.6 ± 37.5 K/µL, lactate dehydrogenase rose by 81.5 (44.3, 140.8) U/L, and leukocytes rose by 3.4 (2.2, 7.2) K/µL on postoperative day 1.Conclusions: The venous smart canula®allows for optimal venous drainage at low negative drainage pressures, facilitating sufficient perfusion in MICS.
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- 2022
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8. Cascaded neural network-based CT image processing for aortic root analysis
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Krüger, Nina, Meyer, Alexander, Tautz, Lennart, Hüllebrand, Markus, Wamala, Isaac, Pullig, Marius, Kofler, Markus, Kempfert, Jörg, Sündermann, Simon, Falk, Volkmar, and Hennemuth, Anja
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Purpose: Careful assessment of the aortic root is paramount to select an appropriate prosthesis for transcatheter aortic valve implantation (TAVI). Relevant information about the aortic root anatomy, such as the aortic annulus diameter, can be extracted from pre-interventional CT. In this work, we investigate a neural network-based approach for segmenting the aortic root as a basis for obtaining these parameters. Methods: To support valve prosthesis selection, geometric measures of the aortic root are extracted from the patient’s CT scan using a cascade of convolutional neural networks (CNNs). First, the image is reduced to the aortic root, valve, and left ventricular outflow tract (LVOT); within that subimage, the aortic valve and ascending aorta are segmented; and finally, the region around the aortic annulus. From the segmented annulus region, we infer the annulus orientation using principal component analysis (PCA). The area-derived diameter of the annulus is approximated based on the segmentation of the aortic root and LVOT and the plane orientation resulting from the PCA. Results: The cascade of CNNs was trained using 90 expert-annotated contrast-enhanced CT scans routinely acquired for TAVI planning. Segmentation of the aorta and valve within the region of interest achieved an F1 score of 0.94 on the test set of 36 patients. The area-derived diameter within the annulus region was determined with a mean error below 2 mm between the automatic measurement and the diameter derived from annotations. The calculated diameters and resulting errors are comparable to published results of alternative approaches. Conclusions: The cascaded neural network approach enabled the assessment of the aortic root with a relatively small training set. The processing time amounts to 30 s per patient, facilitating time-efficient, reproducible measurements. An extended training data set, including different levels of calcification or special cases (e.g., pre-implanted valves), could further improve this method’s applicability and robustness.
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- 2022
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9. Endoaortic Balloon Occlusion During Minimally Invasive Mitral Valve Surgery
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Van Praet, Karel M., Kofler, Markus, Sündermann, Simon H., and Kempfert, Jörg
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- 2022
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10. Real-Time Ventricular Volume Measured Using the Intracardiac Electromyogram
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Schmid Daners, Marianne, Hall, Sophie, Sündermann, Simon, Cesarovic, Nikola, Kron, Mareike, Falk, Volkmar, Starck, Christoph, Meboldt, Mirko, and Dual, Seraina A.
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Supplemental Digital Content is available in the text.Left ventricular end-diastolic volume (EDV) is an important parameter for monitoring patients with left ventricular assist devices (LVADs) and might be useful for automatic LVAD work adaptation. However, continuous information on the EDV is unavailable to date. The depolarization amplitude (DA) of the noncontact intracardiac electromyogram (iEMG) is physically related to the EDV. Here, we show how a left ventricular (LV) volume sensor based on the iEMG might provide beat-wise EDV estimates. The study was performed in six pigs while undergoing a series of controlled changes in hemodynamic states. The LV volume sensor consisted of four conventional pacemaker electrodes measuring the far-field iEMG inside the LV blood pool, using a novel unipolar amplifier. Simultaneously, noninvasive measurements of EDV and hematocrit were recorded. The proposed EDV predictor was tested for statistical significance using a mixed-effect model and associated confidence intervals. A statistically significant (p= 3e–07) negative correlation was confirmed between the DA of the iEMG and the EDV as measured by electric impedance at a slope of –0.069 (–0.089, –0.049) mV/mL. The DA was slightly decreased by increased hematocrit (p= 0.039) and moderately decreased with the opening of the thorax (p= 0.003). The DA of the iEMG proved to be a significant, independent predictor of EDV. The proposed LV volume sensor is simple to integrate into the inflow cannula of an LVAD and thus has the potential to inform the clinician about the state of LV volume in real time and to automatically control the LVAD.
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- 2021
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11. SLL-PEEP Ventilation to Improve Exposure in Minimally Invasive Right Anterolateral Minithoracotomy Aortic Valve Replacement
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Richter, Gregor, Van Praet, Karel M., Hommel, Matthias, Sündermann, Simon H., Kofler, Markus, Meyer, Alexander, Unbehaun, Axel, Starck, Christoph, Jacobs, Stephan, Falk, Volkmar, and Kempfert, Jörg
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Objective An accepted landmark to assess feasibility of surgical aortic valve replacement (SAVR) via right anterolateral minithoracotomy (RALT) is the aortic-midpoint to right-sternal-edge distance. We aimed to evaluate single left lung positive-end-expiratory-pressure (SLL-PEEP) ventilation inducing an intraoperative rightward shift of the ascending aorta to improve exposure.Methods Nineteen patients with aortic stenosis undergoing SAVR via RALT were prospectively analyzed. SLL-PEEP ventilation (20,395 cmH2O) via a double-lumen endotracheal tube was applied immediately before transthoracic aortic cross-clamping, thereby inducing rightward shift of the ascending aorta to enhance exposure. We analyzed preoperative computed tomography (CT) reconstructions and intraoperative video recordings. Primary endpoint was extent of rightward shift induced by SLL-PEEP ventilation; secondary endpoints were procedure times and safety events.Results Mean age was 61 ± 14.8 years and 6 of 19 (31.6%) were female. Mean EuroSCORE II was 0.81% ± 0.04%, STS-PROM was 1.13% ± 0.74%, and mean aortic rightward shift induced by SLL-PEEP ventilation was 10.32 ± 4.14 mm (4 to 17 mm; P= 0.003). Median shift in the group considered suitable for the RALT approach by preoperative CT-scan evaluation was 14.2 mm (IQR 11) and in the less suitable group 11.5 mm (IQR 5). Mean procedure time was 167 ± 28.9 min, CPB time was 105.7 ± 18.4 min, and cross-clamp time was 64.5 ± 13 min. Fifteen patients (79%) received SAVR via RALT with implantation of a bioprosthesis, whereas a rapid-deployment-prosthesis was used in 4 patients (21%). Ten of 19 (53%) patients who were classified as less suitable preoperatively received SAVR via RALT after SLL-PEEP ventilation. No strokes were observed.Conclusions The SLL-PEEP ventilation maneuver during SAVR via RALT significantly enhances aortic exposure. There were no safety events associated with this maneuver and we were able to demonstrate significant rightward aortic shift in every single patient.
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- 2021
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12. Distinctive Paravalvular Jets of a Novel Self-Expanding Transcatheter Aortic Valve With a Unique Skirt Design.
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Romero Dorta, Elena, Mattig, Isabel, Kösters, Lorenz, Sündermann, Simon H., Spethmann, Sebastian, Stangl, Karl, and Dreger, Henryk
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- 2023
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13. Interactive editing of virtual chordae tendineae for the simulation of the mitral valve in a decision support system
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Walczak, Lars, Tautz, Lennart, Neugebauer, Mathias, Georgii, Joachim, Wamala, Isaac, Sündermann, Simon, Falk, Volkmar, and Hennemuth, Anja
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Purpose: Decision support systems for mitral valve disease are an important step toward personalized surgery planning. A simulation of the mitral valve apparatus is required for decision support. Building a model of the chordae tendineae is an essential component of a mitral valve simulation. Due to image quality and artifacts, the chordae tendineae cannot be reliably detected in medical imaging. Methods: Using the position-based dynamics framework, we are able to realistically simulate the opening and closing of the mitral valve. Here, we present a heuristic method for building an initial chordae model needed for a successful simulation. In addition to the heuristic, we present an interactive editor to refine the chordae model and to further improve pathology reproduction as well as geometric approximation of the closed valve. Results: For evaluation, five mitral valves were reconstructed based on image sequences of patients scheduled for mitral valve surgery. We evaluated the approximation of the closed valves using either just the heuristic chordae model or a manually refined model. Using the manually refined models, prolapse was correctly reproduced in four of the five cases compared to two of the five cases when using the heuristic. In addition, using the editor improved the approximation in four cases. Conclusions: Our approach is suitable to create realistically parameterized mitral valve apparatus reconstructions for the simulation of normally and abnormally closing valves in a decision support system.
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- 2021
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14. Combining position-based dynamics and gradient vector flow for 4D mitral valve segmentation in TEE sequences
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Tautz, Lennart, Walczak, Lars, Georgii, Joachim, Jazaerli, Amer, Vellguth, Katharina, Wamala, Isaac, Sündermann, Simon, Falk, Volkmar, and Hennemuth, Anja
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Purpose: For planning and guidance of minimally invasive mitral valve repair procedures, 3D+t transesophageal echocardiography (TEE) sequences are acquired before and after the intervention. The valve is then visually and quantitatively assessed in selected phases. To enable a quantitative assessment of valve geometry and pathological properties in all heart phases, as well as the changes achieved through surgery, we aim to provide a new 4D segmentation method. Methods: We propose a tracking-based approach combining gradient vector flow (GVF) and position-based dynamics (PBD). An open-state surface model of the valve is propagated through time to the closed state, attracted by the GVF field of the leaflet area. The PBD method ensures topological consistency during deformation. For evaluation, one expert in cardiac surgery annotated the closed-state leaflets in 10 TEE sequences of patients with normal and abnormal mitral valves, and defined the corresponding open-state models. Results: The average point-to-surface distance between the manual annotations and the final tracked model was
. Qualitatively, four cases were satisfactory, five passable and one unsatisfactory. Each sequence could be segmented in 2–6 min. Conclusion: Our approach enables to segment the mitral valve in 4D TEE image data with normal and pathological valve closing behavior. With this method, in addition to the quantification of the remaining orifice area, shape and dimensions of the coaptation zone can be analyzed and considered for planning and surgical result assessment.\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$1.00\,\hbox {mm} \pm 1.08\,\hbox {mm}$$\end{document} - Published
- 2020
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15. Machine learning for real-time prediction of complications in critical care: a retrospective study.
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Meyer, Alexander, Zverinski, Dina, Pfahringer, Boris, Kempfert, Jörg, Kuehne, Titus, Sündermann, Simon H, Stamm, Christof, Hofmann, Thomas, Falk, Volkmar, and Eickhoff, Carsten
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KIDNEY diseases ,HOSPITAL admission & discharge ,INTENSIVE care units ,ACUTE kidney failure ,MACHINE learning ,INTENSIVE care patients ,CLINICAL prediction rules ,KIDNEY failure ,DEEP learning - Abstract
Summary Background The large amount of clinical signals in intensive care units can easily overwhelm health-care personnel and can lead to treatment delays, suboptimal care, or clinical errors. The aim of this study was to apply deep machine learning methods to predict severe complications during critical care in real time after cardiothoracic surgery. Methods We used deep learning methods (recurrent neural networks) to predict several severe complications (mortality, renal failure with a need for renal replacement therapy, and postoperative bleeding leading to operative revision) in post cardiosurgical care in real time. Adult patients who underwent major open heart surgery from Jan 1, 2000, to Dec 31, 2016, in a German tertiary care centre for cardiovascular diseases formed the main derivation dataset. We measured the accuracy and timeliness of the deep learning model's forecasts and compared predictive quality to that of established standard-of-care clinical reference tools (clinical rule for postoperative bleeding, Simplified Acute Physiology Score II for mortality, and the Kidney Disease: Improving Global Outcomes staging criteria for acute renal failure) using positive predictive value (PPV), negative predictive value, sensitivity, specificity, area under the curve (AUC), and the F 1 measure (which computes a harmonic mean of sensitivity and PPV). Results were externally retrospectively validated with 5898 cases from the published MIMIC-III dataset. Findings Of 47 559 intensive care admissions (corresponding to 42 007 patients), we included 11 492 (corresponding to 9269 patients). The deep learning models yielded accurate predictions with the following PPV and sensitivity scores: PPV 0·90 and sensitivity 0·85 for mortality, 0·87 and 0·94 for renal failure, and 0·84 and 0·74 for bleeding. The predictions significantly outperformed the standard clinical reference tools, improving the absolute complication prediction AUC by 0·29 (95% CI 0·23–0·35) for bleeding, by 0·24 (0·19–0·29) for mortality, and by 0·24 (0·13–0·35) for renal failure (p<0·0001 for all three analyses). The deep learning methods showed accurate predictions immediately after patient admission to the intensive care unit. We also observed an increase in performance in our validation cohort when the machine learning approach was tested against clinical reference tools, with absolute improvements in AUC of 0·09 (95% CI 0·03–0·15; p=0·0026) for bleeding, of 0·18 (0·07–0·29; p=0·0013) for mortality, and of 0·25 (0·18–0·32; p<0·0001) for renal failure. Interpretation The observed improvements in prediction for all three investigated clinical outcomes have the potential to improve critical care. These findings are noteworthy in that they use routinely collected clinical data exclusively, without the need for any manual processing. The deep machine learning method showed AUC scores that significantly surpass those of clinical reference tools, especially soon after admission. Taken together, these properties are encouraging for prospective deployment in critical care settings to direct the staff's attention towards patients who are most at risk. Funding No specific funding. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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16. ConVes: The Sutureless Aortic Graft Anastomotic Device.
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Dual, Seraina Anne, Muller, Alissa, Boës, Stefan, Brinkmann, Oliver, Steffanoni, Séline, Falk, Volkmar, Meboldt, Mirko, Schmid Daners, Marianne, and Sündermann, Simon
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Purpose Less invasive left ventricular assist device implantation became feasible with the development of smaller devices. This study evaluated a sutureless aortic anastomosis device to facilitate the implant procedure. Description The novel anastomotic device deploys and anchors an acute-angled stent in the aortic wall to create a sutureless outflow graft anastomosis in the ascending aorta. Four aortic anastomoses were performed on the beating hearts of two pigs without cross-clamping or cardiopulmonary bypass. Evaluation The procedure was fast and simple. The time of anastomosis averaged 8.1 minutes, with merely oral instructions to the operating surgeon. The design of the stent allowed the outflow graft to be implanted with the intended angulation of 45 degrees. Conclusions This proof-of-concept study demonstrates the feasibility and short-term success of the proposed sutureless anastomotic device. Further preclinical studies are necessary to evaluate long-term durability of the anastomosis. [ABSTRACT FROM AUTHOR]
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- 2018
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17. User-dependent variability in mitral valve segmentation and its impact on CFD-computed hemodynamic parameters
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Vellguth, Katharina, Brüning, Jan, Tautz, Lennart, Degener, Franziska, Wamala, Isaac, Sündermann, Simon, Kertzscher, Ulrich, Kuehne, Titus, Hennemuth, Anja, Falk, Volkmar, and Goubergrits, Leonid
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Purpose: While novel tools for segmentation of the mitral valve are often based on automatic image processing, they mostly require manual interaction by a proficient user. Those segmentations are essential for numerical support of mitral valve treatment using computational fluid dynamics, where the reconstructed geometry is incorporated into a simulation domain. To quantify the uncertainty and reliability of hemodynamic simulations, it is crucial to examine the influence of user-dependent variability in valve segmentation. Methods: Previously, the inter-user variability of landmarks in mitral valve segmentation was investigated. Here, the inter-user variability of geometric parameters of the mitral valve, projected orifice area (OA) and projected annulus area (AA), is investigated for 10 mitral valve geometries, each segmented by three users. Furthermore, the propagation of those variations into numerically calculated hemodynamics, i.e., the blood flow velocity, was investigated. Results: Among the three geometric valve parameters, AA was least user-dependent. Almost all deviations to the mean were below 10%. Larger variations were observed for OA. Variations observed for the numerically calculated hemodynamics were in the same order of magnitude as those of geometric parameters. No correlation between variation of geometric parameters and variation of calculated hemodynamic parameters was found. Conclusion: Errors introduced due to the user-dependency were of the same size as the variations of calculated hemodynamics. The variation was thereby of the same scale as deviations in clinical measurements of blood flow velocity using Doppler echocardiography. Since no correlation between geometric and hemodynamic uncertainty was found, further investigation of the complex relationship between anatomy, leaflet shape and flow is necessary.
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- 2019
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18. Virtual downsizing for decision support in mitral valve repair
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Neugebauer, Mathias, Tautz, Lennart, Hüllebrand, Markus, Sündermann, Simon, Degener, Franziska, Goubergrits, Leonid, Kühne, Titus, Falk, Volkmar, and Hennemuth, Anja
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Purpose: Various options are available for the treatment of mitral valve insufficiency, including reconstructive approaches such as annulus correction through ring implants. The correct choice of general therapy and implant is relevant for an optimal outcome. Additional to guidelines, decision support systems (DSS) can provide decision aid by means of virtual intervention planning and predictive simulations. Our approach on virtual downsizing is one of the virtual intervention tools that are part of the DSS workflow. It allows for emulating a ring implantation based on patient-specific lumen geometry and vendor-specific implants. Methods: Our approach is fully automatic and relies on a lumen mask and an annulus contour as inputs. Both are acquired from previous DSS workflow steps. A virtual surface- and contour-based model of a vendor-specific ring design (26–40 mm) is generated. For each case, the ring geometry is positioned with respect to the original, patient-specific annulus and additional anatomical landmarks. The lumen mesh is parameterized to allow for a vertex-based deformation with respect to the user-defined annulus. Derived from post-interventional observations, specific deformation schemes are applied to atrium and ventricle and the lumen mesh is altered with respect to the ring location. Results: For quantitative evaluation, the surface distance between the deformed lumen mesh and segmented post-operative echo lumen close to the annulus was computed for 11 datasets. The results indicate a good agreement. An arbitrary subset of six datasets was used for a qualitative evaluation of the complete lumen. Two domain experts compared the deformed lumen mesh with post-interventional echo images. All deformations were deemed plausible. Conclusion: Our approach on virtual downsizing allows for an automatic creation of plausible lumen deformations. As it takes only a few seconds to generate results, it can be added to a virtual intervention toolset without unnecessarily increasing the pipeline complexity.
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- 2019
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19. Machine learning for real-time prediction of complications in critical care: a retrospective study
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Meyer, Alexander, Zverinski, Dina, Pfahringer, Boris, Kempfert, Jörg, Kuehne, Titus, Sündermann, Simon H, Stamm, Christof, Hofmann, Thomas, Falk, Volkmar, and Eickhoff, Carsten
- Abstract
The large amount of clinical signals in intensive care units can easily overwhelm health-care personnel and can lead to treatment delays, suboptimal care, or clinical errors. The aim of this study was to apply deep machine learning methods to predict severe complications during critical care in real time after cardiothoracic surgery.
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- 2018
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20. Turbulent Kinetic Energy Assessed by Multipoint 4-Dimensional Flow Magnetic Resonance Imaging Provides Additional Information Relative to Echocardiography for the Determination of Aortic Stenosis Severity.
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Binter, Christian, Gotschy, Alexander, Sündermann, Simon H., Frank, Michelle, Tanner, Felix C., Lüscher, Thomas F., Manka, Robert, and Kozerke, Sebastian
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Background—Turbulent kinetic energy (TKE), assessed by 4-dimensional (4D) flow magnetic resonance imaging, is a measure of energy loss in disturbed flow as it occurs, for instance, in aortic stenosis (AS). This work investigates the additional information provided by quantifying TKE for the assessment of AS severity in comparison to clinical echocardiographic measures. Methods and Results—Fifty-one patients with AS (67±15 years, 20 female) and 10 healthy age-matched controls (69±5 years, 5 female) were prospectively enrolled to undergo multipoint 4D flow magnetic resonance imaging. Patients were split into 2 groups (severe and mild/moderate AS) according to their echocardiographic mean pressure gradient. TKE values were integrated over the aortic arch to obtain peak TKE. Integrating over systole yielded total TKE
sys and by normalizing for stroke volume, normalized TKEsys was obtained. Mean pressure gradient and TKE correlated only weakly (R²=0.26 for peak TKE and R²=0.32 for normalized TKEsys ) in the entire study population including control subjects, while no significant correlation was observed in the AS patient group. In the patient population with dilated ascending aorta, both peak TKE and total TKEsys were significantly elevated (P<0.01), whereas mean pressure gradient was significantly lower (P<0.05). Patients with bicuspid aortic valves also showed significantly increased TKE metrics (P<0.01), although no significant difference was found for mean pressure gradient. Conclusions—Elevated TKE levels imply higher energy losses associated with bicuspid aortic valves and dilated ascending aortic geometries that are not assessable by current echocardiographic measures. These findings indicate that TKE may provide complementary information to echocardiography, helping to distinguish within the heterogeneous population of patients with moderate to severe AS. [ABSTRACT FROM AUTHOR]- Published
- 2017
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21. Extraction of open-state mitral valve geometry from CT volumes
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Tautz, Lennart, Neugebauer, Mathias, Hüllebrand, Markus, Vellguth, Katharina, Degener, Franziska, Sündermann, Simon, Wamala, Isaac, Goubergrits, Leonid, Kuehne, Titus, Falk, Volkmar, and Hennemuth, Anja
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The importance of mitral valve therapies is rising due to an aging population. Visualization and quantification of the valve anatomy from image acquisitions is an essential component of surgical and interventional planning. The segmentation of the mitral valve from computed tomography (CT) acquisitions is challenging due to high variation in appearance and visibility across subjects. We present a novel semi-automatic approach to segment the open-state valve in 3D CT volumes that combines user-defined landmarks to an initial valve model which is automatically adapted to the image information, even if the image data provide only partial visibility of the valve. Context information and automatic view initialization are derived from segmentation of the left heart lumina, which incorporates topological, shape and regional information. The valve model is initialized with user-defined landmarks in views generated from the context segmentation and then adapted to the image data in an active surface approach guided by landmarks derived from sheetness analysis. The resulting model is refined by user landmarks. For evaluation, three clinicians segmented the open valve in 10 CT volumes of patients with mitral valve insufficiency. Despite notable differences in landmark definition, the resulting valve meshes were overall similar in appearance, with a mean surface distance of $$1.62 \pm 2.10$$ 1.62±2.10 mm. Each volume could be segmented in 5–22 min. Our approach enables an expert user to easily segment the open mitral valve in CT data, even when image noise or low contrast limits the visibility of the valve.
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- 2018
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22. Development of a modeling pipeline for the prediction of hemodynamic outcome after virtual mitral valve repair using image-based CFD
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Vellguth, Katharina, Brüning, Jan, Goubergrits, Leonid, Tautz, Lennart, Hennemuth, Anja, Kertzscher, Ulrich, Degener, Franziska, Kelm, Marcus, Sündermann, Simon, and Kuehne, Titus
- Abstract
Severe mitral valve regurgitation can either be treated by a replacement or a repair of the valve. The latter is recommended due to lower perioperative mortality and better long-term survival. On the other hand, recurrence rates after mitral valve repair are high compared to those after replacements and the repair intervention can cause induced mitral valve stenosis. So far, there are no methods to predict the hemodynamic outcome of a chosen treatment or to compare different treatment options in advance. To overcome this, diastolic mitral valve hemodynamics are simulated using computational fluid dynamics after different virtual treatments of the valve. The left ventricular geometry of one patient was reconstructed using trans-esophageal echocardiography and computed tomography data. Pre-op hemodynamics are simulated using a referenced wall model to avoid expansive modeling of wall motion. Subsequently, the flow structures are compared to in vivo measurements. After manipulating the patient-specific geometry in order to mimic a restrictive mitral annuloplasty as well as a MitraClip intervention, hemodynamics results are calculated. Good agreements exist between calculated pre-op hemodynamics and in vivo measurements. The virtual annuloplasty did not result in any remarkable change of hemodynamics. Neither the pressure drop nor the velocity field showed strong differences. In contrast, the virtual MitraClip intervention led to a complete change in blood flow structures as well as an elevated pressure drop across the valve. The presented approach allows fast simulation of the diastolic hemodynamic situation before and after treatment of a mitral valve insufficiency. However, this approach is limited to the early diastolic phase of the cardiac cycle and needs to be validated using a larger sample size.
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- 2018
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23. Die neue EACTS/ESC-Leitlinie im Spannungsfeld Operation versus Katheterintervention – Perspektive des Herzchirurgen
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Sündermann, Simon H., Unbehaun, Axel, Kempfert, Jörg, and Falk, Volkmar
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- 2018
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24. Impact of patient-specific LVOT inflow profiles on aortic valve prosthesis and ascending aorta hemodynamics.
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Bruening, Jan, Hellmeier, Florian, Yevtushenko, Pavlo, Kelm, Marcus, Nordmeyer, Sarah, Sündermann, Simon H., Kuehne, Titus, and Goubergrits, Leonid
- Subjects
AORTIC valve ,HEMODYNAMICS ,AORTA ,PROSTHETICS ,PROSTHETIC heart valves - Abstract
Patient-specific models become increasingly important in cardiovascular research as they allow prediction of surgical procedures. While the left ventricular outflow profile is an essential boundary condition, it remains unknown before treatment takes place. To overcome this problem, hemodynamics after virtual valve replacement were calculated based on different inlet profiles at the left ventricular outflow tract: a generic plug profile and a profile derived from 4D-flow-MRI. Spatially averaged parameters within the aorta were not significantly altered using either profile. A generic profile might be sufficient for the prediction of hemodynamics, circumventing the problem of predicting change in patient-specific boundary conditions. [ABSTRACT FROM AUTHOR]
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- 2018
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25. Experience with a standardized protocol to predict successful explantation of left ventricular assist devices.
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Hrytsyna, Yuriy, Kneissler, Simon, Kaufmann, Friedrich, Müller, Marcus, Schoenrath, Felix, Mulzer, Johanna, Sündermann, Simon H., Falk, Volkmar, Potapov, Evgenij, and Knierim, Jan
- Abstract
Patients with a continuous-flow left ventricular assist device may show recovery of myocardial function with unloading. Identifying candidates for and predicting clinical and hemodynamic stability after left ventricular assist device explantation remain challenging. Retrospective analysis of patients who underwent evaluation for left ventricular assist device explantation following a standardized protocol from January 2016 to March 2020. Patients who met screening criteria underwent echocardiography under "baseline," "minimal net flow," and "pump stop" conditions. If the protocol criteria were met, right heart catheterization with left ventricular assist device stoppage and occlusion of the outflow graft with a balloon catheter were performed. In patients with pulmonary capillary wedge pressure less than 16 mm Hg, explantation was performed under "pump stop" conditions. A total of 544 patients were screened. Of these, 57 (10.5%) underwent a total of 73 echocardiography under "baseline" "minimal net flow" and "pump stop" conditions and 46 underwent left ventricular assist device stoppage and occlusion of the outflow graft with balloon catheter maneuvers. Complications during the procedure were rare. Ultimately, 21 patients (3.9%) underwent explantation. The left ventricular ejection fraction at baseline was 55.5% ± 6.5%. The mean pulmonary capillary wedge pressure was 8.1 ± 2.6 mm Hg and increased to 10.7 ± 2.9 mm Hg under left ventricular assist device stoppage and occlusion of the outflow graft with a balloon catheter. A nonischemic cause of cardiomyopathy was more likely to be found in patients who underwent explantation (20/21 patients [95%], P =.020). The survival 1 year after explantation was 95.2%, with 1 death occurring 222 days after left ventricular assist device explantation. At follow-up (median 24.9 months [interquartile range, 16.4-43.1 months]), patients were in New York Heart Association class 1 (61.9%), 2 (28.6%), and 3 (9.5%). Our 4-year experience with a standardized protocol for left ventricular assist device explantation showed a low rate of adverse events. If all criteria are met, explantation can be performed safely and with an excellent survival and functional class. [Display omitted] [ABSTRACT FROM AUTHOR]
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- 2022
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26. Operative Therapie – Mitralklappenrekonstruktion oder Mitralklappenersatz?
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Sündermann, Simon and Falk, Volkmar
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- 2017
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27. Frailty Assessed by the Forecast is a Valid Tool to Predict Short-Term Outcome after Transcatheter Aortic Valve Replacement
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Kobe, Adrian R., Meyer, Alexander, Elmubarak, Hassan, Kempfert, Jörg, Pavicevic, Jovana, Maisano, Francesco, Walther, Thomas, Falk, Volkmar, and Sündermann, Simon H.
- Abstract
Objective The term frailty is frequently used during decision-making in transcatheter heart valve procedures. Nevertheless, frailty is still measured by eyeballing rather than by using standardized frailty assessments. In a previous study, we developed a frailty score in a cardiac surgical patient population including patients, who underwent transcatheter aortic valve replacement (TAVR). Here, we present the results from the subsequent validation study focusing on the TAVR cohort.Methods One hundred thirty patients underwent TAVR. Frailty assessment using the FORECAST (Frailty predicts death One yeaR after Elective CArdiac Surgery Test) was performed. The European System for Cardiac Operative Risk Evaluation and The Society of Thoracic Surgeons (STS) score were assessed as well. Follow-up included assessment of in-hospital and 30-day mortality and morbidity and quality of life using the Short Form-36 questionnaire.Results Mean age was 83.3 years, and 50% were female. Logistic European System for Cardiac Operative Risk Evaluation was 14.9 ± 8.7%, and STS score was 5.1 ± 3.4%. Mean ± standard deviation FORECAST score was 4.8 ± 3.3 points of 15. In-hospital and 30-day mortality were 6.9% and 7.7%, respectively. Thirty-day Short Form-36 assessment showed a decrease in quality of life in five of ten items after the intervention. Receiver operating characteristic curves showed that the FORECAST is a valid tool to predict in-hospital mortality (area under the receiver operating characteristic curve, 0.73). By combining the FORECAST and the STS score, this effect was even higher (area under the receiver operating characteristic curve, 0.77; P = 0.021). Stratifying the patients according to the FORECAST score showed best survival in the lowest frailty group.Conclusions The FORECAST is a valid tool to assess frailty in TAVR patients. The FORECAST is easily assessable and can be included in daily clinical routine.
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- 2016
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28. Frailty Assessed by the Forecast is a Valid Tool to Predict Short-Term Outcome after Transcatheter Aortic Valve Replacement
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Kobe, Adrian R., Meyer, Alexander, Elmubarak, Hassan, Kempfert, Jörg, Pavicevic, Jovana, Maisano, Francesco, Walther, Thomas, Falk, Volkmar, and Sündermann, Simon H.
- Abstract
Objective The term frailty is frequently used during decision-making in transcatheter heart valve procedures. Nevertheless, frailty is still measured by eyeballing rather than by using standardized frailty assessments. In a previous study, we developed a frailty score in a cardiac surgical patient population including patients, who underwent transcatheter aortic valve replacement (TAVR). Here, we present the results from the subsequent validation study focusing on the TAVR cohort.Methods One hundred thirty patients underwent TAVR. Frailty assessment using the FORECAST (Frailty predicts death One yeaR after Elective CArdiac Surgery Test) was performed. The European System for Cardiac Operative Risk Evaluation and The Society of Thoracic Surgeons (STS) score were assessed as well. Follow-up included assessment of in-hospital and 30-day mortality and morbidity and quality of life using the Short Form-36 questionnaire.Results Mean age was 83.3 years, and 50% were female. Logistic European System for Cardiac Operative Risk Evaluation was 14.9 ± 8.7%, and STS score was 5.1 ± 3.4%. Mean ± standard deviation FORECAST score was 4.8 ± 3.3 points of 15. In-hospital and 30-day mortality were 6.9% and 7.7%, respectively. Thirty-day Short Form-36 assessment showed a decrease in quality of life in five of ten items after the intervention. Receiver operating characteristic curves showed that the FORECAST is a valid tool to predict in-hospital mortality (area under the receiver operating characteristic curve, 0.73). By combining the FORECAST and the STS score, this effect was even higher (area under the receiver operating characteristic curve, 0.77; P = 0.021). Stratifying the patients according to the FORECAST score showed best survival in the lowest frailty group.Conclusions The FORECAST is a valid tool to assess frailty in TAVR patients. The FORECAST is easily assessable and can be included in daily clinical routine.
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- 2016
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29. Mitral valve surgery: Right lateral minithoracotomy or sternotomy? A systematic review and meta-analysis.
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Sündermann, Simon H., Sromicki, Juri, Rodriguez Cetina Biefer, Héctor, Seifert, Burkhardt, Holubec, Tomas, Falk, Volkmar, and Jacobs, Stephan
- Abstract
Objective To update the current evidence on mitral valve surgery through a lateral minithoracotomy versus median sternotomy. Methods A comprehensive literature research was performed for studies comparing mitral valve surgery through a right lateral minithoracotomy (MIVS) and median sternotomy in MEDLINE, EMBASE, Cochrane Central, CTSnet, and Google Scholar for the most recent literature up to April 2013. A systematic review and meta-analysis was performed on the studies found in the literature. Results More than 20,000 patients from 45 studies were included in this study. Stroke rate and all-cause mortality up to 30 days was similar in both groups. The length of stay in the intensive care unit, respirator dependence, and hospital stay were significantly shorter in the MIVS group. Furthermore, blood drainage volume and blood transfusions were decreased in the MIVS group. In contrast, cardiopulmonary bypass time, crossclamp time, and procedure time were longer in the MIVS group. Postoperative new atrial fibrillation was less in the MIVS group. More aortic dissections occurred in the MIVS group. The rates of reexploration and postoperative renal failure were similar in both groups. Conclusions MIVS and conventional mitral valve surgery have a similar perioperative outcome. Mitral valve surgery via a right lateral minithoracotomy seems to be favorable with regard to resource-related outcome. [ABSTRACT FROM AUTHOR]
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- 2014
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30. Surviving 20 Years After Heart Transplantation: A Success Story.
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Rodriguez Cetina Biefer, Hector, Sündermann, Simon H., Emmert, Maximilian Y., Enseleit, Frank, Seifert, Burkhardt, Ruschitzka, Frank, Jacobs, Stephan, Lachat, Mario L., Falk, Volkmar, and Wilhelm, Markus J.
- Abstract
Background: We report the long-term outcomes of patients who survived 20 years or greater after heart transplantation. Methods: From 1985 to 2012, 386 patients underwent heart transplantation at our institution. Patient data were analyzed retrospectively for transplants performed from 1985 to 1991. The Kaplan-Meier method was used for survival analyses. Results: In total, 133 patients were included. The mean age of the 20-year survivors at transplant was 43.6 ± 11.4 years. The mean ischemic time was 71.2 ± 34.0 minutes. The overall actuarial survival rates at 1, 10, and 20 years were 82.7%, 63.9%, and 55.6%, respectively. The most common causes of death were graft rejection (21%), malignancy (21%), infection (15%), and cardiac allograft vasculopathy (CAV, 14%). After 1, 10, and 20 years, the rejection-free survival rates were 19%, 13%, and 13%, respectively, and the malignancy-free survival rates were 99%, 67%, and 61%. The CAV-free survival rates were 97%, 48%, and 42%, respectively, and the infection-free survival rates were, respectively, 70%, 15%, and 14%. The actuarial diabetes-free survival rates at 1, 10, and 20 years were 85%, 80%, and 79%, respectively. Actuarial hypertension-free survival was 56% after 1 year and 26% after 10 and 20 years. Two patients received a second heart transplant. Conclusions: A remarkable number of patients survived 20 years or greater after heart transplantation, confirming the procedure as the gold standard for end-stage heart failure. Complications resulting from immunologic events and immunosuppressive therapy determine post-transplant mortality and morbidity. Due to improvements in immunosuppressive management in recent years, long-term survival is likely to increase. [Copyright &y& Elsevier]
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- 2014
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31. Minimally Invasive Cardiac Surgery: Removal of an Interatrial Intraseptal Bronchogenic Cyst through a Periareolar Approach
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Van Praet, Karel M., Stamm, Christof, Sündermann, Simon H., Meyer, Alexander, Unbehaun, Axel, Montagner, Matteo, Nazari Shafti, Timo Z., Starck, Christoph, Jacobs, Stephan, and Kempfert, Jörg
- Abstract
A 58-year-old white male with a history of stroke and deep vein thrombosis presented with an interatrial intraseptal mass. Cardiac-computed tomography demonstrated a thin-walled, well-demarcated cyst in the inferior border of the fossa ovalis protruding into both atria. Removal of the interatrial intraseptal cyst was performed using a minimally invasive three-dimensional endoscopic periareolar approach.
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- 2018
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32. Minimally Invasive Cardiac Surgery: Removal of an Interatrial Intraseptal Bronchogenic Cyst through a Periareolar Approach
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Van Praet, Karel M., Stamm, Christof, Sündermann, Simon H., Meyer, Alexander, Unbehaun, Axel, Montagner, Matteo, Nazari Shafti, Timo Z., Starck, Christoph, Jacobs, Stephan, and Kempfert, Jörg
- Abstract
A 58-year-old white male with a history of stroke and deep vein thrombosis presented with an interatrial intraseptal mass. Cardiac-computed tomography demonstrated a thin-walled, well-demarcated cyst in the inferior border of the fossa ovalis protruding into both atria. Removal of the interatrial intraseptal cyst was performed using a minimally invasive three-dimensional endoscopic periareolar approach.
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- 2018
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33. Simulated Prosthesis Overlay for Patient-Specific Planning of Transcatheter Aortic Valve Implantation Procedures
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Sündermann, Simon H., Gessat, Michael, Maier, Willibald, Kempfert, Jörg, Frauenfelder, Thomas, Nguyen, Thi D. L., Maisano, Francesco, and Falk, Volkmar
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Objective We tested the hypothesis that simulated three-dimensional prosthesis overlay procedure planning may support valve selection in transcatheter aortic valve implantation (TAVI) procedures.Methods Preoperative multidimensional computed tomography (MDCT) data sets from 81 consecutive TAVI patients were included in the study. A planning tool was developed, which semiautomatically creates a three-dimensional model of the aortic root from these data. Three-dimensional templates of the commonly used TAVI implants are spatially registered with the patient data and presented as graphic overlay. Fourteen physicians used the tool to perform retrospective planning of TAVI procedures. Results of prosthesis sizing were compared with the prosthesis size used in the actually performed procedure, and the patients were accordingly divided into three groups: those with equal size (concordance with retrospective planning), oversizing (retrospective planning of a smaller prosthesis), and undersizing (retrospective planning of a larger prosthesis).Results In the oversizing group, 85% of the patients had new pacemaker implantation. In the undersizing group, in 66%, at least mild paravalvular leakage was observed (greater than grade 1 in one third of the cases). In 46% of the patients in the equal-size group, neither of these complications was observed.Conclusions Three-dimensional prosthesis overlay in MDCT-derived patient data for patient-specific planning of TAVI procedures is feasible. It may improve valve selection compared with two-dimensional MDCT planning and thus yield better outcomes.
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- 2015
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34. Simulated Prosthesis Overlay for Patient-Specific Planning of Transcatheter Aortic Valve Implantation Procedures
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Sündermann, Simon H., Gessat, Michael, Maier, Willibald, Kempfert, Jörg, Frauenfelder, Thomas, Nguyen, Thi D. L., Maisano, Francesco, and Falk, Volkmar
- Abstract
Objective We tested the hypothesis that simulated three-dimensional prosthesis overlay procedure planning may support valve selection in transcatheter aortic valve implantation (TAVI) procedures.Methods Preoperative multidimensional computed tomography (MDCT) data sets from 81 consecutive TAVI patients were included in the study. A planning tool was developed, which semiautomatically creates a three-dimensional model of the aortic root from these data. Three-dimensional templates of the commonly used TAVI implants are spatially registered with the patient data and presented as graphic overlay. Fourteen physicians used the tool to perform retrospective planning of TAVI procedures. Results of prosthesis sizing were compared with the prosthesis size used in the actually performed procedure, and the patients were accordingly divided into three groups: those with equal size (concordance with retrospective planning), oversizing (retrospective planning of a smaller prosthesis), and undersizing (retrospective planning of a larger prosthesis).Results In the oversizing group, 85% of the patients had new pacemaker implantation. In the undersizing group, in 66%, at least mild paravalvular leakage was observed (greater than grade 1 in one third of the cases). In 46% of the patients in the equal-size group, neither of these complications was observed.Conclusions Three-dimensional prosthesis overlay in MDCT-derived patient data for patient-specific planning of TAVI procedures is feasible. It may improve valve selection compared with two-dimensional MDCT planning and thus yield better outcomes.
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- 2015
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35. Diastolic Aorto–Right-Atrial Fistulation in Aortic and Tricuspid Valve Endocarditis
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Frey, Lukas, Starck, Christoph, Falk, Volkmar, and Sündermann, Simon
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- 2014
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36. Outcome of Patients Treated with Engager Transapical Aortic Valve Implantation: One-Year Results of the Feasibility Study
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Sündermann, Simon H., Grünenfelder, Jürg, Corti, Roberto, Rastan, Ardawan J., Linke, Axel, Lange, Rüdiger, Falk, Volkmar, and Bleiziffer, Sabine
- Abstract
Objective The aim of this study was to investigate the short-term and midterm outcome of the Engager transcatheter aortic valve implantation (TAVI) system, a transapical self-expanding valve device with anatomic orientation.Methods Transapical aortic valve implantation with the Engager valve prosthesis was performed in 10 patients. Endpoints were defined according to the Valve Academic Research Consortium recommendations for reporting outcomes of TAVI in clinical trials. Follow-up has been completed after 30 days and 1 year.Results All patients underwent the implantation procedure successfully. No device-related or delivery system–related complications were observed. One patient died of non–device-related reasons at postoperative day 23 in multiorgan failure. At 30-day follow-up, no more than mild transvalvular and paravalvular aortic regurgitation were seen. After 1 year, no transvalvular regurgitation was observed as assessed by transthoracic echocardiography. None of the patients had more than mild paravalvular leakage. The mean ± SD gradient was 15.3 ± 4.2 mm Hg. New York Heart Association class decreased one degree in mean and sustained until 1-year follow-up. No more patients died until 1-year follow-up.Conclusions Application of the Engager TAVI system is safe and reliable. Prosthesis deployment in an anatomically correct position was facilitated by the design of the valve prosthesis and successful in all patients. No device-related or delivery system–related complications occurred. Procedural, short-term, and midterm results up to 1 year concerning the aortic valve performance are promising, with stable mean gradients and low rates of even mild regurgitation.
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- 2013
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37. Outcome of Patients Treated with Engager Transapical Aortic Valve Implantation: One-Year Results of the Feasibility Study
- Author
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Sündermann, Simon H., Grünenfelder, Jürg, Corti, Roberto, Rastan, Ardawan J., Linke, Axel, Lange, Rüdiger, Falk, Volkmar, and Bleiziffer, Sabine
- Abstract
Objective The aim of this study was to investigate the short-term and midterm outcome of the Engager transcatheter aortic valve implantation (TAVI) system, a transapical self-expanding valve device with anatomic orientation.Methods Transapical aortic valve implantation with the Engager valve prosthesis was performed in 10 patients. Endpoints were defined according to the Valve Academic Research Consortium recommendations for reporting outcomes of TAVI in clinical trials. Follow-up has been completed after 30 days and 1 year.Results All patients underwent the implantation procedure successfully. No device-related or delivery system–related complications were observed. One patient died of non–device-related reasons at postoperative day 23 in multiorgan failure. At 30-day follow-up, no more than mild transvalvular and paravalvular aortic regurgitation were seen. After 1 year, no transvalvular regurgitation was observed as assessed by transthoracic echocardiography. None of the patients had more than mild paravalvular leakage. The mean ± SD gradient was 15.3 ± 4.2 mm Hg. New York Heart Association class decreased one degree in mean and sustained until 1-year follow-up. No more patients died until 1-year follow-up.Conclusions Application of the Engager TAVI system is safe and reliable. Prosthesis deployment in an anatomically correct position was facilitated by the design of the valve prosthesis and successful in all patients. No device-related or delivery system–related complications occurred. Procedural, short-term, and midterm results up to 1 year concerning the aortic valve performance are promising, with stable mean gradients and low rates of even mild regurgitation.
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- 2013
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38. Obesity Should Not Deter a Surgeon from Selecting a Minimally Invasive Approach for Mitral Valve Surgery
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Reser, Diana, Sündermann, Simon, Grünenfelder, Jürg, Scherman, Jacques, Seifert, Burkhardt, Falk, Volkmar, and Jacobs, Stephan
- Abstract
Objective Obesity is highly prevalent in modern patient populations. Several studies have published conflicting outcomes after minimally invasive surgery with regard to morbidity and mortality. Some instances consider obesity as a relative contraindication for this approach because of inadequate exposure of the surgical field. Our aim was to investigate the outcomes of minimally invasive mitral valve surgery through a right lateral minithoracotomy in patients with a body mass index (BMI) of 30 kg/m2or greater.Methods We conducted a retrospective database review between January 1, 2009, and December 31, 2011. Preoperative, intraoperative, postoperative, and follow-up data of 225 consecutive patients were collected.Results The patients were stratified according to their BMI: 108 had a normal weight with a BMI of lower than 25 kg/m2(18–24), 90 were overweight with a BMI of 25 to 29 kg/m2, and 27 were obese with a BMI of 30 kg/m2(30–41) or greater. Statistical analysis showed significantly longer ventilation times in the obese group, whereas all other variables were similar. Survival, major adverse cardiac and cerebrovascular event-free survival, valve competency, and freedom from reoperation were also comparable.Conclusions Our data suggest that obesity should not deter a surgeon from selecting a minimally invasive approach. Despite longer postoperative ventilation times, a BMI of 30 kg/m2or greater does not influence short- and medium-term outcome. Obese patients may even benefit from this approach because it avoids the need for sternotomy and therefore reduces the risk for sternal wound infection.
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- 2013
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39. Obesity Should Not Deter a Surgeon from Selecting a Minimally Invasive Approach for Mitral Valve Surgery
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Reser, Diana, Sündermann, Simon, Grünenfelder, Jürg, Scherman, Jacques, Seifert, Burkhardt, Falk, Volkmar, and Jacobs, Stephan
- Abstract
Objective Obesity is highly prevalent in modern patient populations. Several studies have published conflicting outcomes after minimally invasive surgery with regard to morbidity and mortality. Some instances consider obesity as a relative contraindication for this approach because of inadequate exposure of the surgical field. Our aim was to investigate the outcomes of minimally invasive mitral valve surgery through a right lateral minithoracotomy in patients with a body mass index (BMI) of 30 kg/m2or greater.Methods We conducted a retrospective database review between January 1, 2009, and December 31, 2011. Preoperative, intraoperative, postoperative, and follow-up data of 225 consecutive patients were collected.Results The patients were stratified according to their BMI: 108 had a normal weight with a BMI of lower than 25 kg/m2(18–24), 90 were overweight with a BMI of 25 to 29 kg/m2, and 27 were obese with a BMI of 30 kg/m2(30–41) or greater. Statistical analysis showed significantly longer ventilation times in the obese group, whereas all other variables were similar. Survival, major adverse cardiac and cerebrovascular event-free survival, valve competency, and freedom from reoperation were also comparable.Conclusions Our data suggest that obesity should not deter a surgeon from selecting a minimally invasive approach. Despite longer postoperative ventilation times, a BMI of 30 kg/m2or greater does not influence short- and medium-term outcome. Obese patients may even benefit from this approach because it avoids the need for sternotomy and therefore reduces the risk for sternal wound infection.
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- 2013
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40. One-year follow-up of patients undergoing elective cardiac surgery assessed with the Comprehensive Assessment of Frailty test and its simplified form.
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Sündermann, Simon, Dademasch, Anika, Rastan, Ardawan, Praetorius, Julian, Rodriguez, Héctor, Walther, Thomas, Mohr, Friedrich-Wilhelm, and Falk, Volkmar
- Abstract
Assessment of perioperative risk of elderly patients in cardiac surgery is demanding. Most of the commonly used cardiac surgery risk scores over-or underestimate individual risk. Therefore, we recently developed a 'frailty score', the comprehensive assessment of frailty (CAF) score that showed a good prediction of 30-day mortality. The aim of the study was to evaluate the ability of the new score predicting one-year outcome. CAF was preoperatively applied to 400 patients ≥ 74 years that were admitted to cardiac surgery between September 2008 and January 2010. For 213 of these patients one-year follow-up was assessed by telephone interview until April 2010. One hundred and ten male and 103 female patients were included. Twenty-five percent underwent isolated coronary revascularization, 35% isolated valve procedures and 26% underwent combined procedures. One-year mortality was 12.2%. Patients who died within one year had a median frailty score of 16 [5;33] compared to 11 [3;33] to the one-year survivors (P=0.001). A new, easily applicable score ('Frailty predicts death One yeaR after Elective Cardiac Surgery Test') was built out of the basic score and showed a promising ability to predict one-year mortality. CAF is a new additional tool to assess prognosis of elderly patients before cardiac surgical interventions. The 'CAF' score facilitates prediction of mid-term outcome of high-risk elderly patients.
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- 2011
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41. Continuous Heart Volume Monitoring by Fully Implantable Soft Strain Sensor
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Dual, Seraina A., Llerena Zambrano, Byron, Sündermann, Simon, Cesarovic, Nikola, Kron, Mareike, Magkoutas, Konstantinos, Hengsteler, Julian, Falk, Volkmar, Starck, Christoph, Meboldt, Mirko, Vörös, János, and Schmid Daners, Marianne
- Abstract
Cardiothoracic open‐heart surgery has revolutionized the treatment of cardiovascular disease, the leading cause of death worldwide. After the surgery, hemodynamic and volume management can be complicated, for example in case of vasoplegia after endocarditis. Timely treatment is crucial for outcomes. Currently, treatment decisions are made based on heart volume, which needs to be measured manually by the clinician each time using ultrasound. Alternatively, implantable sensors offer a real‐time window into the dynamic function of our body. Here it is shown that a soft flexible sensor, made with biocompatible materials, implanted on the surface of the heart, can provide continuous information of the heart volume after surgery. The sensor works robustly for a period of two days on a tensile machine. The accuracy of measuring heart volume is improved compared to the clinical gold standard in vivo, with an error of 7.1 mL for the strain sensor versus impedance and 14.0 mL versus ultrasound. Implanting such a sensor would provide essential, continuous information on heart volume in the critical time following the surgery, allowing early identification of complications, facilitating treatment, and hence potentially improving patient outcome. A soft flexible, strain sensor outperforms traditional clinical methods to measure left ventricular heart volume. The sensor can be directly applied to clinical settings in post heart surgery scenarios, and provide essential, continuous information on heart volume. Such technology would allow early identification of complications, using less personnel resources, facilitating treatment, and hence potentially improving patient outcome.
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- 2020
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42. Turbulent Kinetic Energy Assessed by Multipoint 4-Dimensional Flow Magnetic Resonance Imaging Provides Additional Information Relative to Echocardiography for the Determination of Aortic Stenosis Severity
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Binter, Christian, Gotschy, Alexander, Sündermann, Simon H., Frank, Michelle, Tanner, Felix C., Lüscher, Thomas F., Manka, Robert, and Kozerke, Sebastian
- Abstract
Supplemental Digital Content is available in the text.
- Published
- 2017
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43. Finite Element Stent Modeling for the Postoperative Analysis of Transcatheter Aortic Valve Implantation
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Hopf, Raoul, Gessat, Michael, Russ, Christoph, Sündermann, Simon H., Falk, Volkmar, and Mazza, Edoardo
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In order to evaluate the performance of stents used in transcatheter aortic valve implantation (TAVI), finite element simulations are setup to reconstruct patient-specific contact forces between implant and its surrounding tissue. Previous work used structural beam elements to setup a numerical model of the CoreValve stent used in TAVI and developed a procedure for implementing kinematic boundary conditions from noisy computer tomography (CT) scanning data. This study evaluates element size selection and quantitatively investigates the choice of a linear elastic constitutive model for the Nitinol stent under physiological loading conditions. It is shown that this simplification leads to reliable results and enables a huge reduction in computation time. Further, the procedure used to compensate for noisy postoperative CT data is tested by adding artificial noise. It is concluded that for physiologically relevant loading ranges, the procedure yields convergent results and successfully eliminates the influence of the noise.
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- 2017
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