Publications by authors named "Wildhirt S"

Objective: Due to severely limited donor heart availability, durable mechanical circulatory support remains the only treatment option for many patients with end-stage heart failure. However, treatment complexity persists due to its univentricular support modality and continuous contact with blood. We investigated the function and safety of reBEAT (AdjuCor GmbH), a novel, minimal invasive mechanical circulatory support device that completely avoids blood contact and provides pulsatile, biventricular support.

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The limited regenerative capacity of the heart after a myocardial infarct results in remodeling processes that can progress to congestive heart failure (CHF). Several strategies including mechanical stabilization of the weakened myocardium and regenerative approaches (specifically stem cell technologies) have evolved which aim to prevent CHF. However, their final performance remains limited motivating the need for an advanced strategy with enhanced efficacy and reduced deleterious effects.

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Advances in ventricular assist device (VAD) technology for the treatment of end-stage congestive heart failure (CHF) are needed to cope with the increasing numbers of patients that cannot be provided with donor hearts for transplantation. We develop and investigate a novel extravascular VAD technology that provides biventricular, epicardial pressure support for the failing heart. This novel VAD concept avoids blood contact that is accompanied with typical complications such as coagulation and infections.

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For treatment of advanced heart failure, current strategies include cardiac transplantation or blood-contacting pump technology associated with complications, including stroke and bleeding. This study investigated an individualized biventricular epicardial augmentation technology in a drug-induced porcine failing heart model. A total of 11 pigs were used, for the assessment of hemodynamics and cardiac function under various conditions of support pressures and support durations (n = 4), to assess device positioning and function by in vivo computer tomographic imaging (n = 3) and to investigate a minimally invasive implantation on the beating heart (n = 4).

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A model for patient-specific cardiac mechanics simulation is introduced, incorporating a 3-dimensional finite element model of the ventricular part of the heart, which is coupled to a reduced-order 0-dimensional closed-loop vascular system, heart valve, and atrial chamber model. The ventricles are modeled by a nonlinear orthotropic passive material law. The electrical activation is mimicked by a prescribed parameterized active stress acting along a generic muscle fiber orientation.

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Background: Patients suffering from acute type A aortic dissection undergo replacement of the ascending aorta, the proximal hemiarch or complete aortic arch, depending on the extent of the individual pathology. In a subset of these treated patients, secondary pathologies of the distal anastomosis or the remaining distal part of the aorta occur. The treatment of these pathologies is challenging, requiring major surgical re-do procedures with aortic arch replacement under extracorporeal circulation and hypothermic circulatory arrest.

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Introduction: The use of glues to repair disrupted tissue during acute type-A aortic dissection (TAD) surgery may be discontinuous, and cause embolization and cell necrosis. We report a method of fibrin sealant patch (FSP) to reinforce dissected aortic tissue with a collagen double layer coated with fibrinogen/thrombin on either side (TachoSil®; Takeda, Konstanz, Germany).

Methods: In 12 patients (seven male, 66.

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Objective: Nonrobotic total endoscopic coronary bypass grafting is commonly considered as technically too difficult. After endoscopic practicing in a simple box model, we questioned this statement in a more sophisticated training model.

Methods: In a handmade chest model containing a mechanically actuated porcine heart, anastomoses between homologous vein and shunted anterior coronary artery were performed using Prolene 7-0 sutures or U-clips in 20 anastomoses each.

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Background: Acute aortic dissection type A (AADA) is a life-threatening vascular emergency. Clinical presentation ranges from pain related to the acute event, collapse due to aortic rupture or pericardial tamponade, or manifestations of organ or limb ischaemia. The purpose of this review was to clarify important clinical issues of AADA management, with a focus on diagnostic and therapeutic challenges.

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METASTATIC LESIONS IN THE SUPERIOR VENA CAVA AND THE RIGHT ATRIUM ARE DIFFICULT TO DIAGNOSE: in computed tomography (CT), they are easily misinterpreted as artifacts, and the same region may be difficult to access using echocardiography. We present a case of asymptomatic metastasis of a malignant melanoma which was overlooked initially due to deficiencies in imaging. Using 18F-fluorodeoxyglucose positron emission tomography-CT, the metastasis was clearly identified and finally treated successfully.

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Background: Optimal timing of elective aortic valve replacement (AVR) for severe aortic stenosis (AS) is challenging. Hence, a sensitive marker in AS patients indicating increasing risk after AVR would be of great clinical value. In the present study, we hypothesized that mild-to-moderate pulmonary hypertension (PH) assessed prior to AVR is a sensitive marker for adverse events in patients after successful AVR.

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Background: The radial artery (RA) is known as an atherosclerosis-prone vessel in contrast to the atherosclerosis-resistant internal thoracic artery (ITA). The purpose of the present study was to compare the gene expression profile of these arteries from the same patient in order to identify genes involved in atherogenesis or intimal hyperplasia.

Methods: Paired specimens of RA and ITA (n=6) were analyzed by histomorphometry and whole genome microarray.

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This review outlines and discusses the newest technologies used for cardiopulmonary bypass (CPB) including changes in pump technology, oxygenators, filters, and priming. In addition, evidence-based and experience-based procedures are presented in line with the recommendations given on what CPB-related practices are safe and effective.

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Background: Magnetic Resonance Imaging (MRI) and transthoracic echocardiography have been shown to be noninvasive highly sensitive diagnostic tools to identify changes in LV mass and volume. We therefore investigated the effects of mitral valve repair (MVR) on LV function parameters including ejection fraction (EF; %), indices of LV mass (LVMI; g/m2) and volume (LVEDVI, LVESVI; mL/m2) as detected by MRI and echocardiography.

Methods: Eight consecutive patients (mean age 53.

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Minimally invasive aortic valve replacement using the inversed L-like partial upper sternotomy has evolved during the last 10 years. It is performed with excellent results with regard to sternal stability and cosmesis. However, the lateral incision may result in sternal overriding, instability, or fracture.

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We present a case of a large pseudoaneurysm of the ascending aorta, originating from the purse-string suture of the cardioplegia line which was essentially asymptomatic but was diagnosed during patient follow up for fever and elevated white blood count of unknown origin. During intraoperative transesophageal echocardiography, a free floating tumor was localized in his right atrium which after removal appeared to be an infected embolus with excessive neutrophils and monocytoid cells interspersed with cell debris and fibrin. Material send for culture was positive for streptococci, whereas tissues cultures from the pseudoaneurysm were essentially negative.

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Background: Cardiopulmonary bypass (CPB) is known to induce systemic inflammation and cardiac dysfunction associated with a significant morbidity. Aim of the study was to develop an in vivo model of rat CPB with hypothermic cardiac arrest and the use of cardioplegia.

Material And Methods: The CPB circuit consisted of a venous reservoir, membrane oxygenator, heat exchanger, and roller pump.

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The introduction of telemanipulator systems into cardiac surgery enabled the heart surgeon to perform minimally invasive procedures with high precision and stereoscopic view. For further improvement and especially for inclusion of autonomous action sequences, implementation of force-feedback is necessary. The aim of our study was to provide a robotic scenario giving the surgeon an impression very similar to open procedures (high immersion) and to enable autonomous surgical knot tying with delicate suture material.

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Background: Carriers of the factor V Leiden mutation (FVL) are resistant to activated protein C proteolysis. Therefore, they are at increased risk of thromboembolic events. Aprotinin is an unspecific proteinase inhibitor frequently used during cardiac surgery procedures to reduce bleeding.

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Background: Atrial fibrillation (AF) occurs in 20-40% of patients after open heart surgery and leads to an increased morbidity and prolonged hospital stay. Earlier studies have demonstrated that depressed baroreflex function predicts mortality and major arrhythmic events in patients surviving myocardial infarction. Cardiac surgery per se leads to decreased baroreflex sensitivity (BRS) and heart rate variability (HRV).

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Superior vena cava syndrome is a rare complication after pacemaker implantation. The present report outlines how underestimation of clinically relevant symptoms of superior vena cava syndrome early after pacemaker implantation may result in severe complication with the need for major surgical intervention. Superior vena cava syndrome should be diagnosed early because immediate thrombolytic therapy is effective in the majority of patients and avoids the requirement for interventional or surgical efforts.

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Background: Coronary artery bypass grafting (CABG) using radial arteries has become a standard procedure for younger patients in many centers. However, advanced atherosclerotic changes may limit its use in older patients. We studied the effects of age on morphologic and histopathologic findings in CABG patients aged 70 years and older.

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Optimal port placement is a delicate issue in minimally invasive endoscopic surgery, particularly in robotically assisted surgery. A good choice of the instruments' and endoscope's ports can avoid time-consuming consecutive new port placement. We present a novel method to intuitively and precisely plan the port placement.

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