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Comprehensive information on the characteristics of surgical heart valves (SHVs) is essential for optimal valve selection. Such information is also important in assessing SHV function after valve replacement. Despite the existing regulatory framework for SHV sizing and labelling, this information is challenging to obtain in a uniform manner for various SHVs. To ensure that clinicians are adequately informed, the European Association for Cardio-Thoracic Surgery (EACTS), The Society of Thoracic Surgeons (STS) and American Association for Thoracic Surgery (AATS) set up a Task Force comprised of cardiac surgeons, cardiologists, engineers, regulatory bodies, representatives of the International Organization for Standardization and major valve manufacturers. Previously, the EACTS–STS–AATS Valve Labelling Task Force identified the most important problems around SHV sizing and labelling. This Expert Consensus Document formulates recommendations for providing SHV physical dimensions, intended implant position and hemodynamic performance in a transparent, uniform manner. Furthermore, the Task Force advocates for the introduction and use of a standardized chart to assess the probability of prosthesis–patient mismatch and calls valve manufacturers to provide essential information required for SHV choice on standardized Valve Charts, uniformly for all SHV models. [ABSTRACT FROM AUTHOR]

Comprehensive information on the characteristics of surgical heart valves (SHVs) is essential for optimal valve selection. Such information is also important in assessing SHV function after valve replacement. Despite the existing regulatory framework for SHV sizing and labelling, this information is challenging to obtain in a uniform manner for various SHVs. To ensure that clinicians are adequately informed, the European Association for Cardio-Thoracic Surgery (EACTS), The Society of Thoracic Surgeons (STS) and American Association for Thoracic Surgery (AATS) set up a Task Force comprised of cardiac surgeons, cardiologists, engineers, regulatory bodies, representatives of the International Organization for Standardization and major valve manufacturers. Previously, the EACTS–STS–AATS Valve Labelling Task Force identified the most important problems around SHV sizing and labelling. This Expert Consensus Document formulates recommendations for providing SHV physical dimensions, intended implant position and haemodynamic performance in a transparent, uniform manner. Furthermore, the Task Force advocates for the introduction and use of a standardized chart to assess the probability of prosthesis–patient mismatch and calls valve manufacturers to provide essential information required for SHV choice on standardized Valve Charts, uniformly for all SHV models. [ABSTRACT FROM AUTHOR]

Objective. To test the feasibility of a CT-compatible, ex vivo, perfused porcine heart model for myocardial perfusion CT imaging. Methods. One porcine heart was perfused according to Langendorff. Dynamic perfusion scanning was performed with a second-generation dual source CT scanner. Circulatory parameters like blood flow, aortic pressure, and heart rate were monitored throughout the experiment. Stenosis was induced in the circumflex artery, controlled by a fractional flow reserve (FFR) pressure wire. CT-derived myocardial perfusion parameters were analysed at FFR of 1 to 0.10/0.0. Results. CT images did not show major artefacts due to interference of the model setup. The pacemaker-induced heart rhythm was generally stable at 70 beats per minute. During most of the experiment, blood flow was 0.9–1.0 L/min, and arterial pressure varied between 80 and 95 mm/Hg. Blood flow decreased and arterial pressure increased by approximately 10% after inducing a stenosis with FFR ≤ 0.50. Dynamic perfusion scanning was possible across the range of stenosis grades. Perfusion parameters of circumflex-perfused myocardial segments were affected at increasing stenosis grades. Conclusion. An adapted Langendorff porcine heart model is feasible in a CT environment. This model provides control over physiological parameters and may allow in-depth validation of quantitative CT perfusion techniques. [ABSTRACT FROM AUTHOR]

OBJECTIVES Aortic valve regurgitation, fusion and thrombosis are commonly reported clinical complications after continuous flow ventricular assist device implantations; however, the complex interaction between reduced pulsatile flow physiology and aortic valve functions has not been studied experimentally. To address this, a continuous flow left ventricular assist device was implanted in four swine ex vivo beating hearts and then operated at baseline (device off, no flow) and at device speeds ranging between 8500 and 11 500 rpm under healthy and experimentally created failing heart conditions. METHODS At baseline and after each speed increase, aortic, left ventricular, left atrial and pulse pressure signals were monitored to assess the haemodynamic status of the ex vivo heart, aortic valve opening time and the transvalvular pressure changes. Aortic root and device flows were recorded with flow probes. Left ventricular pressure–volume loops were measured with a conductance catheter. Changes in aortic leaflet motion and end-diastolic aortic root diameter were recorded with epicardial echocardiography. RESULTS A two-chamber healthy and failing ex vivo beating heart model was successfully created. At increasing device flows, aortic valve open time steadily decreased from 36 ± 7% of the baseline cardiac cycle to 0% at 11 500 rpm in the healthy heart and from 18 ± 16 to 0% in failing heart mode (P < 0.05). Aortic transvalvular pressure increased from 25 ± 5 mmHg (baseline) to 67 ± 7 mmHg (11 500 rpm) in the healthy heart and from 10 ± 9 mmHg (baseline) to 73 ± 8 mmHg (11 500 rpm) in failing heart mode (P < 0.05). Aortic root diameters were significantly increased at speeds exceeding 10 500 rpm in the healthy heart mode (P < 0.05 vs baseline) and approached statistical significance in failing hearts. CONCLUSIONS Increasing assist device flows resulted in pressure overload above the aortic leaflets, impaired leaflet functions, caused aortic root dilatation and altered leaflet coaptation at the central portion of the aortic valve in both modes. We conclude that the deleterious effect of the reduced pulsatile flow on the aortic valve functions and haemodynamics is immediate and such an insult may explain the structural changes of the aortic valve causing leaflet fusion and/or regurgitation in the chronic phase. [ABSTRACT FROM PUBLISHER]

An ex vivo aneurysm model that closely resembles the in vivo situation can provide an important tool for testing therapies. The model should mimic a variety of conditions, such as in vivo hemodynamics and native arterial structure and characteristics, avoiding animal experimentation.  Therefore, the aim of this study is to develop an ex vivo aneurysm model by vessel wall stiffening to be used to assess treatment strategies. Porcine carotid arteries from slaughterhouse animals were used to evaluate the acute effect of different concentrations of Rose Bengal on distensibility. This sono-sensitive compound was activated by several ultrasound frequencies, resulting in stiffening of the treated arteries of which the most effective combination was selected. In a pulsatile ex vivo vascular bioreactor treated and control porcine carotid arteries were subjected to physiological conditions for 10 days. During culture, hemodynamics showed increased mean pressure and decreased pulsatility in treated arteries compared to controls. Change in vessel morphology and significant increase of distal diameter was observed in the treated arteries but not in the controls. Histology of treated arteries revealed dissection-like lesions distally and aneurysm-like structure proximally. Finally, a stent graft was deployed in one treated artery and cultured demonstrating the feasibility of testing endovascular devices in the model. In conclusion, we developed an ex vivo model reproducing the onset of aneurysm formation. This could represent a promising tool for early stage device testing thereby reducing the need for animal studies.

Transcatheter treatment of structural heart disease is becoming an everyday reality for an increasing number of surgeons, and effective training modalities for basic guide-wire skills, catheter handling, and periprocedural imaging are of growing relevance. In this video tutorial we present a beating-heart porcine model used as a high-fidelity training simulator for transcatheter cardiac valve procedures.  We demonstrate a complete transcatheter edge-to-edge mitral valve repair procedure, including periprocedural imaging, clip deployment, and quality control. Various mitral valve pathologies can be simulated, including the demonstrated leaflet prolapse. Trainees practice clip navigation within the left atrium, transmitral passage, and clip orientation as well as grasping mitral valve leaflets to treat mitral regurgitation.  Periprocedural imaging is achieved via epicardial echocardiography and left ventricular cardioscopy, and these imaging modalities are also relied on to guide surgeons during the simulations, as required. The beating heart model enables realistic demonstration of the hemodynamic consequences of valve repair, and we believe that this simulator represents a valuable adjunct to surgical training., (© The Author 2018. Published by MMCTS on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Background and Aim: The cardiac lymphatic system drains excess fluid from the cardiac interstitium. Any impairment or dysfunction of the lymph structures can result in the accumulation of interstitial fluid, and may lead to edema and eventually cardiac dysfunction. Lymph originates directly from the interstitium and carries real-time information about the metabolic state of cells in specific regions of the heart. The detailed anatomy of the epicardial lymphatic system in individuals is broadly unknown. Generally, the epicardial lymphatic system is not taken into consideration during heart surgery. This study investigates the feasibility of detailed mapping and cannulation of the porcine epicardial lymphatic system for use in preservation of explanted hearts and heart failure studies in pigs and humans., Methods: The anatomy of the epicardial lymphatic systems of forty pig hearts was studied and documented. Using a 27 G needle, India ink was introduced directly into the epicardial lymphatic vessels in order to visualise them. Based on the anatomical findings thus obtained, two cannulation regions for the left and right principal trunks were identified. These regions were cannulated with a 26 G intravenous Venflon cannula-over-needle, and a Galeo Hydro Guide F014 wire was used to verify that the lumen was patent., Results: The main epicardial lymphatic collectors were found to follow the main coronary arteries. Most of the lymph vessels drained into the left ventricular trunk, which evacuates fluid from the left heart and also partially from the right heart. The right trunk was often found to drain into the left trunk anterior basally. Right heart drainage was highly variable compared to the left. In addition, the overall cannulation success rate of the selected cannulation sites was only 57%., Conslusions: Mapping of the porcine epicardial lymphatic anatomy is feasible. The right ventricular drainage system had a higher degree of variability than the left, and the right cardiac lymph system was found to be partially cleared through the left lymphatic trunk. To improve cannulation success rate, we proposed two sites for cannulation based on these findings and the use of Venflon cannulas (26 G) for cannulation and lymph collection. This method might be helpful for future studies that focus on biochemical sample analysis and decompression., Relevance for Patients: Real-time biochemical assessment and decompression of lymph may contribute to the understanding of heart failure and eventually result in preventive measures. First its relevance should be established by additional research in both arrested and working porcine hearts. Imaging and mapping of the epicardial lymphatics may enable sampling and drainage and contribute to the prevention or treatment of heart failure. We envision that this approach may be considered in patients with a high risk of postoperative left and right heart failure during open-heart surgery.

Hypothermia may attenuate reperfusion injury and thereby improve acute myocardial infarction therapy. Systemic cooling trials failed to reduce infarct size, perhaps because the target temperature was not reached fast enough. The use of selective intracoronary hypothermia combined with intracoronary temperature monitoring allows for titrating to target temperature and optimizing the cooling rate. We aimed to the test the feasibility of intracoronary cooling for controlled, selective myocardial hypothermia in an isolated beating pig heart. In five porcine hearts the left anterior descending artery (LAD) was occluded by an over-the-wire balloon (OTWB). After occlusion, saline at 22°C was infused through the OTWB lumen for 5 minutes into the infarct area at a rate of 30 ml/min. Thereafter the balloon was deflated but infusion continued with saline at 4°C for 5 minutes. Distal coronary temperature was continuously monitored by a pressure/temperature guidewire. Myocardial temperature at several locations in the infarct and control areas was recorded using needle thermistors. In the occlusion phase, coronary temperature decreased by 11.4°C (range 9.4-12.5°C). Myocardial temperature throughout the infarct area decreased by 5.1°C (range 1.8-8.1°C) within three minutes. During the reperfusion phase, coronary temperature decreased by 6.2°C (range 4.1-10.3°C) and myocardial temperature decreased by 4.5°C (range 1.5-7.4°C). Myocardial temperature outside the infarct area was not affected. In the isolated beating pig heart with acute occlusion of the LAD, we were able to rapidly "induce, maintain, and control" a stable intracoronary and myocardial target temperature of at least 4°C below body temperature without side effects and using standard PCI equipment, justifying further studies of this technique in humans.