Relevant bibliographies by topics / Leaflet thrombosis

Academic literature on the topic 'Leaflet thrombosis'

Author: Grafiati
Published: 10 December 2022
Last updated: 28 January 2023

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Journal articles on the topic "Leaflet thrombosis"

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Khodaee, Farhan, Mohammed Barakat, Mostafa Abbasi, Danny Dvir, and Ali N. Azadani. "Incomplete expansion of transcatheter aortic valves is associated with propensity for valve thrombosis." Interactive CardioVascular and Thoracic Surgery 30, no. 1 (September 5, 2019): 39–46. http://dx.doi.org/10.1093/icvts/ivz213.

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Abstract OBJECTIVES Clinical and subclinical leaflet thromboses are increasingly recognized complications following transcatheter aortic valve replacement. Identification of the risk factors is important to mitigate the occurrence of leaflet thrombosis in transcatheter aortic valves (TAVs) and ensure their long-term function. The goal of this study was to determine the effect of incomplete expansion of TAVs on the likelihood of leaflet thrombosis following transcatheter aortic valve replacement. METHODS Using experimental and computational methods, 3-dimensional unsteady flow fields of 26-mm SAPIEN 3 valves expanded to 3 different diameters (i.e. 26.0 mm, 23.4 mm and 20.8 mm) were determined in patient-specific geometries. The diameters corresponded to 100%, 90% and 80% stent expansion, respectively. To address the potential difference in the likelihood of leaflet thrombosis, blood residence time (i.e. stasis) and viscous shear stress on the surface of TAV leaflets were quantified and compared. RESULTS The results indicated that TAV underexpansion increased blood stasis on the TAV leaflets. Blood residence time on the surface of the leaflets after 80% and 90% TAV expansion on average was 9.4% and 4.1% more than that of the fully expanded TAV, respectively. In addition, areas of blood stasis time of more than 0.5 s, which are highly prone to platelet activation, increased linearly as the degree of TAV underexpansion increased. CONCLUSIONS Incomplete expansion of TAVs increases blood stasis on the surface of TAV leaflets. Regions of blood stasis promote platelet activation and thrombotic events. TAV underexpansion can therefore increase the risk of leaflet thrombosis in patients with transcatheter aortic valve replacement.
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Piayda, Kerstin, Tobias Zeus, Horst Sievert, Malte Kelm, and Amin Polzin. "Subclinical leaflet thrombosis." Lancet 391, no. 10124 (March 2018): 937–38. http://dx.doi.org/10.1016/s0140-6736(18)30534-8.

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Makkar, Raj, and Tarun Chakravarty. "Early Leaflet Thrombosis." JACC: Cardiovascular Interventions 11, no. 12 (June 2018): 1172–74. http://dx.doi.org/10.1016/j.jcin.2018.05.030.

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Sondergaard, Lars, Cesna Sigitas, Manik Chopra, Gintautas Bieliauskas, and Ole De Backer. "Leaflet Thrombosis after TAVI." European Heart Journal 38, no. 36 (September 21, 2017): 2702–3. http://dx.doi.org/10.1093/eurheartj/ehx473.

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Carabello, Blase A. "Bioprosthetic Valve Leaflet Thrombosis." Journal of the American College of Cardiology 75, no. 8 (March 2020): 867–69. http://dx.doi.org/10.1016/j.jacc.2019.12.038.

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Lieben, Liesbet. "Leaflet thrombosis after AVR." Nature Reviews Cardiology 14, no. 5 (May 2017): 256. http://dx.doi.org/10.1038/nrcardio.2017.54.

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Plitman Mayo, Romina, Halit Yaakobovich, Ariel Finkelstein, Shawn C. Shadden, and Gil Marom. "Numerical models for assessing the risk of leaflet thrombosis post-transcatheter aortic valve-in-valve implantation." Royal Society Open Science 7, no. 12 (December 2020): 201838. http://dx.doi.org/10.1098/rsos.201838.

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Leaflet thrombosis has been suggested as the reason for the reduced leaflet motion in cases of hypoattenuated leaflet thickening of bioprosthetic aortic valves. This work aimed to estimate the risk of leaflet thrombosis in two post-valve-in-valve (ViV) configurations, using five different numerical approaches. Realistic ViV configurations were calculated by modelling the deployments of the latest version of transcatheter aortic valve devices (Medtronic Evolut PRO, Edwards SAPIEN 3) in the surgical Sorin Mitroflow. Computational fluid dynamics simulations of blood flow followed the dry models. Lagrangian and Eulerian measures of near-wall stagnation were implemented by particle and concentration tracking, respectively, to estimate the thrombogenicity and to predict the risk locations. Most of the numerical approaches indicate a higher leaflet thrombosis risk in the Edwards SAPIEN 3 device because of its intra-annular implantation. The Eulerian approaches estimated high-risk locations in agreement with the wall sheer stress (WSS) separation points. On the other hand, the Lagrangian approaches predicted high-risk locations at the proximal regions of the leaflets matching the low WSS magnitude regions of both transcatheter aortic valve implantation models and reported clinical and experimental data. The proposed methods can help optimizing future designs of transcatheter aortic valves with minimal thrombotic risks.
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Marcelli, Emanuela, Barbara Bortolani, Ivan Corazza, and Laura Cercenelli. "A Novel Sensorized Heart Valve Prosthesis: Preliminary In Vitro Evaluation." Sensors 18, no. 11 (November 13, 2018): 3905. http://dx.doi.org/10.3390/s18113905.

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Background: Recent studies have shown that subclinical valve thrombosis in heart valve prosthesis (HVP) can be responsible for reduced leaflet motion detectable only by advanced imaging diagnostics. We conceived a novel sensorized HVP able to detect earlier any thrombus formation that may alter the leaflets motion using an electric impedance measurement, IntraValvular Impedance (IVI). Methods: For IVI measurement, dedicated electrodes are embedded in the structure of the HVP to generate a local electric field that is altered by the moving valve leaflets during their cyclic opening/closing. We present preliminary in vitro results using a first prototype of sensorized mechanical heart valve connected to an external impedance measurement system. The prototype was tested on a circulatory mock loop system and the IVI signals were recorded during both normal dynamics and experimentally induced altered working of the leaflets. Results: Recordings showed a very repetitive and stable IVI signal during the normal cyclic opening/closing of the HVP. The induced alterations in leaflet motion were reflected in the IVI signal. Conclusions: The novel sensorized HVP has great potential to give early warning of possible subclinical valve thrombosis altering the valve leaflet motion, and to help in tailoring the anticoagulation therapy.
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Phifer, Travis J., and Michael S. Rohr. "The Pathogenesis of Leaflet Failure in Prosthetic Venous Valves." Phlebology: The Journal of Venous Disease 3, no. 2 (June 1988): 115–21. http://dx.doi.org/10.1177/026835558800300208.

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Recent work from this laboratory established feasibility for long-term patency of properly designed valvular xenografts placed without technical fault in the inferior vena cava. Limitations of that work however, included perileaflet fibrosis with reduction of leaflet mobility. The current study evaluates perileaflet thrombosis potentiated by the nonendothelialized leaflet surface as the primary pathogenic mechanism of this problem. The study includes 18 pericardial xenograft valvular bioprostheses and nine jugular vein valvular autografts placed in the inferior vena cava of 27 dogs All animals received a single bolus of heparin (100u/kg) 5min before vascular clamping. The valves were removed and examined from 1 day to 7.5 months after placement. In valvular xenografts, perileaflet thrombosis by 1 day progressed to dense fibrosis at 2 months. Despite limitation of leaflet motion, this process caused luminal occlusion in only three valves (83% patency). There were no failures in the nine valvular autografts, with normal valve leaflets and no evidence of thrombus formation as late as 6 months. Perileaflet thrombosis in pericardial xenograft bioprostheses is a primary event in the ultimate fibrosis of these prosthetic venous valves. Inhibition of thrombosis by the venous endothelial lining may be an explanation for success with the smaller valvular autografts in the same haemodynamic environment.
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Ng, Arnold C. T., David R. Holmes, Michael J. Mack, Victoria Delgado, Raj Makkar, Philipp Blanke, Jonathon A. Leipsic, Martin B. Leon, and Jeroen J. Bax. "Leaflet immobility and thrombosis in transcatheter aortic valve replacement." European Heart Journal 41, no. 33 (September 1, 2020): 3184–97. http://dx.doi.org/10.1093/eurheartj/ehaa542.

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Abstract Transcatheter aortic valve replacement (TAVR) has grown exponentially worldwide in the last decade. Due to the higher bleeding risks associated with oral anticoagulation and in patients undergoing TAVR, antiplatelet therapy is currently considered first-line antithrombotic treatment after TAVR. Recent studies suggest that some patients can develop subclinical transcatheter heart valve (THV) thrombosis after the procedure, whereby thrombus forms on the leaflets that can be a precursor to leaflet dysfunction. Compared with echocardiography, multidetector computed tomography is more sensitive at detecting THV thrombosis. Transcatheter heart valve thrombosis can occur while on dual antiplatelet therapy with aspirin and thienopyridine but significantly less with anticoagulation. This review summarizes the incidence and diagnostic criteria for THV thrombosis and discusses the pathophysiological mechanisms that may lead to thrombus formation, its natural history, potential clinical implications and treatment for these patients.
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Dissertations / Theses on the topic "Leaflet thrombosis"

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Gonçalves, Flávia Vitória Marques Barbosa. "Trombose Subclínica dos folhetos protésicos pós-substituição valvular aórtica percutânea: do diagnóstico ao tratamento." Master's thesis, 2019. http://hdl.handle.net/10316/89901.

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Trabalho Final do Mestrado Integrado em Medicina apresentado à Faculdade de Medicina
A implantação da válvula aórtica percutânea é um tratamento da estenose aórtica grave e em doentes com risco cirúrgico intermédio a grave. A trombose dos folhetos protésicos é uma complicação recentemente descrita e foi associada a um aumento do risco de eventos tromboembólicos. Neste contexto foi realizada uma pesquisa nas bases de dados: PubMed e Embase sobre a trombose subclínica dos folhetos protésicos após a implantação de uma válvula aórtica percutânea, no período de tempo de 2013 a 2018. Para a realização da presente revisão, utilizaram-se 52 artigos.A trombose subclínica dos folhetos protésicos carateriza-se por redução da mobilidade dos folhetos protésicos, associada a uma hipodensidade dos mesmos. Ocorreu em 15% dos doentes submetidos a uma implantação de uma válvula aórtica percutânea. Em termos diagnósticos, a tomografia computorizada cardíaca é o meio complementar de diagnóstico com maior acurácia para identificar a trombose subclínica dos folhetos protésicos, sendo considerado o método gold standard.Este fenómeno pode evoluir para degenerescência valvular, e consequente obstrução protésica, conduzindo a disfunção cardíaca. Evidenciou-se, também, uma maior ocorrência de acidentes isquémicos transitórios nos doentes com trombose subclínica dos folhetos protésicos.As próteses valvulares de maiores dimensões são um fator de risco para o desenvolvimento da trombose subclínica. O uso de anticoagulantes destaca-se como o melhor método terapêutico para a trombose subclínica dos folhetos protésicos, amenizando a evolução do fenómeno do ponto de vista estrutural e mitigando as suas consequências clínicas. Para além disso, a anticoagulação pode ser adequada também para prevenir, combatendo o ambiente pró-trombótico local.
Transcatheter aortic valve implantation is a treatment option for moderate to high surgical risk severe aortic valve stenosis patients. Leaflet thrombosis is a complication recently described hypothesized to be associated with an increased risk of thromboembolic events. In this context, a PubMed and Embase search was done, targeting articles related to subclinical leaflet thrombosis after transcatheter aortic valve replacement. 52 articles were used in this paper.The subclinical leaflet thrombosis is characterized by reduced leaflet motion associated with hypo-attenuating leaflet thrombosis. It was present in 15% of the patients undergoing transcatheter aortic valve replacement. For diagnose, computer tomography is considered the gold standard method.This phenomenon can lead to valvular degeneration and subsequent prosthesis obstruction. On the other hand, it also was associated with the occurrence of transient ischemic attacks.A larger valve prosthesis is associated with a higher risk of subclinical leaflet thrombosis. The use of anticoagulants is the best therapeutic method for subclinical leaflet thrombosis, preventing its evolution and clinic consequences. In addition to therapeutic use, these anticoagulants could also be used to prevent subclinical leaflet thrombosis. .
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Book chapters on the topic "Leaflet thrombosis"

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Kim, Ung, Shaw-Hua Kueh, Mickaël Ohana, and Jonathon Leipsic. "Subclinical Valve Leaflet Thrombosis." In Structural Heart Cases, 66–67. Elsevier, 2019. http://dx.doi.org/10.1016/b978-0-323-54695-9.00033-0.

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Conference papers on the topic "Leaflet thrombosis"

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Rascon, Alan, Nazmul Hossain, V. M. Krushnarao Kotteda, Christopher Harris, Herbert Janssen, Ellen Dudrey, Vinod Kumar, and Amit Lopes. "Designing an Experimental Setup for Analyzing the Flow Through a 3D Printed Venous Valve System From Arthroscopic Images." In ASME 2022 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/fedsm2022-87419.

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Abstract Deep vein thrombosis (DVT) is a silent killer, with millions of fatalities worldwide and a higher rate occurring during the COVID 19 pandemic. DVT frequently starts as a thrombus in a venous valve pocket, typically in a person’s leg, with minimal-to-no manifestations in the beginning. The venous valve pockets reside behind a pair of leaflets. Working with the muscular system, they prevent the reverse/backward blood flow and promote normal venous blood flow from an extremity to the right heart. It is known that leaflet morphology plays an important role in valve function; however, the effects of leaflet damage on valve function have not been fully explored. This paper discusses an experimental model designed to investigate the role of normal and abnormal leaflet morphology on venous valve function. This is accomplished using a 3D printed valve modeled after arthroscopic images and flow conditions observed in human cadaveric veins. The visualization and evaluation of flow through the model 3D printed venous valve are subjected to qualitative and quantitative assessment to evaluate flow through the valve and trapping of fluid in the valve pocket.
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Herbertson, Luke H., Steven Deutsch, and Keefe B. Manning. "Correlating Leaflet Design and Closing Dynamics With Turbulent Flows Near Bileaflet Mechanical Heart Valves." In ASME 2008 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2008. http://dx.doi.org/10.1115/sbc2008-192508.

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Significant advances have been made in the field of heart valve replacement, especially in terms of anticoagulation therapy and valve design. Mechanical heart valves have been successfully implanted for decades to replace irreparable diseased or failing native valves. However, heart valve patients remain more susceptible to hemolysis and thrombosis [1]. In this experimental study, we focus on the closing dynamics of bileaflet mechanical heart valves to better understand the roles that valve design and environmental conditions have on the local fluid mechanics.
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Boggs, Taylor, Hitomi Yamaguchi, Roger Tran-Son-Tay, Curt DeGroff, and Faris Al-Mousily. "Blood Cell Adhesion on a Polymeric Heart Valve Leaflet Processed Using Magnetic Abrasive Finishing." In ASME 2011 6th Frontiers in Biomedical Devices Conference. American Society of Mechanical Engineers, 2011. http://dx.doi.org/10.1115/biomed2011-66011.

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Heart valve prosthetics replace damaged, malfunctioning valves to improve a patient’s quality of life. Current mechanical valves are durable but suffer from thrombogenicity and flow separation, and can cause blood damage leading to coagulation. While bioprosthetic valves have better haemodynamic function than mechanical valves, the valves suffer from tears due to inflammation and collagen degradation. The absence of living tissue leaves them unable to repair themselves and their antigenicity must be masked. Complications due to thrombosis occur between 1.5% and 3% per year for current mechanical and bioprosthetic valves [1]. Polymeric valves have the potential to exhibit improved haemodynamic performance over mechanical valves without the complications associated with bioprosthetic valves; current issues associated with polymeric valves include calcification, hydrolysis, and durability [2].
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Kotteda, V. M. Krushnarao, Herb F. Janssen, Christopher Harris, and Vinod Kumar. "A Novel Mathematical Framework for the Venous Valve Leaflet Morphology Extracted From In-Vitro Images Using Machine Learning Assisted Stereological Analysis." In ASME 2021 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/fedsm2021-65744.

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Abstract It has been suggested that stasis (stagnant zones over a period of time, dependent on other factors such as age, or underlying medical conditions, such as cancer or covid19) in the valve pockets may increase the risk of clots due to stasis in combination with other factors increases the risk of Deep Venous Thrombosis (DVT) formation, blood stasis may also result in a decrease in the anticoagulants factors that prevent clots from forming, and if the vein wall is damaged this further increases the risk of clot formation. We propose a proactive framework to predict DVT vulnerability, track progression and provide patient care checkpoints is of clear benefit. The framework is based on leading-edge cloud computing technologies and promises to offer user-friendly Software- & Platform-as-a-Service (SaaS/PaaS) solutions via novel machine learning (ML) algorithm and high fidelity blood flow modeling through the venous network under various valve configurations. In this work, we will present the progress made towards the leaflet morphology extraction from in-vitro images using ML assisted stereological analysis for obtaining a sufficiently accurate representation of morphology. Ultimately, the workflow can be tailored to specific patients. The extracted valve is used to identify red-flag stagnant zones by a detailed, physics-based computational study of the blood flow through the leaflet models.
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Roldán, Alejandro, Nancy Sweitzer, Tim Osswald, and Naomi Chesler. "Numerical Simulation of Blood Flow Through Mechanical Heart Valves Using Meshless Techniques." In ASME 2007 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2007. http://dx.doi.org/10.1115/sbc2007-176381.

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Heart valve disease is a major contributor to cardiovascular mortality and morbidity. While bioprosthetic valves have satisfactory hemodynamic performance, mechanical heart valves (MHVs) are more durable, so their clinical use is increasing [1]. Unfortunately, current MHVs cause flow abnormalities, thrombosis and hemolysis [2]; they are therefore at a stage far from duplicating the function of natural valves. Recent improvements in computer performance and numerical methods have resulted in significant breakthroughs in MHV design [2]. In particular, computational fluid dynamics has been used to redesign valves to minimize the production of turbulence, regions of high shear stresses, pressure loss and stagnation regions in the vicinity of the leaflets [3]. These studies have, for the most part, used numerical techniques that require domain discretization such as finite element methods (FEM) or finite difference methods (FDM). However, these methods cannot represent the complexity of the moving and deforming boundaries present in an operating valve without extraordinarily high computational costs. That is, methods that use domain discretization require a fine mesh in small gaps between leaflets and near the valve housing. As a result, simplifying assumptions are typically made which introduce error into the results. We have recently implemented two meshless numerical techniques — the boundary element method (BEM) and the radial functions method (RFM) — that compute fluid flow fields without domain discretization and thus can model valve leaflet motions and unsteady flow with reasonable computational costs. The goal of this study was to model blood flow through mechanical heart valves using these techniques. In this paper we present the results of BEM simulations of heart valves in a range of open states. RFM techniques, which can efficiently simulate the nonlinear effects of inertia in the domain, are also described.
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Cooper, Benjamin T., Breigh N. Roszelle, Tobias C. Long, Steven Deutsch, and Keefe B. Manning. "A Fluid Dynamics Study Focusing on Wall Shear Rates Within the Penn State 12 cc Pulsatile Pediatric Ventricular Assist Device: A Comparison of Mechanical Heart Valve Types." In ASME 2007 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2007. http://dx.doi.org/10.1115/sbc2007-175441.

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Previous studies have shown that the interrelated flow characteristics necessary for the prevention of thrombosis in a pulsatile ventricular assist device (VAD) are a strong inlet jet, a late diastolic recirculating flow, and adequate wall washing (greater than 500 s−1). Particle image velocimetry was used to compare the flow fields in the chamber of the 12 cc Penn State pediatric pulsatile VAD using two valves: Björk-Shiley Monostrut (BSM) tilting-disc valves at the inlet and outlet and Carbomedics (CM) bi-leaflet valves at the inlet and outlet. In conjunction with the flow evaluation, wall shear data were calculated and analyzed to help to quantify wall washing. The major orifice inlet jet of the device containing BSM valves was more intense which led to better circulation and wall washing than the three jets produced by the CM valves Regurgitation through the CM valve was observed and served as a significant hindrance to the development of the rotational flow.
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Zadeh, Parnian Boloori, Hamid N.-Hashemi, Scott C. Corbett, and Ahmet U. Coskun. "Calcification of Trileaflet Polyurethane Heart Valve." In ASME 2010 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2010. http://dx.doi.org/10.1115/sbc2010-19486.

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Heart valve disease is a common type of cardiac disease that causes a large number of mortalities worldwide. Patients with severe heart valve problems are required to undergo heart valve replacement surgeries. Mechanical and bioprosthetic heart valves are the current available prostheses for patients in need of a heart valve replacement surgery. Mechanical heart valves are susceptible to thromboembolism and thrombosis and bioprosthetic valves have a limited life-span because of leaflet wear and calcification. Different polyurethane valves were suggested as an alternative material. However, prior results indicated that tested polyurethanes failed due to calcification. The mechanism for polyurethane calcification is not yet completely understood. Kou Imachi et al. [2], suggested that the calcification is due to entrapment of blood proteins and/or phospholipids in microgaps in the polymer and subsequent attraction of Ca ion, leading to formation of calcium phosphate (Ca3(PO4)2). Bisphosphonates (BP), which are considered to enhance the calcification resistance of polymers once covalently bonded to the material, indicated promising results in some studies. Focus of the present study is the trileaflet polyurethane valve, originally developed in the design of the AbioCor® replacement heart, and has demonstrated excellent durability and hemocompatibility in clinical evaluation. Over the past three years, this valve has been modified and its potential as a replacement valve have been studied [1]. Valve hemodynamic analysis showed that it is comparable to bioprosthetic valve in terms of fluid flow, pressure drop and regurgitation [1]. In order to ensure the suitability of the trileaflet polyurethane valve as a replacement valve its fatigue and calcification resistance are studied. The purpose of this paper is to simulate calcification of trileaflet polyurethane valves in an in vitro accelerated test and compare that with that of tissue valves. Furthermore the effect of bisphosphonate modified polyurethane on calcification is studied.
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O'Donnell, Valerie. "The biosynthesis and action of enzymatically-oxidized lipids during innate immunity and inflammation." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/emxs7632.

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In this presentation, I will review our knowledge about the generation and biological action of enzymatically-oxidized phospholipids (eoxPL) formed by circulating blood cells during inflammation and clotting. While the existence of nonenzymatically-oxidized PL has been known about since the 1990's, the fact that similar lipids are generated endogenously by enzymes, and that they act as part of innate immunity, has only been known for about the last 15 years. In our laboratory, using precursor scanning tandem mass spectrometry, in collaboration with Robert Murphy in Denver, we identified related families of lipids that are formed by the action of lipoxygenases/cyclooxygenases, and the Lands pathway acting in series. EoxPL comprise primarily mono-oxygenated arachidonate esterified to phosphatidylcholine and phosphatidylethanolamine, termed HETE-PC or HETE-PE, although there are also lower abundance forms derived from docosahexaenoic and eicosapentaenoic acids formed in human platelets. HETE-PL are mainly generated on acute activation of cells (platelets, neutrophils) or are present basally in eosinophils and some monocyte populations. They are not secreted, and instead stay in the membrane compartment and to some extent are present on the outer leaflet of cells. When externalised by platelets, they can enhance blood clotting through changing membrane biophysics. We also found they can activate PPARγ and regulate neutrophil antibacterial activities. All these are events of importance for innate immunity. In collaboration with clinical colleagues, we are looking at their generation in atherosclerosis, rheumatoid arthritis and venous thrombosis. We found that they are elevated in antiphospholipid syndrome, along with higher levels of autoantibodies that recognise them being present in the plasma of patients. Mice lacking eoxPL are protected against lesion development in a model of abdominal aortic aneurysm (AAA), and eoxPL are detected in human AAA lesions. Last, the Lands cycle esterification of oxylipins may represent a mechanism for reducing their bioactivity during inflammation.
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Farrell, Laura-Lee, Deepak Nair, Ross Milner, and David Ku. "Thrombotic Potential of a Prosthetic Vein Valve." In ASME 2007 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2007. http://dx.doi.org/10.1115/sbc2007-175925.

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Over seven million Americans suffer from chronic venous insufficiency, secondary to valvular dysfunction, with few effective clinical therapies. Chronic Venous Insufficiency (CVI) is a painful and debilitating disease that affects the superficial and deep veins of the legs. After deep venous thrombosis, the vein valves leaflets become adherent, fold over, or are absorbed into the vein wall. Incompetent valves allow reflux and subsequent pooling of blood in the legs. The resultant CVI causes severe leg edema, skin breakdown, and possible gangrene. Current clinical therapies are only modestly effective and include vein stripping and ligation, valvuloplasty, vein valve transposition, and vein valve transplantation. Valvuloplasty is the most definitive of CVI treatment, though this surgical treatment is rarely performed due to its difficulty. The quest for a better solution continues.
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Sewell-Loftin, M. K., Daniel M. DeLaughter, Joey V. Barnett, and W. David Merryman. "Collagen-Hyaluronic Acid Hydrogels Provide Enhanced EMT of Endocardial Cells." In ASME 2013 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/sbc2013-14204.

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A viable tissue engineered heart valve (TEHV) replacement would eliminate disadvantages associated with currently available prosthetics, such as thrombosis and increased risk of valve calcification. Viable TEHVs also are promising in that they can actively remodel and grow, as they would be populated with cells similar to native valves. Valvular interstitial cells (VICs) organize and maintain the complex structure of valves throughout the life of an organism. Considerable effort has been made towards identifying a source of VICs for next generation prosthetic heart valves. Despite this effort, the mechanisms by which VICs are produced in development, via endocardial epithethelial-to-mesenchymal transformation (EMT), are not fully understood. EMT is the critical first step in the formation of heart valve leaflets in utero, and thus a thorough understanding of the biomechanical and signaling environments that regulate EMT could lead to advancements in viable TEHVs.
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