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UNDERSTANDING AND MODELING PATHWAYS TO THROMBOSIS
Title
UNDERSTANDING AND MODELING PATHWAYS TO THROMBOSIS.
Creator
Seligson, John, Kassab, Alain, University of Central Florida
Abstract / Description
Intra-vessel thrombosis leads to serious problems in patient health. Coagulation can constrict blood flow and induce myocardial infarction or stroke. Hemodynamic factors in blood flow promote and inhibit the coagulation cascade. Mechanically, high shear stress has been shown to promote platelet activation while laminar flow maintains plasma layer separation of platelets and endothelial cells, preventing coagulation. These relationships are studied experimentally, however, physical properties...
Show moreIntra-vessel thrombosis leads to serious problems in patient health. Coagulation can constrict blood flow and induce myocardial infarction or stroke. Hemodynamic factors in blood flow promote and inhibit the coagulation cascade. Mechanically, high shear stress has been shown to promote platelet activation while laminar flow maintains plasma layer separation of platelets and endothelial cells, preventing coagulation. These relationships are studied experimentally, however, physical properties of thrombi, such as density and viscosity, are lacking in data, preventing a comprehensive simulation of thrombus interaction. This study incorporates experimental findings from literature to compile a characteristic mechanical property data set for use in thrombosis simulation. The focus of this study's simulation explored how thrombi interact between other thrombi and vessel walls via Volume of Fluid method. The ability to predict thrombosis under specific hemodynamic conditions was also a feature of the data collection. Using patient specific vessel geometry, the findings in this study can be applied to simulate thrombosis scenarios. The possible applications of such a simulation include a more precise method for estimation of patient myocardial infarction or stroke risk and a possible analysis of vessel geometry modification under surgery.
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Date Issued
2015
Identifier
CFH0004837, ucf:45440
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFH0004837
Computational Fluid Dynamics Study of Thromboembolism as a Function of Shunt Size and Placement in the Hybrid Norwood Palliative Treatment of Hypoplastic Left Heart Syndrome
Title
Computational Fluid Dynamics Study of Thromboembolism as a Function of Shunt Size and Placement in the Hybrid Norwood Palliative Treatment of Hypoplastic Left Heart Syndrome.
Creator
Seligson, John, Kassab, Alain, DeCampli, William, Mansy, Hansen, University of Central Florida
Abstract / Description
The Hybrid Norwood procedure has emerged as a promising alternative palliative first stage treatment for infants with Hypoplastic Left Heart Syndrome (HLHS). The procedure is done to provide necessary blood flow to the pulmonary and systemic regions of the body. The procedure can affect hemodynamic conditions to be pro-thrombotic, and thrombus particles can form and release from the vessel walls and enter the flow. Assuming these particles are formed and released from the shunt surface, a...
Show moreThe Hybrid Norwood procedure has emerged as a promising alternative palliative first stage treatment for infants with Hypoplastic Left Heart Syndrome (HLHS). The procedure is done to provide necessary blood flow to the pulmonary and systemic regions of the body. The procedure can affect hemodynamic conditions to be pro-thrombotic, and thrombus particles can form and release from the vessel walls and enter the flow. Assuming these particles are formed and released from the shunt surface, a Computational Fluid Dynamics (CFD) model can be used to mimic the patient's vasculature geometry and predict the occurrence of embolization to the carotid or coronary arteries, as well as the other major arteries surrounding the heart. This study used a time dependent, multi-scale CFD analysis on patient-specific geometry to determine the statistical probability of thrombus particles exiting each major artery. The geometries explored were of a nominal and patient specific nature. Cases of 90% and 0% stenosis at the aortic arch were analyzed, including shunt diameters of 3mm, 3.5mm, and 4mm. Three different placements of the shunt were explored as well. The intent of this study was to suggest best methods of surgical planning in the Hybrid Norwood procedure by providing supporting data for optimal stroke and myocardial infarction prevention.
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Date Issued
2017
Identifier
CFE0006655, ucf:51232
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0006655