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" Mechanochemical Thrombosis Models "
Thrombosis, the formation of a clot inside a blood vessel, causes a host of
medical problems, including heart attack, stroke, pulmonary embolism, and bleeding
disorders. Thrombosis complicates surgical procedures and any intervention or
implant where artificial materials contact blood. Models of thrombosis may be
useful for improving cardiovascular device design, improving experimental model
interpretation, or diagnosis of thrombosis risk. This presentation will review
several computational models of thrombosis that link fluid mechanics, cellular
transport, cellular activation, and coagulation kinetics.
Commercial computational fluid dynamics (CFD) software was used to model the
aggregation of platelets from flowing blood onto a growing thrombus. Blood was
treated as a fluid, and platelets as a pseudochemical species transported by
convection and shear-enhanced diffusion. Platelet activation was either assumed or
modeled as a first-order reaction due to thrombin generation at the thrombus
surface. The model is well correlated with experimental measurements in tubular
and converging geometry, but the activation kinetics suggest that activation is
either more rapid that previously reported, or not necessary for initial
platelet-thrombus interaction. Recently the effect of thrombus growth has been
modeled by creating an expanding porous zone.
Under low-shear flow conditions, platelet transport is reduced and surface-driven
coagulation kinetics may become important. Continuum models of coagulation
kinetics in flowing blood are currently not tractable, and lumped parameter
modeling has been used to study the role of mass transport and surface reactivity
in coagulation. Such models have potential use for cardiovascular device design
and management of thrombosis risk but require experimental validation.
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