ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

Mural Thrombosis in a Two-Level Computational Approach; Combination
of Continuum and Particle-Based Methods
1. ABSTRACT
S.M.R. Hassani 1 , N. Fatouraee 2
Blood, as a complex fluid, incorporates many components which influence the process
of platelet aggregation in different scales; Chemical activation of coagulant factors in
microscale, cells suspension in mesoscale and plasma flow in macroscale. To model the
process, the proper approach is to consider as many characteristics of the process as
possible. In our work, we implemented the Dissipative Particle Dynamics (DPD)
method to simulate plasma flow and platelet suspension in a 2D channel. Beside this,
the transport of coagulant factors and their activation modeled by a set of interconnected
convection-diffusion-reaction (CDR) equations. The results have shown that number of
deposited-platelet growth rate as well as distribution of aggregated platelets are in a
good agreement with the prior computational and the in-vitro studies. In conclusion, the
proposed approach, in comparison with prior works, provides a deeper view on the
phenomenon since it illuminates the colloidal characteristic of the flow and eliminates
the uncertainty involved with the distance-dependent activation models.
2. INTRODUCTION
One of the most crucial functions of blood constituent is to contribute in coagulation
mechanism which in pathological cases turns into thrombosis and embolisation. Fragmentation
of mural thrombosis is the major cause of the ischemic myocardial infarction. Strokes play as
third leading cause of death in United States and the thromboembolic strokes includes 80% of
them. Therefore, the computational modeling of clot formation process can help investigators to
reach a better understanding of the phenomenon and may also help to optimize endovascular
prosthesis design, clinical interventions, and extracorporeal devices designs as future goals.
There is a vast history of research in the area of thrombogenesis computational
modeling, hence adding new features to the computational models needs a great
knowledge of thrombosis physiology; the critical core of the thrombosis is the
interconnected activation of coagulant factors in blood, resulting in an insoluble fibrin,
which creates a matrix to entrap cells and links between the adhered platelets. The
accompanying processes to the activation cascade are: the platelet activation
accommodated by the coagulant factors in their vicinity, the activated platelets adhesion
to each other and the subendothelial layers, and the release of additional coagulant
factors by the activated platelets [1]. These processes, creating a positive feedback loop,
have multiscale characteristics that in many different computational approaches, some
of these scales, have been illuminated through scholar papers.
To briefly include the history of mural thrombosis modeling, we should start from
1 Research Assistant, Biological Fluid Mechanics Research Laboratory, Department of Biomedical
Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran 15914;
mhassani86@aut.ac.ir
2 Associate Professor, Biological Fluid Mechanics Research Laboratory, Department of Biomedical
Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran 15914;
nasser@aut.ac.ir