Título: | NUMERICAL PREDICTION OF HEMODYNAMIC PATTERNS DURING A CARDIAC CYCLE FOR ONE HEALTHY AND 30 ANEURYSMATIC AORTAS | ||||||||||||
Autor: |
GABRIELA DE CASTRO ALMEIDA |
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Colaborador(es): |
ANGELA OURIVIO NIECKELE - Orientador BRUNO ALVARES DE AZEVEDO GOMES - Coorientador |
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Catalogação: | 03/FEV/2025 | Língua(s): | ENGLISH - UNITED STATES |
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Tipo: | TEXT | Subtipo: | THESIS | ||||||||||
Notas: |
[pt] Todos os dados constantes dos documentos são de inteira responsabilidade de seus autores. Os dados utilizados nas descrições dos documentos estão em conformidade com os sistemas da administração da PUC-Rio. [en] All data contained in the documents are the sole responsibility of the authors. The data used in the descriptions of the documents are in conformity with the systems of the administration of PUC-Rio. |
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Referência(s): |
[pt] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=69236&idi=1 [en] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=69236&idi=2 |
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DOI: | https://doi.org/10.17771/PUCRio.acad.69236 | ||||||||||||
Resumo: | |||||||||||||
This study presents the validation of a physical/numerical model designed to
predict the ascending aorta flow in a healthy patient, aiming to extend its
application to analyze other patients, specifically, with ascending aortic aneurysm
(AAoA). Applying the patient-specific model (PSM) concept, the results provided
by the Four-dimensional Flow Magnetic Resonance Imaging (4D-Flow MRI)
technique were used in the simulation employing the Computational Fluid
Dynamics (CFD) approach, with a turbulence model capable of predicting
laminar/turbulent regime transitions during the cardiac cycle. Boundary condition
based on measured flow rate was imposed at the aorta s inlet. At the outlets, the
physiological percentages of inlet flow rate corresponding to each output were
considered, as well as the three-element Windkessel model to establish a more
accurate approximation of the pressure-flow relationship. The favorable results
obtained on pressure, flow rate and shear stress profiles at various positions along
the aorta and throughout the cardiac cycle, validated the potential application of
PSM to other patients, in particular patients with AAoA. AAoA is a silent disease
with high mortality, and factors associated with a worse prognosis are not yet fully
known. Aiming to relate flow dynamics characteristics with the disease,
personalized anatomic models were obtained from angiotomography scans of 30
patients in two different years (with intervals of one to three years between them).
Based on the volume difference of the ascending aorta from one year to another,
two groups were defined: one with aneurysm growth and another without growth.
The flow field during the cardiac cycle and the geometry corresponding to each
group were compared to find patterns that may indicate the aneurysm growth from
the first exam. Although there was no clear trend between the two patient groups,
higher time-averaged pressure ( ) values were observed in patients with
aneurysm growth, as well as longer time periods during the cycle with the aorta
subjected to high values of shear stress. The present study explored the
remodeling process of patients with aneurysm and how the geometry and flow
pattern can impact its growth, contributing to a better understanding of aortic
pathophysiology.
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