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Improved prediction of disturbed flow via hemodynamically-inspired geometric variables.

TitleImproved prediction of disturbed flow via hemodynamically-inspired geometric variables.
Publication TypeJournal Article
Year of Publication2012
AuthorsBijari PB, Antiga L, Gallo D, Wasserman BA
Secondary AuthorsSteinman DA
JournalJ Biomech
Volume45
Issue9
Pagination1632-7
Date Published2012 Jun 01
ISSN1873-2380
KeywordsAdult, Carotid Arteries, Computer Simulation, Hemorheology, Humans, Models, Cardiovascular, Regional Blood Flow, Young Adult
Abstract

Arterial geometry has long been considered as a pragmatic alternative for inferring arterial flow disturbances, and their impact on the natural history and treatment of vascular diseases. Traditionally, definition of geometric variables is based on convenient shape descriptors, with only superficial consideration of their influence on flow and wall shear stress patterns. In the present study we demonstrate that a more studied consideration of the actual (cf. nominal) local hemodynamics can lead to substantial improvements in the prediction of disturbed flow by geometry. Starting from a well-characterized computational fluid dynamics (CFD) dataset of 50 normal carotid bifurcations, we observed that disturbed flow tended to be confined proximal to the flow divider, whereas geometric variables previously shown to be significant predictors of disturbed flow included features distal to the flow divider in their definitions. Flaring of the bifurcation leading to flow separation was redefined as the maximum relative expansion of the common carotid artery (CCA), proximal to the flow divider. The beneficial effect of primary curvature on flow inertia, via suppression of flow separation, was characterized by the in-plane tortuosity of CCA as it enters the flare region. Multiple linear regressions of these redefined geometric variables against various metrics of disturbed flow revealed R(2) values approaching 0.6, better than the roughly 0.3 achieved using the conventional shape-based variables, while maintaining their demonstrated real-world reproducibility. Such a hemodynamically-inspired approach to the definition of geometric variables may reap benefits for other applications where geometry is used as a surrogate marker of local hemodynamics.

DOI10.1016/j.jbiomech.2012.03.030
Alternate JournalJ Biomech
PubMed ID22552156
PubMed Central IDPMC3371282
Grant ListN01HC55020 / HL / NHLBI NIH HHS / United States
MOP-62934 / / Canadian Institutes of Health Research / Canada
N01HC55018 / HL / NHLBI NIH HHS / United States
N01-HC-55022 / HC / NHLBI NIH HHS / United States
N01-HC-55016 / HC / NHLBI NIH HHS / United States
U01 HL075572 / HL / NHLBI NIH HHS / United States
N01HC55022 / HL / NHLBI NIH HHS / United States
N01-HC-55021 / HC / NHLBI NIH HHS / United States
U01 HL075572-01 / HL / NHLBI NIH HHS / United States
N01HC55015 / HL / NHLBI NIH HHS / United States
N01-HC-55019 / HC / NHLBI NIH HHS / United States
N01-HC-55015 / HC / NHLBI NIH HHS / United States
N01-HC-55020 / HC / NHLBI NIH HHS / United States
N01HC55016 / HL / NHLBI NIH HHS / United States
N01HC55019 / HL / NHLBI NIH HHS / United States
U01HL075572-01 / HL / NHLBI NIH HHS / United States
N01-HC-55018 / HC / NHLBI NIH HHS / United States
N01HC55021 / HL / NHLBI NIH HHS / United States