Document Detail


Influence of inlet boundary conditions on the local haemodynamics of intracranial aneurysms.
MedLine Citation:
PMID:  19675980     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Haemodynamics is believed to play an important role in the initiation, growth and rupture of intracranial aneurysms. In this context, computational haemodynamics has been extensively used in an effort to establish correlations between flow variables and clinical outcome. It is common practice in the application of Dirichlet boundary conditions at domain inlets to specify transient velocities as either a flat (plug) profile or a spatially developed profile based on Womersley's analytical solution. This paper provides comparative haemodynamics measures for three typical cerebral aneurysms. Three dimentional rotational angiography images of aneurysms at three common locations, viz. basilar artery tip, internal carotid artery and middle cerebral artery were obtained. The computational tools being developed in the European project @neurIST were used to reconstruct the fluid domains and solve the unsteady Navier-Stokes equations, using in turn Womersley and plug-flow inlet velocity profiles. The effects of these assumptions were analysed and compared in terms of relevant haemodynamic variables within the aneurismal sac. For the aneurysm at the basilar tip geometries with different extensions of the afferent vasculature were considered to study the plausibility of a fully-developed axial flow at the inlet boundaries. The study shows that assumptions made on the velocity profile while specifying inlet boundary conditions have little influence on the local haemodynamics in the aneurysm, provided that a sufficient extension of the afferent vasculature is considered and that geometry is the primary determinant of the flow field within the aneurismal sac. For real geometries the Womersley profile is at best an unnecessary over-complication, and may even be worse than the plug profile in some anatomical locations (e.g. basilar confluence).
Authors:
Alberto Marzo; Pankaj Singh; Philippe Reymond; Nikos Stergiopulos; Umang Patel; Rodney Hose
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Computer methods in biomechanics and biomedical engineering     Volume:  12     ISSN:  1476-8259     ISO Abbreviation:  Comput Methods Biomech Biomed Engin     Publication Date:  2009 Aug 
Date Detail:
Created Date:  2009-08-13     Completed Date:  2009-11-16     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9802899     Medline TA:  Comput Methods Biomech Biomed Engin     Country:  England    
Other Details:
Languages:  eng     Pagination:  431-44     Citation Subset:  IM    
Affiliation:
Department of Medical Physics, School of Biomedical Sciences, University of Sheffield, Sheffield, UK. a.marzo@sheffield.ac.uk
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MeSH Terms
Descriptor/Qualifier:
Blood Flow Velocity / physiology
Blood Pressure / physiology
Cerebral Arteries / pathology,  physiopathology
Cerebrovascular Circulation / physiology
Computer Simulation*
Hemodynamics / physiology
Humans
Imaging, Three-Dimensional
Intracranial Aneurysm / pathology,  physiopathology*
Models, Cardiovascular*
Models, Neurological
Stress, Mechanical

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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