The influence of an unilateral carotid artery stenosis on brain oxygenation.
We study the impact of varying degrees of unilateral stenoses of an carotid artery on pulsatile blood flow and oxygen transport from the heart to the brain. For the numerical simulation a model reduction approach is used involving non-linear 1-D transport equation systems, linear 1-D transport equations and 0-D models. The haemodynamic effects of vessels beyond the outflow boundaries of the 1-D models are accounted for using a 0-D lumped three element windkessel model. At the cerebral outflow boundaries the 0-D windkessel model is extended by metabolic autoregulation, based on the cerebral oxygen supply. Additionally lumped parameter models are applied to incorporate the impact of the carotid stenosis. Our model suggests that for a severe unilateral stenosis in the right carotid artery the partial pressure of oxygen in the brain area at risk can only be restored, if the corresponding cerebral resistance is significantly decreased and if the circle of Willis (CoW) is complete.
Institute for Numerical Mathematics, Technische Universität München, Boltzmannstr. 3, D-85748 Garching b. München, Germany. Electronic address: koeppl@ma.tum.de.
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T
Köppl
Department of Hydromechanics and Modelling of Hydrosystems, Pfaffenwaldring 61, D-70569 Stuttgart, Germany.
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M
Schneider
Walter-Brendel-Centre of Exp. Medicine, Ludwig-Maximilians-Universität, Marchionistr. 27, D-81377 München, Germany.
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U
Pohl
Institute for Numerical Mathematics, Technische Universität München, Boltzmannstr. 3, D-85748 Garching b. München, Germany.
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B
Wohlmuth
D001783:Blood Flow Velocity; D001921:Brain / Q000503:physiopathology*; D016893:Carotid Stenosis / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D002941:Circle of Willis / Q000503:physiopathology*; D003198:Computer Simulation; D006801:Humans; D008955:Models, Cardiovascular; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption; D011673:Pulsatile Flow; D014655:Vascular Resistance
D010100:Oxygen
Circle of Willis; Domain decomposition; Model reduction; Multi-scale model; Oxygen supply; Stenosis; Transport equations