Numerical Analysis of Oxygen Transport in an Aortic Vessel.

Oxygen transport to a vessel of an aortic arch was numerically analyzed using the finite volume method. Oxygen delivery to the vessel is achieved through two pathways ; one is direct transport from blood flow in the lumen and the other is via the vaso vasorum. The oxygen transport from blood to the vessel consists of several processes ; release from hemoglobin, convection to the vessel wall, simple diffusion, and metabolism in the vessel. The blood is assumed to be fully developed and a flow field previously calculated from physiological aortic flow was used for the calculation of concentration fields. Our results show that even under normal physiological conditions, there exists very low O2 tension region in the middle of the vessel tissue. The secondary flow causes to make the minimum of oxygen tension near the inner side of bend. The tension near the inside is 20% less than that of the outside. This nonuniformity of oxygen tension in the circumferential direction may be associated with the localized formation of atherosclerotic lesions.