Internal geometry of arterial bifurcations.

The internal geometries of 137 arterial bifurcations were measured, using enlarged angiographic pictures, to determine the position of the apex of each bifurcation in relation to the ostium of the parent artery. The measurements, relating to different parts of the cardiovascular system of man and some to that of rabbit and pig, were compared with each other and with a theoretical model of an 'optimum' arterial bifurcation. The results were found to be consistent with a position of the apex which is optimum from the point of view of local hemodynamics. In that position, the apex lies on a straight dividing streamline which divides the flow in the parent artery in the proportion required by the two branches.