Blood velocity in the abdominal aorta and common iliac artery of man

In view of a possible contribution of turbulent flow upon atherogenesis, particularly at bifurcations of vessels, an evaluation of the nature of flow in man in the abdominal aorta and common iliac artery was made. Velocity was measured in eight resting patients with a hot film velocity probe. A particular effort was made to record velocity in the region of the bifurcation of the aorta at the common iliac arteries. No high frequency disturbances of velocity were observed in the abdominal aorta or common iliac arteries, either during systole or diastole in any of the patients. Peak velocity in the aorta, at the level of the renal artery, was 28 ± 4 cm/sec (mean ± SEM), at the aortic bifurcation it was 27 ± 4 cm/sec and at the common iliac artery it was 24 ± 4 cm/sec. The peak Reynolds number, measured at the aortic bifurcation (in four patients), ranged from 400 to 1100, and in the common iliac artery it ranged from 390 to 620. Absence of turbulent flow in the abdominal aorta and common iliac arteries in resting patients suggests that turbulence does not initiate atherosclerosis in these areas. However, a possible contribution of turbulence to atherosclerosis, once plaque formation has caused an irregularity of arterial walls, cannot be excluded.