The diameter of the distal abdominal aorta and the aetiology of local atheroma.

: In our patients it was found that small sized prostheses were usually implanted to replace obliterated aortic bifurcations. Consequently, the question was considered whether the haemodynamic processes involved in the lysis of the aortic wall at the bifurcation and in the succeeding atherosclerotic lesions were related to the small diameter of the aorta in these cases. In an extensive angiographic and ultrasonic study on men without atherosclerotic lesions, the diameter of the abdominal aorta was determined (control group). Aortic diameter appears to depend on age as well as body length. We also found a difference between the average diameters for women and for men. Of our patients who were operated on, over 35% had an aortic diameter below the 95% population lower boundary line of the control group, while for over 90%, the diameter was below the average of the control group. On analysis of our data the explanation for the aetiology of atheromatosis at the aortic bifurcation must be much more complicated than current hemodynamic theories suggest.