Predilection of occlusive disease for the left iliac artery.

Eighty-six consecutive patients operated on for atherosclerotic occlusion of the aortoiliac segment were examined regarding the severity of the disease in the left or right iliac arteries. Sixty-nine percent of 78 patients were found to have predominantly more severe lesions on the left side. A study of the geometric anatomy of the aortoiliac region in 14 male and 12 female cadavers revealed that the right common iliac take-off angle was wider than the left and the radius of curvature of the right osculating circle at the aortoiliac bifurcation was smaller than the left, with the asymmetry of the region being much more marked in males than in females. The predilection of occlusive disease for the left iliac artery is explained on the basis of these differences in local geometric anatomy and their effect on the local hemodynamics.