Direct measured systolic pressure gradients across the aorto-iliac segment in multiple-level-obstruction arteriosclerosis.

Patients with severe ischemia due to multi-level obstructions in the leg arteries both above and below the region were assessed preoperatively by intraarterial brachial and femoral artery pressure measurements. The systolic pressure drop along aorto-iliac obstructions was compared to the angiographic findings. A consistent pressure gradient was found in the various types of arterial occlusions. In patients with occlusion of both the aorta and the iliac arteries, the systolic pressure drop was about 60% (range, 50-78%, SD 9%). The various types of iliac artery occlusions resulted in quite uniform systolic pressure drops of about 50% (range 35-68%, SD 9%). In contrast, the systolic pressure drop along different types of iliac stenoses showed a wide variation, ranging from a minimal drop to about 60%. The degree of stenosis on the angiogram was correlated significantly with the pressure drop. Due to large variations, however, the angiographic information was found to be useless in the individual patient. No difference in the pressure drop was found between cases in which rich and poor collateral networks were visualized.