Femoral/Axillary Volume Flow Ratio as a New Index for the Assessment of Iliac Atherosclerosis

OBJECTIVE: To measure the arterial volume flow (VF) with duplex scan, calculate femoral/axillary VF ratio, and discuss its applicability as a new index for the hemodynamic significance of an aorto-iliac occlusive lesion. METHODS: Several measures of VF were obtained consecutively with duplex scan in both common femoral and axillary arteries of healthy volunteers with no signs of atherosclerosis and patients with documented evidence of occlusive aorto-iliac disease with segmental pressure measurement. Then the patient group was sent to complimentary evaluation for a second confirmatory examination. RESULTS: There were a total of 635 measures of VF performed in 10 healthy volunteers and 8 patients with severe iliac stenoses or occlusion, 2 of then with bilateral disease. When comparing normal participants and patients with severe iliac stenoses or occlusion, there was statistical significant difference between these 2 groups (P < .01 Mann-Whitney). Similar result was found when comparing patient with diseased limbs with their own contralateral normal side (P < .05 Wilcoxon). And measuring the VF only during the systolic phase was a much more sensitive parameter for differentiating the normal from the diseased. Besides that a good correlation between proximal thigh pressure index and femoral/axillary systolic flow ratio was found in the patient group (P < .01 Spearman correlation). CONCLUSION: The femoral/axillary VF ratio is useful in assessing the hemodynamic significance of aorto-iliac disease, and the systolic femoral-axillary ratio may also be useful as a follow-up tool.