The ability of qualitative assessment of the common femoral Doppler waveform to screen for significant aortoiliac disease.

OBJECTIVE To study the ability of a qualitative assessment of the common femoral Doppler waveform to screen for significant aortoiliac disease. DESIGN Prospective, semi-blind study. SETTING Vascular laboratory, University Hospital. METHODS A total of 118 aortoiliac segments were studied in 73 patients. Each aortoiliac segment was graded as normal or abnormal from visual interpretation of the common femoral Doppler waveform obtained by colour duplex ultrasound. Full ultrasound assessment of the aortoiliac vessels acted as the "gold standard". Abnormal aortoiliac segments were defined by the presence of at least one > or = 50% diameter reducing lesion, whereas vessels considered "normal" included those with disease between 0-49% diameter reduction. An increase in peak systolic velocity of two-fold or greater was used to define a > or = 50% diameter reducing stenosis. Agreement between common femoral waveform analysis and the duplex scans was measured by the Kappa statistic. RESULTS The Kappa value for the agreement between common femoral waveform analysis and duplex scans was 0.74 (95% CI; 0.62-0.86). This represents substantial agreement. Doppler waveform analysis had a sensitivity of 95%, specificity of 80% and accuracy of 87% for the prediction of a significant aortoiliac stenosis seen by ultrasound. CONCLUSION Visual interpretation of the common femoral Doppler waveform is a sensitive and accurate technique for the prediction of significant aortoiliac stenosis. It is of particular value when full ultrasound aortoiliac assessments are not feasible due to time constraints, obesity or the presence of bowel gas.