A Comparison of Photoplethysmography, Doppler Ultrasound and Duplex Scanning in the Assessment of Venous Insufficiency

Abstract

Effective surgical treatment for venous insufficiency depends on an accurate assessment of the veins. Phlebography, giving an anatomical view, is now being replaced by non-invasive methods of examination which give both anatomical and physiological information. This study compared the diagnoses obtained from three methods of non-invasive assessment: photoplethysmography, continuous wave Doppler ultrasound and duplex scanning. One hundred and twentyfour limbs were evaluated by each of the three methods. There was concordance about the diagnosis between all three methods in 42.2%. Duplex and Doppler agreed in 62%; duplex and PPG in 60.5%; Doppler and PPG in 54.8%. Confirmation of the results using invasive methods showed duplex to be the most accurate method for detecting deep vein reflux. We would question the efficacy of tourniquets in controlling reflux, leading to misinterpretation of the PPG results and Doppler ultrasound results.