ABSTRACT

The technique measures light reflection from the skin on the dorsum of the foot or behind the medial malleolus. Reflection from red blood cells in the dermis relates to local blood volume. Light absorption decreases as veins empty and venous pressure falls with exercise. Venous pressure is measured through a needle in a dorsal foot vein connected to a pressure transducer, amplifier and recorder. The hand-held continuous-wave (CW) Doppler unit is still used by some to assess each great saphenous vein, small saphenous vein and deep veins. However, duplex ultrasound has largely replaced this technique; the European Society for Vascular Surgery consensus statement holds that CW Doppler is not recommended for the diagnostic work-up of chronic venous disease. Superficial venous disease has come to be defined by reflux in superficial veins shown by ultrasound, but symptoms or complications seen in real life are due to venous pooling and venous hypertension.