[Duplexsonography investigation in patients with venous ulcer]

Venous hypertension due to venous insufficiency causes venous ulcers. Duplexsonography is a widely accepted non invasive method to assess venous insufficiency with venous reflux measurements. Retrograde venous flow is defined as venous reflux. The testing of venous reflux is reliable if transvalvular pressure is sufficiently high and transvalvular flow velocity exceeds 30 cm/s. Reflux testing in the proximal leg veins (V. femoralis communis, V. femoralis, V. saphena magna) is done using a standardised Valsalva Manoeuvre (exspiration into a tube up to a pressure of 30 mmHg, pressure established within 0.5 seconds, pressure hold for 3 seconds). Distal leg vein testing (V. poplitea, V. tibialis posterior, V. saphena parva) is recommended with a two handed - compression distally to the tested veins. The most important parameter is venous reflux time, a cut off of > 2 seconds is recommended.