[Study of venous insufficiency].

Investigation of chronic venous insufficiency of the lower limbs can now be done by numerous techniques, which should nevertheless not replace clinical examination and a pragmatic approach. Ultrasound techniques have definitively surpassed phlebography. Doppler examination, due to its excellent cost-effectiveness ratio, is a basic technique for initial investigation. Pulsed echo-doppler, with or without colour coding, is the method of reference in the study of superficial and deep reflux. Phlebography is still indicated before surgery in complex reflux of the popliteal fossa and in rare cases of post-thrombotic syndromes; it remains the most reliable method when deep valvular dysgenesis is suspected. Quantified methods of investigating venous function (ambulatory venous pressure, dynamic volumetry of the foot, air plethysmography, treadmill plethysmography) are useful to analyse complex cases and severe venous insufficiency. Photoplethysmography is a useful complement to doppler examination in assessing reflux in clinical practice.