Significance of popliteal reflux in relation to ambulatory venous pressure and ulceration.

Fifty-one patients (55 limbs) who had had deep venous thrombosis (DVT) extending into the femoral or iliofemoral segment three to five years earlier and ten limbs of ten healthy volunteers were studied. The ambulatory venous pressure (AVP) was measured by inserting a needle in a vein on the foot; the presence of reflux in the popliteal vein was determined by a directional Doppler ultrasonic blood velocity detector. All patients had ascending venography. The results suggest that the most important factor in determining the AVP and ulceration in postthrombotic limbs is the condition of the popliteal valves. Ulceration does not occur even in the presence of occlusion if the popliteal valves are competent. The extent of DVT and recanalization or the failure of recanalization is of secondary importance.