Fig. 1.

Hemodynamic paradox. Strain gauge plethysmographic parameters refill time t-90 and t-50 as well as refill volumes (I and II) evaluated in patients with a grave form of chronic venous insufficiency showed the severest hemodynamic disorder before surgery, and utter normalization of the hemodynamic situation 1 week after abolition of saphenous reflux. B, before; A, after operation. Curiously enough, at the same time preconditions for recurrent reflux and for progressive comeback of the previous pathological situation were generated (III). Pressure difference of 37.4 ± 6.4 mm Hg arising between the femoral vein and saphenous remnant during calf pump activity triggers biophysical and biochemical events that induce progressive enlargement of pre-existing minor communications between deep and superficial veins in the thigh; the process ultimately results in recurrent reflux. The sign + means higher pressure; the sign − means lower pressure. The dashed line shows the boundary of the ambulatory pressure gradient between thigh and lower leg veins occurring in healthy persons. For more details see text.