The postthrombotic syndrome in relation to venous hemodynamics, as measured by means of duplex scanning and strain-gauge plethysmography

Purpose: Venous hemodynamics were evaluated in relation to the postthrombot ic syndrome (PTS) 7 to 13 years after deep venous thrombosis (DVT). Methods: The presence of flow, reflux, and compressibility of 1394 vein seg ments in 82 patients was assessed by means of duplex scanning. The venous o utflow resistance was measured by means of strain-gauge plethysmography. Th e venous hemodynamics were related to the clinical severity of the PTS, cha racterized by the CEAP (clinical, etiologic, anatomic, pathophysiologic) cl assification. Results: In patients with severe clinical symptoms of PTS, the prevalence o f reflux was significantly higher. There was no relationship between the se verity of the PTS and the noncompressibility or the combination of reflux a nd noncompressibility or an increased venous resistance. By means of multip le regression analysis with the variables of age, gender, reflux, and venou s resistance, age and reflux were shown to be the main contributors to the severity of PTS. Significantly more patients (64%) with severe signs of PTS had a combination of deep and superficial reflux. In each of the traceable vein segments, the mean of the CEAP classification was calculated for the vein segments with and without reflux. In the proximal superficial femoral vein (P < .001), distal superficial femoral vein (P < .05), and popliteal v ein (P < .05), a significantly higher mean CEAP classification was found in the veins with reflux, whereas in the distal, long, and short saphenous ve ins, no such relationship was found. Conclusion: Most patients with severe PTS had a combination of deep and sup erficial reflux. Reflux in the deep proximal veins contributes significantl y to the PTS.