The presence of reflux in the femoral vein (FV) and popliteal vein (POPV) after acute deep vein thrombosis (DVT) is considered to contribute to the development of advanced post-thrombotic syndrome (PTS). However, a quantification of reflux has yet to be determined. The purpose of study was to determine the indicative parameters reflecting the progression of PTS.Methods
Venous abnormalities were evaluated in 131 limbs out of 130 patients who completed a six-year follow-up after an acute DVT. Clinical manifestations were categorized according to the clinical, etiologic, anatomic, and pathophysiologic (CEAP) classification, and the patients were divided into two groups at a six-year follow-up point: group I, C0–3Es,As,d,p,Pr,o, early chronic venous insufficiency (CVI); group II, C4–6Es,As,d,p,Pr,o, advanced CVI. Venous segments were examined whether they were occluded or recanalized. The reflux parameters assessed were the diameter (cm), the reflux time (RT; s), the peak reflux velocity (PRV; cm s−1), and total refluxed volume, and these parameters were assessed especially in the FV and POPV at the two-year (early phase) and subsequent six-year (late phase) follow-up points after DVT.Results
There were 98 limbs in group I and 33 in group II. The frequency of venous reflux was significantly higher in group II (<0.0001). In contrast, the proportion of occlusion did not differ between the groups (P = 0.138). The proportions of FV and POPV incompetence were significantly higher in group II (P < 0.0001 and P < 0.0001, respectively). In these veins, the RT did not improve the discrimination power between the two groups. In contrast, the PRV had significant discrimination power in these veins at both the two- and six-year follow-up points. In the superficial venous system, there were no significant differences in any of the determined parameters between the groups. In group II, 19 patients (58%), who had early symptoms of CVI at the two-year follow-up point, subsequently developed advanced symptoms of PTS. After calculating a suitable cutoff point using receiver operating characteristic curves analysis at the two-year follow-up point, multivariable analysis showed that a PRV of >25.4 cm s−1 in the POPV was the strongest independent predictor of advanced CVI [odds ratio (OR) 60.32; 95% confidence interval (95CI) 43.1–1238.97, P < 0.0001]. Similarly, in the FV, a PRV of >24.5 cm s−1 was found to be a strong predictor of advanced CVI (OR 25.77, 95CI 10.56–331.12, P < 0.0001).Conclusions
These findings suggest that the presence of a high PRV in the proximal deep veins is an independent predictor of advanced symptoms of PTS.