Quantification of venous reflux parameters using duplex scanning and air plethysmography

Objective: To compare different duplex-and air plethysmography (APG)-derived parameters between patients with relatively early and those with advanced chronic venous insufficiency (CVI), and to investigate the indicative parameters reflecting the progression of CVI.

Methods: Design: Prospective study at the University Hospital. Patients: In total 686 limbs in 574 patients at various clinical stages of CVI were included. The clinical manifestations were categorized according to the CEAP (clinical, aetiologic, anatomic and pathophysiologic) classification, and the patients were divided into two groups: group I (C_1-3E_P,SA_S,D,PP_R,O, relatively early stage of CVI) and group II (C_4-6E_P,SA_S,D,PP_R,O, advanced CVI). The distribution of venous insufficiency including the sapheno-femoral junction (SFJ), great saphenous vein (GSV), sapheno–popliteal junction (SPJ), common femoral vein (CFV), femoral vein (FV), popliteal vein (POPV), thigh perforators (TPV) and calf perforators (CPV) was determined by duplex ultrasound. The main duplex-derived parameters assessed were the reflux time (RT; s), peak reflux velocity (PRV; cm/s) and peak reflux flow (PRF; mL/s). The venous reflux was assumed to be present if the duration of reflux was ≥0.5 s. The data obtained by APG were on VV (mL), VFI (mL/s), EF (%) and RVF (%).

Results: There was no significant difference in overall superficial venous reflux between the groups (P=0.331). The frequency of deep and perforating vein incompetence differed only when superficial reflux was included in group II. The VFI and RVF were significantly higher in secondary CVI than in primary CVI (P=0.0001, 0.003, respectively). In the secondary CVI, patients with reflux and obstruction showed significantly higher RVF than those with reflux alone (P=0.003). The RT did not improve the discrimination power between the groups. In contrast, the PRV had significant discrimination power at the SFJ (P<0.0001) and SPJ (P=0.022), and in the GSV (P<0.0001), the FV (P=0.017), and the POPV (P=0.0003). The PRF was significantly higher in group II at the SFJ (P<0.0001), in the GSV (P=0.002), in the CFV (P=0.011), in the FV (P=0.027), and the POPV (P=0.016).

Conclusions: This present study has suggested the importance of superficial venous insufficiency in the development of advanced CVI. In the secondary CVI, obstruction affects the RVF alone. The PRV and PRF are better parameters than the RT for discrimination of clinical severity in both superficial and deep venous insufficiency, and should be used to quantify venous valvular insufficiency.