Comparison of Four Haemodynamic Tests that Quantify Superficial Venous Insufficiency

Abstract

Reflux assessment with ultrasound (U/S) is usually qualitative. Quantitative measurements of superficial venous insufficiency (SVI) include the venous arterial flow index (VAFI), recirculation index (RCI), venous filling index (VFI), and the postural diameter change (PDC) of the saphenous trunk. The aim was to investigate their relationship. This was an observational study performed on patients with varicose veins and hospital employees. Four haemodynamic parameters were measured in 21 legs from 16 subjects. Legs were divided into no reflux (n=7) and reflux (n=14). The VAFI is the U/S ratio of common femoral vein volume flow divided by the common femoral artery volume flow, performed supine. The RCI is the U/S ratio of reflux volume over antegrade volume within the saphenous trunk after calf compression, standing. The VFI is the rate of calf volume increase on dependency measured in mL/s, using air plethysmography. The PDC is the percentage reduction of the saphenous trunk diameter from standing to lying, using U/S. The clinical part of the CEAP classification was: C0=3, C1=4, C2=5, C3=1, C4a=1, C4b=6, C5=1. All four tests demonstrated significant differences between the two groups with minimal overlap (Mann Whitney U test): VAFI (p=.028), RCI (p<.0005), VFI (p=.001), and PDC (p=.014). Furthermore, significant correlations were observed with the tests: VAFI vs. RCI (r=.532, p=.015), VFI (r=.489, p=.025) and PDC (r=-.474, p=.030); RCI vs. VFI (r=.446, p=.043) and PDC (r=-.527, p=.014). Superficial venous drainage insufficiency should not be confined to an U/S assessment of the presence of reflux, which is qualitative. Quantitative data may be provided using the VAFI, RCI, VFI, and PDC. Understanding why there are significant correlations among these parameters and the preferred objective reference test requires further work.