Comparing Venous Reflux in Reverse Trendelenburg Position to Standing Position Using Duplex Ultrasound

Chronic venous insufficiency (CVI) is a common vascular disorder ranging from asymptomatic varicose veins to venous ulceration. Venous reflux, the primary pathophysiologic mechanism, is typically evaluated using duplex ultrasound (DUS) in the standing position (SP). However, some patients cannot tolerate SP and require assessment in the reverse Trendelenburg (RT) position.

We conducted a cross-sectional study to compare venous reflux detection using DUS in the SP versus RT. A total of 105 patients with CVI were evaluated, with disease severity classified using the revised Clinical-Etiological-Anatomical-Pathophysiological system. Vein diameter and reflux duration were measured at the saphenofemoral junction (SFJ), great saphenous vein (GSV), saphenopopliteal junction (SPJ), and small saphenous vein (SSV). Agreement between positions was assessed using Cohen kappa, and paired differences in reflux detection were evaluated using McNemar test.

Overall agreement between positions was high across venous segments, with concordance of 83% at the SFJ, 78% in the GSV, 95% in the SSV, and 81% at the SPJ. Reflux was detected more frequently in RT than in SP at the SFJ (174 vs. 149 limbs; P < 0.001), and a similar trend observed at the GSV (159 vs. 146 limbs; P = 0.061). Reflux detection at the SSV was similar between positions. Mean vein diameters at the SFJ and GSV were significantly smaller in RT (both P ≤ 0.01).

RT DUS demonstrates good agreement with SP and detects reflux more frequently at the SFJ. RT positioning may represent a reliable initial diagnostic approach, and combining RT and SP may further improve diagnostic yield in CVI assessment.