Haemodynamic study of left nonthrombotic iliac vein lesions: a preliminary report.

Nonthrombotic iliac vein lesions (NIVLs) are significant causes of chronic venous insufficiency (CVI) in the left lower limb and symptom recurrence following left lower limb varicose vein treatment. The goal of this study was to explore the haemodynamic and morphological characteristics of iliac veins in patients with NIVLs. Pressure at the caudal end of the stenotic left common iliac vein (LCIV) segment, local blood flow velocity, and time-averaged wall shear stress in the stenotic segment exhibited positive correlations with the clinical CVI classification (R = 0.92, p < 0.001; R = 0.94, p < 0.001; R = 0.87, p < 0.001), while the relative retention time showed a negative correlation (R = -0.94, p < 0.001). The pressure difference (∆P) between the two ends of the stenotic segment and the velocity difference (∆V) between the stenotic segment and the caudal end were positively correlated with the clinical classification (R = 0.92, p < 0.001; R = 0.9, p < 0.001). The cross-sectional area stenosis rate and length of the stenotic LCIV segment were positively correlated with the clinical classification (R = 0.93, p < 0.001; R = 0.63, p < 0.001). The results suggest that haemodynamic assessment of the iliac vein could effectively portray blood flow disturbances in stenotic segments of the LCIV, potentially reflecting the degree of iliac vein stenosis. Haemodynamic indicators are correlated with the severity of clinical CVI symptoms.