Quantitative venous severity scoring using the venous arterial flow index by duplex sonography

BACKGROUND. Volume flow, as the product of the mean blood flow velocity by the cross sectional area, means an interesting hemodynamic pattern that can be calculated by duplex. OBJECTIVE. To quantify the severity of venous insufficiency using the correlation between the volume flow in the common femoral vein (VFV) and artery (VFA), called the venous arterial flow index (VAFI). METHODS. A total of 163 consecutive patients were included: 46 patients with postthrombotic syndrome (PTS, group 1), 38 patients with complete varicosity of the greater saphenous vein (group 2), 40 patients with only segmental or truncal varicosity (group 3), and 39 patients with competent veins (group 4). Under standardized conditions, duplex sonography was performed to calculate volume flow in the common femoral vein and artery as a product of mean blood flow velocity (v_m) and precise diameter (d = 2πr) of the vessel due to the formula VF = v_m × πr² (L/min). Division of the venous and arterial volume flow data calculated the VAFI. RESULTS. Significant differentiation of VFV (P < .001) and VAFI (P < .0001) between varicose veins and healthy limbs were found. In PTS the mean VFV was 0.50 L/min and the mean VAFI was 1.465. In the complete varicosity group, mean VFV was 0.46 L/min and mean VAFI was 1.48. In group 3, the mean VFV was 0.41 L/min and the mean VAFI was 1.31. In healthy persons, mean VFV was 0.36 L/min and mean VAFI was 0.87. CONCLUSION. The VAFI can be used to quantify the hemodynamic severity in venous insufficiency.