Study of time threshold value of venous reflux in lower extremity veins with color Doppler ultrasonography

Objective To determine time threshold value of venous reflux in lower extremity veins with color Doppler ultrasonography.Methods Forty patients who would perform venous valve reconstruction in the first valve of superficial femoral vein and 20 normal lower extremities were detected with color Doppler ultrasonography, their venous reverse time was measured in the first valve of superficial femoral vein, results of measuring and surgical detection were compared. Results Color Doppler ultrasonography had high accuracy (95%) for the evaluation of venous reflux when time threshold value of venous reflux was defined as reverse flow for greater than 0.5 second. Conclusions Color Doppler ultrasonography can accurately identify limbs with and without venous reflux when venous reflux is defined as reverse flow greater than 0.5 second.