REFINEMENTS IN THE ULTRASONIC-DETECTION OF POPLITEAL VEIN REFLUX

Color-flow and duplex ultrasonography were used to determine the optim al method for documenting venous valvular reflux. Popliteal veins were examined in 10 normal limbs and 11 limbs with clinical evidence of ch ronic venous insufficiency (CVI). Peak reflux velocity (spectral) and duration of reflux (spectral and color) were measured with the patient in supine and standing positions, with manual and pneumatic compressi on applied sequentially to thigh and calf. Manual and pneumatic compre ssion produced equivalent reflux velocity and duration. In normal limb s peak reflux velocity was always less than 22 cm/sec, with a mean rev erse flow duration of 0.3 sec +/- 0.03 (SEM). In limbs with CVI, reflu x velocity varied widely among protocols. Reflux duration and velocity were greater in the supine position than in the standing position for both normal limbs and limbs with CVI (p < 0.04). Duration was signifi cantly increased for thigh versus calf compression in normal limbs (p < 0.001) but decreased in limbs with CVI (p < 0.003). Methods that use d thigh compression or supine position were less capable of discrimina ting normal limbs from limbs with CVI. Standing calf compression provi ded the greatest rates of sensitivity (91%), specificity (100%), and a ccuracy (95%). Compared with spectral Doppler scanning, color-flow ult rasonography produced a consistently shorter reflux duration (p < 0.00 1). In limbs with CVI with a mean spectral duration of 2.5 sec +/- 0.2 (SEM), mean color Doppler duration was 0.7 sec shorter. Our results d emonstrate that popliteal vein incompetence is identified optimally by reflux duration after standing calf compression; adequate manual comp ression is sufficient to identify reflux; color-flow Doppler ultrasono graphy may underestimate reflux duration.