A NONINVASIVE SCREENING-TEST TO DETECT CRITICAL DEEP VENOUS REFLUX

Purpose: The venous filling index (VFI) was introduced as a noninvasiv e measure of venous valvular reflux. Because it is quantitative, ident ifying increasingly severe reflux should be possible. The purpose of t his study is to evaluate the sensitivity and predictive value of the V FI as a predictor of phlebographically demonstrated ''critical'' venou s reflux. Methods: Thirty-one limbs with suspected venous insufficienc y underwent both descending phlebography and air plethysmography. Nine Limbs had deep venous reflux ending above the knee on descending phle bography (group 1), and 22 limbs had ''critical'' deep reflux to the b elow-knee level (group 2). The VFI, ejection fraction, and residual vo lume fraction were calculated, and a tourniquet was used to distinguis h superficial from deep venous reflux. Results: Three of six group 2 l imbs with a VFI less than 7 had obliteration of their iliac veins. Tou rniquet application improved the VFI in 13 limbs, all of which showed either phlebographic or venous duplex evidence of greater saphenous in competence. Conclusions: A VFI greater than 7 showed a 73% sensitivity and 100% positive predictive value of identifying ''critical venous r eflux.'' The VFI may underestimate the degree of reflux in patients wi th proximal venous obstruction. Improvement of venous hemodynamics wit h tourniquet application suggests that venous reflux might be improved in some patients by correcting superficial venous insufficiency.