A NONINVASIVE SCREENING-TEST TO DETECT CRITICAL DEEP VENOUS REFLUX

Purpose: The venous filling index (VFI) was introduced as a noninvasive measure of venous valvular reflux. Because it is quantitative, identifying increasingly severe reflux should be possible. The purpose of this study is to evaluate the sensitivity and predictive value of the VFI as a predictor of phlebographically demonstrated ''critical'' venous reflux. Methods: Thirty-one limbs with suspected venous insufficiency underwent both descending phlebography and air plethysmography. Nine Limbs had deep venous reflux ending above the knee on descending phlebography (group 1), and 22 limbs had ''critical'' deep reflux to the below-knee level (group 2). The VFI, ejection fraction, and residual volume fraction were calculated, and a tourniquet was used to distinguish superficial from deep venous reflux. Results: Three of six group 2 limbs with a VFI less than 7 had obliteration of their iliac veins. Tourniquet application improved the VFI in 13 limbs, all of which showed either phlebographic or venous duplex evidence of greater saphenous incompetence. Conclusions: A VFI greater than 7 showed a 73% sensitivity and 100% positive predictive value of identifying ''critical venous reflux.'' The VFI may underestimate the degree of reflux in patients with proximal venous obstruction. Improvement of venous hemodynamics with tourniquet application suggests that venous reflux might be improved in some patients by correcting superficial venous insufficiency.