A rational approach to detection of significant reflux with duplex Doppler scanning and air plethysmography

Several techniques are currently available for the detection of venous reflux. We have attempted to determine the relative value and accuracy of available techniques to develop a logical strategy of investigation in reflux venous insufficiency.

The morphologic distribution of venous incompetence (erect duplex and descending venography); the results of ambulatory venous pressure measurement, venous refilling time, the Valsalva test, and air-plethysmography (venous refilling index, VFI); and the clinical severity were described in 118 consecutive limbs. In an attempt to validate the tests, results were correlated with the clinical severity classification (class 0, n = 34; class 1, n = 42; class 2, n = 11; class 3, n = 31) and with a standardized quantification of reflux (multisegment score) as seen on standing duplex Doppler scanning with rapid deflation cuffs.

Twenty-nine percent of limbs with severe venous disease (class 2/3) had pure deep insufficiency, only 6% had pure superficial disease, and the remainder had a combination. A history of previous thrombosis and the presence of posterior tibial vein incompetence were markedly common with ulcer disease (84% and 42%, respectively). The duplex Doppler multisegment score correlated strongly with clinical severity classification (r = 0.97). The venous refilling time and VFI had the highest sensitivity in identifying severe venous disease (class 2/3), and the ambulatory venous pressure had excellent specificity.

For noninvasive determination of reflux, the combination of VFI and duplex scanning not only localized reflux but also separated severe clinical vein disease from mild, with high sensitivity and specificity. Air plethysmography may also provide valuable information regarding calf muscle pump and outflow obstruction.