Quantitative Assessment of Chronic Venous Insufficiency Using Duplex Ultrasound and Air Plethysmography

Abstract

Purpose Using noninvasive methods, we studied patients 5 years after they received an index deep vein thrombosis (DVT) to quantify venous reflux in the lower limb and to relate it to venous disease severity. Methods Thirty-eight patients (76 limbs) with DVT were studied 5 years after being diagnosed by ultrasound and/or venography and treated with warfarin through a hospital-in-the-home program. There were 15 men and 23 women, their average age (±SD) was 56.7 years (±16 years), and their average body mass index (±SD) was 28.8 (±5.7 kg/m2). The limbs were classified according to the clinical, etiologic, anatomic, and pathophysiologic (CEAP) clinical classification. There were 10 limbs in CEAP class 0, 28 in classes 1–3, and 22 in classes 4–6. Duplex ultrasound and air plethysmography (APG) techniques were used to assess venous reflux. A total of 14 limbs of healthy volunteers underwent APG of the lower limb for comparison. Results At follow-up, 60 limbs exhibited reflux, 35 in the DVT affected limb and 25 in the non-DVT limb. DUS indexes did not differentiate between venous disease severity in terms of reflux duration or reflux flow volume. APG indexes were significantly different, with venous filling index (VFI) being most discriminating. In limbs with skin changes, median (range) VFI was 3.5 mL/sec (1.6–17), compared with 1.5 ml/sec (0.6–3.4) in limbs with class 0, 2.1 ml/sec (0.6–11) in limbs with classes 1–3, and 0.8 ml/sec (0.6–1.7) in normal controls. Conclusion Duplex ultrasound provides excellent anatomical imaging, but its indexes lack discrimination in relation to disease severity. However, APG indexes do differ in relation to clinical venous disease severity, and VFI appear to be a useful index for following the progression of chronic venous insufficiency disease.