Merino wool graduated compression stocking increases lower limb venous blood flow: A randomized controlled trial

Introduction Graduated compression stockings represent a nonpharmacological approach to reduce the risk of deep vein thrombosis (DVT) and pulmonary embolism (PE) due to prolonged immobility through reducing lower limb venous stasis. A novel merino wool, double-layer, below-knee graduated compression stocking has been developed to reduce the risk of air travel-related DVT and PE. Methods Twenty healthy adult participants were randomized to wear the novel graduated compression stocking on either the left or right leg. Doppler ultrasound measurements of popliteal venous blood flow were made on both legs over a 120-minute period. The primary outcome was peak systolic velocity in the popliteal vein at 120 minutes. Secondary outcomes included mean flow velocity, total volume flow, vein cross-sectional area, and change in ankle and calf measurements. Results The popliteal vein peak systolic velocity was 0.35 cm/s (95% confidence intervals [CI], 0.22 to 0.49, P