Comparison of the visualisation of the subclavian and axillary veins: An ultrasound study in healthy volunteers

Abstract

ObjectiveTo compare the area of the lumen of the axillary and subclavian veins using ultrasound (US) in 50 healthy volunteers. MethodsUsing an ultrasound device, depth, area, short axis vein length and long axis vein, vein-artery and vein-pleura distances were measured for axillary and subclavian approaches. ResultsThe mean cross-sectional area of the axillary vein was greater than the mean cross-sectional area of the subclavian vein (327±89 mm2 versus 124±46 mm2, P<0.001). Both the mean transverse (10±2mm versus 9±2mm) and longitudinal axes (39±8mm versus 17±7mm) of the axillary vein were greater than those of subclavian vein (P<0.01, P<0.001, respectively). The depths of the axillary and subclavian veins were similar (21±6mm versus 20±6mm, P=0.43). The axillary and subclavian arteries were visualised in 3 and 45 volunteers, respectively (P<0.001). The pleura was seen in 25 and 37 volunteers with the axillary and subclavian approaches, respectively (P=0.01). The distance between the pleura and the subclavian vein was smaller (6±2mm versus 8±3mm, P<0.04). ConclusionThe present US study shows that visualisation of the axillary vein under US is greater than that for the subclavian vein, mainly due to a better alignment with the long axis of the axillary vein leading to a greater cross-sectional area of the axillary vein. Trial register numberNCT01647815.