The axillary vein is the large vein in the axilla that receives blood from the arm and becomes the subclavian vein as it passes under the clavicle. It is routinely evaluated during upper extremity venous duplex ultrasound when there is clinical suspicion of deep vein thrombosis in the arm, which can occur in patients with central venous catheters, pacemaker leads, or certain anatomical conditions. On ultrasound, the normal axillary vein should be easily compressible and show respiratory variation in its Doppler signal. Loss of compressibility, visible thrombus within the vein, or absent Doppler flow are signs of axillary vein thrombosis.
Sonography Term