Venous Thoracic Outlet Syndrome Diagnosed Using Duplex Ultrasound

Abstract

Venous thoracic outlet syndrome (TOS) is a complex condition involving compression, irritation, or direct injury of the subclavian vein as it courses between the first rib, the clavicle, and the scalene muscle. Compression of the subclavian vein is a potential cause of axillosubclavian vein thrombosis. Duplex examination with color flow Doppler and appropriate abduction maneuvers can be used to identify patients with this syndrome. We describe the case of a 52 year-old female patient with a history of bilateral upper-extremity swelling and pain and a past history of bilateral subclavian deep vein thromboses (DVT). She was referred to our clinic to try and determine the cause of her upper-extremity DVTs. A venous duplex examination with abduction maneuvers was performed. Bilateral subclavian veins were studied in varying degrees of abduction to assess for the presence of venous TOS. The duplex examination revealed normal color flow and a respirophasic pulsed Doppler waveform in the subclavian veins bilaterally with the patient lying supine in the resting position. With abducting the arms, significant changes were noted. Occlusion of the subclavian vein was observed at its proximal segment with absent color flow and pulsed Doppler spectrum. Flow was reestablished after having the patient relax her arm to its resting position. These findings were documented in both the right and left subclavian veins. There was no evidence of residual DVT or venous reflux on either side. These findings suggested that subclavian vein compression at the thoracic outlet may have been responsible for the patient's bilateral deep vein thromboses. Duplex ultrasound examination with abduction maneuvers is an effective method that can be used to diagnose venous TOS. When a patient presents with upper-extremity swelling and/or a history of otherwise unexplained axillosubclavian DVT, the technologist should add abduction maneuvers to the venous duplex examination to help determine the cause.