Emergent Care / Stabilization:

• Symptomatic patients require emergent care.
• Initiate systemic heparin for stabilization.

Causes / typical injury mechanism: This is most commonly caused by atherosclerosis. Rare causes include:

• External compression (ie, arterial thoracic outlet syndrome)
• Trauma (ie, clavicle fracture)
• Iatrogenic (ie, central venous access)
• Other (ie, fibromuscular dysplasia, neurofibromatosis, autoimmune vasculitis, radiation exposure)

Classic history and presentation:

• Arm claudication
• Muscle fatigue
• Rest pain
• Distal limb ischemia

Prevalence: This presents in less than 1% of the total population, and is found in 11%-18% of patients with peripheral vascular disease.

Risk factors:

• Obesity
• Hypertension
• Diabetes mellitus (type 1, type 2)
• Smoking

Pathophysiology: Subclavian artery thrombosis is caused by vessel wall / intimal damage in an area of shear stress, often in the setting of a hypercoagulable state, resulting in the cascade of platelet aggregation and proliferation of smooth muscle that forms an atherosclerotic plaque.

Grade / classification system: Based upon symptoms at presentation –

• Asymptomatic
• Symptomatic
• Claudication
• Critical limb ischemia
• Acute limb ischemia