Subclavian steal syndrome
Background
- A stenosis of the subclavian artery, proximal to the origin of the vertebral vessel, results in decreased perfusion pressure to the distal subclavian artery, leading to retrograde flow in the ipsilateral vertebral artery with exercise of the ipsilateral arm. In short, the arm steals blood flow from the vertebrobasilar system resulting in neurologic and upper extremity symptoms due to arterial insufficiency.
- There is an increased incidence of left-sided subclavian stenosis
- The presence of collateral blood supply is the main determinant of which patients develop neurologic symptoms
Etiology
- Atherosclerosis
- Thoracic Outlet
- Congenital Anomalies
- Takayasu's Arteritis
Clinical Features
Symptoms in Upper Extremity
- Pain
- Fatigue
- Coolness
- Paresthesias
- Numbness
Neurologic Symptoms
- Dizziness, Lightheadedness
- Vertigo
- Syncope
Differential Diagnosis
- Thoracic Outlet Syndrome
- Verebrobasilar Insufficiency
- Syncope
Evaluation
Physical Exam Findings
- Supraclavicular bruit, thrill
- Systolic BP in ipsilateral brachial artery is reduced compared to opposite side
- Ipsilateral radial pulse with decreased amplitude and delayed arrival
Diagnostic Tests
- Routine testing for atherosclerosis: Lipid Panel, Glucose
- Doppler Ultrasound
- Chest XRay, EKG
- CTA, MRA
- Angiography
Management
Medical management
- Treat atherosclerosis
- Antiplatelet Therapy
- Anticoagulant Therapy
Surgical management
Indicated for symptomatic patients
- Angioplasty with Endovascular Stenting
- CEA (in patients with associated carotid disease) by increasing collateral blood flow
- Surgical Bypass
Disposition
- If symptomatic, admit with consults to Vascular Surgery, Neurology
- If incidental finding, consider close outpatient follow up