subclavian steal syndrome Flashcards
what is subclavian steal syndrome?
a rare condition causing syncope or neurological deficits when blood supply to the affected arm is increased through exercise
there is stenosis or occlusion of the subclavian artery proximal to the vertebral artery origin, so in arm activity and increased activity where there is increased oxygen demeaned, get reversal of blood supply to the posterior cerebral circulation via the vertebral artery
what is the pathophysiology for subclavian steal syndrome?
In order to compensate for the increased oxygen demand in the arm, blood is drawn from the collateral circulation, which results in reversed blood flow in the ipsilateral vertebral artery (or less commonly the internal thoracic artery).
the result is syncope or neurological deficit
what commonly causes stenosis in the subclavian artery?
atherosclerosis
what are the risk factors for subclavian steal syndrome?
- increasing age
- hyperlipidaemia
- hypertension
- smoking
- DM
what are the clinical features of subclavian steal syndrome?
arm activity causing reversal of blood supply to the posterior cerebral circulation via the vertebral artery can result in a wide range of cerebral symptoms
e.g
- vertigo
- diplopia
- dysphagia
- dysarthria
- visual loss
- syncope
- arm claudication due to occluding lesions
- arm pain
- paraesthesia
what investigations can be done into subclavian steal syndrome?
- initially, duplex US scan which can show retrograde flow in affected vertebral artery during exercise
- definitive investigation is via CT angiography or MR angiography
how is this managed conservatively?
- anti platelet and statin therapy
- modifiable CV risk factors should be addressed e.g smoking
how is this managed surgically?
- endovascular or bypass techniques
- use of percutaneous angioplasty and stenting
- by pass considered for longer or distal occlusions
