Subclavian steal syndrome Flashcards
1
Q
What is subclavian steal syndrome?
A
- Rare condition
- Causes syncrope or neurological defects
- Blood supply to the affected arm is increased during exercises
- Secondary to a proximal stenosing lesion (before vertebral artery branch) or occlusion in subclavian artery
2
Q
Pathophys of SSS
A
- Compensating for increased oxygen demand in the arm, blood is drawn from collateral circulation
- = reversed blood flow in ipsilateral vertebral artery (or less commonly internal thoracic)
3
Q
Underlying cause of SSS
A
- Atherosclerosis - MOST common
- Vasculitis
- Thoracic outlet syndrome
- Complications following aortic coarctation repair
4
Q
What is coronary subclavian steal syndrome?
A
- Occurs in patients who have undergone internal mammary artery graft for coronary bypass
- Increase in O2 demand in left arm then steals blood from IMA leading to cardiac ischaemia
5
Q
Symptoms of SSS
A
During arm activity - reversal of blood supply to posterior cerebral circulation =
* Vertigo
* Diplopia
* Dysphagia
* Dysarthria
* Visual loss
* Syncope
* Arm claudication
6
Q
Investigations for subclavian steal syndrome
A
- Duplex US scan - can show retrograde flow in affected vertebral artery during exercise
- Routine CXR to assess for external compression of subclavian artery
- Then eventually CT angiograph or MR angiograph
7
Q
Disease severity scoring of SSS
A
- Pre-subclavian steal - purely reduced anterograde vertebral flow
- Intermittent alternating flow - antegrade flow in diastolic phase, retrograde in systolic phase
- Advanced disease - permanent retrograde flow
8
Q
Conservative management SSS
A
- Antiplatelet
- Statin therapy
- Modify CV risk factors - lifestyle
9
Q
Surgical management SSS
A
- Endovascular - percutaneous angioplasty +/- stenting - higher rates of restenosis though
- Bypass - considered for longer or distal occlusions eg carotid-subclavian bypass or axillo-axillary bypass
10
Q
A
