Signs & symptoms that arise from retrograde vertebral artery flow or retrograde internal thoracic artery flow due to proximal Subclavian Artery stenosis or occlusion
Classification
Vertebral-Subclavian Steal syndrome:
Vertebral Artery serves as a collateral to supply blood to the arm (the blood from the brain to the upper limb is considered to be “stolen” as it is blood flow that the brain must do without) → Possible cerebral ischemia
Coronary-Subclavian Steal syndrome:
Post-op CABG using Internal Thoracic Artery = Distal Internal Thoracic Artery diverted to the LAD → If proximal Subclavian Artery Stenosis, blood may flow backward from the heart causing myocardial ischaemia
Aetiology
Atherosclerosis of Subclavian Artery
Cervical rib → Causing compression of subclavian artery
Takayasu’s arteritis
Tumour encasement
Iatrogenic: Post-Aortic Stent graft placement for Thoracic Aneurysm
Clinical
Symptoms of effort fatigue in involved extremity
Presyncope / syncope
Blood pressure differential between arms
Look for other stigmata of PVD
Investigations
USS, CTA, Angiogram
Management
Stenting / angioplasty of subclavian stenosis (but this is not useful in the setting of a thoracic outlet syndrome / cervical rib, as the stent will itself become compressed
Surgery
Endarterectomy
Bypass grafting from the common carotid to the subclavian artery distal to the lesion or transposition of the subclavian a beyond the lesion