Subclavian steal syndrome (SSS) is a vascular disorder characterized by the reversal of blood flow in the subclavian artery due to stenosis or occlusion in the proximal subclavian artery.
It is also sometimes called as left or right subclavian steal syndrome depending upon the anatomical side of artery involved
This reversal of blood flow occurs to compensate for reduced blood supply to the affected arm, resulting in various clinical manifestations.
what are the causes of subclavian steal syndrome?
Subclavian steal syndrome occurs due to atherosclerosis where a plaque builds up and narrows the subclavian artery.
Other causes can include fibromuscular dysplasia, thoracic outlet syndrome, arterial dissection, and previous vascular surgery.
What is the pathology of subclavian steal syndrome?
Subclavian steal syndrome involves the following steps:
Atherosclerosis or other underlying conditions leading to occlusion in the proximal subclavian artery.
As a result, blood flow to the arm becomes limited, leading to decreased blood pressure in the affected subclavian artery.
To compensate for the reduced blood supply, blood flow reverses direction, stealing blood from the brain's posterior circulation.
The reversal of blood flow through the vertebral artery results in symptoms such as dizziness, syncope, or neurological deficits.
What are the clinical signs and symptoms of subclavian steal syndrome?
Signs and symptoms of subclavian steal syndrome can vary but some common ones are:
Arm claudication: Fatigue, weakness, or pain in the affected arm.
Vertebrobasilar insufficiency: Symptoms related to reduced blood supply to the brainstem and cerebellum, like dizziness, vertigo, blurred vision etc.
Neurological deficits: Depending on the severity and duration of the phenomenon, patients may experience transient ischemic attacks or stroke, manifesting as motor or sensory defects
Blood pressure discrepancy: A significant difference in blood pressure between the two arms.
What are specific investigations to confirm the diagnosis of subclavian steal syndrome?
Investigations:Subclavian steal syndrome tests are the following investigations can help confirm diagnosis
Doppler ultrasound or subclavian steal ultrasound: Used to assess blood flow in the subclavian arteries and to detect stenosis or occlusion.
Angiography: A more invasive procedure helps visualize the blood vessels and identify the location and severity of arterial narrowing.
Computed tomography angiography (CTA) or magnetic resonance angiography (MRA):Provide detailed images of the blood vessels and can identify arterial obstructions.
Blood pressure measurement: Comparing blood pressure in both arms to detect any significant difference.
How a case of subclavian steal syndrome can be managed?
Specific Management: The management of subclavian steal syndrome depends on the severity of symptoms and the underlying cause
Medical therapy:Antiplatelet medications, such as aspirin or clopidogrel, to prevent further clot formation
Endovascular treatment: Angioplasty with or without stenting is often performed to dilate the narrowed subclavian artery, restoring normal blood flow.
Surgical intervention: In cases where endovascular treatment is not feasible or unsuccessful.