Vascular surgery: subclavian steal syndrome: practice question

A General Surgery question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

Try it

General Surgery · Vascular surgery: subclavian steal syndrome

Sample item

A 60-year-old man has episodes of dizziness and diplopia when he exercises his left arm. Blood pressure is 100/60 mmHg in the left arm and 150/85 mmHg in the right, with a delayed left radial pulse. What explains his symptoms?

AAortic arch dissection involving the right carotidBProximal left subclavian stenosis with reversed vertebral artery flowCCervical rib compressing the brachial plexusDBilateral carotid stenosis

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

B. Proximal left subclavian stenosis with reversed vertebral artery flow

Stenosis or occlusion of the subclavian artery proximal to the vertebral origin lowers distal pressure. During arm exercise the vertebral artery flow reverses to supply the arm, causing vertebrobasilar ischaemia. A pressure difference of more than 15 to 20 mmHg between arms supports it; treatment is angioplasty and stenting or bypass.

Option by option

A. Aortic arch dissection involving the right carotid
Dissection would present acutely with severe pain, not exercise-related dizziness.
B. Proximal left subclavian stenosis with reversed vertebral artery flow (correct)
Correct. Retrograde vertebral flow steals blood from the posterior circulation during arm work.
C. Cervical rib compressing the brachial plexus
Cervical rib causes neurogenic arm symptoms or subclavian compression without exercise-linked posterior circulation symptoms.
D. Bilateral carotid stenosis
Carotid disease causes anterior circulation events and does not produce an arm pressure differential.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this General Surgery question

What is the answer to this General Surgery question?

The best answer is B, Proximal left subclavian stenosis with reversed vertebral artery flow. Stenosis or occlusion of the subclavian artery proximal to the vertebral origin lowers distal pressure.

Why is "Aortic arch dissection involving the right carotid" not the answer?

Dissection would present acutely with severe pain, not exercise-related dizziness.

Why is "Cervical rib compressing the brachial plexus" not the answer?

Cervical rib causes neurogenic arm symptoms or subclavian compression without exercise-linked posterior circulation symptoms.

Why is "Bilateral carotid stenosis" not the answer?

Carotid disease causes anterior circulation events and does not produce an arm pressure differential.

What concept does this question test?

It tests Vascular surgery: subclavian steal syndrome in General Surgery. During arm exercise the vertebral artery flow reverses to supply the arm, causing vertebrobasilar ischaemia. A pressure difference of more than 15 to 20 mmHg between arms supports it; treatment is angioplasty and stenting or bypass.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Vascular surgery: subclavian steal syndrome?

Learn classic signs and eponyms alongside what they diagnose. Then use the flashcards and the other General Surgery questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.