In thoracic outlet syndrome (TOS), the arterial variant is least common but most dangerous. Which structure is characteristically involved in arterial TOS?
- A Subclavian artery, often associated with a cervical rib causing post-stenotic aneurysm ✓
- B Brachial plexus (lower trunk C8-T1)
- C Subclavian vein (Paget-Schroetter syndrome)
- D Axillary nerve compression by the scalene triangle
Correct answer: A. Subclavian artery, often associated with a cervical rib causing post-stenotic aneurysm
Explanation
Arterial thoracic outlet syndrome involves the subclavian artery and is most commonly associated with a complete cervical rib or an elongated C7 transverse process that compresses and kinks the subclavian artery, leading to post-stenotic dilatation and aneurysm formation. Thrombus forms within the aneurysm and can embolize distally, causing digital ischemia or upper limb claudication. Treatment involves cervical rib resection with arterial reconstruction. Paget-Schroetter syndrome (effort thrombosis) is the venous form.
Reference: Bailey & Love's Short Practice of Surgery, 27th ed.
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Written and medically reviewed by the StethoPrep medical team.