Variant of subclavian steal syndrome: unusual anatomical relationship between left subclavian artery and left vertebral artery

A woman in her 70s presented to her general practitioner (GP) with a 3-month history of left upper arm pain and weakness. A significant difference in bilateral blood pressures was noted and a further history elicited coolness in her left arm without functional compromise. A CT angiography revealed variant subclavian steal syndrome with a subclavian arterial stenosis, which was proximal to both the internal mammary and thyrocervical trunk and her left vertebral artery originating from the aortic arch. She was referred to a vascular surgeon but declined surgical intervention. Her symptoms remain stable with 6-month follow-up from her GP. This case highlights the importance of considering vascular aetiologies in upper limb pain and weakness. Our case reviews the differential diagnoses of upper limb pain and weakness, consequently leading to the discussion of an interesting variant of subclavian stenosis.