Subclavian steal syndrome

This code represents a cerebrovascular insufficiency caused by retrograde blood flow in the vertebral artery, shunting blood from the brain to the ipsilateral arm. It typically results from a severe stenosis or occlusion of the subclavian artery proximal to the origin of the vertebral artery. Patients often present with symptoms of vertebrobasilar ischemia (e.g., dizziness, syncope) and/or upper extremity ischemia (e.g., arm claudication, paresthesias).

Use this code when documentation clearly indicates a diagnosis of subclavian steal syndrome, often confirmed by vascular imaging studies such as duplex ultrasound, MRA, or CTA demonstrating the characteristic retrograde vertebral artery flow. It is appropriate for patients experiencing symptoms directly attributable to this phenomenon.

• Ensure documentation specifies "subclavian steal syndrome" and not just subclavian artery stenosis, as the steal phenomenon is key.
• Consider co-reporting codes for the underlying subclavian artery stenosis or occlusion if separately documented and clinically significant.
• Review for associated neurological symptoms (e.g., transient ischemic attack, vertigo) that may require additional coding.