Cardiology Coding Alert

Question: I have a complete carotid duplex report that shows weakness, syncope, and mild plaque formation, but it doesn't show evidence of significant carotid stenosis. Which diagnosis code should I choose?

Washington Subscriber

Answer: You should choose the diagnosis code based upon what the complete carotid duplex scan shows. However, if the scan does not explain why the patient is experiencing syncope, you should code the signs and the symptoms of the syncope, rather than the underlying condition, as the primary diagnosis.

According to the ICD-10 Official Guidelines, "Codes that describe symptoms and signs, as opposed to diagnoses, are acceptable for reporting purposes when a related definitive diagnosis has not been established (confirmed) by the provider."

Unknown: Because the cause of the syncope is unknown, you will report R55 (Syncope and collapse), which includes blackout, fainting, and vasovagal attacks.

Stenosis: However, if the scan does end up revealing stenosis, you should code for that condition. Your choices are:

• I65.21, Occlusion and stenosis of right carotid artery
• I65.22, ... of left carotid artery
• I65.23, ... of bilateral carotid arteries
• I65.29, ... of unspecified carotid artery
• I65.8, ... of other precerebral arteries
• I65.9, ... of unspecified precerebral artery.

Important: An "Includes" note for all of the above codes states, "Includes embolism of precerebral artery, narrowing of precerebral artery, obstruction (complete) (partial) of precerebral artery, and thrombosis of precerebral artery."

Don't forget: You should still report the complete carotid duplex using 93880 (Duplex scan of extracranial arteries; complete bilateral study).

Bonus: Duplex imaging should include at least the common carotid artery, internal carotid artery, external carotid artery, and vertebral artery. This involves imaging from the clavicle to the jaw.