Radiology Coding Alert

Target specific codes for thrombosis and embolism when reporting cerebral infarction.

When your radiologist performs angiography, catheterization, or stent procedures in the carotid artery for conditions such as stenosis, you’ll need more information to accurately report the condition under ICD-10.

You should be ready to implement these changes when ICD-10 goes into effect on Oct. 1, 2015.

ICD-9 codes: ICD-9 offers two codes for carotid artery stenosis:

• 433.10 — Occlusion and stenosis of carotid artery without cerebral infarction
  
• 433.11 — Occlusion and stenosis of carotid artery with cerebral infarction.
  

ICD-10 codes: Each of the ICD-9 codes grows to different code choices under ICD-10. That’s because the new code set accounts for whether the stenosis is in the right, left, unspecified, or bilateral carotid arteries.

If your physician doesn’t specify the side, your direct crosswalk for 433.10 will be I65.29 (Occlusion and stenosis of unspecified carotid artery) under ICD-10.

Provided that your physicians provide adequate documentation, you can select from the following codes which map to ICD-9 code 433.10.

• I65.21 — Occlusion and stenosis of right carotid artery
• I65.22 — Occlusion and stenosis of left carotid artery
• I65.23 — Occlusion and stenosis of bilateral carotid arteries.

Check Thrombosis vs Embolism for Cerebral Infarction

When your physician documents cerebral infarction due to occlusion of carotid artery, you will pay attention to type of occlusion besides the laterality of the pathology. There are codes specific for occlusion due to thrombosis and embolism.

Thrombosis vs embolism: Your physician will document a thrombus or an embolus as a source of occlusion in the vessel. A thrombus is a solid mass consisting of blood cells like platelets and other blood components like fibrin. This mass forms in the vessel and is essentially

occluding. A thrombus is formed when the inner lining of blood vessels is injured. Due to sheer forces of blood in the vessel, a segment of the thrombus may break and dislodge to be carried away along the blood stream. These fragments are called emboli. The dislodged fragment(s) then occlude vessels in the arterial tree.

When the blood vessel supplying a particular area of the brain is occluded, the blood supply to the brain is compromised and the brain tissues are damaged. The symptoms may vary depending upon which areas of the brain have been affected.

For cerebral infarction caused by occlusion of the right and left carotid arteries, you have ICD-10 codes I63.031 (Cerebral infarction due to thrombosis of right carotid artery) and I63.032 (Cerebral infarction due to thrombosis of left carotid artery), respectively. Similarly, you have codes I63.131 (Cerebral infarction due to embolism of right carotid artery) and I63.132 (Cerebral infarction due to embolism of left carotid artery) for cerebral infarction caused by embolism in the right and left carotid arteries, respectively.

When your physician does not specify the right or left side for the thrombosis in carotid artery, you submit code I63.039 (Cerebral infarction due to thrombosis of unspecified carotid artery). Similarly, for unspecified side for embolism, you submit code I63.139 (Cerebral infarction due to embolism of unspecified carotid artery).

There may be situations when your physician will specify which carotid artery (right or left) was occluded but will not specify of the cause of occlusion was a thrombus or embolus. In this case, you will submit codes I63.231 (Cerebral infarction due to unspecified occlusion or stenosis of right carotid arteries) and I63.232 (Cerebral infarction due to unspecified occlusion or stenosis of left carotid arteries) for the right and left carotid arteries, respectively. However, if your physician neither specifies the side (right or left) of the carotid artery nor the cause for occlusion (thrombus or embolus), you will submit code I63.239 (Cerebral infarction due to unspecified occlusion or stenosis of unspecified carotid arteries).