ICD-10-PCS Root Operation Selection For Treatment of Cerebral Aneurysms

Coding for treatment of cerebral aneurysms may seem a little intimidating because the procedure is performed on the arteries of the brain, but understanding what an aneurysm is and how it is treated and how those two things relate to selection of the correct root operation for reporting these procedures makes ICD-10-PCS coding for treatment of a cerebral aneurysm a no brainer.

What is an aneurysm?

An aneurysm is a dilation/pouch/bulge similar to a bubble or balloon that develops in the side of an artery at an area of weakness. A cerebral aneurysm is simply the development of one of these dilations/pouches/bulges in a cerebral artery.

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Aneurysms may develop in any area of the body, but they are most commonly found in the following arteries:

• Aorta
• Cerebral
• Popliteal
• Mesenteric
• Splenic

Some aneurysms are congenital, and others develop over time. Discovery of an aneurysm could be incidental to performance of radiologic imaging studies such as CT, MRI, angiogram or ultrasound for another condition or may occur during investigation of symptoms routinely associated with aneurysm.

Intact aneurysms are often asymptomatic, but they may be/become symptomatic if they press on surrounding nerves or other tissue or if they rupture. Some symptoms, such as pain, or shock from a rupture, could be associated with any artery, but some symptoms vary depending on the site of the aneurysm and whether it has ruptured. For example, symptoms related to a cerebral aneurysm could include nausea and vomiting, dizziness, confusion, vision changes and paralysis and symptoms of aortic aneurysm could include a pulsating abdominal mass or loss of blood to the extremities.

How is a cerebral aneurysm treated?

Since aneurysms form in weak areas of the artery, they are prone to rupturing. Rupture of a cerebral artery can lead to stroke or death, so treating this type of aneurysm is significant. Common methods of treatment include clipping or embolization of the aneurysm.

Clipping: Clipping is a procedure that prevents rupture of a cerebral aneurysm or further bleeding from an aneurysm that has already ruptured by placing a clip that lies along the side of the artery and across the neck of the aneurysm to cut off the flow of blood. This is an open, invasive, intracranial procedure performed by microsurgical technique via craniotomy.

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Embolization: This is a percutaneous and thus less invasive procedure because it is performed intravascularly via a catheter. During embolization, a catheter is used to transport small metal coils and then place them within the aneurysm. The body heals around the coils which further blocks the flow of blood into the aneurysm. Embolization with coils may be performed alone or in combination with the insertion of other devices such as stents or balloons that divert blood flow away from and help keep the coils within the aneurysm. In some cases, a stent may be used alone to divert blood flow away from the aneurysm.

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ICD-10-PCS coding for treatment of a cerebral aneurysm

ICD-10-PCS root operation definitions
To accurately assign an ICD-10-PCS code for treatment of a cerebral aneurysm, the root operation that represents the objective of the procedure needs to be reported. Two root operations whose objectives deal with managing blood flow with an artery are Occlusion and Restriction.

Based on their definitions, the objective of the root operations Occlusion and Restriction both relate to what happens to the lumen of a tubular body part such as an artery, with the objective of Occlusion being closing off the lumen completely and the objective of Restriction being partially closing the lumen of the artery. So, what exactly is the lumen of an artery? The lumen is the hollow space between the walls of the artery that allows the passage of blood. In the case of an aneurysm the wall of the artery bulges, widening the lumen at that point and as discussed previously making it more prone to breaking. When coding for treatment of an aneurysm, a key to correct root operation selection is understanding that the space within the aneurysm, is part of the artery’s lumen. The focus of treatment is to narrow the lumen of the artery and partially close it off by excluding the area within the aneurysm. Narrowing or partially closing off the lumen by excluding the portion within the aneurysm, by any method, including clipping, embolization and/or stent insertion, meets the definition of the root operation Restriction.

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ICD-10-PCS guidelines
Assignment of the root operation Restriction for treatment of cerebral aneurysm is supported by ICD-10-PCS coding guideline B3.12 which states, “Embolization of a cerebral aneurysm is coded to the root operation Restriction…” Since clipping an aneurysm has the same objective as embolization it holds that Restriction is the correct root operation for this procedure as well.

Occlusion vs. Restriction for vessel embolization procedures

B3.12
If the objective of an embolization procedure is to completely close a vessel, the root operation Occlusion is coded. If the objective of an embolization procedure is to narrow the lumen of a vessel, the root operation Restriction is coded.

Examples: Tumor embolization is coded to the root operation Occlusion because the objective of the procedure is to cut off the blood supply to the vessel. Embolization of a cerebral aneurysm is coded to the root operation Restriction, because the objective of the procedure is not to close off the vessel entirely, but to narrow the lumen of the vessel at the site of the aneurysm where it is abnormally wide.

Note: In some cases of aneurysm with severe brain/arterial injury in may be necessary to prevent continued flow through an artery. If the surgeon totally occludes an artery by putting a clip across its lumen to completely cut off blood supply rather than clipping along the side of the vessel to close only the aneurysmal portion of the vessel the root operation would be Occlusion.

Examples

• We then continued dissection along right M1 segment till we came to the visualization of right middle cerebral artery bifurcation. Aneurysm was then found at the point of bifurcation. Careful dissection continued along the aneurysm’s dome till both M2 branches were identified. A single application of slightly curved Sugita micro clip was then utilized which obliterated the aneurysm completely. At this moment, micro-Doppler was used to evaluate the flow and excellent flow was noticed in all vessels including fetal posterior communicating artery and no flow was noticed in the aneurysm.
• We then dissected the sylvian fissure proximally to distally along ICA/M1 until the MCA bifurcation was identified. Under interrupted bouts of temporary clipping of the M1, we dissected out both M2 branches and both aneurysm lobes. We then identified the neck of the aneurysm, verified everything was free of perforators, and prepared for clipping, Further details are noted above in "Intraoperative Details". We then performed intraoperative fluorescein angiography which demonstrated aneurysm to be completely obliterated and the parent vessel and the exiting branches described above to all be patent, Both aneurysms were punctured also to ensure no residual/leak left. A small piece of the larger dome was sent to pathology.

In both of these cases a clip was placed to partially close off the lumen of the artery by excluding the portion within the aneurysm (“<obliterated the aneurysm completely”, “demonstrated aneurysm to be completely obliterated”) , but blood flow within the rest of the lumen was maintained (“excellent flow was noticed in all vessels, “the parent vessel and the exiting branches described above to all be patent”) , so the correct root operation to report for both of these procedures is Restriction.

Take Away

Cerebral artery aneurysms carry the potential for stroke or death if the aneurysm ruptures. The objective of treatment is to lower the possibility of rupture or control bleeding from an already ruptured aneurysm by cutting off the flow of blood into the aneurysm. This can be accomplished via several methods including clipping, embolization and/or insertion of stents or other flow diverting devices. The key to correct ICD-10-PCS coding of these procedures is understanding that the aneurysm itself is part of the lumen of the artery and in most cases, the methods used to address the aneurysm represent partially closing off the lumen of the artery which is reported with the ICD-10-PCS root operation Restriction.

References

ICD-10-PCS Root Operation Definitions

ICD-10-PCS Official Coding Guidelines

Coding Clinic for ICD-10-CM/PCS, Second Quarter 2016 Page: 30

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