Neurosurgery Coding Alert

First off, you need to remember that an AV malformation is different from an aneurysm. An AV malformation represents a variety of structurally abnormal blood vessel types. Some examples include arteriovenous malformation, capillary hemangioma, and venous angioma.

In contrast, an aneurysm represents a weakening of an arterial blood vessel wall, resulting in a dilated outpouching from the weak-walled vessel, rendering it susceptible to rupture. (It is important to note that an aneurysm can be associated with an AV malformation, prompting treatment of both conditions.)

When your surgeon treats an AV malformation with excision, choose a code from the sets discussed below, depending on the notes from the encounter. (Per CPT^®, all of the codes discussed in this article include “craniotomy when appropriate for the procedure.”).

Report 61680 for Simple Supratentorial

The first codes in the set are for supratentorial AV malformation surgeries. Code these procedures with:

• 61680 (Surgery of intracranial arteriovenous malformation; supratentorial, simple)
• 61682 (… supratentorial, complex)

“In determining whether the arteriovenous malformation is simple or complex, you should look for the following characteristics: size, venous drainage, and location,” explains Gregory Przybylski, MD, immediate past chairman of neuroscience and director of neurosurgery at the New Jersey Neuroscience Institute, JFK Medical Center in Edison, New Jersey. “A simple AV malformation is no larger than 3 cm in diameter, has only superficial venous drainage, and is not located in an eloquent area of the brain.”

Those structures located above the tentorium cerebelli, a membrane separating the upper and lower portions of the brain, would be considered supratentorial. These structures include (among others) frontal, parietal, temporal, and occipital lobes; basal ganglia; and thalamus.

Example: A 2 cm AV malformation near the surface of the right frontal lobe with superficial venous drainage would be considered a simple supratentorial AV malformation. In contrast, a 2 cm AV malformation in the left thalamus with deep venous drainage would be considered a complex AV malformation.

“It is important to understand that if any one or more characteristics meets the definition of complex — size greater than 3 cm, deep venous drainage, location in an eloquent area of the brain — the AV malformation would be considered complex,” says Przybylski.

Report 61686 for Complex Infratentorial

The next codes in the set are for infratentorial AV malformation surgeries. Code these procedures with:

• 61684 (Surgery of intracranial arteriovenous malformation; infratentorial, simple)
• 61686 (… infratentorial, complex)

The definition of simple and complex is the same as it is for supratentorial AV malformations. “Infratentorial lesions involve the brainstem and cerebellum. Those structures located below the tentorium cerebelli would be considered infratentorial,” explains Przybylski.

The final codes in the set are for dural AV malformation surgeries. Code these procedures with:

• 61690 (Surgery of intracranial arteriovenous malformation; dural, simple)
• 61692 (… dural, complex)

“This dural type of AV malformation is not differentiated by supratentorial or infratentorial location,” says Przybylski. “Instead, a simple dural AV fistula is a malformation supplied by a single meningeal artery, whereas a complex dural AV fistula is a malformation supplied by multiple meningeal arteries.”