Neurosurgery Coding Alert

Surgeon/coder communication and flawless documentation are a must for 61580-61598

To find the appropriate skull-base surgery approach code, look to the surgeon's documentation to determine the fossa he targeted and whether he cut into the dura.
 
When you've used this information to narrow your search, confer with the surgeon to verify the exact structures he moved or removed so you can select the code that best describes the procedure. 1. Identify the Location of the Lesion  The first step in choosing a skull-base approach code is to determine the precise area of the skull base the surgeon wishes to access. In other words, you should ask, "What is the location of the lesion the surgeon needs to address?"

CPT divides the skull base into three constituent parts: the anterior (frontal) cranial fossa (61580-61586), middle (temporal) cranial fossa (61590-61592), and posterior (cerebellar) cranial fossa (61595-61598).
 
Don't Worry About the Point of Entry ... Yet Although the initial access can become a factor in code selection, you should first narrow your code selection by the destination the surgeon wishes to reach, rather than the method he used to get there. This is because the surgeon can access any of the fossae via several entry points or approach techniques, says Richard D. Bucholz, MD, professor and associate director of the division of neurosurgery at St. Louis University in Missouri.

Example: The surgeon's op notes specify that he used an orbitocranial approach to access the anterior cranial fossa.

 If you focus first on the approach, you could mistakenly choose 61592 (Orbitocranial zygomatic approach to middle cranial fossa [cavernous sinus and carotid artery, clivus, basilar artery or petrous apex] including osteotomy of zygoma, craniotomy, extra- or intradural elevation of temporal lobe) as the correct code.

If you look more closely, however, you'll see that 61592 applies to the middle cranial fossa. In this case, you should narrow your code selection to the 61580-61586 category, which applies specifically to the anterior cranial fossa.2. Determine Intra- or Extradural Next, determine whether the surgeon performs dissection intra- or extradurally. An intradural approach requires that the surgeon cut the dura, the tough elastic membrane that holds the brain in place, Bucholz says.

Tip: If the surgeon does not specify "intradural" or "extradural" in the operative report, you may look further in the documentation for evidence of a watertight closure (for instance, "The dura was repaired") following the eventual definitive procedure. If the surgeon repaired the dura, the dissection was intradural.

Example: The surgeon specifies approach to anterior cranial fossa with intradural dissection.

First, narrow your code selection by location (anterior fossa, 61580-61586).
 
Next, rule out all codes in this category that specify an extradural approach (because the surgeon, in this case, cut the dura), and you further narrow [...]