Neurosurgery Coding Alert

Warning: Some surgeons don't use CPT terms to describe approach procedures

When a neurosurgeon performs a skull base surgery, deciding on the correct approach code can confuse even the most competent coders.

There are 14 codes to choose from when your surgeon performs this procedure, and they may be used singly or in combination, so you-ll often need to check the notes thoroughly before you can decide on the correct code. Also, there are times when the physician's notes may not describe the procedure in CPT terms, further complicating the code-choice conundrum.

You can combat unclear skull base surgery claims with a solid knowledge of anatomy and good communication between the physicians and the coding department.

Step 1: Locate the Area the Surgeon Accessed

 The first fact you-ll need to find on the encounter form for skull base surgery approach claims is the area in which the surgeon entered the cranial fossa. The skull base is divided into three parts: anterior cranial fossa, middle cranial fossa, and posterior cranial fossa, says Jackie Morton, coder at West Virginia's Neurological Associates Inc. Since the surgeon can access any of these fossa regions through several entry points, you-ll need to decide on the area the surgeon targets before addressing the point of entry, Morton says.

-First, I determine if the exposure was of the anterior, middle or posterior cranial fossa, by using the anatomical areas that are involved (i.e., where the dissection led to). Then I like to determine the method of approach,- starting with where the initial incision was made,- says Jennifer Schmutz, CPC, health information coder with Neurosurgical Associates LLC in Salt Lake City.

Example: The operative notes state that the surgeon accessed the anterior cranial fossa using craniofacial approach. First, you can narrow your code choices to the Anterior Cranial Fossa section of CPT (61580-61586) since the notes indicate that the surgeon accessed this area.
 
Once you-ve addressed the access area, narrow your choices further by only considering the codes from that section that use the craniofacial approach:

- 61580 -- Craniofacial approach to anterior cranial fossa; extradural, including  lateral rhinotomy, ethmoidectomy, sphenoidectomy, without maxillectomy or orbital enteration

- 61581 -- ... extradural, including lateral rhinotomy, orbital exenteration, ethmoidectomy, sphenoidectomy and/or maxillectomy

- 61582 -- ... extradural, including unilateral or  bifrontal craniotomy, elevation of frontal lobe(s), osteotomy of base of anterior cranial fossa

- 61583  -- ... intradural, including unilateral or bifrontal craniotomy, elevation or resection of frontal lobe, osteotomy of base of anterior cranial fossa.

However, you-re not ready to choose the proper approach code yet.

Step 2: Answer Intra/Extradural Question Next

Once you have settled on a region of the cranial fossa and an approach method, you-ll need to find out if the neurosurgeon used intradural or extradural dissection during the procedure.

The dissection method should be recorded somewhere in the op notes. If the notes indicate that the surgeon opened the dura during the approach, you should consider the approach intradural; if the notes do not describe an opening of the dura, the physician probably used an  extradural approach, Schmutz says.

Example: The encounter form states that the neurosurgeon accessed the anterior cranial fossa using craniofacial approach. There is no mention of the surgeon opening the dura during the procedure. Based on this information, you can narrow your choices to only those codes that describe extradural dissection of the anterior cranial fossa: 61580, 61581, 61582.

To make coding easier, you may want to ask your surgeons to separate the operative note into approach and definitive procedure portions. That way, you -can determine what was included as part of the approach and what was done as the definitive portion of the procedure,-  Schmutz says.

Step 3: Ask Doctor if You-re Unsure About Mobilized Structures

The final step in choosing the proper skull base surgery approach code is discovering which internal structures the neurosurgeon exposed or mobilized. Once you figure this out, you-re ready to select a code.

Example: The encounter form states that the neurosurgeon accessed the anterior cranial fossa using craniofacial approach. There is no mention of the surgeon opening the dura. During the encounter, the physician performed a lateral rhinotomy and sphenoidectomy. Withall of the above information, you should be able to make the correct code choice. On the claim, you should report 61581 for the encounter.

Caveat: Making a final decision on the proper skull base approach code is often difficult for coders because the physicians may not use the same terminology that CPT uses to describe the procedures.

For instance, on a skull base surgery approach claim, the surgeon's notes may describe a lateral rhinotomy as -incision along nose to expose optic nerve.- Or the notes might read -removed rear floor of the anterior fossa to gain access to other structures- when the physician performs an osteotomy.

Best bet: Have a detailed knowledge of cranial anatomy and procedure terms so you can be ready when the surgeon submits a skull base surgery approach claim. You may also want to ask the neurosurgeon to review the CPT terms so he can help point you to the proper skull base approach code.

-Ideally, the surgeon should use CPT terminology to describe her surgical procedures. But it is very important to have a basic knowledge of the skull base anatomy,- says Judy Montgomery, CPC, project coordinator at University of Pittsburgh Physicians department of neurosurgery and neurophysiology. The coder should also have the -ability to seek clarification from the surgeon- on op notes when necessary, she says.

4. Don't Slack on Your ICD-9 Coding

When your physician performs skull base approach surgery, be sure to include the most accurate and complete diagnosis coding possible to ensure your claim's success, experts say. According to Montgomery, some ICD-9 codes that may accompany skull base approach codes on a claim include:

- 070.0 -- Viral hepatitis A with hepatic coma

- 191.1 -- Malignant neoplasm of brain; frontal lobe

- 192.1 -- Malignant neoplasm of other and unspecified parts of nervous system; cerebral meninges

- 198.3 -- Secondary malignant neoplasm of other specified sites; brain and spinal cord

- 225.0 -- Benign neoplasm of brain and other parts of nervous system; brain

- 225.2 -- Benign neoplasm of brain and other parts of nervous system; cerebral meninges

- 239.6 -- Neoplasms of unspecified nature; brain

- 430 -- Subarachnoid hemorrhage

- 431 -- Intracerebral hemorrhage

- 437.3 -- Other and ill-defined cerebrovascular disease; cerebral aneurysm, nonruptured

- 747.81 -- Other specified anomalies of circulatory system; anomalies of cerebrovascular system