Neurosurgery Coding Alert

Intracranial aneurysms occur in different locations of the brain. Neurosurgeons address them with a variety of techniques and approaches, and CPT 2001 contains well over a dozen codes to describe procedures commonly used. Neurosurgery coders must navigate a complex and confusing maze of highly technical descriptions to find the best code for particular intracranial aneurysm surgeries, and if they choose incorrectly, payment for these very expensive procedures can easily be reduced or denied.

Also, CPT 2001 introduced two new codes (61697 and 61698) while another was altered (61700) in an attempt to make coding more specific for these procedures. It is critical that the coding families into which many of these fall and the guidelines for using them are clearly understood.

CPT 2001 Coding Changes for Intracranial Aneurysms

The new codes and definition revisions have been added to distinguish between simple and complex intracranial aneurysms. Eric Sandham, CPC, compliance educator for Central California Faculty Medical Group, a group practice and training facility associated with the University of California at San Francisco in Fresno, states that these additions may be the result of an increase in submissions to insurance carriers of 61700 (surgery of simple intracranial aneurysm, intracranial approach; carotid circulation) and 61702 (vertebrobasilar circulation) both appended with modifier -22 (unusual procedural services), indicating a more complex surgery. Accordingly, the CPT committee decided to add codes to define what a complex intracranial aneurysm is 61697 (surgery of complex intracranial aneurysm, intracranial approach; carotid circulation) and 61698 (vertebro-basilar circulation). The following text also was added to distinguish between simple and complex intracranial aneurysms: 61697-61698 involve aneurysms that are larger than 15mm or with calcification of the aneurysm neck, or with incorporation of normal vessels into the aneurysm neck, or a procedure requiring temporary vessel occlusion, trapping or cardiopulmonary bypass to successfully treat the aneurysm.

Note: There are circumstances that may still arise in which the procedure is complicated but the work performed does not fit the definition and requirements of 61697 or 61698. In these cases, they would not be considered complex and 61700 or 61702 would still be used with modifier -22 to indicate the additional difficulty of the procedures.

Correct Coding for Skull Base Surgeries

Sandham, who is also a coder specializing in neurosurgical procedures, states that coders are under the impression that the skull base definitive procedure codes (61600-61616) for the resection or excision of a neoplastic, vascular or infectious lesion, cannot apply to an aneurysm because they are normally used for brain tumors. However, if the aneurysm is in the middle cranial fossa and the neurosurgeon performed a skull base approach, they are appropriate. For example, 61613 (obliteration of carotid aneurysm, arteriovenous malformation, or carotid-cavernous fistula by dissection within cavernous sinus) describes the removal of a carotid aneurysm with a skull base approach. Note: When using skull base codes, the approach and, if performed, the repair/reconstruction procedure also are coded with the definitive procedure.

Additional CPT Coding for Intracranial Aneurysms

There is some indication in CPT Assistant that other definitive procedure codes may also be applied. Sandham explains, as follows, under what circumstances they should be used:

61703 surgery of intracranial aneurysm, cervical approach by application of occluding clamp to cervical carotid artery [Selverstone-Crutchfield type] is for an intracranial, not cervical, aneurysm. With this procedure, the neurosurgeon approaches through the neck and then applies the occluding clamp (which means to shut or close off) to the cervical carotid artery before it gets to the skull. This will stop the blood flow to the aneurysm and shrink it.

61705 surgery of aneurysm, vascular malformation or carotid-cavernous fistula; by intracranial and cervical occlusion of carotid artery is a combined approach through the skull and the neck and is used when the neurosurgeon exposes the aneurysm in both areas and places clips across it so the blood cannot get into it. Then the neurosurgeon collapses it so that the aneurysm will heal.

61708 by intracranial electrothrombosis is when a neurosurgeon makes a hole in the skull and uses electrothrombosis (a kind of cautery) to destroy the aneurysm by putting an electrical current over arteries and veins to prevent bleeding.

61710 by intra-arterial embolization, injection procedure, or balloon catheter is when a neuro-surgeon uses a balloon catheter, or an injection procedure to inject tiny beads to seal off the neck of the aneurysm or to place small coils into it, filling it up so that the neurosurgeon can then collapse the aneurysm. This differs from 61624 in that it requires a craniotomy approach instead of a percutaneous catheter placement.

Documentation Requirements

Sandham reports that the key when coding for an intracranial aneurysm is to obtain a detailed operative report from the neurosurgeon. The narrative report should list the reasons why the neurosurgeon took each step in the operating room and describe the procedure in detail. Send a copy of the operative report with the claim to explain the code choice. If 61697 or 61698 are used then the coder should document one or more of the complicating factors listed in the text above.

Coding Diagnoses, Signs and Symptoms

According to Michael W. Potter, MD, president of Cascade Neurosurgery and Spine, Inc. in, Medford, Ore., there are only a couple of ICD-9 codes that relate to aneurysms, and there is no diagnosis code for a ruptured aneurysm, which is the most common form. In the rare instance that an aneurysm code is necessary, I use the one for subarachnoid hemorrhage (430.0) or the nonruptured aneurysm (437.3), states Potter.

If there are no appropriate aneurysm codes, report the signs and symptoms. Potter explains that the symptoms of an intracranial aneurysm can range from: mild headache (784.0), severe headache (346.9), headache with neurological deficits such as paralysis (438x), and coma (780.01). Some present by enlarging and pressing on neurological structures. For example, there is one group of aneurysms that can press on the third nerve which controls eye and eye lid movement so the patient can get a droop of the lid (374.41), paralysis of eye movements (378.50), and enlargement of the pupil (379.43).