Neurosurgery Coding Alert

Various treatments are available for patients suffering from trigeminal neuralgia (350.1), so coding can be tricky. By understanding how to properly code for these procedures, you can optimize your reimbursement.

Trigeminal neuralgia is a devastating condition that causes the patient to suffer attacks that can be triggered by the lightest touch on the face. A woman putting on makeup, a man shaving, a parent experiencing the subtle touch of their childs hand all could result in bouts of the most excruciating pain that a person can endure. Treatments for this condition started in the 1920s when surgeons would simply cut the trigeminal nerve. This primitive approach would stop the pain but also would result in numbness throughout the face. Over the decades a variety of other and more successful procedures have been developed.

1. Microvascular decompression. In this surgery, a small opening is made in the skull so that the arteries and veins are lifted away from the trigeminal nerve to relieve the pain that is being caused by the pressure of the arteries and veins on the nerve. The arteries and veins are lifted away using a Teflon bridge or some other type of padding that will not be broken down by the body. According to Peter J. Jannetta, MD, chairman of the Trigeminal Neuralgia Association medical advisory board and a member of the department of neurosurgery at Allegheny General Hospital in Pittsburgh, Pa., if the neurosurgeon excises the veins running on the brain, he or she can cut the recurrence substantially. It is possible that after the first couple of years the veins will regenerate, but the recurrence rate is only 0.5 percent per annum, much lower than the recurrence rate with other procedures.

There are two CPT codes that you can use for this procedure. The correct one is chosen depending on the approach the neurosurgeon uses to get to the trigeminal nerve. If the approach is further along the nerve, past the brain stem, code 61450 (craniectomy, subtemporal, for section, compression, or decompression of sensory root of gasserian ganglion) would be used. If the approach is through the brain stem, which is a much more complex procedure, then it would be coded 61458 (craniectomy, suboccipital; for exploration or decompression of cranial nerves). CPT code 69990 (use of operating microscope), an add-on code, is used to indicate the microdissection.

2. Balloon compression. In this procedure, a tube is inserted through a puncture in the cheek. It is guided to a natural hole in the skull by x-ray. A tiny balloon is inflated so that it squeezes the trigeminal nerve. Pressure is carefully applied to create a lesion that will stop the pain. The correct coding is based on where along the nerve the balloon compression is performed.

Ronald Brisman, MD, a member of the Trigeminal Neuralgia Association medical advisory board, is an associate professor of clinical neurosurgery at the Neurological Institute, which has 12 neurosurgeons on staff in New York City, states that if the lesion is created beyond the foramen ovale, then code 61790 (creation of a lesion by stereotactic method, percutaneous, by neurolytic agent [e.g., alcohol, thermal, electrical, radiofrequency]; gasserian ganglion) is used. Rhonda Petruziello, CPC, reimbursement specialist for neurosurgery at Cleveland Clinic Foundation in Cleveland, Ohio, reports that if the lesion is created at the foramen ovale then 64610 (destruction by neurolytic agent, trigeminal nerve; second and third division branches at foramen ovale under radiologic monitoring) is used. Both of these CPT codes include radiologic monitoring of the procedure and should not be coded separately.

3. Radiofrequency rhizotomy. In this procedure, a hollow needle is inserted into the patients cheek. It is guided to the base of the skull with x-rays, and once the needle is in place, an electrode is sent through. While the patient is awake, an electrical current is sent through to determine where the patient feels the trigeminal nerve pain. When the correct spot is located, the patient is put back to sleep and the electrical current generates heat that damages the nerve. Arlene Liestman-Phillips, CPC, RHIT, who has been coding for three years and is currently the professional services coder for neurosurgery and neurology at Oregon State University in Portland, and coder for Kim J. Burchiel, MD, a member of Trigeminal Neuralgia Association medical advisory board, reports that this procedure is coded using 61790.

4. Glycerol rhizotomy. In this surgery, a needle is inserted into the patients cheek, and glycerol is injected into the trigeminal cistern. This strips away some of the nerves insulation so that the nerve is damaged. This procedure is coded with CPT code 61790.

5. Gamma knife radiosurgery. This is a noninvasive procedure during which highly focused beams of radiation are used to damage a site on the trigeminal nerve. The gamma knife targets 201 beams of Cobalt 60 radiation on a tiny area of the nerve, and where the beams overlap, a lesion is created. This is an outpatient surgery, and the patient goes home after a few hours.

Stacey Lang, coding and physician reimbursement analyst at Allegheny General Hospital in Pittsburgh, Pa., states that the proper codes for this procedure are 61793 (stereotactic radiosurgery [particle beam, gamma ray or linear accelerator], one or more sessions) for the gamma knife and 20660 (application of cranial tongs, caliper, or stereotactic frame, including removal [separate procedure]) for the head frame. She cautions neurosurgeons to be aware that according to the Correct Coding Initiative (CCI), 20660 is bundled into code 61793 and will not be paid for separately for a Medicare claim, but it may be paid by some third-party carriers.

Petruziello recommends using modifier -22 (unusual procedural services) if the gamma knife is done in more than one area rather than listing 61793 more than once. Code 61795 (stereotactic computer assisted volumetric [navigational] procedure, intracranial, extracranial, or spinal), an add-on code, can be used for the computer assistance needed for this complicated procedure. Petruziello cautions coders to be aware that in the April 7 Federal Register, Medicare changed the status of code 61795 to an inpatient procedure code, and this code may not be reimbursed on these grounds because gamma knife is considered an outpatient procedure.

6. Dorsal root entry zone (DREZ). The DREZ procedure uses electric current to remove nerves to stop pain signals. This procedure can have serious complications, including hearing loss, hemiparesis (342.9) (weakness of the arm and leg on one side of the body), and ataxia (781.3) (difficulty coordinating the motions of one arm or leg). Jannetta reports that this procedure is a major operation and because of the above complications is considered a last resort when all other treatment options have been pursued. The code for this procedure is 61790.

Note: Some of these procedures may need to be performed again during the 90-day global period because of a recurrence of pain. In such cases, the coder should add a -78 modifier (return to the operating room for a related procedure during the postoperative period) to the CPT code for the repeated procedure.