Neurosurgery Coding Alert

Multiple sessions within 90 days? Call on 1 modifier to make the difference

Pay attention when your surgeon performs cranioplasty (cranial reconstruction) following an earlier craniotomy or craniectomy. There's an easy way to make sure you don't miss even one coding step for reporting previous bone flaps.

Often, the repair will involve using a cranial bone flap harvested during the previous session. When this occurs, you must be sure that you have reported not only the cranioplasty or craniectomy and subsequent repair, but also any steps the surgeon took to preserve and retrieve the bone flap.

Procedures involving cranial bone flaps generally occur over two separate operative sessions, each of which you will want to report separately and completely.

During the first session, the surgeon will perform a primary craniectomy or craniotomy for exploration, evacuation of hematoma, decompression or other indicated purpose. This procedure involves removing a portion of bone (the "bone flap") from the skull to allow for intracranial access.

When immediate replacement of the bone flap may aggravate intracranial hypertension from brain swelling, the surgeon may choose to create a subcutaneous "pocket" in the patient's abdominal wall in which to place the bone flap for safe keeping, says Gregory Przybylski, MD, director of neurosurgery at the New Jersey Neuroscience Institute, JFK Medical Center in Edison. The belly provides a sterile environment to store the flap, and because the tissue is the patient's own, there is no immune response. At a later date, when brain swelling has subsided, the surgeon will remove the stored flap and replace it into the skull for repair and reconstruction.

To describe creating the subcutaneous pocket and placing the bone flap for later retrieval, use +61316 (Incision and subcutaneous placement of cranial bone graft [list separately in addition to code for primary procedure]).

The AMA's CPT 2003 Changes: An Insider's View further explains, "Add-on code 61316 was created to describe the temporary placement of a cranial bone graft into a distant site for future retrieval. This procedure involves incision and creation of a subcutaneous pocket into a suitable area (usually the abdominal wall) for temporary housing of a cranial bone flap that may be retrieved and subsequently used for cranial repair procedures."

Because 61316 is an add-on code, you must also report an appropriate primary procedure code. Accepted primary procedures for 61316 include craniectomy 61304, 61312, 61313, 61322, 61323, 61570 and 61571, as well as cranial decompression 61340 and various surgeries for intracranial arteriovenous malformations and aneurysms, as described by 61680-61705.

Coding example: The surgeon performs a decompressive craniectomy by removing a bone flap to relieve intracranial hypertension following brain injury and swelling. There is no documented repair of the dura or any further intracranial excisions. The surgeon makes a subcutaneous incision in the abdomen and places the bone flap in the incision for preservation and future repair.

In this case, you should report the following:

- 61322 for the decompressive craniectomy (primary procedure). This includes creating and removing the flap.

- 61316 to describe creating the subcutaneous pocket and placing the bone flap for later retrieval. Because this is an add-on procedure, payers should not apply the "multiple-procedure reduction" to this code.

You shouldn't automatically report 61316 if the op report specifies that the surgeon removed a bone flap from the skull, says Eric Sandhusen, CHC, CPC, director of compliance for the Columbia University department of surgery. In some cases, for instance, the surgeon may remove a bone flap from the skull but chooses to freeze-dry the flap rather than place it in a subcutaneous pocket. There is no code to describe preparing and freezing a cranial bone flap, and you would not report this procedure separately.

In other cases, the surgeon may remove a cranial bone flap and simply discard it. If reconstruction occurs at a later time, the surgeon will use a prosthetic plate or graft bone from another area of the body. You cannot report a separate code if the surgeon discards the flap, Przybylski says.

If the surgeon does place the cranial bone flap in a subcutaneous pocket (61316), be sure to also report the graft's retrieval, using +62148 (Incision and retrieval of subcutaneous cranial bone graft for cranioplasty [list separately in addition to code for primary procedure]), during the subsequent cranioplasty to repair the skull, Sandhusen says.

Don't overcode: Code 62148 includes repair of the temporary placement site, so you should not charge separately for wound repair in addition to 62148.

Because 62148 is an add-on code, you must report an additional appropriate primary procedure code (in this case, the cranioplasty). Approved primary procedure codes for use with 62148 include all cranioplasty codes 62140-62147.

Keep in mind that if the cranial repair occurs during the initial surgery's 90-day global period, you should append modifier 58 (Staged or related procedure or service by the same physician during the postoperative period) to the appropriate cranial repair code(s).

Example: About nine weeks (63 days) following a decompressive craniectomy, the surgeon returns the patient to the operating room for final repair of the operative site. By this time, brain swelling has subsided, and the surgeon can safely replace the cranial bone flap removed during the earlier session.

The primary procedure in this case is bone flap replacement (62143, Replacement of bone flap or prosthetic plate of skull). You will append modifier 58 to 62143 to indicate that this is a "staged" repair following within the 90-day global period of a related procedure.

In addition, the surgeon must access and remove the previously stored graft from the subcutaneous pocket in the abdomen. To claim this procedure, you should report 62148, which includes the repair of the storage site.

Next month: Cranioplasty codes 62140-62147.