Neurosurgery Coding Alert

Graft procedures may be reported in addition to other procedures, such as arthrodesis (22548-22812) and spinal instrumentation (22840-22855), but should be used only when the graft is not bundled to a more extensive procedure (see below for example). And, bone grafts, although not specifically defined as add-on procedures, "are reported in addition to codes for the definitive procedure(s)" and should not be appended with modifier -51 (Multiple procedures), according to CPT.

Many payers will accept only one bone graft code per operative session. If an autograft and allograft are used during the same procedure, therefore, report only the more extensive (i.e., autograft) procedure. If autograft morselized bone is mixed with bone marrow obtained by needle aspiration (e.g., from the ilium), report only the autograft or the aspiration.

Note: According to CPT, the correct code to report needle aspiration of bone marrow for bone grafting is 38220 (Bone marrow aspiration).

However, the language in CPT instructing providers to bill only one bone graft per operative session was eliminated in 2001, and some coders have reported success billing 20931 and 20931-59 (Distinct procedural service), for instance, for grafts placed at multiple levels. When billing in this manner, be sure to include an operative report clearly illustrating that two separate interspaces (e.g., C5/C6 and C6/C7) were treated.

Note that use of modifier -62 (Two surgeons) is specifically prohibited with all bone graft codes 20900-20938.

Neurosurgeons may access several codes for grafts during cranial procedures. Codes 20900 (Bone graft, any donor area; minor or small [e.g., dowel or button]) and 20902 ( major or large) for instance, may be used to describe bone grafts for skull reconstruction following head injury. These are autograft codes that include harvesting of the graft from any area.

The surgeon may also place fat grafts to fill empty cavities after excision, such as following pituitary tumor removal. This procedure should be reported with 20926 (Tissue grafts, other [e.g., paratenon, fat, dermis]).

Repair of cranial defect with bone graft should be reported using 62146 (Cranioplasty with autograft [includes obtaining bone grafts]; up to 5 cm diameter) or 62147 ( larger than 5 cm diameter), depending on the size of the defect. These codes also include harvesting and placement. Unlike many graft procedures, 62146 and 62147 are not modifier -51 exempt.

For instance, replacement of the bone flap is typically included as integral to most intracranial procedures, says Eric Sandham, CPC, compliance educator for Central California Faculty Medical Group (CCFMG), a group practice and training facility associated with the University of California at San Francisco in Fresno. But if a portion of the bone flap has been excised or is unusable (for example, due to invasive meningioma, 61512), cranial reconstruction is reported in addition using 62146 or 62147, as appropriate, with modifier -51 appended.

Repair of the dura is a common procedure during or following spinal or cranial surgery. Generally, the dura (the membrane surrounding the brain and spinal cord that maintains cerebrospinal fluid pressure) is repaired directly or by placing a graft over the damaged area to create a watertight seal. Because a graft repair requires minor additional effort compared to a direct repair, in most cases it is not separately billable. However, harvest of a graft for dural repair may be billable, Sandham says.

Code 20920 (Fascia lata graft; by stripper) or 20922 ( by incision and area exposure, complex or sheet) is appropriate if a portion of the fascia lata (the thick band of connective tissue under the dermal layers of the thigh) is harvested to prepare a watertight seal for repair of the dura. Most commonly, this will be done at closing following intracranial surgery.

Note: According to CPT, 20920 and 20922 are modifier -51 exempt.

Code 63710 (Dural graft, spinal) describes placement of a dural graft (most commonly synthetic dura substitute or bovine pericardium) for repair of the dura over the spine only, says Kee D. Kim, MD, associate professor with the department of neurosurgery at the University of California, Davis. Because 63710 does not include the approach and closure, it should be reported when a graft is placed to repair the dura during another, related procedure. There is no analogous cranial dural graft code, although 62100 (Craniotomy for repair of dural/cerebrospinal fluid leak, including surgery for rhinorrhea/otorrhea) includes graft placement for dural repair.

CPT includes a specific code for secondary dural repair with graft following skull base surgery. Code 61618 (Secondary repair of dura for CSF leak, anterior, middle or posterior cranial fossa following surgery of the skull base; by free tissue graft [e.g., pericranium, fascia, tensor fascia lata, adipose tissue, homologous or synthetic grafts) is appropriate "if extensive dural grafting or extensive skin grafts are required" during a later operative session, according to CPT.

If the dural repair occurs during the definitive procedure's (e.g., skull base surgery's) global period and was planned at the time of that procedure, report 61618 with modifier -58 (Staged or related procedure or service by the same physician during the postoperative period) appended. If the repair was not planned at the time of the definitive procedure, report the appropriate code with modifier -78 (Return to the operating room for a related procedure during the postoperative period) appended, says Steven Hysell, MD, of CCFMG.

An operating microscope (+69990 Microsurgical techniques, requiring use of operating microscope [list separately in addition to code for primary procedure]) may be used during some graft procedures. Although non-Medicare carriers will often pay for +69990, CMS has published a restrictive list of codes with which +69990 may be separately reimbursed. Among the codes included in this list are graft procedures 62100 and 63710. Therefore, if the operating microscope is used during either of these procedures, +69990 should be separately reported and reimbursed. Documentation should specify that the operating microscope was used.

Note: Code +69990 is an add-on code for which payment should not be reduced.