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General Surgery Coding Alert

Four Tips to Optimize Billing for Post-burn Grafts and Flaps

Published on Sun Jul 01, 2001

Following treatment, full-thickness burns must be covered to restore the skin barrier, reduce the risk of infection and prevent fluid and electrolyte loss. Covering also reduces scarring -- which can restrict range of motion (scar tissue is inflexible and frequently contracts, and is also more easily damaged and burned). 

Typically, the affected area is dbrided and covered, or in some cases closed, using a graft or flap. Coding these services can be challenging because:

 
  • The size, location and type (full or split thickness) of the graft or flap may not be documented adequately.

  • The wrong ICD-9 code may be linked to the appropriate graft or flap procedure.

  • A series of staged grafts or flaps may be performed within the global period.

  • The medical terminology may be confusing.
    •  
    Any of these may result in payment that does not reflect the surgeon's work. Failing to distinguish between an allograft and a xenograft, for instance, could lead to incorrect coding. Similarly, linking an incorrect diagnosis code to the creation of a graft or flap may end in a denial.
     
    Tip No. 1: Don't Forget to Bill Site Preparation Code(s)
     
    After escharotomy (16035-16036) and necessary subsequent dbridements (16010-16030), the affected area must be covered with either a graft or flap. Graft or flap creation may be performed immediately, or weeks, after the initial escharotomy but usually takes place during the escharotomy's 90-day global period. 

    Before grafts or flaps can be created, however, the affected area must be cleared of all remaining eschar, skin debris and subcutaneous tissue to create a healthy, vascular tissue bed upon which the graft or flap is formed. CPT includes two codes for this preparation:

  • 15000 -- surgical preparation or creation of recipient site by excision of open wounds, burn eschar, or scar (including subcutaneous tissues); first 100 sq cm or one percent of body area of infants and children

  •   +15001 -- ... each additional 100 sq cm or each additional one percent of body area of infants and children (list separately in addition to code for primary procedure).
    •  
    Because it is an add-on code, +15001 should never be used on its own. Similarly, 15000, although not an add-on code per se (it does not have a "+" to its left in the CPT book and its descriptor does not include terminology to indicate it is an add-on code), also should not be used on its own, says Marcella Bucknam, CPC, senior practice coder with the University of Omaha in Nebraska. "This code is used to report the preparation of a site for a graft. If you don't do a graft, there is no reason to perform this service -- which means 15000 shouldn't be billed," she says.

    In some cases the closure may not be performed during the same session as the preparation of the recipient site, notes Diane Elvidge, CPC, a coding specialist with Princeton Reimbursement Group in Minneapolis. In these cases, 15000 can be billed when performed alone. 

    "This is a good example of why 15000 isn't officially designated as an add-on code," Elvidge says. "With burn patients in particular, the surgeon will often prepare the recipient site but not close it immediately because individuals with burns have high rates of infection. If the area has infection after dbridements and other prepping, the surgeon will dress and bandage the wound only."

    Another reason 15000 isn't an add-on code, she notes, is that often different physicians perform the two procedures. For instance, a general surgeon may prepare the site and a plastic surgeon may create the graft or flap.

    Although 15000 is assigned 6.84 relative value units (RVUs) when performed in the office, some surgery coders may forget to bill for the service, possibly in part because the surgeon has not documented the service adequately in the operative report. To bill these codes correctly, the surgeon's procedure notes should clearly state that the preparation was performed and document the size of the area that will receive the graft.

    Note: Some commercial carriers do not pay for this service.

    Tip No. 2: Document Size, Location and Thickness
     
    The graft codes for using the individual's own tissue are differentiated by size, location and thickness (full or split). CPT includes two primary split-thickness graft codes and four primary full-thickness graft codes:

  • 15100 -- split graft, trunk, arms, legs; first 100 sq cm or less, or one percent of body area of infants and children

  • 15120 -- ... face, scalp, eyelids, mouth, neck, ears, orbits, genitalia, hands, feet and/or multiple digits; first 100 sq cm or less, or one percent of body area of infants and children

  • 15200 -- full thickness graft, free, including direct closure of donor site, trunk; 20 sq cm or less

  • 15220 -- ... scalp, arms, and/or legs; 20 sq cm or less
    •  
  • 15240 -- ... forehead, cheeks, chin, mouth, neck, axillae, genitalia, hands, and/or feet; 20 sq cm or less

  • 15260 -- ... nose, ears, eyelids, and/or lips; 20 sq cm or less.
    •  
    Split-thickness grafts are usually less complicated than full-thickness grafts because only the top layer of the skin (epidermis) is used, leaving the deeper layers intact. These grafts survive transplantation more readily and are generally more successful. However, they lack suppleness, hair will not grow on them and they look less like normal skin.

    Full thickness grafts look more like skin and can withstand more trauma if they are successfully implanted. These grafts include the deeper layers of skin (dermis), down to the subcutaneous tissue.

    Because a full-thickness graft involves additional work, the required area to use the codes -- and their associated add-on codes (15101, 15121, 15201, 15221, 15241 and 15261) -- differs substantially. For example, if the patient requires a 180-sq-cm split-thickness graft on the trunk, codes 15100 and 15101 (... each additional 100 sq cm, or each additional one percent of body area of infants and children, or part thereof [list separately in addition to code for primary procedure]) should be billed. A 35-sq-cm full-thickness graft in the same area would be coded 15200 and 15201 (... each additional 20 sq cm [list separately in addition to code for primary procedure]).
     
    Note: If more than 100 additional sq cm are required for a split-thickness graft (or more than an additional 20 sq cm for full-thickness), the add-on code should be listed twice (or more) on the HCFA claim form. Some carriers may prefer that you indicate these graft multiples in the units box.

    The correct code can be selected only if all information about size, location and depth is included in the operative report. But, "Some surgeons omit almost all the relevant information," Elvidge says. "They may write 'graft was applied' or something similar and neglect to mention the thickness, where it was placed and how big it was." She adds that if a full-thickness graft was performed, the surgeon should note the specific layers of skin involved; otherwise, only a split-thickness graft can be billed.

    Furthermore, if documentation does not explicitly state that the graft was bigger than 100 sq cm (or, in the case of a full-thickness graft, 20 sq cm), only the primary code may be used.
     
    Tip No. 3: Understand the Medical Terminology
     
    If the patient does not have sufficient skin available to cover a burned area, the surgeon may apply something else as a (often temporary) substitute.

    If human skin (typically, from a cadaver) is applied, the procedure is called an allograft or homograft, and should be coded 15350 (application of allograft, skin; 100 sq cm or less) and, if necessary, 15351 (... each additional 100 sq cm [list separately in addition to code for primary procedure]). 

    If nonhuman animal tissue is used, the xenograft should be coded 15400 (application of xenograft, skin; 100 sq cm or less) and 15401 (... each additional 100 sq cm [list separately in addition to code for primary procedure]).
     
    CPT 2001 also includes two new codes to describe grafts using artificial substances -- 15342 (application of bilaminate skin substitute/neodermis; 25 sq cm) and 15343 (... each additional 25 sq cm [list separately in addition to code for primary procedure]).

    Because allografts, xenografts and skin substitutes do not grow after application, they are used only if the patient does not have enough skin available for a full- or split-thickness graft. In these cases, the allograft, xenograft or skin substitute is used to form a temporary "bandage" to keep the wound covered until enough of the patient's own tissue can be harvested and regrafted.
     
    If the patient has severe scarring or burns that go down to the bone, or if reconstruction is required, a flap closure may be necessary. Because flaps are connected to healthy skin elsewhere in the body, they include blood vessels and nerves that replenish the affected area and promote healing. Flap closures are more complex than grafts and are often performed by plastic surgeons. In some cases general surgeons do perform these procedures. Applicable codes include formation of direct or tubed pedicle (15570-15576), delay or sectioning of flap (15600-15630) and intermediate transfer of pedicle flap (15650).
     
    When billing for flaps, differentiate between the donor and recipient sites. Most flap codes are determined based on the recipient site; however, the "delay of flap" codes should be selected based on the donor site.
     
    Tip No. 4: Use Modifier -58
     
    Patients with burns often return for additional treatments. After the initial escharotomy, for example, the affected area may require one or more dbridements. These are separately payable if modifier -58 (staged or related procedure or service by the same physician during the postoperative period) is appended to the appropriate code. Similarly, any grafts performed within 90 days of the escharotomy must also be appended with modifier -58 to be separately payable.
     
    Burn patients also typically require many return trips to the operating room after a graft or flap has been performed. Most graft procedures discussed in this article -- with the exception of the application of bilaminate skin substitute (15342) -- include a 90-day global period (15342 has a 10-day global). Therefore, the appropriate code for any additional grafts or flaps performed during the global period of another graft should also have modifier -58 appended.
     
    If the patient has multiple burns, and several different or similar grafts are applied during the same session, modifier -59 (distinct procedural service) should be attached to indicate that the grafts (full- or split-thickness, allograft or xenograft, for instance) were performed at different anatomic sites.
     
    Finally, because infections frequently occur in burn sites, the surgeon may debride the area to remove the infection before applying a graft. In such cases, the appropriate ICD-9 burn code (see General Surgery Coding Alert, June 2001) should be the primary diagnosis for the graft. If an infection diagnosis is used, the claim may be denied because infection does not provide medical necessity for grafts or flaps.

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