Medical Coding Tissue Transfer or Rearrangement
I often see incorrect medical coding for “flaps”, which were adjacent tissue transfers, 14000-14350. Coders do not always understand that you can only code for the closure of the primary and secondary defect, but not for each flap that is created. Surgeons may have to create multiple flaps to close a defect, but the multiple flaps cannot be coded since there is only one primary defect. Also, the removal of the lesion to create the primary defect is considered included in the adjacent tissue arrangement.
Per CPT® Assistant July 2008, Volume 18: Issue 7, Coding Communication, Adjacent tissue transfer or rearrangement procedures (local flaps) are also referred to as “rotation flaps”, “transposition flaps” and “advancement flaps”.
Types of Tissue Transfer
A rotation flap is a curvilinear flap that closes a defect by a rotating the skin around a pivot point. A transposition flap is cut, lifted, and transferred over intervening tissue onto the defect. This type of flap is also referred to as a rhombic, bilobed, or nasolabial fold flap. And with an advancement flap, tissue is moved in a straight line and stretched over the defect. This is also referred to as a V-Y repair or flap.
The primary defect is usually created from the excision of a benign or malignant lesion. The creation of the primary defect is included in an adjacent tissue transfer and not separately coded. Adjacent tissue transfers create secondary defects by their very nature, lifting-up skin and moving the skin over to cover the primary defect. Closing the secondary defect is also coded in addition to the adjacent tissue transfer. The secondary closure may be part and parcel of the adjacent tissue transfer, which closes both the primary and secondary defect, or an additional graft may be needed to close the secondary defect, requiring an additional grafting code.
If the adjacent tissue transfer closed both the primary defect and the secondary defect, add both the size of primary defect plus the size of the secondary defect to determine the size of the flap that is coded. If a split thickness graft or free graft is used to close the secondary defect, only the primary defect would be used to determine the size of the adjacent tissue flap that is coded. Let’s look at some examples.
Examples of Tissue Transfer
A .5 cm lesion is removed from the lip and face. Since the lesion was malignant, the primary defect after margins was 1.6 sq.cm. The surgeon performs an adjacent tissue transfer from the cheek to close the defect, creating a secondary defect with flap dimensions of 3.2 cm x 1.0 cm which equals a secondary defect of 3.2 cm. The primary defect and the secondary defect are 1.6 cm plus 3.2 cm or 4.8 cm. The adjacent tissue transfer will be coded as 14060, adjacent tissue transfer or rearrangement. eyelids, nose, ears and/or lips, defect size 10 sq. cm or less.
A 3.5 cm malignant lesion is removed from the face with .5 cm margins from the cheek. This results in a 4.5 cm excised diameter defect. The primary defect is 4.5 cm x 4.5 cm or 20.25 square cm. The secondary defect required a split thickness graft harvested from the abdomen and was not closed by the adjacent tissue graft. This would be coded as: 14041 Adjacent tissue transfer or rearrangement, forehead, cheeks, chin, mouth, neck axillae, genitalia, hands and/or feet, defect 10.1 sq. cm to 30.0 sq. cm and 15120 Split thickness autograft, face, scalp, eyelids, mouth, neck, ears, orbits, genitalia, hands, feet, and/or multiple digits, first 100 sq. cm or less.
A large defect is created in the nasolabial fold and the surgeon needs to create three flaps to close the defect. Even though three flaps are created, three flaps cannot be coded because there is only one defect. But the closure of the secondary defects that are created by all of the flaps may be coded for, so make sure they are accounted for in your coding and included in the claim.
Keep in mind that in all of these examples, the excision of the lesion was not separately coded and billed. The instructions that CPT® includes in the section notes state that the excision of benign lesion (11400-11446) or malignant lesion (11600-11646) is not separately reportable with 14000-14302. NCCI is consistent with these instructions, bundling these codes together. However, other defect creations, such as Mohs micrographic surgery, and excision/radical resection of tumors of soft tissue (subcutaneous tissue, subfacisal, intramuscular) codes, eg: 21552-51558 are not considered incidental to these flaps and are not bundled.