Neurosurgery Coding Alert

Answer: Most Medicare and third-party payers do not reimburse separately for a silastic dural expansion graft. The graft is considered a part of the major procedure. In this case the craniotomy and the subdural hematoma evacuation is coded 61312 (craniectomy or craniotomy for evacuation of hematoma, supratentorial; extradural or subdural). The reason generally given by carriers is that the dura must be closed whether the graft is used or not. That the silastic dural expansion graft is a synthetic graft and not a harvested autograft is another factor that also goes toward denial of additional payment because there is little work involved in acquiring or securing the graft.

If the graft is done at a different date from the major surgery it may be possible to gain separate reimbursement for the secondary replacement of the bone flap by using 62143 (replacement of bone flap or prosthetic plate of skull) appended with modifier -58 (staged or related procedure or service by the same physician during the postoperative period). Separate reimbursement may also be possible if, at another date, a cranioplasty is performed. If so, be sure to note the autograft size from the operative report and, depending on that data, code either 62146 (cranioplasty with autograft [includes obtaining bone grafts]; up to 5 cm diameter) or 62147 (... larger than 5 cm diameter) appended with modifier -58.