Neurosurgery Coding Alert

Question: Our surgeon routinely performs 61343 to repair Chiari malformation. Now we have a case where he completed that procedure and also resected an additional cyst in the cerebellar tonsil during the Chiari malformation decompression. Can we code both procedures? If so, do we append a modifier?

New Mexico Subscriber

Answer: You should consider looking at craniectomy procedures represented by 61343 (Craniectomy, suboccipital with cervical laminectomy for decompression of medulla and spinal cord, with or without dural graft [e.g., Arnold-Chiari malformation) and 61524 (Craniectomy, infratentorial or posterior fossa; for excision or fenestration of cyst). The Correct Coding Initiative (CCI) edits currently do not bundle these codes, so you should be able to report both on the claim with sufficient documentation. If resection of the cyst was distinct and separate from the work required to decompress the Chiari malformation, you can report both codes.

Tricky: Not sure whether to append modifier 51 (Multiple procedures) or 59 (Distinct procedural service) to the second procedure code? In this case, modifier 59 is appropriate because the craniectomies are performed on a separate lesion. CPT 2010's Appendix A modifier 59 definition states in part that, "Modifier 59 is used to identify procedures/services, other than E/M services, that are not normally reported together, but are appropriate under the circumstances. Documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual."