Neurosurgery Coding Alert

Question: The surgeon performed a right L4-L5 lumbar microdiskectomy using the microscope for microdissection. While he was performing this procedure, he discovered a CSF leak from an erosive durotomy on the dorsal surface of the L5 root near the axilla. A primary repair of the CSF leak was done next, though the CSF leak was not caused by the procedure he performed. Is the CSF leak separately billable even though he is working in that same region and the approach was through the same incision?

New York Subscriber

Answer: The procedure would be reported as 63030 (Laminotomy [hemilaminectomy], with decompression of nerve root[s], including partial facetectomy, foraminotomy and/or excision of herniated intervertebral disc, including open and endoscopically-assisted approaches; 1 interspace, lumbar). The repair of the durotomy would be considered incidental to the primary procedure.

If significant additional work was required for the dural repair, you would append modifier -22 (Increased Procedural Services:...). Although the microdissection is separately reportable with 69990 (Microsurgical techniques, requiring use of operating microscope (List separately in addition to code for primary procedure) by CPT® rules, CMS considers this a bundled service and will deny payment for microdissection.