I am not aware of category 1 code that would describe this. I think if I was billing for the procedure I would use an unlisted code. Below is not your scenario but a post surgery injection from AMA CPT Assistant Sept 2010
Surgery: Nervous System
Question:The patient has postmastectomy pain in the scar tissue area and not in the muscle. An injection was performed into the scar tissue of the chest area using a mixture of triamcinolone topical, lidocaine with epinephrine, and bupivacaine hydrochloride with epinephrine. What CPT code should be reported for this procedure?
Answer:Injection of painful scar tissue is reported using CPT code 64999,Unlisted procedure, nervous system.
When reporting an unlisted code to describe a procedure or service, it is necessary to submit supporting documentation (eg, procedure report) along with the claim to provide an adequate description of the nature, extent, and need for the procedure, and the time, effort, and equipment necessary to provide the service.