I have a doctor that provided a revision of a fascia lata sling that was performed before 1970. The doctor used a suture to secure the fascia lata sling in a posterior superior direction to the temporalis fascia in a horizontal mattress type fashion. There is no code for this type of procedure. I was consulted to use CPT 20999 with a comparison code, but there is no comparison code that I can find that qualifies. Has anyone come across this issue and have any advice?