Radiology Coding Alert

Question: CPT 36870< (Thrombectomy, percutaneous, arteriovenous fistula, autogenous or nonautogenous graft [includes mechanical thrombus extraction and intra-graft thrombolysis]) for a patient on June 22 and then again when a second doctor performed the same service on Aug. 6. I used modifier -79 because I know there is a 90-day global period. I coded 996.73 (Other complications of internal prosthetic device, implant, and graft; due to renal dialysis device, implant, and graft) for both. Medicare won't pay for the second thrombectomy. Am I not allowed to code 36870 the second time just because I coded it once already and there's a 90-day global period?

California subscriber

Answer: A complication requiring a return to the operating room (meaning a room specifically equipped for surgery) should not be included in the global period. Try using modifier -78 (Return to the operating room for a related procedure during the postoperative period) if you want to get paid.

You should check with your local carrier, but Medicare generally considers procedures with the same diagnosis code to be "related" in this situation. Modifier -78 is therefore more appropriate than -79 (Unrelated procedure or service by the same physician during the postoperative period). But your reimbursement may be reduced because of the global period.

A global period (90 days for major surgeries) generally includes the surgery, as well as hospital or office visits related to uncomplicated follow-up care that is within the global time limit. The global period does not include postoperative complications (e.g., bleeding or infections) or unrelated services (e.g., services by another specialty).

Don't overlook: Even though two doctors were involved, modifier -78 or -79 could be correct in some situations. If your doctors use a group number instead of individual numbers for billing purposes, payers will consider them to be one physician for coding purposes.

However, this is only correct if both physicians were in the same practice and/or billing under the same group provider number. Also, the report should clearly document the cause for providing the repeat service.

For example, if there was interim progression of disease (perhaps a new underlying stenosis or inflow obstruction not present during the first presentation), the payer should not reduce payment. If there is such a reduction, appeal. If the second procedure is related to a failure in durability of the primary procedure, the payer may or may not reduce payment. - The answers for You Be the Coder and Reader Questions were reviewed by Cindy C. Parman, CPC, CPC-H, RCC, co-owner of Coding Strategies Inc. in Powder Springs, Ga.; and Gary S. Dorfman, MD, FACR, FSIR.