Radiology Coding Alert

Some carriers are erroneously bundling services like angioplasty into CPT 36870 (thrombectomy, percutaneous, arteriovenous fistula, autogenous or nonautogenous graft [includes mechanical thrombus extraction and intra-graft thrombolysis]) even though it should be paid separately.

AV dialysis fistula maintenance is performed with kidney patients undergoing regular dialysis treatments, according to Gerald Johnson, MHA, CHE, administrator of diagnostic and therapeutic radiology services at the Danville Regional Medical Center in Danville, Va. When dialysis is needed, a urologist and surgeon create a reservoir or fistula in the patients forearm, and insert a shunt to connect the arterial and venous systems. This shunt allows blood to be routed out of the patient through dialysis equipment and back into the patient.

Because of the slower flow of blood, clots sometimes form in the fistula, interfering with dialysis. An interventional radiologist may then perform a thrombectomy, remove the clot and re-establish the flow of blood through the shunt. In other instances, a vascular surgeon may also need to perform an open excision of the clot.

Some Carriers Wrongly Bundle

On occasion, the interventional radiologist may first attempt balloon angioplasty to reopen the lumen, Johnson says. If that effort fails, the physician will then perform the thrombectomy to declot the fistula. Both services should be documented and reported. Some coders state, however, that many carriers inappropriately deny the angioplasty as bundled into the thrombectomy.

These bundling problems are a carry-over from temporary HCPCS Code G0159, which was replaced by 36870 this year, Johnson notes. Carriers began including related services with the level II code and have continued the practice this year, despite the fact that this code was not intended to be inclusive. Organizations like the Society for Cardiovascular and Interventional Radiology (SCVIR) are working closely with Medicare policymakers to correct this, and many coders say their carriers have gradually begun paying for the component codes.

The many steps of the declot procedure may be coded and billed separately.

Step 1: Access to the AV graft. The interventionalist percutaneously punctures the fistula to begin the declotting procedure, according to Lisa Grimes, radiology special procedures technologist and reimbursement specialist for The University of Texas/Houston, Health Science Center. This is coded with nonselective code 36145 (introduction of needle or intracatheter; arteriovenous shunt created for dialysis [cannula, fistula, or graft]).

Sometimes, the radiologist will create two access points on opposites sides of the site if he or she cant effectively reach the clot from one side, she explains. Dictation will often say, Accessed in a crossing fashion.

If two access points are necessary, coders would assign 36145 twice. Grimes notes that many carriers require modifier -59 (distinct procedural service), although others may require modifier -51 (multiple procedures). Still others require no modifiers. She recommends that coders ask local carriers for their policy.

Step 2: Performing the fistulagram. The radiologist will then perform a fistulagram or graftogram to visualize the narrowing or blockage affecting the site, Grimes says. The fistulagram, reported with 75790 (angiography, arteriovenous shunt [e.g., dialysis patient], radiological supervision and interpretation), includes the fistula itself, along with venous outflow up to and including the superior vena cava prior to and after the declot.

Although some coders say the fistulagram may be repeated after the declotting procedure and reported twice, most experts note they have been advised that the postprocedure imaging is included in the original study and would not be billed separately.

Step 3: Fistula declotting. The declotting of the fistula is reported with 36870, Johnson says. This code describes all percutaneous methods of opening thrombosed dialysis shunts. These techniques may include mechanical thrombectomy which are devices that physically remove the clot as well as lyse and wait, and short infusions of thrombolytic agents.

The code does not include infusions of thrombolytic agents lasting longer than an hour, angioplasty or intravascular stenting. If these procedures are undertaken, appropriate codes would be reported in addition to 36870.

Grimes also notes that 36870 carries a 90-day global period, indicating that the procedure and services directly related to it (e.g., sedation), as well as normal, uncomplicated follow-up care, are included. However, if the graft fails or develops a new clot during this time, the radiologist may return to the interventional suite and report the service with modifier -78 (return to the operating room for a related procedure during the postoperative period). Carriers will virtually always discount reimbursement on a related service appended with modifier -78.