Ask Dr. Z

Hoping you might provide assistance in regards the following: Specifically it concerns an AV graft, in which percutaneous thrombectomy (36870) is performed. After intervention, collateral vein in mid-fistula is determined to be stealing 50% of flow from AV graft and ligation is performed. Based on 2012 SVS recommendation, code 36832 would be appropriate for the ligation of collateral, as we are revising the flow of graft. However, the physician performed percutaneous thrombectomy during the same session. Codes 36870 and 36832 represent an NCCI coding conflict with no modifier override. Would you recommend reporting code 36833 despite having not performed open thrombectomy? Or report the ligation with unlisted code 37799?