Ask Dr. Z

I realize that, for purposes of coding CPT procedures, an AV dialysis shunt (fistula or graft) is defined as beginning at the arterial anastomosis and extending to the right atrium. Procedures performed in any of those veins are considered shunt procedures. Based upon that definition I have assumed that problems with those same veins, all the way to the right atrium, would be reported with shunt diagnosis codes in ICD-10-CM. For example: I would use the shunt diagnosis code T82.868A for thrombus of the brachiocephalic vein in one of these patients. However, my auditor would use the regular venous thrombus code I82.290. Who is right, and where does the fistula or graft end and the vein begin for ICD-10 diagnosis coding?