Ask Dr. Z

Can you please help clarify catheterization of just the external carotid? "Patient presents for arteriogram and embolization. Femoral is accessed and catheter is placed in the thoracic aorta with angiogram revealing common carotid, subclavian, and innominate patency. Wire is changed followed by selective cath of the external carotid into the thyroidal vessel with angiogram, revealing AV malformation, which was coiled." What do we do with procedures when a carotid wasn't performed, only external carotid? Codes 36227 and 36228 do not work with 36221 per coding guidelines. The verbiage suggests that the physician was going to perform embolization but was verifying condition. I have seen two of these cases where they only select the external carotid (36227) and, in this case, went beyond into the thyroid artery. Code 37242 is for coil, but can we proceed to 36217 for thyroid cath? And in the other case where they went directly to the external for angio, how do we code?