Ask Dr. Z

I have an attempted TCAR procedure in which after insertion of flow reversal and CCA exposure the attempted wire crossing dissected the plaque causing an obstruction. The physician thought it was a thrombus and attempted aspiration with no thrombus return. He ended up doing a standard endarterectomy using the flow reversal system and a separate incision. My question is, since he did a separate incision would I be able to code the TCAR with a -53 modifier since he still utilized the flow reversal? I would think since this is part of a clinical study it would need to be reviewed. Also, would the intraoperative arteriography be codable? The sheath was able to be advanced to the ECA. I would greatly appreciate your coding advice for this scenario.