Ask Dr. Z

What CPT code should be reported for a balloon redilation of a previously placed stent for aortic coarctation? The patient is a 13-year-old who has had multiple procedures for aortic coarctation, including most recently a P3110 stent placed four years prior. The procedures documented on this visit included R/L heart cath, ascending aorta angio, descending aorta angio, RV angio, pulmonary artery angio, and balloon dilation of the existing stent. (The coarctation stent was redilated first with a 15 mm ZMED balloon and then with a 16 mm ATLAS balloon, inflated to 10 atmospheres.) Is there a specific CPT code for the balloon redilation of the stent, or would this be an unspecified code?