Ask Dr. Z

I am confused about code 47801 for choledochal stent. In one of your questions in 2006 a case was provided where code 47556 was recommended whether dilation occured or not prior to stent placement. I have a case where the physician placed a 10mmx6mm stent across the common bile duct with post angioplasty with 10mm balloon. Contrast injection to confirm patency. Since the intent of the balloon was for post dilitation would code 47801 be correct? I am confused about this code and when to use vs 47556 when stent is implanted. Thank you.