Injection of carbon dioxide instead of iodinated contrast to display the common bile duct during endoscopic retrograde cholangiopancreatography

Common bile duct (CBD) stones are usually caused by biliary tract infection, biliary stricture, duodenal peripapillary diverticulum, Oddis sphincter dysfunction, and so on. Treatment is preferably with endoscopic retrograde cholangiopancreatography (ERCP), where an iodine-containing contrast agent is injected into the CBD to display the stone under fluoroscopy and then to confirm complete removal of the stone(s). We described a 65-year-old woman with CBD stones who had undergone cardiac pacemaker implantation and was allergic to iodinated contrast media. We performed ERCP + lithotomy + stent implantation under local anesthesia, with injection of carbon dioxide instead of iodinated contrast into the CBD, and successfully visualized the stones under fluoroscopy and then confirmed complete removal of them. The patient was generally in good condition without complications. Thus, we have demonstrated in this case report that carbon dioxide can be used as a safe, economical, and effective alternative to iodinated contrast agent during ERCP.