Snare-assisted precutting and dual-knife fistulotomy performed during difficult biliary cannulation in a patient with an ectopic papilla of Vater.

Endoscopic retrograde cholangiopancreatography is widely used in the diagnosis and treatment of pancreatobiliary diseases; however, successful biliary cannulation is a prerequisite for this operation. We herein present a new method in a patient in whom cannulation was difficult. A 56-year-old man was admitted to the hospital with choledocholithiasis. Endoscopic retrograde cholangiopancreatography was performed, and duodenoscopy revealed that the patient's duodenal papilla was located at the initial part of the horizontal segment of the duodenum. Because of the ectopic location of the duodenal papilla, the guidewire could not be inserted into the biliary and pancreatic duct. Therefore, we performed a new method to resolve the problem of difficult cannulation. A polypectomy snare was used to excise the mucosa covering the surface of the intramural segment of the common bile duct, and a dual knife was used to form a fistula. A guidewire was then inserted through the stoma into the bile duct. After the procedure, the bile duct was successfully cannulated and the stones were removed. No complications occurred. This new method may be an alternative treatment to precutting for difficult biliary cannulation in patients with a protruded papilla of Vater.