In patients with pancreatic duct cannulation initially by chance, double guide wire technique and trans pancreatic sphincterotomy facilitate biliary cannulation and show the similar success rates. The incidence of post-procedure pancreatitis was similar in the two groups, but post-procedure hyperamylasemia was significantly higher in the DGT group.

This was a prospective, randomized study conducted in three tertiary referral hospital in Korea. Three endoscopists performed the ERCP who had ERCP experience more than ten years From October 2010 to August 2012, ERCPs were performed on patients with pancreatobiliary diseases at Soonchunhyang University Seoul Hospital, Hanyang University Guri Hospital and Kosin University Gospel Hospital. Bile duct cannulation was attempted for various reasons (removal of bile duct stones, biliary stenting, cytology of bile, biopsy of the bile duct, etc.).

Patients who satisfied the following inclusion criteria were enrolled in this study: (1) initially pancreatic duct cannulation by chance, (2) successful insertion of the guidewire into the pancreatic duct to at least half of the presumed total length of the pancreatic duct,, and (3) age 20 years or older. Exclusion criteria were: (1) refusal the ERCP, (2) previous endoscopic sphincterotomy or endoscopic papillary balloon dilatation, (3) acute pancreatitis at the time of the procedure, (4) pregnancy and (5) anatomical change due to past surgery; total gastrectomy, Billroth II operation, Whipples's operation etc. Patients who satisfied the inclusion criteria were randomly assigned to either the double-guidewire technique (DGT) group or the transpancreatic precut sphincterotomy (TPS) group; A randomization list for group allocation was generated by using computer-based pseudo-random number generators. We compared both techniques , for a maximum of ten extra attempts which are CBD cannulation by each methods. We obtained the written informed consent from all enrolled patients.

Inclusion Criteria:

• ERCP patient, over 20 years old, pancreatic duct cannulation patients by chance

Exclusion Criteria:

• refuse the ERCP, post procedure state(EST, subtotal gastrectomy, Whipples' Op except gastroduodenostomy), use another method, under 20 years old.