Is the double-guidewire technique used to facilitate selective bile duct cannulation or to prevent post-ERCP pancreatitis?

We read with great interest the article entitled “Early use of double-guidewire technique to facilitate selective bile duct cannulation: the multicenter randomized controlled EDUCATION trial” [1]. In this multicenter study, the authors randomly assigned patients to undergo the early double-guidewire technique (EDG group) or repeated use of single-guidewire cannulation (RSG group), after a guidewire was unintentionally inserted into the main pancreatic duct. They found that, within 10 attempts and 10 minutes from the initial cannulation attempt, the EDG technique neither facilitated selective bile duct cannulation nor decreased the incidence of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) compared with the RSG technique.

We have some comments and questions about the paper. The endoscopist considered placement of a pancreatic stent if the cannulation attempts exceeded the limit of 10 attempts and 10 minutes; stent placement was performed in 16 % of patients in the RSG group and 18 % of the EDG group. We think that a pancreatic stent should be placed in all of the patients after performing biliary sphincterotomy. The primary aim of advancing a guidewire into the pancreatic channel is to place a pancreatic stent in order to prevent PEP. Estimating the direction of the common bile duct is the secondary aim. In the EDG group, the guidewire in the pancreatic duct was advanced deep into the body of the pancreas, and injection of small amounts of contrast was permitted for this purpose. This means that some of the patients probably experienced repeated traumas to the side branches of the pancreatic duct. We are keen to know the following: Was there any difference between the number of these attempts in the two groups? Do the authors think that pancreatic stent placement may decrease the incidence of PEP in such patients? Was there any difference in the number of unintentional insertions of a guidewire into the pancreatic channel between patients in the EDG and RSG groups who achieved selective bile duct cannulation? Were the guidewires inserted into the main duct or into side branches? What is the effect of duct type on the development of PEP?

The authors classified endoscopists who had been practicing for  < 4 years as trainees and  ≥ 4 years as experts. Is this classification based on a study? As far as we know, endoscopists who have performed more than 200 ERCPs after their education period, regardless of the period, can be categorized as an expert. Were there any procedures started by a trainee and finished by an expert? What was the impact of a change in hands on the development of PEP?

• References

• 1 Sasahira N, Kawakami H, Isayama H et al. Early use of double-guidewire technique to facilitate selective bile duct cannulation: the multicenter randomized controlled EDUCATION trial. Endoscopy In press 2015. DOI: 10.1055/s-0034-1391228.