Therefore, the terminology for WGC might involve a mixture of technical factors. Another issue is that multiple WGC attempts per se might result in post-ERCP pancreatitis. Most operators who

perform a WGC only once might have a favorable result for the prevention of post-ERCP pancreatitis,11 in contrast to multiple operators, including click here trainees, who perform multiple WGC.12 Therefore, the outcome of a WGC for the prevention of post-ERCP pancreatitis might vary among institutions due to various WGC techniques and involvement by trainees.11,12 In this issue of the Journal of Gastroenterology and Hepatology,13 Nakai et al. suggest that 50 cases might be the learning curve for WGC trainees. Although this study has a retrospective design with methodological flaws, this result might still provide clues for the Roscovitine datasheet above-mentioned conflicting results of WGC. In Nakai et al.’s study, biliary cannulation by WGC had a high success rate, with a median time to cannulation of 3 min for the first 50 cases. The post-ERCP pancreatitis rate was as low as 4% in the first 50 cases, and lower (2%) in the next 200 cases. They suggested that the introduction of WGC was effective in the first 50 cases and did not increase the rate of post-ERCP pancreatitis in biliary therapeutic ERCP. However, this conclusion should be cautiously interpreted

because guidewire manipulation was performed by an assistant endoscopist in this study; it is unclear

whether this learning curve represents trainees as operators or assistant endoscopists. Although WGC might obviate the risk of post-ERCP pancreatitis, multiple attempts at a WGC by trainees might have a chance of post-ERCP pancreatitis, as mentioned. In a previous study by an experienced endoscopist,1 post-ERCP pancreatitis occurred in two patients with suspected find more sphincter of Oddi dysfunction (SOD) and WGC (3 and 4 unintentional pancreatic duct [PD] guidewire passes). Therefore, repeated, unintentional PD guidewire cannulation might develop into post-ERCP pancreatitis in a high-risk group of post-ERCP pancreatitis, such as those with SOD after WGC by an experienced endoscopist or a low-to high-risk group of post-ERCP pancreatitis after WGC by a trainee. Likely mechanisms are mechanical trauma or an increase in hydrostatic pressure by the repeated introduction of a guidewire into the main PD.1 During the training period, therefore, limiting multiple attempts of WGC are essential to prevent post-ERCP pancreatitis. The no-touch technique on the PD is the best way to prevent post-ERCP pancreatitis. If touching is inevitable, limiting it, along with WGC, or putting in a prophylactic pancreatic stent, rather than using a conventional contrast injection, is the best strategy for the prevention of post-ERCP pancreatitis.