A prospective randomized study of loop-tip versus straight-tip guidewire in wire-guided biliary cannulation.

Background: Wire-guided cannulation has been widely accepted as a useful technique for achieving selective biliary access because it has significantly increased the success rate of biliary cannulation compared with conventional contrast-assisted cannulation. Unlike conventional guidewires with a straight tip, a loop-tip guidewire (LGW) has a closed distal loop that may facilitate less traumatic access through the epithelial folds of the intra-duodenal biliary segments. The aim of this study was to compare the performance of a LGW with a straight-tip guidewire (SGW) in achieving successful selective biliary cannulation.

Methods: From December 2014 to December 2015, we performed 192 wire-guided biliary cannulations for a naïve papilla in a randomized controlled trial. Patients were randomly assigned to the LGW group (n = 96) or the SGW group (n = 96). Our study protocol did not include crossover to the other guidewire arm if randomized wire-guided cannulation proved unsuccessful within the first 10 min.

Results: There was no significant difference in primary successful biliary cannulation between the two groups (LGW group: 86.5%; SGW group: 77.1%; p = 0.134). The rate and the mean number of unintentional pancreatic duct cannulations during wire-guided biliary cannulation were significantly lower in the LGW group than in the SGW group (LGW group: 14.6%; SGW group: 28.1%; p = 0.034; LGW group: 0.2 ± 0.5; SGW group: 0.6 ± 1.3; p = 0.007). Post-ERCP pancreatitis developed in 5.2% of patients in the LGW group and 8.3% of patients in the SGW group (p = 0.567).

Conclusions: The biliary cannulation rate of the LGW was not significantly different from those of conventional guidewires. Use of the LGW was associated with a lower rate of unintentional pancreatic duct cannulation during wire-guided biliary cannulation than use of the SGW.