A prospective randomized study of thin versus regular-sized guide wire in wire-guided cannulation

Endoscopic retrograde cholangiopancreatography (ERCP) is a valuable tool in the diagnosis and management of various pancreatobiliary disorders. Our aim was to evaluate whether the combination of a thin guide wire and a thin sphincterotome would facilitate selective cannulation of the bile duct and reduce the incidence of post-ERCP pancreatitis (PEP) by reducing papillary trauma when compared with a regular-sized hydrophilic guide wire. Between June 2011 and February 2012, we performed 100 biliary cannulations for a native papilla in a randomized controlled trial. Having given their written informed consent, patients were randomly assigned to a 0.025-inch guide wire and sphincterotome group (n = 50) or to a 0.035-inch guide wire and sphincterotome group (n = 50). Number of cannulation attempts, number of accidental guide wire passages into the pancreatic duct, secondary cannulation techniques after failed primary cannulation, time to change the technique, and time for successful cannulation were collected in a database. Patients were followed up after ERCP, and all post-ERCP complications were recorded. Primary cannulation was successful in 80 %. With accessory techniques, cannulation of the biliary duct was achieved in every case except one. There was no difference in primary cannulation rate between the 0.025-inch and 0.035-inch wire groups (n = 40 in each group). PEP was diagnosed in two patients (2.0 %), one in each study group. Postsphincterotomy bleeding occurred in one patient (1.0 %). The thickness of the hydrophilic guide wire does not appear to affect either the success rate of primary cannulation or the risk of complications.