Primary Needle-Knife Fistulotomy Versus Standard Transpapillary Technique for Cannulation of Long-Size Papilla: A Randomized Clinical Trial.

Introduction: The morphology of the major papilla plays a crucial role in the selection of the cannulation method for the common bile duct during endoscopic retrograde cholangiopancreatography. Nevertheless, there is limited evidence available that compares the efficacy and safety of cannulation approaches in certain papilla morphologies. The aim of this study was to assess the safety and effectiveness of 2 cannulation methods, including primary needle-knife fistulotomy (pNKF) and standard transpapillary (STP), in patients with long-size papilla.

Methods: A total of 260 patients with intact long-size papilla were enrolled and were randomly assigned to the pNKF or STP groups (n = 130 in each group). The primary endpoint was the rate of postendoscopic retrograde cholangiopancreatography pancreatitis. Biliary cannulation success rates, the duration of cannulation and the overall procedure, and the incidence of adverse events were also compared between the groups. All of the patients were hospitalized for at least 24 hours after the procedure.

Results: A total of 125 (96.2%) patients in the pNKF and 114 (87.7%) patients in the STP groups had successful primary biliary cannulation ( P = 0.01) and were included in the final analysis. Postendoscopic retrograde cholangiopancreatography pancreatitis occurred in 11 patients in the STP group and 3 patients in the pNKF group (9.6% vs 2.4%, P = 0.02; number needed to treat [95% confidence interval] = 13.9 [7.5-83.2]). Moreover, compared with the pNKF, STP was associated with more cannulation attempts (3.4 vs 2.5, P < 0.001) and longer cannulation time (258 vs 187 seconds, P < 0.001).

Discussion: In patients with long-size papilla, pNKF is a safer, easier, and more efficient approach to gain primary biliary access than the STP technique.