S2285 Primary Needle-Knife Fistulotomy Is an Effective and Safer Alternative to Conventional Cannulation in ERCP: A Systematic Review and Meta-Analysis

Introduction: In patients at high risk for post-ERCP pancreatitis (PEP), conventional ERCP cannulation (CEC) carries a PEP risk of up to 14%. Primary needle-knife fistulotomy (pNKF) has emerged as an alternative technique, allowing selective biliary access while minimizing trauma to the papillary orifice. This meta-analysis aims to compare the efficacy and safety of pNKF versus CEC. Methods: A systematic literature search was performed using PubMed, Scopus, Embase, and Web of Science through May 2025. Studies were included if they compared pNKF (as the primary access method) to CEC in biliary drainage. Studies using pNKF as rescue/salvage therapy were excluded. Pooled odds ratios (ORs) and mean differences (MDs) with 95% confidence intervals (CIs) were calculated using random-effects models and the Mantel-Haenszel method. Heterogeneity was assessed via the I² statistic. The primary outcome was PEP. Secondary outcomes included cannulation success, procedure time, and other adverse events. Results: Our search strategy resulted in 1874 citations, of which, 36 were reviewed in full text and a total of 5 studies (4 RCTs and 1 retrospective study) met the inclusion criteria and included in the final analysis. Our analysis included 948 patients (pNKF = 473 vs CEC = 475). Compared to CEC, pNKF was associated with a significantly lower risk of PEP (1.5% vs 6.7%; OR = 0.24, [95% CI: 0.09-0.63], P < 0.01) with no observed heterogeneity between included studies (I2 = 0%). Although there was no difference in the cannulation success rate between the 2 cohorts (OR = 4.16, [95% CI: 0.69-25.25], P = 0.89, I2 = 83%), NKF was associated with a lower rate of overall adverse events (OR = 0.39, [95% CI: 0.20-0.75], P = 0.01, I2 = 0%). Furthermore, there was no difference in the total procedural time (MD = 5.43, [95% CI: - 986 to 997], P = 0.95, I2 = 96%) between both cohorts. No significant differences were observed in bleeding, perforation, cholangitis, or mortality. Conclusion: Primary needle-knife fistulotomy significantly reduces the risk of post-ERCP pancreatitis and overall adverse events without compromising cannulation success. These findings support the selective use of pNKF as a first-line approach in patients at elevated risk for PEP.