Safety and Efficacy of Primary Needle-Knife Fistulotomy in Patients at High Risk for Post-ERCP Pancreatitis: A Prospective Multicenter Pilot Study Comparing Endoscopists with Different Levels of ERCP and NKF Experience.

BACKGROUND AND

aimsPrimary needle-knife fistulotomy (NKF) may reduce post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) in high-risk patients, but safety data across operators with differing prior ERCP and NKF experience are scarce. We evaluated the efficacy and safety of primary NKF according to prior operator experience.

methodsThis prospective, multicenter, non-randomized pilot study enrolled 139 patients with a naïve ampulla and at least one PEP risk factor at six Korean tertiary centers. Endoscopists were grouped as Group A (limited experience in both ERCP and NKF), Group B (extensive ERCP but limited NKF experience), or Group C (extensive experience in both). Cannulation rate, cannulation time, adverse events, and learning curves were compared.

resultsThe overall biliary cannulation rate was 98.6%, without intergroup difference. Adverse events occurred in 13.6, 4.2, and 0% in Groups A, B, and C, respectively (P = .012). Cannulation time was shortest and total procedure time longest in Group A. Baseline common bile duct diameter and papillary morphology differed significantly across groups, limiting causal attribution of the adverse-event differences to operator experience. The exploratory learning-curve analysis included only eight events, with no significant difference between Groups A and B (P = .09).

conclusionsPrimary NKF achieved high technical success across experience groups. Adverse events were more frequent in Group A; however, non-randomized allocation, baseline anatomical imbalances, heterogeneous post-cannulation management, and sparse event data preclude attributing this difference to operator experience. These hypothesis-generating findings neither establish a competency threshold nor define when primary NKF can be performed independently.