Pancreatic stent improves the success rate of needle-knife papillotomy in patients with difficult biliary cannulation.

Background: Needle-knife precut papillotomy (NKP) is typically performed freehand. However, it remains unclear whether pancreatic stent (PS) placement can improve the outcomes of NKP.

Aim: To explore whether PS placement improves the success rate of NKP in patients with difficult biliary cannulation.

Methods: This single-center retrospective study included 190 patients who underwent NKP between January 2017 and December 2021 after failed conventional biliary cannulation. In cases with incidental pancreatic duct cannulation during conventional biliary cannulation, the decision for pre-NKP PS placement was made at the endoscopist's discretion. The primary outcome was the difference in the NKP success rate between patients with and without PS placement; the secondary outcome was the adverse event rate.

Results: Among the 190 participants, 82 received pre-NKP PS (PS-NKP group) whereas 108 did not [freehand or freehand NKP (FH-NKP) group]. Post-NKP selective biliary cannulation was successful in 167 (87.9%) patients, and the PS-NKP had a significantly higher success rate than the FH-NKP group (93.9% vs 83.3%, P = 0.027). The overall adverse event rates were 7.3% and 11.1% in the PS-NKP and FH-NKP groups, respectively (P = 0.493). A periampullary diverticulum (PAD) and significant intraoperative bleeding during NKP were independently associated with NKP failure; however, a pre-NKP PS was the only predictor of NKP success. Among the 44 participants with PADs, the PS-NKP group had a non-significantly higher NKP success rate than the FH-NKP group (87.5% and 65%, respectively; P = 0.076).

Conclusion: PS significantly improved the success rate of NKP in patients with difficult biliary cannulation.