Insulation-tipped nano knife-assisted primary precut versus conventional cannulation for biliary access: a multicenter randomized trial on efficacy and safety.

BACKGROUND

Endoscopic retrograde cholangiopancreatography (ERCP) remains the gold standard for Common bile duct (CBD) stone management, yet biliary cannulation challenges persist in some cases. There are limited data on primary Insulation-tipped (IT) knife precut for the biliary cannulation. Our aim was to investigate the efficacy and safety of IT nano knife-assisted primary precut in comparison to conventional cannulation for biliary access for the first time.

METHODS

This multicenter randomized controlled trial compared the efficacy and safety of primary IT knife nano-assisted precut sphincterotomy (group A) versus conventional cannulation (group B) in 340 patients with choledocholithiasis. Outcomes included initial/overall biliary cannulation success, procedural time, and adverse events (AEs).

RESULTS

Group A demonstrated superior initial cannulation success compared to group B (85.9% vs. 74.1%, P = 0.007), particularly in type 2 ampullary morphology (96.0% vs. 46.8%, P < 0.001). Overall success rates and cannulation time were equivalent statistically after rescue techniques. Post-precut mucosal exposure subtypes further predicted initial cannulation success [type A vs. C (100% vs. 71.0%, P < 0.001); type B vs. C (92.7% vs. 71.0%, P = 0.002)]. There were no significant differences between group A and B in the postprocedure AEs.

CONCLUSIONS

The IT knife nano improves initial biliary cannulation success, especially in challenging type 2 ampullae, without increasing AEs. Its design enhances procedural precision, supporting primary precut as a first-line strategy. With the accumulation of data, primary IT knife nano precut may reduce reliance on repeated cannulation attempts.