# Stepwise Algorithm for Biliary Cannulation in Endoscopic Retrograde Cholangiopancreatography in the Era of Endoscopic Ultrasound‐Guided Biliary Drainage: A Single‐Center Retrospective Cohort Study

## TL;DR

A stepwise algorithm for biliary cannulation during ERCP achieves high success rates but increases the risk of adverse events.

## Contribution

The study evaluates a structured stepwise algorithm for biliary cannulation and identifies risk factors for adverse events.

## Key findings

- The stepwise algorithm achieved a final cannulation success rate of 97.8%.
- Advanced cannulation techniques increased the risk of adverse events compared to wire-loaded cannulation.
- Endoscopic ultrasound-guided rendezvous had the highest success rate among salvage techniques.

## Abstract

Endoscopic retrograde cholangiopancreatography (ERCP) is an essential procedure for the management of biliary diseases. Successful biliary cannulation is the first step. Advanced cannulation techniques, such as the double‐guidewire technique (DGW), precut techniques, and endoscopic ultrasound (EUS)‐guided rendezvous (RV), have been developed to improve cannulation success. However, comprehensive evaluations of a structured cannulation algorithm remain limited.

To evaluate the status of biliary cannulation and associated adverse events (AEs) using a stepwise cannulation algorithm.

A retrospective evaluation of 1,000 consecutive patients with a naïve papilla who underwent ERCP for biliary disease was performed between 2012 and 2022. Biliary cannulation was attempted using a stepwise algorithm, beginning with wire‐loaded cannulation (WLC), followed by DGW, precut techniques, and EUS‐RV. The primary endpoint was overall technical success; secondary endpoints included AEs, incidence of post‐ERCP pancreatitis (PEP), and risk factor analysis.

Initial WLC achieved selective biliary cannulation in 69.2% of cases. Salvage techniques achieved high success rates: DGW (74.9%), precut techniques (77.6%), and EUS‐RV (97.0%). Overall, the final cannulation success rate was 97.8%. The overall AE rate was 7.5%, with PEP being the most common (6.1%). AEs were significantly more frequent in advanced cannulation techniques than WLC (13.3% vs. 5.2%, p < 0.001). Multivariate analysis identified advanced cannulation techniques, pancreatography, and metallic stent placement as independent factors increasing the risk of PEP.

A structured stepwise approach achieves very high biliary cannulation success in patients with a naïve papilla, though advanced cannulation techniques increase AE risk. Appropriate timing and positioning of EUS‐RV may further optimize safety and efficacy in biliary cannulation.