The Usefulness of the Alpha-Retroflex Position in Biliary Cannulation on Single-Balloon Enteroscopy-Assisted Endoscopic Retrograde Cholangiopancreatography in Patients with Roux-en-Y Gastrectomy: A Retrospective Study

Introduction. Balloon enteroscopy-assisted endoscopic retrograde cholangiopancreatography (BE-ERCP) is a useful therapeutic procedure that provides promising results in patients with surgically altered anatomy. However, biliary cannulation in BE-ERCP remains challenging. Therefore, in patients with Roux-en-Y gastrectomy, this study aimed to evaluate a BE-ERCP cannulation strategy that includes the newly developed alpha-retroflex scope position. Methods. This was a retrospective review of 52 patients with Roux-en-Y gastrectomy who underwent BE-ERCP at two centers between April 2017 and December 2022. In these patients, three types of scope position had been used for biliary cannulation: straight (S-position), J-retroflex (J-position), and alpha-retroflex (A-position). First, the S-position was used for biliary cannulation. Then, if biliary cannulation was difficult with this position, the J-position was used, followed by the A-position, if necessary. Results. The biliary cannulation success rate was 96.6% (50/52). The S-, J-, and A-positions achieved successful biliary cannulation in 24 (48%), 14 (28%), and 12 patients (24%), respectively. No adverse events, including post-ERCP pancreatitis and perforation, occurred. Conclusion. This was the first study of a cannulation strategy that included the A-position in addition to the S- and J-positions. The study showed that the A-position is feasible and safe in BE-ERCP in patients with Roux-en-Y gastrectomy.