A Challenging Case of Endoscopic Retrograde Cholangiopancreatography Due to an Intradiverticular Papilla.

Periampullary diverticulum (PAD) is often encountered and associated with increased technical complexity and risk of procedural failure, particularly when the papilla is located within the diverticular lumen. We report a case of a 52-year-old male patient with biliary leakage secondary to metastatic colorectal carcinoma, in whom standard ERCP attempts failed due to the papilla's position within PAD. Given the challenging anatomy, endoscopic ultrasonography (EUS) was employed to evaluate biliary anatomy and facilitate guided access. Utilizing a cautery-enhanced lumen-apposing metal stent (LAMS), a successful EUS-guided choledochoduodenostomy was performed under fluoroscopic guidance, resulting in adequate biliary drainage without complications. A follow-up at two weeks demonstrated clinical improvement (normalizing bilirubin levels) and resolution of the biliary leakage. This case illustrates the potential utility of EUS-guided lumen-apposing stent placement, specifically the Hot-Axios, as a minimally invasive alternative in difficult biliary interventions involving PAD, with implications for reducing procedural time and improving success rates in anatomically complex scenarios.