Ultrathin endoscope-assisted pancreatobiliary interventions: from direct transpapillary access to created access...

ERCP is the standard endoscopic approach for pancreatobiliary diseases, but it relies mainly on fluoroscopic assessment and cannot provide direct intraductal visualization. Ultrathin upper gastrointestinal endoscopes, originally developed for transnasal or pediatric endoscopy, have therefore been used as forward-viewing platforms for direct observation and therapy in the bile duct, pancreatic duct, gallbladder, and peripancreatic cavities. This review summarizes ultrathin endoscope-assisted interventions through both natural and created access routes, excluding dedicated mother-baby and digital single-operator cholangiopancreatoscopy systems as the main focus.

Direct transpapillary peroral cholangioscopy is the most established application. It has been used for detection of residual stones, lithotripsy for difficult bile duct stones, evaluation of biliary strictures and intraductal tumors, targeted biopsy, and selective biliary drainage. Various access-assisting techniques and multibending ultrathin endoscopes have improved technical success. However, direct transpapillary insertion remains technically demanding because it requires scope exchange, reinsertion, ductal cannulation with a relatively large endoscope, and maintenance of intraductal stability. EUS-created access routes can provide stable conduits for direct endoscopic intervention.

With the rapid development of dedicated cholangiopancreatoscopy, direct transpapillary use of ultrathin endoscopes is likely to become more selective and complementary. Created access routes may expand the value of ultrathin endoscopes, but evidence for these approaches remains limited, and their clinical role requires further evaluation.