Endoscopic approach to the bile duct in the patient with surgically altered anatomy

Endoscopic retrograde cholangiopancreatography (ERCP) in surgically altered anatomy can be technically challenging, because of three main problems that must be overcome: (1) endoscopically traversing the altered luminal anatomy, (2) cannulating the biliary orifice from an altered position, and (3) performing biliary interventions with available ERCP instruments. This article addresses the most common and most challenging variations in anatomy encountered by a gastroenterologist performing ERCP. It also highlights the innovations and progress that have been made in coping with these anatomic variations, with special attention paid to altered anatomy from bariatric surgery.