Table 1.

Factors Underlying Difficult Bile Duct Stones

Category	Conditions	Reasons for difficulty
Patient characteristics	Unstable condition	Risk for adverse events
Coagulopathy	Risk for bleeding
Anatomy	Surgically altered anatomy	Scope insertion, biliary cannulation
	Periampullary diverticulum	Biliary cannulation
Biliary stricture	Stone extraction
Stone characteristics	Large stone	Need for lithotripsy
Impacted stone	Need for cholangioscopy
Endoscopist	Less experienced	Less skills and knowledge