Incidence and significance of ultrastructural changes in the common bile duct in lithiasis with dilatation of the duct.

Scanning electron microscopy was used to define the difference in incidence of morphologic changes between dilated and non-dilated common bile ducts in patients with choledocholithiasis. In the dilated ducts there were large, crater-like fenestrations in the epithelial surface, associated with focal epithelial sloughing. The incidence of such changes was significantly greater than in the non-dilated ducts. The mechanism of the changes is postulated to comprise biliary stasis and subepithelial infiltration of bile through epithelial fenestrations.