Balloon Dilatation of the Ampulla of Vater

In order to evaluate possible local tissue injury following balloon dilatation of the ampulla of Vater, the ampullas of 10 rabbits were dilated. The ampullas and the common bile ducts were examined histologically two months afterwards. All the ampullas were found to be normal. In one case aggregations of lymphoid cells were found in the thin wall of the common bile duct. Cholangiography was performed in 8 of the animals two months after dilatation. This was done to evaluate gross signs of local injury, i.e. strictures. All these were normal.