A model of biliary pancreatic reflux.

A primate model for the study of biliary pancreatic reflux under relatively physiological conditions is described. Cannulas were inserted into the gallbladder and the common bile duct of rhesus monkeys, and a pedicled segment of small bowel was used to create a pancreaticocutaneous fistula after resection of the spleen and pancreatic tail. Following recovery, Hypaque was instilled into the gallbladder with maintenance of common duct pressure within a normal range. The pancreatic duct was visualized in 21 of 34 radiographic studies (19 monkeys). Small amounts of iodine were detected in the fistula effluent of nine of 11 animals that refluxed radiologically. Radioactive polyethylene glycol (PEG-C14) was instilled into the gallbladder and pancreatic fistula drainage sampled by aspiration (26 studies, four monkeys). When compared to controls without PEG instillation (six studies, four monkeys), there was a significant rise in fistula counts beginning 50 minutes after injection and peaking at 180 minutes. In a second series of studies, pancreatic fistula aspiration was replaced by a flush technique using a triple-lumen cannula which allowed constant monitoring and control of fistula pressure. A statistically significant rise and fall of radioactivity after PEG introduction again was demonstrated. These data demonstrate taht biliary pancreatic reflux can occur and be quantitated under these experimental conditions.