RESUMO
BACKGROUND: Pancreatic juice reflux to the common bile duct and gallbladder is observed in the pancreaticobiliary maljunction (PBM), and various pathological conditions occur in the biliary tract. However, the mechanism of pancreatic juice reflux has not been discussed yet. This study aimed to investigate the mechanism of this phenomenon from the perspective of the fluid dynamics theory. METHODS: A fluid dynamics model of PBM without biliary dilatation having gallbladder function and of the pressure of sphincter of Oddi was developed. Water (as bile juice and pancreatic juice) was flowed to these models with a flow rate similar to that in humans. Pancreatic and bile juice flow and bile duct pressure were observed in three phases of gallbladder function. Moreover, the same experiment was performed in the PBM without biliary dilatation model without gallbladder. RESULTS: Pancreatic juice reflux could be observed when the gallbladder was passively expanded with the pressure in the bile duct lower than that in the sphincter of Oddi. However, pancreatic juice reflux was not observed in the model without gallbladder. CONCLUSIONS: Gallbladder function may be strongly involved in pancreatic juice reflux in PBM without biliary dilatation. Cholecystectomy may be able to stop the reflux of pancreatic juice.
