Function of the Minor Duodenal Papilla in Pancreas Divisum as Determined by Duodenoscopy Using Indigo Carmine Dye and a pH Sensor

Objectives: The objective of this study was to evaluate the function of the minor duodenal papilla and to investigate the relationship between the history of acute pancreatitis and individual dorsal pancreatogram findings and the minor papilla function in pancreas divisum. Methods: Eight of the 21 patients with PD diagnosed by endoscopic retrograde cholangiopancreatography had a history of acute pancreatitis (group A), and 13 patients did not (group B). The reaction of pancreatic juice excreted via the minor papilla was evaluated after intravenous administration of secretin, by observing the repulsion of indigo carmine dye scattered on the surface of the minor papilla. Results: The function of the minor papilla was classified into two types. In 12 patients, all of the pigment on the minor papilla was repelled within 5 min of secretin administration (type I), and in the remaining nine patients it was not (type II). After secretin administration, the pH of the minor papilla surface in type I was significantly higher than that in type II. There was no significant difference between the type I and type II patients in exocrine pancreatic function, as evaluated by a BT‐PABA test. In the group A patients, the rate of occurrence of dorsal duct dilation (including changes of the terminal shape) was significantly greater than in the group B patients. The function of the minor papilla in the group A patients was significantly worse than in the group B patients. Outflow obstruction of pancreatic juice, i.e., “relative stenosis of the minor papilla,” was considered to be present in the patients with type II papilla, and, therefore, the patients with type II papilla might suffer from acute pancreatitis resulting from poor drainage of pancreatic juice and excessive pressure in the dorsal duct. Conclusion: The finding that patients with PD have one of two types of minor papilla will be useful for understanding the condition and selecting the therapeutic plan for individual patients.