Occult pancreatobiliary reflux in patients with a normal pancreaticobiliary junction.

Background: The aim of this study was to investigate pancreatobiliary reflux in individuals with a normal pancreaticobiliary junction.

Methods: Seventy-four patients with a normal pancreaticobiliary junction, as determined by ERCP, underwent secretin injection MRCP before cholecystectomy. Based on changes in the diameter of the biliary system after secretin injection, patients were categorized into enhanced or nonenhanced groups.

Results: Biliary amylase was measured in the 4 patients allocated to the enhanced group and 60 in the nonenhanced group. The mean (SD) biliary amylase level in the gallbladder was 123,723 (115,125) IU/L in the enhanced group and 238 (507) IU/L in the nonenhanced group (p < 0.0001). The mean (SD) biliary amylase level in gallbladders with carcinoma (n = 7) was 68,281 (106,500) IU/L, which was significantly higher than that in gallbladders without carcinoma (p < 0.01).

Conclusion: Pancreatobiliary reflux similar to that seen in patients with pancreaticobiliary maljunction can occur in individuals with a normal pancreaticobiliary junction and may be associated with carcinoma of the gallbladder. Secretin injection MRCP is useful for identifying these individuals.