Background: The aim of this study was to evaluate the degree of occult pancreatobiliary reflux by measuring the biliary amylase levels in the common bile duct (CBDA) and gallbladder (GBA) at endoscopic retrograde cholangiopancreatography (ERCP).
Methods: Eligible patients included 86 consecutive cases of pancreaticobiliary disease with prospective implementation of bile collection during an ERCP procedure. Patients with pancreatobiliary maljunction (PBM) were excluded. Nineteen cases of eligible patients had simultaneous collection of gallbladder bile. Bile was further collected by cholecystectomy in 8 cases.
Results: Twenty-two cases (26%) revealed a CBDA level higher than serum amylase (high bile amylase level, HBA group) and 64 cases exhibited a CBDA level lower than serum (LBA group). The mean values of CBDA in the HBA and LBA groups were 5502 IU/l and 29 IU/l, respectively. The rate of HBA was significantly higher in patients who were elderly, had a dilated common bile duct, and those with choledocholithiasis (P <0.05). Three cases (16%) showed a CBDA greater than twice the GBA. Eleven cases (58%) exhibited a GBA higher than the CBDA. The values of GBA obtained during ERCP and cholecystectomy were consistent.
Conclusions: These findings suggest that even non-PBM cases can exhibit occult pancreatobiliary reflux, which can thereby cause biliary disease.