Endoscopic papillary balloon dilation reduces sphincter function at least transiently or partially, which may allow pancreatobiliary and duodenobiliary reflux to occur. This study prospectively evaluated pancreatobiliary and duodenobiliary reflux after endoscopic papillary balloon dilation.

In 12 patients with choledocholithiasis, ductal bile was sampled for amylase concentration and bacterial culture during ERCP, before and at 7 days to 5 years after endoscopic papillary balloon dilation. To provide comparative and control data, ductal bile was sampled in 12 patients with gallbladder cholesterol polyps and 6 with anomalous pancreaticobiliary junction who did not undergo endoscopic papillary balloon dilation.

Amylase concentrations in ductal bile from patients with choledocholithiasis before endoscopic papillary balloon dilation were marginally significantly higher (before Bonferroni correction) compared with concentrations in bile from patients with gallbladder polyps. The concentration of amylase in bile was significantly increased at 7 days after endoscopic papillary balloon dilation compared with that before endoscopic papillary balloon dilation; the level was comparable with that of patients with an anomalous pancreaticobiliary junction. Subsequently, the amylase concentration gradually decreased and was approximately equal to the pre-endoscopic papillary balloon dilation level at 1 year. Bacteriocholia was frequent (67%–92%) for up to 3 months after endoscopic papillary balloon dilation but was rare thereafter.

Endoscopic papillary balloon dilation causes transient pancreatobiliary and duodenobiliary reflux. However, reflux is no longer present at 1 year after endoscopic papillary balloon dilation.