Pancreatic stent migration into the main pancreatic duct during endoscopic papillary balloon dilation.

We report the first case of pancreatic stent (PS) migration placed early into the main pancreatic duct (MPD) during endoscopic retrograde cholangiopancreatography (ERCP) due to subsequent endoscopic papillary balloon dilation. A 74-year-old woman who complained of fever and abdominal pain was diagnosed with acute calculous cholangitis. On ERCP, a needle-knife precut papillotomy was performed from the orifice because of difficult cannulation. Because of unintentional guidewire insertion into the MPD from the orifice, a PS with bilateral flaps was promptly placed to prevent post-ERCP pancreatitis. After successful biliary cannulation from the orifice alongside the PS, endoscopic papillary balloon dialtion was performed, leading to PS migration into the MPD during the dilation. Two days after the first ERCP, the migrated PS was successfully removed on the second ERCP. The strategy of early PS placement in the ERCP session appears theoretically promising for preventing post-ERCP pancreatitis. However, early PS placement during the ERCP session should be noted to pose the risk of migration into the MPD, especially when pushing the device into the bile duct.