Usefulness of a novel drill dilator in removing a migrated biliary plastic internal stent

A 45-year-old woman referred to hospital for preoperative evaluation of perihilar cholangiocarcinoma ([Fig. 1]) had multiple biliary plastic internal stents placed previously ([Fig. 2] a). Endoscopic retrograde cholangiography (ERC) was performed to evaluate tumor extent and replace the plastic internal stents. ERC revealed that a nylon-threaded plastic stent (Through & Pass, 7 Fr, 9 cm; Gadelius Medical, Tokyo, Japan) placed in the left hepatic duct (B2) had migrated into the peripheral bile duct ([Fig. 2] b). The nylon threads had entered the common bile duct and the migrated plastic stent could not be removed by pulling them.