LAUSR

Long-term biliary stenting can result in complications such as stent migration, fistulas, and stent–stone complexes [1]. We report a case of an uncoveredmetallic stent exhibiting stent–stone complexes that was successfully removed using peroral direct cholangioscopy (PDCS) and the stent-in-stent technique [2]. An 89-year-old woman was admitted with fever and abdominal pain. Computed tomography revealed a metallic stent placed above the papilla and many stones at the hilar level of the bile duct (▶Fig. 1). Ten years ago, a fully covered self-expandablemetallic stent (FCSEMS) was implanted for a choledochoduodenal fistula due to bile duct stones; however, followup was interrupted after treatment. We were unable to remove the FCSEMS with rat-tooth forceps because the mesh of the stent was exposed and the inside of the stent was filled with stones. Unable to pass a guidewire through the stent (▶Fig. 2), we performed PDCS (SpyScope DS II; Boston Scientific) with electronic hydraulic lithotripsy to crush the stones within the stent (▶Fig. 3) and create space for devices to pass through the inside [3]. We cleaned the inside of the stent with a balloon catheter (Extractor; Boston Scientific), and then placed an additional FCSEMS (Bonastent; Medico’s Hirata) within the old stent (▶Fig. 4). One month later, we used a snare under fluoroscopic guidance and successfully removed both stents (▶Video 1; ▶Fig. 5) [4, 5]. It has been reported that partially covered and uncovered SEMS can be removed using the stent-in-stent technique with a success rate of approximately 80% [4]. When placing FCSEMS for benign biliary strictures, prolonged stent implantation should be avoided, and we advise preparation for potential complications.