Removal of an embedded "covered" biliary stent by the "stent-in-stent" technique

A 46-year-old man was admitted with obstructive jaundice and cross-sectional imaging with computed tomography suggested distal biliary obstruction. A distal common bile duct stricture was found at endoscopic retrograde cholangiopancreatography (ERCP) and cytology was benign. A 6 cm fully covered self-expanding metal stent (SEMS) was inserted across the stricture to optimize biliary drainage. However, the SEMS could not be removed at repeat ERCP a few months later. A further fully covered SEMS was inserted within the existing stent to enable extraction and both stents were retrieved successfully a few weeks later. Fully covered biliary (SEMS) are used to treat benign biliary strictures. This is the first reported case of inability to remove a fully-covered biliary SEMS. Possible reasons for this include tissue hyperplasia and consequent overgrowth into the stent proximally, or chemical or mechanical damage to the polymer covering of the stent. Application of the stent-in-stent technique allowed successful retrieval of the initial stent.