Efficacy of the Stent-in-Stent Technique as a Rescue Method for Removing Embedded Metallic Biliary Stents.

Abstract

<h4>Objectives</h4>Self-expandable metal stents (SEMS) may become embedded because of tissue hyperplasia or tumor ingrowth, making their removal challenging. The stent-in-stent (SIS) method, which involves placing another SEMS inside to compress the tissue and aid removal, is a known rescue approach for stent removal. However, its efficacy across anatomical routes, optimal timing of removal, and predictors of difficult stent removal remain unclear.<h4>Methods</h4>We retrospectively reviewed 17 patients treated between April 2018 and May 2025. Embedded stents were placed via the transpapillary route, endoscopic ultrasonography-guided hepaticogastrostomy (EUS-HGS), or choledochojejunal anastomosis. Technical success rates and adverse events were evaluated.<h4>Results</h4>The overall technical success rate was 76.5%, with rates of 80.0%, 100%, and 33.3% for the transpapillary route, EUS-HGS, and choledochojejunal anastomosis, respectively. Three of the four failures occurred when removal was attempted within 4 weeks of the second stent placement. Stent removal was successful in 100% of the hyperplasia cases but in 60% of the ingrowth cases. Cholecystitis occurred in one case after the second stent placement.<h4>Conclusions</h4>The SIS method is feasible for the transpapillary route and EUS-HGS but may show limited efficacy in choledochojejunal anastomosis. Stent removal 4 weeks after the second stent placement improves the success rate. The SIS method may be less effective in cases of malignant ingrowth.