Biliary self-expandable metal stent (SEMS) embedment, defined as incorporation of the stent mesh into the biliary wall or overgrowing tissue that precludes standard removal, is an uncommon but clinically relevant adverse event of biliary stenting. Difficult or “embedded” stent removal is estimated to occur in roughly 1–5% of biliary SEMS and can lead to cholangitis, bleeding, and the need for complex reinterventions. According to available literature, clinical success of embedded biliary SEMS removal is strongly influenced by stent indwell time, local endoscopic expertise, and stent design, with markedly lower removal rates reported for uncovered and partially covered SEMS compared with fully covered devices. We aimed to describe the endoscopic techniques and outcomes of embedded biliary metal stent retrieval in a tertiary referral center, and to identify baseline and technical factors associated with successful endoscopic removal.

We performed a retrospective analysis of prospectively collected data on consecutive patients referred between May 2017 and April 2025 for endoscopic treatment of embedded biliary metal stents in a tertiary referral center. Embedded stents were defined as not removable with standard forceps/snare traction and requiring advanced techniques. The primary outcome was complete endoscopic removal of all embedded stents. Secondary outcomes were baseline and technical factors associated with procedural success or failure, assessed applying univariate and multivariate logistic regression models.

Fifty-nine patients (61 embedded stents; 77.9% male; median age 68 years) were included. The underlying indication for index biliary metal stent placement was predominantly benign (over 80%), mainly post-surgical benign biliary strictures and biliary fistulas, whereas malignant strictures accounted for less than one fifth of cases. Despite this benign case mix, almost half of embedded devices were non–fully covered: most stents were fully covered SEMS (49.1%), but 30.1% were uncovered and 15.1% partially covered SEMS, and three lumen-apposing metal stents were also included, highlighting that uncovered or partially covered SEMS are still used in benign settings where long-term removability is desirable. Advanced techniques at first attempt included multiple coaxial stent-in-stent (31.1%), loop-and-sheath (previously described only in a single case report - 29.5%, 61% with mechanical lithotripter), single stent-in-stent (13.1%), balloon dilation and argon plasma coagulation. First-attempt success was 50.9%; a second and third endoscopic procedure were required in 42.6% and 13.1% of cases, respectively, yielding an overall clinical success of 85.4% with a median of 2 procedures per case. Periprocedural and post-procedural adverse events occurred in 29.5% of procedures, mostly cholangitis and bleeding; most were mild–moderate and managed conservatively, with only one death directly related to unresolved embedment. Longer stent indwell time and the occurrence of peri- or post-procedural adverse events were independently associated with clinical failure (both OR ≈2, p<0.05). 

Endoscopic management of embedded biliary metal stents in a tertiary referral setting achieved high overall clinical success, irrespective of stent type, including uncovered and partially covered devices. Stent indwell time and the occurrence of peri- or post-procedural adverse events were the main independent predictors of clinical failure, underscoring the importance of timely stent retrieval, early referral to expert centers, and careful prevention and management of adverse events. Beyond its initial description in a single case report, the repeated successful use of the loop-and-sheath technique in this series suggests that it represents a valuable addition to the armamentarium for complex embedded biliary SEMS, within a flexible, patient-tailored multimodal strategy rather than a rigid stepwise approach.