Endoscopic removal of lumen-apposing metal stents - risk factors for stent embedment, complex removals, and adverse events: analysis from a multicenter prospective case series.

BACKGROUND: Removing lumen-apposing metal stents (LAMSs) may be difficult and even harmful, but these features have seldom been analyzed. We aimed to generate a comprehensive assessment of the feasibility and safety of LAMS retrieval procedures.

METHODS: A prospective multicenter case series including all technically successfully deployed LAMSs between January 2019 and January 2020 that underwent endoscopic stent removal. All retrieval-related data were prospectively recorded using standardized telephone questionnaires as part of centralized follow-up that ended after stent removal had been performed. Multivariable logistic regression models assessed the potential risk factors for complex removal.

RESULTS: For the 407 LAMSs included, removal was attempted in 158 (38.8 %) after an indwell time of 46.5 days (interquartile range [IQR] 31-70). The median (IQR) removal time was 2 (1-4) minutes. Removal was labelled as complex in 13 procedures (8.2 %), although advanced endoscopic maneuvers were required in only two (1.3 %). Complex removal risk factors were stent embedment (relative risk [RR] 5.84, 95 %CI 2.14-15.89; P  = 0.001), over-the-wire deployment (RR 4.66, 95 %CI 1.60-13.56; P  = 0.01), and longer indwell times (RR 1.14, 95 %CI 1.03-1.27; P  = 0.01). Partial and complete embedment were observed in 14 (8.9 %) and five cases (3.2 %), respectively. The embedment rate during the first 6 weeks was 3.1 % (2/65), reaching 15.9 % (10/63) during the following 6 weeks ( P  = 0.02). The adverse event rate was 5.1 %, including seven gastrointestinal bleeds (5 mild, 2 moderate).

CONCLUSIONS: LAMS removal is a safe procedure, mostly requiring basic endoscopic techniques attainable in conventional endoscopy rooms. Referral to advanced endoscopy units should be considered for stents with known embedment or long indwell times, which may require more technically demanding procedures.