Long-term lumen-apposing metal stents in endoscopic ultrasound-guided gallbladder drainage: Late adverse events and stent removal

Table 3 Late adverse events of indwelling lumen-apposing metal stents organized by mechanism

Mechanism	Affected domain	Specific events	Typical timing	Evidence and source
Luminal	Channel patency and drainage	Food impaction; sludge- or stone-related occlusion; recurrent cholecystitis	Accumulates with longer dwell time	Drives recurrent cholecystitis and provides the rationale for coaxial pigtail placement and proactive cholecystoscopy[9,55]; recurrent cholecystitis in 3 of 75 patients[35], in 2 of 55 patients[50] and in 2 of 50 patients[44]; no significant difference by removal status[36]; pooled recurrence beyond 1 year 4.2%[45]
Mural	Stent-wall interaction	Tissue overgrowth; buried LAMS syndrome; delayed bleeding from flange erosion	More apparent with longer dwell time	Mechanistically expected and informed by a dedicated adverse-event meta-analysis[46]; no cohort reports incidence as a primary endpoint; a completely buried stent was documented at 61.5 months[43]; a device with a lower apposing force showed a low rate of buried stent syndrome[23]
Mechanical	Loss of apposition	Migration into the gallbladder lumen or distal migration	Early or late	Migration in 2 of 75 patients[35] and in 7 of 50 patients (14%) in a 3-year registry, in which every migration was asymptomatic[44]; frequently asymptomatic when the stent migrates internally

Rates given are single-study figures unless labeled as pooled. Symptomatic late events cluster in the first year, whereas asymptomatic tissue overgrowth and migration continue to accumulate thereafter[43,44]. Every value in this table is a crude proportion derived from a cohort with high competing mortality and limited observation, and therefore describes that cohort rather than a risk transferable to an individual patient. LAMS: Lumen-apposing metal stent.