A Wolf in LAMS Clothing: The Expansion of Off-Label Indications for Lumen-Apposing Metal Stents

Excerpt

Lumen-apposing metal stents (LAMS) were initially designed to create a temporary communication between the lumen of the digestive tract and adjacent encapsulated pancreatic fluid collections (PFC). These stents, placed under guidance of endoscopic ultrasound (EUS), have improved the speed and efficacy of EUS-guided drainage of pancreatic fluid collections. Though there is ongoing debate regarding the superiority of LAMS over plastic stents, they appear to offer faster and probably superior clinical resolution of PFC, especially with solid necrotic debris, than do plastic stents [1]. Owing to their large internal diameter, LAMS facilitate a free and repeated passage of endoscope into the walled-off necrosis (WON) cavity during direct endoscopic necrosectomy (DEN), especially those with > 40% solid debris, a procedure formerly time consuming and cumbersome when attempted using plastic stents. Despite these advantages, stent maldeployment and bleeding due to prolonged presence in situ are important concerns with LAMS, in particular since their short saddle length demands accurate deployment. Fabricated from the metallic alloy nitinol, their edges may erode the blood vessels in the cavity of WON during the resolution phase leading to hemorrhage due to the formation of pseudoaneurysms [2], mandating a prompt endoscopic reintervention to retrieve the LAMS within 4 weeks [3]. …