EUS-GUIDED DRAINAGE OF NON-ADHERENT PANCREATIC FLUID COLLECTIONS USING THE NOVEL 15MM LENGTH LUMEN-APPOSING METAL STENT

Background: EUS-guided placement of lumen apposing metal stents (LAMS) for drainage of pancreatic fluid collections (PFCs) including pancreatic pseudocysts (PP) and walled off necrosis (WON) has rapidly gained popularity. Despite this, the design of existing stents has largely limited use to collections located within 10mm from the luminal wall. The novel 15mm length LAMS (AXIOS, Boston Scientific, Marlborough, USA) allows treatment of previously excluded, more distant/nonadherent PFCs. Aim: To evaluate the feasibility, early clinical outcomes and safety of the 15mm length LAMS in EUS-guided drainage of PFCs located 10mm from the luminal wall. Methods: We conducted an international multicenter retrospective analysis. Consecutive adult patients who underwent EUS-guided PFC drainage with 15mm length LAMS for collections located 10mm from luminal wall between October 2019 and November 2020 were included. The primary outcome was clinical success, defined as a decrease in PFC size by 50% or to 2cm in diameter at 30 days, and resolution of clinical symptoms without need for surgical intervention. Secondary outcomes included technical success, adverse events (AEs, defined per ASGE lexicon) and rates of recurrence. Continuous variables are presented as median (IQR). Results: A total of 29 patients (48.3% male, median age 56 (47-63) years) had a 15mm length LAMS placed for management of PFCs (22 WON, 7 PP) with median size of 75 (50-107) mm and located 12 (10.1-12.5) mm from the luminal wall (Table 1). The most common indication for drainage was sepsis (nZ14, 48.3%). There was extension to the paracolic gutter in 6 (20.7%) cases. A second LAMS was placed in 3 (10.3%) cases and a coaxial stent was placed in 10 (34.5%). Direct endoscopic necrosectomy (DEN) was performed in 14 (48.3%) for a median of 2 (1- 2.75) sessions and concurrent external drainage was required in 2 (8.7%). Clinical success and technical success were achieved in 100% of cases (Table 2). 27 patients had successful LAMS removal after a median of 28 (20-40) days and 10 (37.0%) had at least one double pigtail stent replaced in the fistula tract. Two patients were awaiting LAMS removal at time of abstract submission. One patient (3.4%) with WON experienced recurrence at 5 weeks following LAMS removal. Median follow-up after LAMS removal was 127 (57-232) days. A total of 3 (10.3%) AEs occurred (1 mild, 2 moderate). Conclusion: This international multicenter study demonstrates high rates of technical and clinical success, and low adverse event rates with the use of the 15mm length LAMS in the management of PFCs located 10mm from the luminal wall. This has important clinical implications in the management of more distant/non-adherent collections in which endoscopic management was previously limited. Future prospective studies are needed to validate this find