Self-Expandable Metal Stent (SEMS) Versus Lumen-Apposing Metal Stent (LAMS) for Drainage of Pancreatic Fluid Collections: A Randomized Clinical Trial

Background and aim Endoscopic ultrasound (EUS)-guided drainage is the gold standard approach for the treatment of encapsulated pancreatic collections (EPCs) including pseudocyst and walled-off pancreatic necrosis (WON), and is associated with an equivalent clinical efficacy to surgical drainage with fewer complications and less morbidity. Drainage may be achieved via several types of stents including a fully covered self-expandable metallic stent (SEMS) and lumen-apposing metal stent (LAMS). However, to date there have been no randomized trials to compare these devices. This study aimed to compare the efficacy and safety of the SEMS versus LAMS for EUS-guided drainage of EPCs. Methods A phase IIB randomized trial was designed to compare the SEMS versus LAMS for the treatment of EPCs. Technical success, clinical success, adverse events (AEs), and procedure time were evaluated. A sample size of 42 patients was determined.
Results There was no difference between the two groups in technical (LAMS 80.95% vs 100% SEMS, p=0.107), clinical (LAMS 85.71% vs 95.24% SEMS, p=0.606) or radiological success (LAMS 92.86% vs 83.33% SEMS, p=0.613). There was no difference in AEs including stent migration rate and mortality. The procedure time was longer in the LAMS group (mean time 43.81 min versus 24.43 min, p=0.001). There was also a difference in the number of intra-procedure complications (5 LAMS vs 0 SEMS, p=0.048). Conclusion SEMS and LAMS have similar technical, clinical, and radiological success as well as AEs. However, SEMS has a shorter procedure time and fewer intra-procedure complications compared to non-electrocauteryenhanced LAMS in this phase IIB randomized controlled trial (RCT). The choice of the type of stent used for EUS drainage of EPCs should consider device availability, costs, and personal and local experience.