Endoscopic therapies for walled-off necrosis

Background and Aims: Management of walled-off necrosis (WON) has focused on a step-up approach using minimally invasive drainage and debridement techniques. This document reviews the technical aspects of endoscopic management of WON, technical and clinical success, adverse event rates for endoscopic drainage, and dedicated endoscopic devices for direct endoscopic necrosectomy (DEN). Methods: The MEDLINE database was searched through April 2022 for relevant articles using the key words walled-off necrosis, endoscopic necrosectomy, interventional EUS, severe acute pancreatitis, necrotizing pancreatitis, and lumen-apposing metal stent. The manuscript was drafted by 2 authors and edited by members of the American Society for Gastrointestinal Endoscopy Technology Committee and subsequently by the American Society for Gastrointestinal Endoscopy Governing Board. Results: Multiple studies have demonstrated acceptable outcomes of primary cystenterostomy for drainage, performed with either plastic double-pigtail stents or fully covered self-expandable metal stents including lumen-apposing metal stents. Subsequent procedures for clearance of necrotic debris can be facilitated with hydrogen peroxide lavage, nasocystic flushing catheters, multiple transluminal gateway technique, dual-modality therapy, and novel DEN devices. Novel DEN devices include EndoRotor Powered Endoscopic Debridement (Interscope, Inc, Northbridge, Mass, USA), waterjet necrosectomy device, and the over-the-scope grasper (Ovesco AG, Tübingen, Germany). These devices were designed to reduce procedural time and the number of necrosectomy sessions for clearance of necrotic debris when compared with traditionally used devices such as polypectomy snares, biliary baskets, and retrieval nets. Conclusions: EUS-guided endoscopic drainage and debridement has become a well-established method for treatment of WON in a step-up paradigm. The use of adjunctive technologies requires further evaluation to define the optimal methods for WON treatment. Further improvements in dedicated DEN devices should lead to improved outcomes and more widespread utilization of endoscopic treatment options.