Novel Uses of Lumen-apposing Metal Stents: A Review of the Literature.

The field of therapeutic endoscopy has seen many recent advancements. One such emerging field is the use of lumen-apposing metal stents (LAMS). Although a few LAMS have been developed, the most commonly reviewed and the only Food and Drug Administration (FDA)-approved LAMS is the Axios stent by Boston Scientific. In 2013, LAMS were initially approved by the FDA for the management of pancreatic fluid collection drainage in the presence walled-off necrosis. Pancreatic fluid collections are traditionally drained with either a plastic stent or a covered biliary self-expanding metal stent. Plastic stents have a double pigtail feature which prevents stent migration. However, their narrow lumen poses limitations as it can lead to early stent occlusion. Fully covered metal stents have larger diameters, allowing improved drainage and decreased stent occlusion but their tubular shape is prone to migration. Consequently, this results in leakage, and frequent retrievals. Over the years, due to their versatility, LAMS now have many off label uses. This includes management of gastric outlet obstruction, superior mesenteric artery syndrome, strictures, gallbladder drainage, and postsurgical collection drainage. In this review, we will be discussing the FDA approved and the nonapproved uses of LAMS.