GI Stents

Endoscopically deployed stents palliate or definitively manage luminal obstruction across the GI and biliary tract. The two dominant device classes are self-expanding metal stents (SEMS) for tubular structures (esophagus, gastroduodenum, colon, biliary tree) and lumen-apposing metal stents (LAMS) for fistulous or transmural drainage between adjacent fluid collections and the GI lumen.

SEMS come in fully covered, partially covered, and uncovered variants. Covered stents resist tumor ingrowth and migrate more readily; uncovered stents anchor by tissue ingrowth but cannot be safely removed. Material (nitinol vs stainless steel), radial force, and flare design vary by indication. Esophageal SEMS palliate malignant dysphagia and seal benign perforations or anastomotic leaks; gastroduodenal SEMS bypass gastric outlet obstruction; colonic SEMS bridge to surgery in left-sided obstructive cancer or palliate inoperable malignancy.

LAMS (e.g., AXIOS) are short, dumbbell-shaped stents with wide flanges that hold two adjacent organ walls in apposition. Their EUS-guided deployment has revolutionized management of pancreatic walled-off necrosis (drainage cavity to gastric lumen), gallbladder drainage in non-surgical candidates, gastrojejunostomy creation, and anastomotic stricture treatment. Bleeding from the cavity wall is the most feared complication; lavage and direct endoscopic necrosectomy through the LAMS lumen are routine adjuncts.