Walled-off pancreatic necrosis (WON) can develop in the late phase of necrotizing pancreatitis. When the WON is accompanied by an infection in the necrotic bed, it becomes a life-threatening complication. Open necrosectomy with drainage has been the standard treatment; however, it is associated with a significant morbidity and high mortality. Therefore, minimally invasive therapeutic alternatives are in demand. Recently, a new treatment algorithm for necrotizing pancreatitis, known as the step-up approach, has been proposed. The initial report on it consisted of percutaneous drainage followed by, if necessary, a minimally invasive retroperitoneal necrosectomy. However, the endoscopic step-up approach, which consists of EUS-guided transluminal drainage followed by, if necessary, endoscopic necrosectomy, was later introduced. Recent studies have suggested that an endoscopic step-up approach might be more advantageous than a minimally invasive surgical step-up approach. A lumen apposing metal stent (LAMS) with a cautery-enhanced delivery system is currently preferred over the conventional plastic stents for endoscopic interventions, because it decreases the technical difficulty of the procedure and may obviate the need for an adjunctive debridement procedure. However, some recent findings suggest that LAMS could be associated with a higher risk of stent-related complications than conventional plastic stents, especially in patients with long-term placement. Therefore, early removal of LAMS at 3 weeks post-intervention is proposed if the WON is resolved on CT examination. Thus, endoscopic interventions have emerged as a key player in the management of WON. However, multidisciplinary treatment approaches should be considered because the endoscopic approach has limitations in treating complicated WON.
Keywords: endoscopic ultrasound; lumen apposing metal stent; necrosectomy.
© 2020 Japan Gastroenterological Endoscopy Society.