Walled-off necrosis (WON) is a pancreatic fluid collection, which contains necrotic tissue after four weeks of the onset of acute pancreatitis. Interventions are required to manage patients with infected WON, for which endoscopic ultrasonography (EUS)-guided drainage has become a first-line treatment modality. For patients who are refractory to EUS-guided drainage, the step-up treatment including endoscopic necrosectomy (EN) and/or additional drainage is considered to subside the infection. Recent evidence suggests that EN immediately after EUS-guided drainage may shorten treatment duration without increasing adverse events. In this randomized trial, the investigators will compare treatment duration between EN immediately after EUS-guided drainage versus the step-up approach in patients with symptomatic WON.
Patients with WON defined according to the revised Atlanta classification
The longest diameter of WON is 4 cm or larger
Patients with at least one out of the following conditions; signs of infection, gastrointestinal symptoms, abdominal symptoms, obstructive jaundice
Patients who need drainage for WON
WON inaccessible by EUS-guided approach
AXIOS stent has already been placed into the WON prior to the enrollment
Severe coagulopathy; Platelet count < 50,000/mm3 or prothrombin time international normalized ratio (PT-INR) >1.5
Patients on antithrombotic agents which cannot be managed according to the "guideline for gastroenterological endoscopy in patients undergoing antithrombotic treatment (Dig Endosc. 2014 Jan;26(1):1-14.)"