Patients will be randomized to either FCSEMS or plastic stents for EUS-guided drainage of WON in a 1:1 manner. Following EUS-guided drainage patients in both groups will be assessed pre- procedure, pre -discharge, weeks 1, 6 and months 3, 6, 12 and 24 months. Information will also be collected from any subsequent hospital admissions related to their walled-off necrosis.