Patient with pancreatic walled-off necrosis (WON) would be treated randomized with lumen-apposing metal stent (LAMS) or double pigtail plastic stents (DPPSs) under the guidance of Endoscopic Ultrasonography. The investigators compare the effect of the two stents, including technical success, clinical success, adverse event, recurrence, and so on.
The purpose of this study is to compare the effect of lumen-apposing metal stent (LAMS) and double pigtail plastic stents (DPPSs) on the drainage of pancreatic walled-off necrosis (WON), mainly to observe the efficacy and safety of LAMS for WON.