Lumen-apposing metal stents (LAMS) versus plastic stents for EUS-guided drainage of walled-off necrosis (WON) (LVPWON): study protocol for a multicenter randomized controlled trial

Abstract Background Endoscopic ultrasonography (EUS)-guided drainage has become the first-line therapy for late peri-pancreatic fluid collection (PFC). Double pigtail plastic stents (DPPS) and lumen-apposing metal stents (LAMS) are commonly used for PFC drainage. Recently, a multi-institutional consensus on PFC drainage has recommended that LAMS should be the standard care for patients with walled-off necrosis (WON). However, given the poor quality of evidence, we aim to perform a large-scale randomized controlled trial to determine whether LAMS is superior to DPPS for WON drainage. Methods/design The study is an open-label, prospective, parallel-group, superiority, multicenter randomized controlled trial. Two hundred and fifty-six patients with WON who will attend 18 tertiary hospitals in China will be randomly allocated to the LAMS or DPPS group before the procedure. The primary endpoint is the clinical success at one month after drainage (reduction in the size of WON to