Although metal stents have been widely used in the endoscopic step-up approach for necrotizing pancreatitis, the exact timing of transmural stent removal has not been well studied. In this prospective, open-label, randomized controlled study, we recruited and enrolled consecutive patients with necrotizing pancreatitis undergoing endoscopic transmural necrosectomy. Eligible participants were randomly assigned to case group (a novel strategy in which the stents were removed during the last necrosectomy when the necrosectomy endpoint was achieved) and control group (the conventional strategy in which the stents were removed after the last necrosectomy when clinical symptoms were relieved and fluid was nearly completely resolved confirmed by imaging). The primary endpoint was the incidence of composite complications within three months of enrollment.

Over the last decade, approaches to managing necrotizing pancreatitis have evolved from open surgery to a minimally invasive approach due to the efficacy and lower morbidity and mortality rates of the latter technique. As one of minimally invasive approaches, endoscopic step-up approach, with transmural drainage whenever feasible and subsequent necrosectomy as required, was first described in 1996 and has evolved to first-line therapy for symptomatic necrotizing pancreatitis. However,The exact timing of transmural stent removal has not been well studied. The conventional strategy for stent removal in the published guidelines has been that patients should undergo follow-up imaging and stent removal at 4-8 weeks if walled-off necrosis has resolved. Here, we introduced a novel strategy in which the stents were removed during the last necrosectomy when the endpoint of endoscopic transmural necrosectomy was achieved, that was, the necrotic tissue was nearly completely removed, and the pink granulation tissue lining the wall was uncovered. Compared to the conventional strategy, the novel strategy avoided one endoscopy procedure. The present study is the first prospective, open-label, randomized controlled study to investigate the efficacy and safety of the novel strategy. We recruited and enrolled consecutive patients with necrotizing pancreatitis undergoing endoscopic transmural necrosectomy. Eligible participants were randomly assigned to case group (a novel strategy in which the stents were removed during the last necrosectomy when the necrosectomy endpoint was achieved) and control group (the conventional strategy in which the stents were removed after the last necrosectomy when clinical symptoms were relieved and fluid was nearly completely resolved confirmed by imaging). The primary endpoint was the incidence of composite complications within three months of enrollment.

Inclusion Criteria:

1. Patients diagnosed with necrotizing pancreatitis according to the 2012 Atlanta classification criteria;
2. Patients aged between 18 and 65 years;
3. Patients who signed the informed consent;

Exclusion Criteria:

1. Patients without transmural stent placement;
2. Patients with transmural plastic stent not metal stent placement before enrollment;
3. Patients who underwent endoscopic transmural necrosectomy in other hospitals before admission;
4. Patients complicated with chronic pancreatitis;
5. Patients complicated with pancreatic tumor;
6. Pregnant or lactating women.