To Evaluate Early (2-Week) vs. Standard (4-Week) Metal Stent Removal Following Endoscopic Ultrasound Guided WON Drainage

Management of walled-off pancreatic necrosis (WON) following acute pancreatitis has been transformed by the use of endoscopic ultrasound (EUS)-guided transluminal drainage with a lumen-apposing metal stent (LAMS). The LAMS provides a large-caliber conduit for drainage and allows for direct endoscopic necrosectomy, leading to faster resolution of collections and reduced need for surgical intervention. However, the optimal timing for LAMS removal remains uncertain.

Prolonged retention of LAMS has been associated with several adverse events, including delayed bleeding due to vascular erosion, buried-stent syndrome, stent migration, and tissue hyperplasia at the tract site. Conversely, premature removal of the stent may lead to incomplete drainage, persistent or recurrent pancreatic fluid collections (PFCs), and the need for repeat interventions. Therefore, determining the ideal balance between minimizing stent-related complications and preventing recurrence is a key clinical challenge.

Early removal of the LAMS-either 2 weeks after insertion or immediately after the last necrosectomy session-may reduce the risk of delayed bleeding and other metal stent-related complications. However, to maintain tract patency and allow residual drainage, placement of a prophylactic double-pigtail plastic stent (DPT) at the time of LAMS removal has been proposed. The DPT provides a smaller but stable drainage channel that may prevent premature tract closure and recurrence of fluid collections.

This randomized controlled trial aims to rigorously test whether early LAMS removal combined with DPT placement offers better long-term outcomes compared to standard 4-week LAMS removal without DPT. The results are expected to provide evidence-based guidance on optimizing stent management in patients with WON undergoing endoscopic necrosectomy, balancing efficacy with safety.

Inclusion criteria

• Age ≥18 years
• Patients with walled-off pancreatic necrosis (WON) undergoing endoscopic ultrasound-guided drainage with lumen-apposing metal stent (LAMS)
• Radiological resolution of the pancreatic fluid collection ≥70% at 2 weeks after index endoscopic drainage, assessed on cross-sectional imaging (CT or MRI)

Exclusion criteria

• Presence of chronic pancreatitis
• Pancreatic malignancy (suspected or confirmed)
• Incomplete endoscopic necrosectomy or persistent large necrotic debris on imaging at 2 weeks after drainage
• Occurrence of major procedure-related adverse events within the first 2 weeks, including:
• Clinically significant bleeding
• Infection requiring additional intervention
• Stent migration
• Inability or unwillingness to provide written informed consent