To Evaluate Early (2-Week) vs. Standard (4-Week) Metal Stent Removal Following Endoscopic Ultrasound Guided WON Drainage (STEP1)

Asian Institute of Gastroenterology, India

Status: Enrolling

Conditions: Walled Off Necrosis

Treatments: Procedure: Standard LAMS Removal with Double-Pigtail Plastic Stent; Procedure: Standard LAMS Removal without DPT

Study type: Interventional

Funder types: Other

Identifiers

NCT07307248

STEP1

Details and patient eligibility

About

In adults with walled-off pancreatic necrosis (WON) undergoing endoscopic ultrasound (EUS)-guided transluminal necrosectomy, does early removal of the lumen-apposing metal stent (LAMS) (at 2 weeks or immediately after the last necrosectomy) with placement of a double-pigtail plastic stent (DPT), compared to delayed LAMS removal at 4 weeks without a DPT, result in a lower rate of pancreatic fluid collection (PFC) recurrence or need for reintervention over 12 months.

Full description

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.

Enrollment: 408 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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408 participants in 2 patient groups

Early Stent Replacement Arm (2-Week LAMS Removal + DPT Placement)

Experimental group

Description:

Participants in this arm will undergo early removal of the lumen-apposing metal stent (LAMS) at 2 weeks after initial endoscopic drainage for walled-off pancreatic necrosis (WON). Following LAMS removal, a double-pigtail plastic stent (DPT) will be placed across the transmural tract to maintain drainage and reduce the risk of recurrent pancreatic fluid collection (PFC). Patients will undergo follow-up imaging at 3, 6, and 12 months to assess recurrence, complications, and need for reintervention.

Treatment:

Procedure: Standard LAMS Removal with Double-Pigtail Plastic Stent

Standard Stent Replacement Arm (4-Week LAMS Removal without DPT)

Active Comparator group

Description:

Participants in this arm will undergo standard removal of the LAMS at 4 weeks after initial endoscopic drainage for walled-off pancreatic necrosis (WON). Patients will be followed at 3, 6, and 12 months to assess recurrence of pancreatic fluid collection (PFC), complications, and reintervention rates.

Treatment:

Procedure: Standard LAMS Removal without DPT