This study is a multicenter, randomized clinical trial designed to compare the effectiveness and safety of a modified 8-mm fully covered self-expandable metal stent (FCSEMS) with a conventional plastic stent for preoperative biliary drainage in patients with pancreatic cancer and malignant biliary obstruction.

In patients who require biliary drainage before surgery, stent placement is commonly performed using endoscopic retrograde cholangiopancreatography (ERCP). However, the optimal stent type remains uncertain.

Participants will be randomly assigned to receive either the modified FCSEMS or a plastic stent. The primary objective is to evaluate the rate of stent-related complications requiring reintervention before surgery. Secondary outcomes include stent patency, adverse events, and surgical outcomes.

The results of this study are expected to help determine the most appropriate stent strategy for patients undergoing surgery for pancreatic cancer.

Pancreatic cancer is a highly aggressive malignancy with a poor prognosis, and many patients present with malignant biliary obstruction at the time of diagnosis. Preoperative biliary drainage is frequently required in patients undergoing neoadjuvant chemotherapy or delayed surgery to relieve jaundice and prevent complications such as cholangitis.

Endoscopic retrograde cholangiopancreatography (ERCP) with stent placement is the standard approach for biliary drainage. Plastic stents (PS) are widely used due to their low cost and ease of removal; however, they are associated with a relatively short patency and frequent occlusion, often necessitating repeated interventions. Fully covered self-expandable metal stents (FCSEMS) have demonstrated longer patency, but concerns remain regarding adverse events and potential impact on subsequent surgical procedures.

A modified non-flared 8-mm diameter FCSEMS has been developed to reduce complications while maintaining adequate patency. Its design includes a dumbbell-shaped structure with a narrower central portion to prevent migration, a fully covered membrane to reduce tissue ingrowth, and a retrieval lasso to facilitate removal. This design may offer advantages over both conventional FCSEMS and plastic stents in the preoperative setting.

This study is a prospective, multicenter, open-label, randomized controlled trial designed to compare a modified 8-mm FCSEMS with a plastic stent for preoperative biliary drainage in patients with pancreatic cancer and malignant biliary obstruction. Eligible patients will be randomly assigned in a 1:1 ratio to receive either the modified FCSEMS or a plastic stent.

The primary endpoint is the stent-related non-event rate at the time of surgery, defined as the proportion of patients who do not require reintervention due to stent-related complications before surgery. Secondary endpoints include the incidence of recurrent biliary obstruction, time to recurrent biliary obstruction, stent-related adverse events, technical success, surgical outcomes, and overall survival.

All procedures will be performed using standard ERCP techniques by experienced endoscopists. Patients will be followed until surgery and throughout the postoperative period to assess clinical outcomes.

The findings of this study are expected to provide evidence to guide optimal stent selection for preoperative biliary drainage in patients with pancreatic cancer, particularly in the context of neoadjuvant treatment strategies.

Inclusion Criteria:

1. Age ≥ 18 years
2. Patients with resectable, borderline resectable, or locally advanced pancreatic cancer with distal malignant biliary obstruction requiring endoscopic biliary drainage
3. Biliary stricture located ≥ 2 cm below the hepatic hilum
4. Serum bilirubin ≥ 3 mg/dL
5. Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2
6. Ability to provide written informed consent

Exclusion Criteria:

1. Presence of distant metastasis
2. Prior biliary stent placement for biliary obstruction
3. Requirement for duodenal stent placement due to gastric outlet obstruction
4. Estimated life expectancy < 3 months
5. Inability to undergo ERCP
6. Any condition that, in the opinion of the investigator, would make participation unsafe or interfere with study outcomes

A plan for sharing individual participant data has not been finalized. Any future data sharing will be considered in accordance with institutional policies, ethical standards, and regulatory requirements.

This study is conducted as an open-label trial. Due to the nature of the endoscopic procedures and the visible differences between the stent types, blinding of participants, care providers, and investigators is not feasible.