Suprapapillary Metal Stent vs. Routine Transpapillary Drainage in Malignant Hilar Biliary Obstruction (SMART-B Trial) (SMART-B)

April 23, 2026 updated by: Hospital de Clinicas de Porto Alegre

Randomized Clinical Trial of Suprapapillary Drainage With Metal Stent vs. Routine Internal-External Transpapillary Drainage in Patients With Malignant Hilar Biliary Obstruction

Malignant hilar biliary obstruction is a condition in which the bile ducts near the liver become blocked due to cancer. This blockage can lead to jaundice (yellowing of the skin and eyes), itching, infection, and impaired liver function. To relieve the obstruction, doctors commonly perform procedures to drain bile and restore its flow.

There are different techniques available for biliary drainage. One common method is percutaneous transpapillary internal-external drainage, in which a catheter is placed through the liver and across the natural opening of the bile duct into the intestine. Another approach is percutaneous suprapapillary drainage using a self-expanding metal stent, which allows bile to drain without crossing into the intestine and may reduce the risk of contamination and infection.

Currently, there is no clear consensus on which of these two techniques is safer or more effective for patients with malignant proximal biliary obstruction. Some studies suggest that avoiding manipulation of the intestinal opening of the bile duct may reduce complications such as infection, but high-quality comparative evidence is lacking.

The purpose of this study is to compare percutaneous suprapapillary drainage with a self-expanding metal stent versus routine percutaneous transpapillary internal-external drainage in patients with malignant proximal biliary obstruction. The study aims to compare the rate of drainage-related complications between the two techniques, as well as to evaluate treatment success, stent patency, and the need for reintervention. In addition, in patients with potentially resectable disease undergoing preoperative biliary drainage, the study will assess and compare surgical outcomes between the two approaches. The results of this study may help determine the safest and most effective drainage strategy for these patients and improve future clinical decision-making.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Malignant hilar biliary obstruction is most commonly associated with perihilar cholangiocarcinoma and represents a complex clinical condition characterized by impaired bile flow at or above the hepatic duct confluence. The resulting cholestasis may lead to progressive hepatic dysfunction, increased risk of infectious complications, and reduced tolerance to systemic or surgical therapies. In selected patients, preoperative biliary drainage is performed to optimize liver function and reduce perioperative risk prior to major hepatectomy.

Percutaneous biliary drainage is widely used in this setting due to its ability to selectively decompress specific hepatic segments, particularly in complex hilar strictures. The conventional approach consists of transpapillary internal-external drainage, in which a catheter is advanced across the obstruction and through the papilla into the duodenum. While effective in achieving biliary decompression, this technique may disrupt the function of the sphincter of Oddi and facilitate duodenobiliary reflux, which has been implicated as a potential mechanism for infectious complications.

Percutaneous suprapapillary drainage with placement of a self-expanding metal stent represents an alternative strategy. By avoiding transpapillary manipulation, this approach preserves sphincter function and may reduce bacterial contamination of the biliary tree. Early clinical data suggest a favorable safety profile, particularly regarding infectious outcomes; however, direct comparisons with conventional transpapillary drainage remain limited, and available studies are constrained by methodological limitations.

An additional area of uncertainty relates to patients with potentially resectable disease. In this subgroup, the choice of drainage technique may influence not only peri-procedural outcomes but also subsequent surgical management. Concerns have been raised regarding the potential impact of metallic stents on operative complexity and resectability, although robust data are lacking.

This randomized clinical trial is designed to compare two percutaneous drainage strategies within a standardized institutional framework. Patients with an indication for percutaneous biliary drainage will be allocated to receive either transpapillary internal-external drainage or suprapapillary drainage with a self-expanding metal stent. The study includes both patients with unresectable disease and those with potentially resectable malignancies, allowing for evaluation across different clinical scenarios.

All procedures will be performed by experienced interventional radiologists using uniform technical protocols, and patients will be managed according to institutional standards of care. Follow-up will include clinical, laboratory, and imaging assessment as appropriate to routine practice.

The study is designed to generate comparative evidence regarding the safety and performance of these two techniques. In addition, a prespecified subgroup analysis will focus on patients with potentially resectable cholangiocarcinoma undergoing preoperative biliary drainage, in order to explore the impact of drainage strategy on subsequent surgical outcomes.

Study Type

Interventional

Enrollment (Estimated)

84

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

  • Name: Cleber R. P. Kruel, Professor
  • Phone Number: 8232 +55(51)3359-8232
  • Email: crkruel@hcpa.edu.br

Study Contact Backup

  • Name: Gabriel L. da Silva, Attending Physician
  • Phone Number: 8232 +55(51)3359-8232
  • Email: gablsilva@hcpa.edu.br

Study Locations

  • Brazil
    • Rio Grande do Sul
      • Porto Alegre, Rio Grande do Sul, Brazil, 90035-903
        • Hospital de Clinicas de Porto Alegre
        • Contact:
        • Contact:
          • Gabriel L. da Silva, Attending Physician
          • Phone Number: 8232 +55(51)3359-8232
          • Email: gablsilva@hcpa.edu.br
        • Sub-Investigator:
          • Gabriel L. da Silva, Attending Physician
        • Sub-Investigator:
          • Leandro A. Scaffaro, Attending Physician
        • Sub-Investigator:
          • Mauricio Farenzena, Attending Physician
        • Sub-Investigator:
          • Flavia H. Feier, Professor
        • Sub-Investigator:
          • Pablo D. Rodrigues, Attending Physician
        • Sub-Investigator:
          • Tomaz J. M. Grezzana, Attending Physician
        • Sub-Investigator:
          • Marcio F. Chedid, Attending Physician
        • Sub-Investigator:
          • William F. Silvano, Attending Physician
        • Sub-Investigator:
          • Francisco C. B. Lemanski, General Surgery Resident
        • Principal Investigator:
          • Cleber R. P. Kruel, Professor

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Age >18 years.
  2. Malignant proximal biliary obstruction on imaging (magnetic resonance cholangiopancreatography or contrast-enhanced abdominal computed tomography) with histopathological confirmation or high clinical and radiological suspicion.
  3. Total bilirubin > 3 mg/dL.
  4. Patients not candidates for potentially curative surgical resection due to locally advanced disease, metastatic disease, or inadequate clinical condition.
  5. Patients with potentially resectable neoplasms, defined as the possibility of achieving complete resection (R0), who meet at least one of the following criteria:

5.1 Estimated future liver remnant <40%, in whom percutaneous portal vein embolization of the side to be resected will also be indicated after initial drainage.

5.2 Prolonged jaundice with total bilirubin >10 mg/dL for more than 14 days. 5.3 Malnutrition, defined as ≥10% unintentional weight loss or albumin <3 g/dL, presumably attributable to cholestasis.

5.4 Indication for neoadjuvant chemotherapy.

Exclusion Criteria:

  1. Tumor with distal extension to the duodenal papilla, precluding suprapapillary drainage.
  2. Prior biliary drainage procedure, either percutaneous (PTBD) or endoscopic (ERCP).
  3. Acute cholangitis, clinically defined as fever (axillary temperature >38°C) and leukocytosis (white blood cell count >10,000/mm³).
  4. Uncorrectable coagulopathy.
  5. Iodinated contrast allergy not amenable to desensitization.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Transpapillary internal-external drainage
Participants undergo percutaneous transpapillary internal-external biliary drainage with placement of a catheter across the obstruction and through the papilla into the duodenum, according to standard institutional practice.
Procedure: Percutaneous transpapillary internal-external biliary drainage
Percutaneous biliary drainage performed by advancing a catheter across the biliary obstruction and through the papilla into the duodenum, allowing internal and external bile drainage.
Other Names:
  • Intervention 1
Active Comparator: Suprapapillary Self-Expanding Metal Stent Drainage
Participants undergo percutaneous suprapapillary biliary drainage with placement of a self-expanding metal stent across the obstruction without crossing the papilla.
Procedure: Percutaneous suprapapillary biliary drainage with self-expanding metal stent
Percutaneous biliary drainage performed by placing a self-expanding metal stent across the biliary obstruction without crossing the papilla.
Other Names:
  • Intervention 2

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Acute cholangitis
Time Frame: Within 90 days after intervention
Defined by clinical criteria, including fever (axillary temperature >38°C) and leukocytosis (white blood cell count >10,000/mm³), in the absence of another infectious source on abdominal and chest imaging.
Within 90 days after intervention
Acute cholecystitis
Time Frame: Within 90 days after intervention
Defined by radiological evidence of cholecystitis associated with fever (axillary temperature >38°C) and leukocytosis (white blood cell count >10,000/mm³).
Within 90 days after intervention
Acute pancreatitis
Time Frame: Within 90 days after intervention
Defined by the presence of at least two of the following criteria: abdominal pain consistent with pancreatitis, elevation of amylase and/or lipase greater than three times the upper limit of normal, or characteristic imaging findings.
Within 90 days after intervention
Bile leak
Time Frame: Within 90 days after intervention
Defined as intra-abdominal bile leakage due to biliary perforation or at the hepatic puncture site, confirmed by imaging.
Within 90 days after intervention
Hemorrhage
Time Frame: Within 90 days after intervention
Defined as clinical or radiological evidence of bleeding requiring blood transfusion or reintervention.
Within 90 days after intervention

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Therapeutic success
Time Frame: Within 30 days after intervention
Defined as a decrease in total bilirubin to <3 mg/dL or a reduction of more than 50% compared to pre-drainage levels
Within 30 days after intervention
Mortality
Time Frame: Within 90 days after intervention
All-cause mortality following biliary drainage.
Within 90 days after intervention
Need for reintervention
Time Frame: Within 30 days after intervention
Requirement for additional percutaneous or endoscopic procedures
Within 30 days after intervention

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Rate of curative surgery
Time Frame: Within 180 days of intervention
Number of patients from group A (patients with potentially resectable neoplasms) who undergo potentially curative surgery
Within 180 days of intervention
90-day postoperative mortality
Time Frame: Within 90 days of curative surgery
Surgical mortality in patients from Group A (patients with potentially ressectable neoplasms) who undergo potentially curative surgery
Within 90 days of curative surgery
90-day postoperative morbidity
Time Frame: Within 90 days of curative surgery
Surgical morbidity in patients from Group A (patients with potentially ressectable neoplasms) who undergo potentially curative surgery according to Clavien-Dindo classification
Within 90 days of curative surgery
Incidence of postoperative liver failure
Time Frame: Within 90 days of curative surgery
Incidence of postoperative liver failure in patients from Group A (patients with potentially ressectable neoplasms) who undergo potentially resectable surgery
Within 90 days of curative surgery
Stent patency duration
Time Frame: Within 180 days of intervention
Duration of stent patency in patients from group B (patients not candidates for potentially curative resection)
Within 180 days of intervention

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Hospital de Clinicas de Porto Alegre

Investigators

  • Study Chair: Cleber R. P. Kruel, Professor, Hospital de Clinicas de Porto Alegre

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

May 1, 2026

Primary Completion (Estimated)

December 31, 2028

Study Completion (Estimated)

December 31, 2028

Study Registration Dates

First Submitted

April 16, 2026

First Submitted That Met QC Criteria

April 23, 2026

First Posted (Actual)

April 30, 2026

Study Record Updates

Last Update Posted (Actual)

April 30, 2026

Last Update Submitted That Met QC Criteria

April 23, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2025-0661
  • 95412526.6.0000.5327 (Other Identifier: Plataforma Brasil)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

All IPD collected throughout the trial

IPD Sharing Time Frame

Beginning 2 months and ending 2 years after the publication of results

IPD Sharing Access Criteria

Access to individual participant data (IPD) and supporting documents (including the study protocol and statistical analysis plan) will be granted to researchers who provide a methodologically sound research proposal. Requests must specify the intended use of the data and will be reviewed by the study investigators in accordance with institutional policies.

Data will be shared in a de-identified format to ensure participant confidentiality. Access will be provided upon reasonable request to the corresponding author, subject to approval by the investigators and applicable ethical and legal requirements. Data will be made available through secure data transfer methods.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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