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

Official title

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

Overview

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.

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.

Interventions

• 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.
• 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.

Primary outcome measures

• Acute cholangitis [Time frame: Within 90 days after intervention]
• Acute cholecystitis [Time frame: Within 90 days after intervention]
• Acute pancreatitis [Time frame: Within 90 days after intervention]
• Bile leak [Time frame: Within 90 days after intervention]
• Hemorrhage [Time frame: Within 90 days after intervention]

Secondary outcome measures (3)

• Therapeutic success [Time frame: Within 30 days after intervention]
• Mortality [Time frame: Within 90 days after intervention]
• Need for reintervention [Time frame: Within 30 days after intervention]

Eligibility criteria

Inclusion criteria

• Age >18 years.
• Malignant proximal biliary obstruction on imaging (magnetic resonance cholangiopancreatography or contrast-enhanced abdominal computed tomography) with histopathological confirmation or high clinical and radiological suspicion.
• Total bilirubin > 3 mg/dL.
• Patients not candidates for potentially curative surgical resection due to locally advanced disease, metastatic disease, or inadequate clinical condition.
• 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

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

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Open label

Primary purpose

Treatment

Study locations

Brazil · 1 center

• Hospital de Clínicas de Porto Alegre — Porto Alegre

Publications

• Coelen RJS, Roos E, Wiggers JK, Besselink MG, Buis CI, Busch ORC, Dejong CHC, van Delden OM, van Eijck CHJ, Fockens P, Gouma DJ, Koerkamp BG, de Haan MW, van Hooft JE, IJzermans JNM, Kater GM, Koornstra JJ, van Lienden KP, Moelker A, Damink SWMO, Poley JW, Porte RJ, de Ridder RJ, Verheij J, van Woerden V, Rauws EAJ, Dijkgraaf MGW, van Gulik TM. Endoscopic versus percutaneous biliary drainage in pa PMID 30122355
• Zhao XQ, Dong JH, Jiang K, Huang XQ, Zhang WZ. Comparison of percutaneous transhepatic biliary drainage and endoscopic biliary drainage in the management of malignant biliary tract obstruction: a meta-analysis. Dig Endosc. 2015 Jan;27(1):137-45. doi: 10.1111/den.12320. Epub 2014 Sep 24. PMID 25040581
• Wiggers JK, Groot Koerkamp B, Cieslak KP, Doussot A, van Klaveren D, Allen PJ, Besselink MG, Busch OR, D'Angelica MI, DeMatteo RP, Gouma DJ, Kingham TP, van Gulik TM, Jarnagin WR. Postoperative Mortality after Liver Resection for Perihilar Cholangiocarcinoma: Development of a Risk Score and Importance of Biliary Drainage of the Future Liver Remnant. J Am Coll Surg. 2016 Aug;223(2):321-331.e1. doi: PMID 27063572
• Shim DJ, Gwon DI, Han K, Kim Y, Ko GY, Shin JH, Ko HK, Kim JH, Kim JW, Yoon HK, Sung KB. Percutaneous Metallic Stent Placement for Palliative Management of Malignant Biliary Hilar Obstruction. Korean J Radiol. 2018 Jul-Aug;19(4):597-605. doi: 10.3348/kjr.2018.19.4.597. Epub 2018 Jun 14. PMID 29962866
• Ribero D, Zimmitti G, Aloia TA, Shindoh J, Fabio F, Amisano M, Passot G, Ferrero A, Vauthey JN. Preoperative Cholangitis and Future Liver Remnant Volume Determine the Risk of Liver Failure in Patients Undergoing Resection for Hilar Cholangiocarcinoma. J Am Coll Surg. 2016 Jul;223(1):87-97. doi: 10.1016/j.jamcollsurg.2016.01.060. Epub 2016 Feb 13. PMID 27049784
• Qumseya BJ, Jamil LH, Elmunzer BJ, Riaz A, Ceppa EP, Thosani NC, Buxbaum JL, Storm AC, Sawhney MS, Pawa S, Naveed M, Lee JK, Law JK, Kwon RS, Jue TL, Fujii-Lau LL, Fishman DS, Calderwood AH, Amateau SK, Al-Haddad M, Wani S. ASGE guideline on the role of endoscopy in the management of malignant hilar obstruction. Gastrointest Endosc. 2021 Aug;94(2):222-234.e22. doi: 10.1016/j.gie.2020.12.035. Epub PMID 34023067
• Pietrzak J, Przybylkowski A. Endoscopic Treatment of Malignant Hilar Biliary Obstruction. Cancers (Basel). 2023 Dec 13;15(24):5819. doi: 10.3390/cancers15245819. PMID 38136363
• Elmunzer BJ, Smith ZL, Tarnasky P, Wang AY, Yachimski P, Banovac F, Buscaglia JM, Buxbaum J, Chak A, Chong B, Cote GA, Draganov PV, Dua K, Durkalski V, Geller BS, Jamil LH, Keswani RN, Khashab MA, Law R, Lo SK, McCarthy S, Selby JB, Singh VK, Taylor JR, Willingham FF, Spitzer RL, Foster LD; INTERCPT study group and the United States Cooperative for Outcomes Research in Endoscopy (USCORE). An Unsuc PMID 32454259

Identifiers

NCT: NCT07558304 · 2025-0661 · 95412526.6.0000.5327

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗