Hepatobiliary · IR Playbook

Biliary Stricture Dilation & Metal Stenting (PTBB/PTBS)

Percutaneous biliary stricture dilation uses transhepatic access and balloon cholangioplasty to restore bile flow across a benign or malignant narrowing. Benign strictures are generally treated with balloon dilation and prolonged internal-external catheter drainage, whereas self-expanding metal stents are primarily used for durable palliation of unresectable malignant obstruction. Technical success is usually greater than 90% after the stricture has been crossed, but sepsis, hemorrhage, duct rupture, stent malposition, and late stent occlusion remain important risks.

Learning objectives

• Differentiate the role of balloon dilation in benign strictures from the role of self-expanding metal stents in malignant obstruction.
• Plan transhepatic access according to stricture level, viable liver volume, portal venous patency, and future surgical or oncologic treatment.
• Select appropriate wires, catheters, balloon diameters, stent type, stent diameter, and landing zones.
• Recognize the technical endpoints of successful dilation and stenting.
• Prevent and manage cholangitis, hemobilia, duct rupture, stent migration, and stent occlusion.

Indications

• Benign postoperative, biliary-enteric anastomotic, duct-to-duct transplant, inflammatory, or ischemic biliary stricture when endoscopic treatment has failed or is not technically possible.
• Unresectable malignant distal or hilar biliary obstruction requiring durable internal palliation after failed or unsuitable endoscopic drainage.
• Persistent flow-limiting stricture despite adequate percutaneous drainage, with biochemical or clinical evidence of inadequate biliary decompression.
• Need to internalize drainage before systemic chemotherapy, locoregional treatment, or palliative discharge.
• Selected refractory benign strictures considered for temporary fully covered removable stenting after multidisciplinary review.

Absolute contraindications

• Uncorrectable coagulopathy for a high-bleeding-risk transhepatic intervention.
• No safe percutaneous transhepatic access route.
• Inability to cross the stricture with a guidewire.
• Active uncontrolled hemobilia for immediate metal stent deployment.

Relative contraindications

• Acute cholangitis, infected bile, or uncontrolled sepsis; establish drainage and treat infection before definitive metal stenting whenever possible.
• Large-volume ascites; perform paracentesis and optimize the patient before tract dilation.
• Potentially resectable malignancy without hepatobiliary multidisciplinary approval.
• Life expectancy less than approximately 30 days when an existing external drain is functioning and internalization is unlikely to improve comfort.
• Intraductal stones, blood clot, or heavy debris likely to cause immediate stent obstruction.
• Progressive liver failure despite technically adequate drainage.

Equipment

• Ultrasound machine with sterile probe cover and fluoroscopy or angiography system with road-mapping capability.
• 21 to 22 G Chiba needle or micropuncture biliary access set with 0.018-inch wire and 4 to 5 Fr introducer.
• 0.035-inch hydrophilic angled and straight guidewires, 150 to 260 cm.
• 0.035-inch stiff or extra-stiff exchange wire with an atraumatic distal tip.
• 0.014-inch or 0.018-inch steerable wire and 2.0 to 2.8 Fr microcatheter for pinhole or angulated strictures.
• 4 to 5 Fr angled, multipurpose, Kumpe, Cobra, or reverse-curve catheter.
• 6 to 10 Fr, 25 to 45 cm vascular or biliary sheath with a hemostatic valve.
• High-pressure noncompliant balloon, typically 4 to 10 mm diameter and 20 to 40 mm length.
• Cutting balloon, commonly 4 to 8 mm diameter, for selected refractory benign or anastomotic strictures.
• Self-expanding biliary metal stent, usually 8 to 10 mm diameter for intrahepatic or hilar ducts and approximately 10 mm for the extrahepatic common duct.
• 8 to 12 Fr locking internal-external biliary drainage catheter.
• Snare, retrieval sheath, biliary brush or forceps biopsy set, contrast medium, and embolization equipment for emergency management of hemobilia.

Procedure steps

1. Confirm whether the goal is benign-stricture dilation, malignant stenting, or both. Review resectability, intended drainage territory, access side, stent type, and whether the procedure should be primary or staged after infection control.Pearl: Benign disease is primarily treated with balloon dilation and prolonged catheter drainage; unresectable malignant disease is treated with a self-expanding metal stent.
2. Aspirate bile for culture and inject dilute contrast gently through the existing catheter or newly established access. Define the stricture in at least two projections and measure its length, upstream duct diameter, distal landing zone, and communication with adjacent ducts.Pearl: Aspirate before injecting and use the minimum pressure required to define the anatomy.
3. Advance a 4 to 5 Fr directional catheter to the stricture and probe with a 0.035-inch hydrophilic wire. For a pinhole, eccentric, or sharply angulated lesion, use a coaxial microcatheter with a 0.014-inch or 0.018-inch steerable wire.Pearl: Use orthogonal projections and direct the catheter tip along the expected duct axis before escalating wire stiffness.
4. Advance the wire into the duodenum or jejunal limb and exchange it for a 260 cm stiff wire with a safe distal loop. Position a 6 to 10 Fr sheath approximately 2 to 5 cm proximal to the lesion to improve pushability and protect the tract.Pearl: A sheath positioned close to the lesion often improves support more safely than excessive guidewire stiffness.
5. Select a high-pressure balloon according to the adjacent normal duct. Avoid more than approximately 20% oversizing for a native duct stricture; a fibrotic surgical anastomosis may tolerate approximately 20% to 30% oversizing. Inflate progressively until the balloon waist resolves.Pearl: A cutting balloon followed by conventional high-pressure dilation may be used for a refractory benign anastomotic stricture.
6. Deflate the balloon and repeat a gentle cholangiogram. Adequate dilation shows disappearance or marked reduction of the waist, free antegrade contrast passage, and absence of clinically significant extravasation.Pearl: A pressure-flow study or capping trial can help determine whether a persistent anatomical waist is functionally significant.
7. For unresectable malignant obstruction, select a self-expanding stent that extends at least 10 mm beyond both ends of the tumor. Choose uncovered or covered construction according to tumor location, side-branch anatomy, migration risk, and the need for potential removal.Pearl: For hilar lesions, select the stent configuration according to the viable hepatic volume that must be drained rather than routinely performing bilateral stenting.
8. If a rigid malignant stricture prevents passage of the delivery system, pre-dilate with a balloon approximately 2 to 3 mm smaller than the intended stent diameter. Maintain stable wire access and limit manipulation.Pearl: Minimal pre-dilation permits device delivery while preserving the stricture as an anchor.
9. Position the radiopaque markers in two projections and account for foreshortening and deployment direction. Release the stent slowly while maintaining sheath and wire stability. For bilateral hilar stents, coordinate side-by-side, Y, T, or stent-in-stent deployment according to the preplanned configuration.Pearl: When the distal lesion approaches the papilla, deliberate transpapillary extension may be safer than leaving an unstable short distal landing zone.
10. Perform gentle completion cholangiography to confirm stent position, lesion coverage, expansion, side-branch drainage, and free flow into bowel. Use cautious balloon expansion only for a critical residual waist or inadequate flow.Pearl: Most self-expanding stents continue to expand after deployment and do not require aggressive routine post-dilation.
11. Place an 8 to 12 Fr internal-external catheter through or immediately above the treated segment when there is infected bile, bleeding, incomplete stent expansion, uncertain drainage, complex hilar anatomy, or a need to preserve access. Cap it only after free internal flow is demonstrated.Pearl: A short-term safety catheter provides decompression, tamponade, and immediate reaccess if the stent fails.
12. Secure the catheter without kinking and obtain a final fluoroscopic image. Document the ducts drained, access route, balloon diameter and pressure, stent diameter, length, type and configuration, residual narrowing, complications, radiation dose, and follow-up plan.Pearl: Explicitly document any opacified or obstructed segments that were not drained.

Complications

• Cholangitis or sepsis, major sepsis approximately 2.5% after percutaneous biliary drainage
• Hemorrhage or hemobilia, major hemorrhage approximately 2.5% after percutaneous biliary drainage
• Duct rupture and bile leak
• Stent malposition or migration
• Pancreatitis or cholecystitis
• Late stent occlusion or recurrent cholangitis, contributing to late complication rates of approximately 18% to 60%
• Pleural complication, generally less than 1% in biliary drainage series

Exam pearls

• Benign stricture: balloon dilation plus prolonged catheter drainage; unresectable malignant stricture: self-expanding metal stent.
• Permanent uncovered metal stents are generally inappropriate for benign biliary strictures.
• Balloon diameter should match the adjacent normal duct; avoid more than approximately 20% oversizing in native ducts.
• Cover a malignant stricture with at least 1 cm of stent beyond both ends.
• In hilar obstruction, drain more than 50% of viable liver and avoid opacifying a segment that cannot be drained.
• Uncovered stent: less migration and preserved side branches but tumor ingrowth; covered stent: less ingrowth but more migration and branch occlusion.
• Bloody biliary drainage followed by gastrointestinal bleeding suggests a hepatic arterial pseudoaneurysm or arterio-biliary fistula.
• Do not aggressively post-dilate a biliary self-expanding metal stent because it continues to expand after deployment.

Viva questions

What is the basic difference between percutaneous treatment of a benign and a malignant biliary stricture?

A benign stricture is generally treated with balloon dilation and prolonged internal-external catheter drainage. An unresectable malignant stricture is usually treated with a self-expanding metal stent for durable internal palliation.

Why should an uncovered metal stent not be routinely placed in a benign biliary stricture?

It is permanent, becomes incorporated by epithelial and fibrous tissue, permits tissue ingrowth, and is difficult or impossible to remove. It may convert a potentially correctable benign lesion into chronic irreversible stent disease.

How do you size the balloon for biliary stricture dilation?

Size the balloon to the adjacent normal duct. Avoid more than approximately 20% oversizing for a native duct stricture; a fibrotic surgical anastomosis may tolerate approximately 20% to 30% oversizing.

How do you size a malignant biliary metal stent?

Use a diameter appropriate to the duct, commonly 8 to 10 mm for intrahepatic or hilar ducts and approximately 10 mm for the common duct. The stent should cover the tumor with at least 1 cm of normal duct beyond both ends.

Which is better, a covered or an uncovered biliary metal stent?

Neither is universally superior. Covered stents reduce tumor ingrowth and may be removable but have greater migration and side-branch occlusion risk; uncovered stents anchor well and preserve side branches but permit tumor ingrowth.

When should both lobes be drained in malignant hilar obstruction?

Both sides should be drained when one system does not decompress an adequate volume of viable liver, when both systems have been opacified or are infected, or when unilateral drainage cannot achieve the functional target. The practical goal is to drain more than 50% of viable hepatic volume.

Why is a safety catheter left after metal stent placement?

It preserves access, provides decompression, permits tamponade of minor bleeding, and allows immediate rescue if the stent is underexpanded, obstructed, or malpositioned.

What are the technical endpoints of successful biliary dilation and stenting?

The stricture is traversed, the balloon waist is abolished or substantially reduced, and contrast flows freely into bowel without major extravasation. For stenting, the lesion is completely covered, the stent is correctly positioned and expanded, and all intended functional segments drain.

References