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Indications / Contraindications
Metallic Stent (SEMS) Indications
- Malignant biliary obstruction (pancreatic cancer, cholangiocarcinoma, hepatic metastases) with confirmed ability to cross obstruction
- Life expectancy >3 months — metallic stents are not easily changed; justify the permanence
- Patient preference for catheter-free drainage
- Following successful internal-external drainage and adequate decompression
Plastic Stent Indications
- Benign strictures (post-op anastomotic, PSC — see benign stricture protocol)
- Bridging to surgery (bilirubin normalization before resection)
- When metallic stent may be premature: uncertain diagnosis, neoadjuvant chemotherapy response assessment
- Situations where retrievability is important
Covered vs Uncovered SEMS
- Uncovered SEMS: Better mucosal purchase, lower migration rate. Tumor ingrowth through mesh → occlusion (median patency ~6–9 months). Preferred for most malignant hilar obstructions.
- Covered SEMS: Longer patency (reduces tumor ingrowth), but higher migration rate. Cannot be used at hepatic hilum — covers segmental duct origins. Preferred for mid/distal CBD malignant obstruction.
Contraindications
- Benign etiology uncertain — never place permanent metallic stent without confirmed malignancy
- Hilar obstruction requiring segmental drainage with covered SEMS (covers duct orifices)
- Short life expectancy (<3 months) — external drain may be simpler to manage
- Active cholangitis — decompress first with external drain; stent when resolved and patient stable
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Pre-Procedure Checklist
Confirmed biliary decompression before stenting. Most operators: PTBD + external drainage for 48–72h FIRST to decompress and reduce cholangitis/sepsis risk. Stent when patient is stable, afebrile, and bilirubin trending down.
Confirmed ability to cross the obstruction on prior cholangiogram. If you have never crossed the obstruction, do not assume stent placement will be straightforward. Prior crossing is a prerequisite.
Stent sizing. Diameter: 8–10 mm standard SEMS. Length = stricture length + 2 cm proximal overhang + 2 cm distal overhang. Measure carefully on MRCP. Account for SEMS foreshortening at deployment.
Antibiotics — mandatory. Piperacillin-tazobactam 3.375g IV or ceftriaxone 1g IV before stent deployment. Continue 24–48h post-stenting.
Fluoroscopy quality check. Ensure good-quality fluoroscopy is available — stent deployment landmarks must be clearly visible. Poor imaging during deployment risks malposition.
Consent: metallic stents are permanent. Counsel patient that uncovered SEMS cannot be retrieved. Covered SEMS sometimes retrievable early. This is a one-way decision for uncovered stents.
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Relevant Anatomy
Biliary Anatomy and Stent Position Landmarks
- Right hepatic duct + left hepatic duct → common hepatic duct (CHD) → CBD → ampulla of Vater (into duodenum)
- Distal CBD stent: tip should terminate in proximal duodenum (just past ampulla). Proximal end above stricture with good purchase in normal duct.
- Hilar stent (Klatskin): left and right duct drainage required. Two stents often needed — “T” or “Y” configuration. Uncovered SEMS only at hilum.
- Intrahepatic duct stent: rare — used for peripheral cholangiocarcinoma or metastatic lymphangitic obstruction.
Stent Foreshortening (Critical)
- Metallic stents are significantly shorter after full expansion than their nominal (pre-deployment) length
- Wallstent: foreshortens ~30–40% — the most pronounced foreshortening of common biliary stents
- WallFlex: foreshortens ~20%
- Nitinol stents (Zilver): foreshorten <10%
- Account for foreshortening in positioning: place slightly more distally than intended final position, then watch stent walk proximally as it opens
Danger Structures
- Hepatic artery branches adjacent to bile duct (portal triad) — pseudoaneurysm if injured
- Portal vein — hemobilia if injured during access
- Pancreatic duct orifice — distal CBD stents crossing the ampulla can obstruct pancreatic drainage → pancreatitis
- Segmental duct origins at hilum — covered stents here will occlude segmental drainage
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Technique
Default RadCall approach · share your own below
Supplies
Established PTBD access (or establish during session)
0.035" stiff guidewire
10–12 Fr access sheath
Metallic stent system (Wallstent, WallFlex, or equivalent — 8–10 mm × appropriate length)
Stent deployment catheter
8–10 mm angioplasty balloon (optional, for post-deployment dilation)
Dilute contrast + syringes
Fluoroscopy
Key Principle: Decompress Before You Stent
Placing a stent in a cholangitic, high-pressure biliary system dramatically increases bacteremia risk. Standard approach: PTBD with external drainage first → 48–72h of decompression and IV antibiotics → stent when patient is stable. Only rush to same-session stenting in rare selected patients with excellent status and no signs of cholangitis.
Steps
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Establish or confirm biliary access
Use existing PTBD catheter tract or establish new access per PTBD technique. Confirm wire position in the duodenum with a wire loop and duodenal contrast fill.
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Cholangiogram
Delineate stricture — measure length, confirm crossing wire still in duodenum. Mark fluoroscopic landmarks: stricture start and end points; nearby vessels; papilla position. This is your targeting map.
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Size the stent
Length = stricture + 2 cm above + 2 cm below. Diameter: 8 mm standard, 10 mm for primary hepatic duct. Add extra length to account for foreshortening (for Wallstent: add ~35% to nominal deployed length when selecting stent).
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Advance stent delivery system
Over guidewire, advance the stent deployment catheter to the correct starting position. The distal radiopaque marker should align just below or at the distal end of the stricture. Confirm position under fluoroscopy before deploying.
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Deploy stent under continuous fluoroscopy
Slowly retract the outer sheath while holding the inner catheter absolutely stable. Watch stent foreshortening as it expands. Metallic stents foreshorten significantly — the proximal end will walk toward you as it opens. Fully deployed when inner catheter releases from stent.
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Post-deployment balloon dilation (optional)
Some operators dilate SEMS with an 8–10 mm balloon after deployment for immediate expansion. Most SEMS self-expand to full diameter over 24–72h. Balloon dilation is most useful when rapid drainage is needed or stent appears pinched.
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Post-deployment cholangiogram
Confirm bile flow through stent into duodenum. Document stent position. Leave residual transhepatic catheter alongside stent for 24–48h — this is your safety valve until stent function is confirmed.
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Confirm patency, then remove external access
At 24–48h: cholangiogram through external catheter confirms stent patent and expanded → then remove external catheter. Do not remove external access before confirming stent function.
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Troubleshooting
Problem
Stent deployed too proximally (inadequate distal coverage)
Likely cause: Insufficient distal advancement of delivery system before deployment, or more foreshortening than anticipated.
Next step: Do not attempt to pull the deployed stent — uncovered SEMS cannot be retracted. Place a second overlapping stent distally (“stent-in-stent”). Size the second stent to overlap the first by at least 1–2 cm.
Problem
Stent deployed too distally (duodenal impaction)
Likely cause: Over-advancement of the delivery system or underestimated foreshortening pulling stent into duodenum.
Next step: If functional drainage is adequate and no duodenal obstruction, may accept the position. If causing duodenal obstruction or pain → surgical consult. A second stent may be placed proximally to extend coverage to the obstruction if stent missed the stricture.
Problem
Acute stent occlusion / insufficient expansion
Likely cause: Stent has not fully expanded (normal for first 24–72h) or immediate sludge/clot plugging.
Next step: If external drain still in place, flush and confirm drain patent. Allow 24–72h for stent self-expansion. If no improvement: balloon dilation through stent lumen with an appropriately sized balloon. Hydrophilic wire + angled catheter to break sludge plugs.
Problem
Stent migration
Likely cause: Covered stents migrate more commonly (lack tissue ingrowth anchor). Distal migration into duodenum is most common direction.
Next step: Covered stent may be retrievable with a snare catheter if migration is recent and stent accessible. If not retrievable: deploy second stent proximal to the migrated stent, overlapping to re-cover the stricture. Surgical retrieval rarely needed.
Problem
Bilateral hilar stenting (Klatskin tumor)
Likely cause: Need for simultaneous left and right hepatic duct drainage with two stents converging at the hilum.
Next step: “Kiss” technique: advance both stents to position simultaneously, then deploy sequentially with the first stent deployed while the second delivery system holds the other stent in place. Or sequential deployment with stent-in-stent overlap. Use uncovered stents only at the hilum.
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Complications
Early / Periprocedural
- Cholangitis / sepsis post-stenting — most dangerous; prophylactic antibiotics and pre-stent decompression are essential prevention
- Hemobilia — hepatic artery injury during access; persistent pulsatile hemobilia → CT angiography → embolization
- Stent malposition — too proximal (missed distal end) or too distal (duodenal impaction)
- Pancreatitis — distal CBD stents occluding pancreatic duct orifice
- Duodenal perforation/obstruction — from stent too far into duodenum
Delayed
- Stent occlusion — tumor ingrowth ~40% at 12 months for uncovered SEMS; less for covered; re-intervention with stent-in-stent
- Stent migration — 5–10% covered SEMS; <2% uncovered
- Recurrent cholangitis — from stent occlusion; new percutaneous access needed
- Liver abscess — undrained biliary segment following stenting of main duct while ignoring a segmental duct
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Post-Procedure Care
Immediate Post-Stent (Day 0–2)
- External transhepatic catheter maintained 24–48h post-stenting to confirm stent function before removing external access
- Cholangiogram at 48h through external catheter: confirm stent patent and expanded → then remove external catheter
- Antibiotics continued 24–48h post-procedure
- Monitor for fever, rigors — signs of cholangitis despite stent
Outpatient Follow-up
- LFTs at 1 week: Expect bilirubin reduction >50% if stent is functional. Flat or rising bilirubin suggests inadequate drainage.
- CT or MRCP at 4–6 weeks: Confirms stent in position, adequate drainage of biliary system, no undrained segments
- Oncology coordination: Chemotherapy protocols (e.g., gemcitabine for pancreatic cancer) typically begin after bilirubin normalization; confirm timing with oncology team
Stent Dysfunction (Jaundice Returns)
- Bilirubin rising after initial decrease: suspect stent occlusion (tumor ingrowth, sludge, migration)
- New percutaneous access → cholangiogram → stent-in-stent (plastic or metallic) or new PTBD beside occluded stent
- Covered stent occlusion: balloon dilation +/– stent-in-stent
- Uncovered stent with tumor ingrowth: place covered plastic or metallic stent through existing stent lumen
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Critical Pearls
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Decompress BEFORE stenting. Placing a stent in a cholangitic, high-pressure system is a bacteremia disaster. External drain + antibiotics → 48–72h → then stent when the patient is stable. Only rarely justified to stent same-session.
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SEMS foreshorten significantly. Metallic stents are much shorter after full expansion than their nominal length. Wallstent foreshortens ~35%. Watch deployment carefully. Position slightly more distally than intended final resting position and let foreshortening work for you.
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Uncovered SEMS only at the hilum. Covered stents CANNOT be used at biliary confluences — they will cover segmental duct orifices, causing isolation of hepatic segments. For any hilar or near-hilar stricture: uncovered SEMS is the only option.
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Bilateral hilar stenting (Klatskin): Drain the hepatic lobe providing the most functional liver volume first. For bilateral complete drainage: kiss technique or sequential deployment. Coordinate with oncology — draining >50% of liver volume is the clinical target.
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Metallic stents are permanent (mostly). Counsel patient before placing uncovered SEMS — cannot retrieve. Covered SEMS can sometimes be retrieved early if migration occurs. This is a significant commitment for the patient — confirm malignancy and life expectancy.
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Leave the external drain post-stenting. Your safety valve for early dysfunction. Do not remove transhepatic access until you have confirmed stent patency and expansion at 24–48h cholangiogram. Early removal before confirmed function is a preventable error.
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Never place metallic stent in active cholangitis. Active infection + foreign body + high-pressure system = life-threatening sepsis. Decompress, treat, stabilize — then stent.
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Stent Type Quick Reference
| Stent | Diameter | Covered | Foreshortening | Best Use | Limitations |
|---|---|---|---|---|---|
| Wallstent (uncovered) | 8 mm | No | ~30–40% | Hilar, mid-CBD malignant | Tumor ingrowth at 6–9 mo |
| WallFlex (partially covered) | 10 mm | Partial | ~20% | Distal CBD malignancy | Migration ~5%; not for hilum |
| Zilver (uncovered nitinol) | 6–8 mm | No | <10% | Peripheral ducts | Less radial force; smaller diameter |
| Plastic biliary stent | 7–10 Fr | N/A | None | Benign, bridge to surgery | Exchange q3 months; occludes faster than SEMS |
Stent Selection Summary
- Hilar (Klatskin) obstruction: Uncovered SEMS only. Covered stents contraindicated at biliary confluence.
- Mid or distal CBD malignant obstruction: Covered or uncovered SEMS acceptable. Covered preferred for longer patency if no hilar involvement.
- Benign stricture: Plastic stent or repeated balloon dilation. Never permanent SEMS for benign disease.
- Life expectancy <3 months: Consider plastic stent or external drain rather than permanent SEMS.
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References & Resources
Primary sources · Key data · Related procedures
Key Guidelines
- ASGE guideline: Role of endoscopy in the evaluation and management of choledocholithiasis
- SIR quality improvement guidelines for biliary interventions
Primary References
- Saad WE, Wallace MJ, Wojak JC, Kundu S, Cardella JF. Quality improvement guidelines for percutaneous transhepatic cholangiography, biliary drainage, and percutaneous cholecystostomy. J Vasc Interv Radiol. 2010;21(6):789–795.
- Soderlund C, Linder S. Covered metal versus plastic stents for malignant common bile duct stenosis: a prospective, randomized, controlled trial. Gastrointest Endosc. 2006;63(7):986–995.
- Kahaleh M, Tokar J, Le T, Yeaton P. Removal of self-expandable metallic Wallstents. Gastrointest Endosc. 2004;60(4):640–644.