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Indications / Contraindications
Indications
- Hypersplenism with thrombocytopenia (platelets <50K) in cirrhotic patients prior to procedures, chemotherapy, or antiviral therapy
- Portal hypertension — adjunct to TIPS or standalone therapy for reducing portal pressure and variceal bleeding risk (second-line, limited evidence)
- Hereditary spherocytosis, ITP, thalassemia — alternative to splenectomy in poor surgical candidates
- Cirrhosis with massive splenomegaly causing mechanical symptoms
- Pre-procedure platelet augmentation — prior to liver biopsy, TIPS, or other SIR Category 2–3 procedures in thrombocytopenic patients
- Pediatric PSE: hereditary hemolytic anemias, ITP resistant to medical therapy, portal hypertension from any etiology
Absolute Contraindications
- Uncontrolled systemic infection
- Absent or inaccessible splenic vasculature
- Prior splenectomy
Relative Contraindications
- Coagulopathy not correctable to INR <1.5
- Left-sided portal hypertension from splenic vein thrombosis (PSE may worsen)
- End-stage liver disease (Child-Pugh C) without transplant plan — risk of overwhelming post-splenectomy infection is elevated
- Active pancreatic disease (pancreatitis) — proximity of splenic artery to pancreatic branches increases risk
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Pre-Procedure Checklist
CT angiography — assess splenic artery anatomy (origin, diameter, tortuosity), splenic size, accessory spleens, visceral anatomy. Plan superselective approach beyond pancreatic branches.
Labs: CBC (baseline platelet count), CMP, INR, blood culture if any signs of infection
VACCINATIONS (critical): Pneumococcal (PCV20 or PCV15 + PPSV23), meningococcal (MenACWY and MenB), and Haemophilus influenzae type b (Hib) — administer ≥2 weeks before procedure. If urgent/emergency PSE: administer vaccines within 2 weeks post-procedure.
Prophylactic antibiotics: cefazolin 1g IV immediately pre-procedure. Post-procedure course: cephalexin 500 mg BID × 5 days.
Informed consent: post-embolization syndrome (near-universal, 3–7 days), splenic abscess (2–3%), OPSI (rare but life-threatening), portal/splenic vein thrombosis, non-target embolization, pancreatic injury
IV access: 2 large-bore PIVs; IV fluids; pain management plan (PCA or scheduled NSAIDs + opioids PRN)
Accessory spleen identification: review CT — if accessory spleens present, PSE may have reduced efficacy for ITP/hypersplenism; counsel patient accordingly
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Relevant Anatomy
Splenic Artery & Branch Anatomy
- Course: celiac axis → splenic artery (tortuous, often massively so in portal hypertension) → hilar branches (superior polar, inferior polar, transverse pancreatic)
- Dorsal pancreatic artery: arises from proximal splenic artery; must advance catheter distal to this before injecting embolic material
- Transverse pancreatic artery: runs along inferior pancreatic margin; also must be distal to this for safe embolization
- Superselective positioning goal: microcatheter tip in distal hilar branches, past all pancreatic branches, to minimize pancreatic embolization risk
Target Embolization Zone
- Lower pole preferred: lower risk of pancreatic tail ischemia; technically easier to embolize selectively
- Accessory spleens: present in 15–30% of patients; must identify on pre-procedure CT; may reduce efficacy for ITP/hypersplenism if not separately embolized
- Extent target: 50–70% of splenic parenchyma devascularized — estimated fluoroscopically by comparing parenchymal blush before and after
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Technique
Default RadCall approach · share your own below
Supplies
5 Fr femoral arterial sheath
5 Fr Cobra or Simmons 1 catheter
Microcatheter (2.7–3 Fr)
Hydrophilic microwire
500–700 micron PVA particles
Embospheres (300–500 micron, alternative)
Iodinated contrast medium
1–3 mL syringes for embolic injection
Intraarterial nitroglycerin (200 mcg for spasm)
Steps
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Arterial Access
Standard right common femoral artery access with micropuncture technique. Upsize to 5 Fr sheath.
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Celiac Angiogram
Cobra catheter (or Simmons 1 if celiac origin is steep) into celiac axis. Celiac angiogram to visualize splenic artery, hepatic artery, left gastric artery. Confirm anatomy and identify splenic artery course and tortuosity.
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Splenic Artery Selection & Angiogram
Advance catheter into proximal splenic artery. Selective splenic angiogram — document parenchymal blush, hilar branch anatomy, and origins of dorsal pancreatic and transverse pancreatic branches.
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Superselective Microcatheter Positioning
Advance microcatheter through guide catheter into distal splenic artery, past the dorsal pancreatic artery and transverse pancreatic branches, into hilar lower pole branches. Confirm position with small hand injection of contrast.
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Embolization
Inject 500–700 micron PVA particles in dilute contrast suspension using 1–3 mL syringes. Inject slowly in 0.5–1 mL aliquots under continuous fluoroscopic monitoring. Never inject against resistance. Stop when significant splenic parenchymal flow reduction is fluoroscopically apparent. Target 50–70% devascularization.
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Completion Angiogram
Celiac angiogram after embolization. Document residual splenic perfusion. Estimate percentage embolized by comparing pre- and post-embolization parenchymal blush. Confirm no non-target embolization of pancreatic, hepatic, or left gastric arteries.
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Access Closure
Remove sheath. Manual compression for 15–20 minutes at femoral arterial access site, or use closure device.
Embolization Endpoint
50%: parenchymal blush reduced by half; lower pole still perfusing. 70%: most hilar branches occluded; significant devascularization. Avoid 100% embolization — equivalent to functional splenectomy, with very high post-embolization syndrome severity and abscess risk.
50%: parenchymal blush reduced by half; lower pole still perfusing. 70%: most hilar branches occluded; significant devascularization. Avoid 100% embolization — equivalent to functional splenectomy, with very high post-embolization syndrome severity and abscess risk.
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Troubleshooting
Problem
Celiac artery origin stenosis or bovine variant anatomy preventing catheter access
Likely cause: Atherosclerosis, celiac arcuate ligament compression, or variant celiac–SMA common origin
Next step: Try Simmons 1 or sidewinder catheter for steep celiac origins. Use a stiff Amplatz wire for additional support. For arcuate ligament compression: forced deep inspiration may open the artery enough to advance the catheter.
Problem
Unable to superselect beyond pancreatic branches
Likely cause: Tortuous splenic artery (common in portal hypertension), vessel spasm, or inadequate catheter support
Next step: Use a longer sheath for proximal support. Buddy wire technique to straighten tortuosity. Intraarterial nitroglycerin 200 mcg for spasm. If superselective positioning truly not achievable: abort procedure to avoid pancreatic embolization — do not inject embolic material from a proximal position.
Problem
Reflux of embolic agent during injection
Likely cause: High-flow splenic artery, excessive injection pressure from large syringe, or catheter tip not sufficiently distal
Next step: Switch to smaller syringe (1–3 mL maximum). Flush with contrast before injecting particles. Use smaller particle size (if currently using 700 micron, switch to 500 micron). Never inject against resistance. Advance microcatheter more distally if anatomy allows.
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Complications
Immediate
- Splenic artery spasm — treat with intraarterial nitroglycerin 200 mcg
- Non-target embolization — pancreatic ischemia, left gastric infarction, hepatic embolization; result of proximal position or reflux
- Pain — severe left upper quadrant and left shoulder pain; nearly universal; expected
- Contrast nephropathy — minimize contrast; pre-hydration
Delayed
- Post-embolization syndrome — fever, LUQ pain, leukocytosis; 3–7 days; expected in up to 73% (higher with larger embolization volumes); managed with NSAIDs and opioids; NOT equivalent to sepsis
- Splenic abscess — 2–3%; fever beyond 7–10 days; CT showing gas in devascularized spleen; requires percutaneous drainage
- Portal/splenic vein thrombosis — assess with Doppler at 1 week
- Overwhelming post-splenectomy infection (OPSI) — rare but life-threatening if vaccines not given; predominantly pneumococcus; patients must receive prompt antibiotics for any febrile illness
- Left-sided pleural effusion — reactive; usually resolves without intervention
- Pancreatic pseudocyst — from inadvertent pancreatic branch embolization
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Post-Procedure Care
Inpatient Monitoring
- 24–48h hospital admission standard — pain control and fever management
- Vital signs q4h × 24h; CBC and CMP at 24h
- Pain management: scheduled NSAIDs (ketorolac IV then ibuprofen PO) + opioids PRN; PCA if severe; expect significant LUQ and left shoulder pain (diaphragmatic irritation)
- Fever management: post-embolization fever is cytokine-mediated and expected; blood cultures if temperature >38.5°C beyond 72h
- NPO until nausea resolves (usually 12–24h); advance diet as tolerated
Platelet Response Timing
- Platelets begin rising 3–7 days post-PSE
- Peak platelet response: 2–4 weeks post-procedure
- Repeat CBC at 1 week, 2 weeks, 4 weeks
- Durability: 60–70% maintain response at 1 year; repeat PSE feasible for recurrence
Discharge & Long-Term Plan
- CT at 72h to confirm 50–70% embolization zone — if <50% embolized: consider early repeat procedure
- Vaccination update if not given pre-procedure (administer within 2 weeks of PSE)
- Consider long-term penicillin prophylaxis — especially in children and high-risk adults
- Educate patient and primary care: any febrile illness requires immediate antibiotic treatment (amoxicillin or equivalent); do not wait for sepsis workup before treating
- Duplex US at 1 month to screen for portal/splenic vein thrombosis
- If PSE for pre-procedure platelet augmentation: schedule downstream procedure 2–4 weeks post-PSE when platelet response has peaked
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Critical Pearls
✶
Vaccinate first — non-negotiable: PSE creates functional asplenia. OPSI from pneumococcus is life-threatening. If proceeding urgently: administer vaccines within 2 weeks post-procedure. Inform the patient and their primary care provider about the life-long need for prompt antibiotics with any febrile illness.
✶
50–70% is the target, not more: Greater than 70% embolization dramatically increases splenic abscess rate and severity of post-embolization syndrome. Less than 50% is often insufficient for a durable platelet response. Aim for the lower pole.
✶
Superselect beyond every pancreatic branch: Pancreatic embolization causes acute pancreatitis or pseudocyst formation. The dorsal pancreatic artery and transverse pancreatic artery must both be proximal to the microcatheter tip before any embolic material is injected.
✶
Post-embolization syndrome is expected, not a complication: Counsel patients pre-procedure that they will have significant left upper quadrant pain and fever for 3–7 days. This is cytokine-mediated devascularization, not sepsis. Distinguish from true splenic abscess (fever persisting beyond 7–10 days, CT showing gas in devascularized spleen).
✶
Platelet response takes 2–4 weeks to peak: Patients planning procedures after PSE must wait for the full platelet response. Schedule downstream procedures 2–4 weeks post-PSE, not the following week.
✶
Repeat PSE is feasible: For partial responders or those with recurrent thrombocytopenia, repeat embolization of residual perfused splenic parenchyma can be performed. Review the 72h CT to identify residual perfused zones and plan the approach for repeat procedure.
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References & Resources
Key Guidelines
- SIR Standards of Practice
- AASLD Portal Hypertension Guidelines (2021)
Primary References
- Sangro B, et al. Partial splenic embolization for the treatment of hypersplenism in cirrhosis. Hepatology. 1993;18(2):309–314. PMID 8340060.
- Noguchi H, et al. Safety and efficacy of partial splenic embolization for thrombocytopenia. J Gastroenterol. 2003;38(1):77–83. PMID 12560905.