Introduction
  • Minimally invasive interventional radiology procedure to reduce splenic blood flow
  • Alternative to splenectomy for managing splenic pathology in pediatric patients
  • Preserves splenic tissue and immune function while addressing underlying condition​s

Indications
  • Traumatic splenic injury with hemodynamic stability (most common indication)
  • Hypersplenism with severe cytopenias refractory to medical management
  • Splenic artery aneurysm or pseudoaneurysm
  • Splenic arteriovenous malformation
  • Portal hypertension with massive splenomegaly and hypersplenism
  • Hereditary spherocytosis with severe anemia
  • Immune thrombocytopenic purpura (ITP) refractory to medical therapy
  • Splenic sequestration crisis in sickle cell disease
 ​

Contraindications
Absolute Contraindications
  • Severe coagulopathy that cannot be corrected
  • Active splenic infection or abscess

Relative Contraindications
  • Renal insufficiency (contrast nephropathy risk)
  • Pregnancy (radiation exposure)
  • Portal vein thrombosis
  • Previous extensive splenic infarction
  • Severe heart failure or hemodynamic instability

Pre-Procedure
  • Complete history and physical examination focusing on bleeding history
  • Assessment of splenic size and tenderness. Cross-sectional studies to establish splenic volume and planned percentage of devascularization.
  • Evaluation for signs of portal hypertension
  • Review of previous imaging studies (CT, MRI, ultrasound)
  • Informed consent discussion with patient and family
  • History including indication and prior procedures.
  • Vaccination history review and pre-procedure immunization optimization

Vaccinations
Pre-Procedure Vaccination (Ideally 2-4 weeks before procedure)
  • Pneumococcal vaccine: PCV13 and PPSV23 per age-appropriate schedule
  • Meningococcal vaccine: Quadrivalent conjugate vaccine (MenACWY) and serogroup B (MenB) if age-appropriate
  • Haemophilus influenzae type b (Hib): Complete age-appropriate series if not already done
  • Influenza vaccine: Annual seasonal vaccine
  • COVID-19 vaccine: Per current CDC recommendations for age group
  • Routine childhood vaccines: Ensure up-to-date per CDC schedule including MMR, varicella, hepatitis A/B
Emergency Procedure Vaccination Protocol
  • If urgent procedure cannot be delayed for optimal vaccination timing
  • Administer available vaccines at least 24-48 hours pre-procedure if possible
  • Priority vaccines: pneumococcal (PCV13/PPSV23) and meningococcal (MenACWY)
  • Document suboptimal timing and plan for booster doses post-procedure
Post-Procedure Vaccination (2-4 weeks after procedure)
  • Booster doses: For any vaccines given in emergency setting with suboptimal timing
  • Completion of series: Any incomplete vaccine series should be continued
  • Annual vaccines: Influenza vaccine annually, COVID-19 boosters per recommendations
  • Additional pneumococcal protection: Consider additional PPSV23 doses in high-risk patients
  • Travel vaccines: If indicated, administer per destination requirements and timing guidelines

Labs
  • Complete blood count with differential and platelet count (aim for >50,000)
  • Comprehensive metabolic panel including creatinine
  • Liver function tests
  • Prothrombin time (PT) and partial thromboplastin time (PTT)
  • International normalized ratio (INR). Target < 1.5 
  • Type and screen or crossmatch for blood products
  • Urinalysis and pregnancy test if applicable

Technique
  • Pre-Procedure Antibiotic Prophylaxis
  • Routine prophylaxis recommended: All patients undergoing splenic artery embolization should receive antibiotic prophylaxis
  • Standard regimen: Cefazolin 1g IV (weight-based dosing for children: 25-50 mg/kg, max 1g) administered immediately pre-procedure
  • Alternative agents: Vancomycin 500-1000 mg IV (15 mg/kg for children) for penicillin/cephalosporin allergies
​
General Protocol
  • General Anesthesia with paralysis.
  • Arterial access via the common femoral, radial or brachial artery.
  • 4/5 French sheath.
  • 4/5 Fr 0.038” Kumpe, Vert or C2 catheter to access the splenic artery.
  • Consider glucagon to reduce bowel motion, 10 mcg/kg (max 500 mcg or 0.5 mg) IV. 
  • Abdominal aortogram can be performed for more thorough evaluation, but can be omitted.
  • Superselective catheterization of splenic artery branches, particularly if considering distal embolization.
  • Identify major pancreatic branches (e.g. dorsal pancreatic artery and greater pancreatic artery).
Embolization Procedure
  • Choice of embolic agent based on target pathology (coils, particles, plugs)
  • Proximal embolization for aneurysms or trauma
  • Distal embolization for hypersplenism (partial embolization)
  • Real-time fluoroscopic guidance during embolic agent deployment
  • Post-embolization angiography to confirm occlusion and assess collateral flow
  • Hemostasis at access site using manual compression or closure device

Proximal splenic artery embolization (PSAE)
  • For aneurysms of the main artery or trauma.
  • Distal to the dorsal pancreatic artery, allows splenic perfusion is maintained through pancreatic collaterals. 
  • Vascular plugs or coils

Distal splenic artery embolization (DSAE)
  • Super-selective distal embolization for hypersplenism (aim for 30-70% devascularization)
  • Lower risk of complications with middle or lower pole splenic branches.

Embolic Agents
  • Microcoils for precise vessel occlusion through microcatheter (Embold or Penumbra coils)
  • Gelfoam pledgets or slurry for temporary occlusion
  • Polyvinyl alcohol particles (300- 500 μm or larger) for distal embolization
  • Amplatzer vascular plugs for larger vessel occlusion, diameter 30-50% larger than the artery
  • N-butyl cyanoacrylate glue for arteriovenous malformations

Proximal splenic artery embolization

Celiac artery angiography visualizing the anatomy of splenic vasculature
Splenic artery angiography (pre-embolization)
Splenic artery angiography (post-embolization using Amplatzer 4 plug and 30 cm Penumbra packing coil) 

Complications
Immediate ComplicationsAccess site hematoma or bleeding
  • Contrast-induced allergic reaction
  • Contrast-induced nephropathy
  • Splenic artery dissection or perforation
  • Non-target embolization
  • Coil migration
Early Complications (24-72 hours)
  • Post-embolization syndrome (fever, pain, nausea)
  • Splenic infarction
  • Splenic abscess formation (risk increases with >70% embolization)
  • Pancreatitis (rare)
  • Left pleural effusion
  • Bacterial peritonitis
Late Complications
  • Splenic necrosis requiring splenectomy
  • Gastric fundal ischemia
  • Collateral vessel formation with re-bleeding
  • Incomplete response requiring repeat procedure
  • Long-term immunocompromise (rare with partial embolization)
  • Increased susceptibility to encapsulated bacterial infections
  • Thromboembolic complications (portal vein thrombosis, pulmonary embolism)
  • Access site complications (pseudoaneurysm, arteriovenous fistula)

Post-Procedure
  • Monitoring in recovery area for 2-4 hours minimum
  • Vital signs assessment every 15 minutes initially
  • Access site monitoring for bleeding or hematoma
  • Pain management with appropriate analgesics
  • Clear liquid diet advancement as tolerated
  • Ambulation after 4-6 hours if stable
  • Anticoagulation management per protocol. Consider low-dose LMWH for high thromboembolic risk patients.
Post-procedure antibiotic administration: Based on embolization extent and risk stratification
  • Moderate embolization (50-70% splenic volume):
    • Amoxicillin/clavulanate 500/125 mg PO BID for 5 days (pediatric: 20-40 mg/kg/day amoxicillin component)
    • Alternative: Cefoperazone 1g IV q12h for 5 days (pediatric: 25-50 mg/kg q12h)
  • Extensive embolization (>70% splenic volume):
    • Amoxicillin/clavulanate 875/125 mg PO BID for 7-10 days (pediatric: 40 mg/kg/day amoxicillin component)
    • Monitor for signs of abscess formation with low threshold for imaging
Discharge criteria: stable vital signs, no access site complications, tolerating oral intake
​
Long-Term Antibiotic Prophylaxis (Post-Splenectomy-Like Prophylaxis)Age-Based Recommendations
  • Children <2 years: Penicillin V 125 mg PO BID or amoxicillin 20 mg/kg/day divided BID
  • Children 2-5 years: Penicillin V 125 mg PO BID or amoxicillin 250 mg PO BID
  • Children >5 years: Penicillin V 250 mg PO BID or amoxicillin 250 mg PO BID
  • Duration: Minimum 1-2 years post-procedure, until age 5 years (whichever is longer)
High-Risk Scenarios Requiring Extended Prophylaxis
  • Immunocompromised patients: Lifelong prophylaxis consideration
  • Extensive embolization (>70%): Extended prophylaxis for 2-3 years
  • Recurrent infections: Indefinite prophylaxis
  • Congenital asplenia equivalent: Lifelong prophylaxis

Follow-up
Clinical & Laboratory Follow-Up
  • Platelets: Platelet count rises 12-24 h after SAE, peaks at 1 or 2 weeks, stabilizes in 2 months at about 2 times higher than that before SAE and correlates with volume of spleen infarction. Stable may be lower than peak and may remain significantly high for up to 8 years.
  • White blood cell: Transient elevation of WBCs is a normal response after splenectomy. It could be found at POD 1, may reach peak at POD 3. Prolonged elevation of WBCs may imply an infection. After SAE, WBCs increase markedly: around 50% at 1 month and 30% at 6 months.
  • Red blood cells: RBCs destruction occurs almost exclusively in the enlarged spleen. Rise in the RBC count may be found 3 months after SAE, significantly increased at 6 months after the procedure - even up to normal level, remaining increased for up to 7.5 years.
  • Alteration of hemodynamics: SAE improves the local hyperdynamic state in the splenic area in cirrhosis. It may increase hepatic arterial and superior mesenteric blood flow.
  • Reduction of splenic volume: Nonembolized volume can be used to predict the functional outcome of SAE. Spleen will shrink gradually in months. CT scan is the practical method to measure splenic infarction.
  • Improvement in gastric mucosa.
  • Improved liver perfusion and function.
  • Improvement in hepatic encephalopathy.
  • Improvement in hepatopulmonary syndrome.

Imaging Follow-Up
  • If distal embolization, consider CT of the abdomen and pelvis with contrast 1 day after to assess the volume of devascularization
  • If concern for infection, consider ultrasound or CT to assess for abscess.

Long-Term Follow-Up (3-6 months)
  • Clinical examination and symptom assessment
  • Laboratory monitoring of blood counts and organ function
  • Cross-sectional imaging (CT or MRI) to assess splenic perfusion
  • Assessment for treatment efficacy and need for additional intervention
  • Vaccination compliance monitoring: Ensure completion of post-procedure vaccination schedule
  • Infection surveillance: Monitor for signs of overwhelming post-splenectomy infection (OPSI)
  • Antibiotic prophylaxis evaluation: Assess need for continuation based on clinical status

References
  1. Gill K, Aleman S, Fairchild AH, et al. Splenic artery embolization in the treatment of blunt splenic injury: single level 1 trauma center experience. Diagn Interv Radiol. 2025;31(4):359-365. doi:10.4274/dir.2024.242789
  2. Yoon HK, Kim JS. Splenic artery embolization for trauma: a narrative review. J Trauma Inj. 2024;37(4):245-258. doi:10.20408/jti.2024.0056
  3. Jones B, Elbakri AS, Murrills C, et al. Splenic artery embolisation for blunt splenic trauma: 10 years of practice at a trauma centre. Ann R Coll Surg Engl. 2024;106(3):283-287. doi:10.1308/rcsann.2023.0118
  4. Bazeboso JA, Mbuyi Mukendi D, Mbongo CL, et al. Partial Splenic Embolization in Paediatric Sickle Cell Disease Patients with Hypersplenism. Cardiovasc Intervent Radiol. 2024;47(5):652-660. doi:10.1007/s00270-024-03701-4
  5. Gowda S, Ghosh T, Rajagopal R, et al. Outcomes after Embolization in Pediatric Abdominal Solid Organ Injury: A Trauma Center Experience. Indian J Radiol Imaging. 2024;34(3):416-421. doi:10.1055/s-0043-1778057
  6. Dhillon NK, Harfouche MN, Hawley KL, et al. Embolization of pseudoaneurysms is associated with improved outcomes in blunt splenic trauma. J Surg Res. 2024;293:656-662. doi:10.1016/j.jss.2023.11.011
  7. Cretcher M, Panick CE, Boscanin A, Farsad K. Splenic trauma: endovascular treatment approach. Ann Transl Med. 2021;9(14):1194. doi:10.21037/atm-20-4381
  8. Annam A, Josephs S, Johnson T, et al. Pediatric trauma and the role of the interventional radiologist. Emerg Radiol. 2022;29(5):903-914. doi:10.1007/s10140-022-02069-7
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