Residency · Residency · Interventional Radiology
Splenic Trauma: Embolization vs. Splenectomy
Introduction
The spleen is the most commonly injured solid organ in blunt abdominal trauma. Non-operative management (NOM) with or without splenic artery embolization (SAE) has become the standard of care for hemodynamically stable patients, achieving splenic salvage rates exceeding 90%. Understanding the role of embolization in augmenting NOM and the indications for operative splenectomy is essential for interventional radiologists.
AAST Spleen Injury Grading Scale
| AAST Grade | Injury Description | Management |
|---|---|---|
| I | Subcapsular hematoma <10%; laceration <1 cm depth | NOM (observation) |
| II | Subcapsular hematoma 10-50%; laceration 1-3 cm | NOM (observation) |
| III | Subcapsular hematoma >50% or expanding; laceration >3 cm | NOM + SAE (if stable) |
| IV | Segmental/hilar vessel injury, >25% devascularization | NOM + SAE or surgery |
| V | Shattered spleen or hilar vascular injury | Surgery (splenectomy) unless stabilized |
Grade I: subcapsular hematoma < 10% surface area; capsular laceration < 1 cm depth. Grade II: subcapsular hematoma 10-50%; parenchymal laceration 1-3 cm depth. Grade III: subcapsular hematoma > 50% or expanding; parenchymal laceration > 3 cm depth. Grade IV: laceration involving segmental or hilar vessels with major devascularization (> 25%). Grade V: shattered spleen or hilar vascular injury with complete devascularization. Higher grades and the presence of contrast extravasation or pseudoaneurysm on CTA increase the role for SAE.
Indications for Splenic Artery Embolization
Active extravasation on CTA in a hemodynamically stable patient. Pseudoaneurysm identified on CTA regardless of injury grade. High-grade injuries (AAST III-V) in hemodynamically stable or stabilized patients. Ongoing transfusion requirements despite resuscitation in patients who are not surgical candidates. Some centers use SAE for all grade III-V injuries to improve NOM success rates. Hemodynamic instability refractory to resuscitation remains an indication for splenectomy, not embolization.
Embolization Techniques
Proximal Splenic Artery Embolization
Coil or plug placement in the main splenic artery (typically mid-body, distal to the dorsal pancreatic artery). Reduces perfusion pressure while maintaining splenic viability through collateral flow (short gastric, left gastroepiploic arteries). Preserves immunologic function in the majority of patients. Technically faster and simpler than selective embolization. Appropriate for diffuse injuries or multiple sites of hemorrhage.
Distal (Selective) Embolization
Superselective catheterization of the specific bleeding intrasplenic branch. Coil embolization at the site of extravasation or pseudoaneurysm. Preserves more splenic parenchyma and blood flow to uninjured segments. Technically more demanding; requires microcatheter access. Appropriate for focal injuries with a single identifiable bleeding source.
Combined Proximal and Distal
Some centers employ a combination approach for high-grade injuries. Selective embolization of the bleeding source followed by proximal coil to reduce rebleeding risk. May offer the best combination of hemostasis and splenic preservation.
Procedure Details
Common femoral artery access with 5F sheath. Celiac arteriography to evaluate splenic artery anatomy and identify bleeding sites. Selective splenic arteriography with DSA to confirm CTA findings. Advance microcatheter coaxially for selective or superselective embolization. Deploy coils (microcoils for distal, standard coils or plugs for proximal). Completion angiography to confirm cessation of extravasation and preserved splenic perfusion. Sheath removal with closure device or manual compression.
Outcomes
NOM with SAE success rate: 85-95% for all grades combined. SAE reduces NOM failure rate from approximately 20-30% to 5-10% in high-grade injuries. Splenic salvage rate: > 90% when SAE is performed appropriately. Rebleeding rate after SAE: 5-10%; requires repeat angiography or surgery. Overall mortality from splenic injury with appropriate management: 5-10%.
Complications of SAE
Splenic infarction: occurs in 20-30% of cases; usually segmental and clinically well tolerated. Splenic abscess: 3-5%; managed with percutaneous drainage and antibiotics. Post-embolization syndrome: fever, left upper quadrant pain, leukocytosis; self-limited in most cases. Rebleeding: may require repeat embolization or splenectomy. Complete splenic infarction/loss: rare with proximal embolization; consider vaccination if occurs.
Splenectomy: When Surgery Is Necessary
Hemodynamic instability refractory to resuscitation. Grade V shattered spleen with hilar disruption. Failed NOM or SAE: ongoing hemorrhage despite embolization. Associated injuries requiring emergent laparotomy. Post-splenectomy patients require vaccination against encapsulated organisms: pneumococcus, meningococcus, Haemophilus influenzae type b (ideally 14 days post-splenectomy).
Post-Procedure Monitoring
ICU admission for serial hemoglobin monitoring (every 6 hours for 24-48 hours). Bed rest with activity restriction for 24-72 hours post-embolization. Repeat CTA if clinical deterioration or falling hemoglobin. Follow-up imaging at 48-72 hours for high-grade injuries. Activity restriction for 6-8 weeks after high-grade splenic injury.
Key Clinical Pearls
Splenic artery embolization significantly improves NOM success rates for high-grade splenic injuries. Proximal embolization reduces perfusion pressure while preserving splenic function via collateral flow. Selective embolization is preferred for focal injuries when technically feasible. Post-embolization splenic infarction is common but usually well tolerated and clinically insignificant. Hemodynamic instability refractory to resuscitation mandates splenectomy, not embolization.
References
- Stassen NA, Bhullar I, Cheng JD, et al. Selective Nonoperative Management of Blunt Splenic Injury: An Eastern Association for the Surgery of Trauma Practice Management Guideline. Journal of Trauma and Acute Care Surgery. 2012;73(5 Suppl 4):S294-S300.
- Bhullar IS, Frykberg ER, Siragusa D, et al. Selective Angiographic Embolization of Blunt Splenic Traumatic Injuries in Adults Decreases Failure Rate of Nonoperative Management. Journal of Trauma and Acute Care Surgery. 2012;72(5):1127-1134.
- Defined the Core Competencies. Defined the Practice Standards. AAST Organ Injury Scaling 2018 Update. Journal of Trauma and Acute Care Surgery. 2018;85(6):1119-1122.
- Defined the Core Practice Guidelines. Defined the Core Clinical Practice Standards. Western Trauma Association Guidelines: Blunt Splenic Injury. 2021.