Residency · Residency · Interventional Radiology
Trauma Angiography and Embolization: Principles
Introduction
Endovascular embolization has become a cornerstone of trauma management, offering a minimally invasive alternative to surgical hemostasis in hemodynamically appropriate patients. Interventional radiologists are integral members of the trauma team, providing rapid angiographic diagnosis and transcatheter embolization for solid organ injuries, pelvic fractures, and vascular injuries across multiple body regions.
Role of IR in the Trauma Algorithm
Hemodynamically stable or stabilized patients with contrast extravasation on CT angiography (CTA) are ideal candidates. Hemodynamically unstable patients who fail initial resuscitation generally require surgery; IR may be used as an adjunct. The hybrid OR/angio suite enables concurrent surgical and endovascular management. IR should be activated early based on CT findings rather than waiting for clinical deterioration. Close communication with trauma surgery, emergency medicine, and anesthesia is essential.
CT Angiography: The Roadmap
CTA is the primary diagnostic tool for identifying the source and severity of hemorrhage. Active extravasation: high-density contrast blush within or adjacent to the injured organ. Pseudoaneurysm: contained vascular injury; may present with delayed hemorrhage. Arteriovenous fistula: abnormal communication between artery and vein. CTA findings guide the decision for observation, embolization, or surgery. Grading systems (AAST organ injury scale) supplement imaging for management decisions.
Angiographic Technique
Vascular Access
Common femoral artery (CFA) is the standard access site; ultrasound-guided puncture recommended. Consider radial artery access for upper extremity or thoracic injuries, or when CFA access is compromised. Use a 5-French vascular sheath as the minimum; upsizing for larger catheters or devices.
Catheter and Wire Selection
Diagnostic catheters: 5F Cobra, SOS Omni, or pigtail for initial aortography. Microcatheters: coaxial systems (2.0-2.8F) for selective and superselective catheterization. Guidewires: hydrophilic wires for navigating tortuous or spastic vessels. Goal is to achieve the most selective catheter position possible to preserve non-injured territory.
Angiographic Assessment
Begin with aortography or regional arteriography to localize hemorrhage. Identify extravasation, pseudoaneurysm, vessel transection, or arteriovenous fistula. Selective catheterization of the feeding vessel confirms the source. DSA (digital subtraction angiography) provides superior resolution for identifying subtle bleeding.
Embolization Principles
Embolization Goals
Hemorrhage control: stop active bleeding while preserving as much organ function as possible. Proximal embolization: occludes the feeding artery upstream; faster but may not prevent collateral refilling. Distal (superselective) embolization: occludes the bleeding vessel at the point of injury; preferred when feasible. Sandwich technique: embolize both proximal and distal to the injury site to prevent backbleeding via collaterals.
Embolic Agent Selection
| Agent | Occlusion Type | Best Application in Trauma | Key Advantage | Key Risk |
|---|---|---|---|---|
| Coils | Permanent, mechanical | Named vessel hemorrhage | Precise, controllable | May miss collateral refilling |
| Gelfoam | Temporary (2-6 weeks) | Diffuse parenchymal hemorrhage | Allows organ recovery | Rebleeding after resorption |
| Particles (PVA/Embospheres) | Permanent, distal | Diffuse distal bleeding | Reaches small branches | Non-target embolization |
| Liquid embolics (NBCA, Onyx) | Permanent | Rapid occlusion, emergent | Very fast, fills irregularities | Difficult to control |
| Vascular plugs (Amplatzer) | Permanent | Large vessel, high-flow | Single deployment | Not for small vessels |
Coils: most commonly used; provide permanent mechanical occlusion; available in pushable and detachable varieties. Gelatin sponge (Gelfoam): temporary agent; resorbs in 2-6 weeks; useful for diffuse hemorrhage. Particles (PVA, Embospheres): for distal, diffuse bleeding not reachable with coils. Liquid embolics (n-BCA, Onyx): for rapid occlusion in emergent settings or when coils are insufficient. Vascular plugs (Amplatzer): rapid occlusion of larger arteries; useful in high-flow situations.
Selection Factors
Match agent to vessel size, flow rate, and clinical urgency. Coils for larger named vessels; particles or Gelfoam for diffuse distal hemorrhage. Avoid non-target embolization by confirming catheter position before deploying agents. Consider end-organ effects: renal, hepatic, and splenic embolization have specific organ-preservation considerations.
Complications of Trauma Embolization
Non-target embolization: particles or liquid agents reflux into unintended territories; can cause ischemia. Post-embolization syndrome: fever, pain, leukocytosis; common after solid organ embolization. Organ infarction: splenic, hepatic, or renal infarcts; usually well tolerated if limited. Rebleeding: from collateral refilling or incomplete embolization; may require repeat angiography. Access site complications: hematoma, pseudoaneurysm, dissection; especially in coagulopathic trauma patients. Contrast-induced nephropathy: minimize contrast volume in patients with renal injury.
Post-Procedure Management
ICU monitoring: continuous hemodynamic monitoring, serial hemoglobin, repeat imaging as needed. Maintain resuscitation targets: MAP > 65 mmHg, hemoglobin > 7 g/dL, correct coagulopathy. CT reassessment if clinical deterioration suggests rebleeding or complications. Follow-up imaging at 48-72 hours for high-grade injuries to assess for delayed complications. Multidisciplinary communication with trauma surgery for ongoing management decisions.
Key Clinical Pearls
CTA with contrast extravasation is the primary indication for trauma embolization in hemodynamically appropriate patients. Superselective embolization preserves organ function; always aim for the most selective catheter position possible. Coils are the workhorse embolic agent; Gelfoam provides temporary hemostasis for diffuse hemorrhage. Non-target embolization is the most feared complication; confirm catheter position before deploying agents. Early IR activation and integration into the trauma team algorithm improves outcomes.
References
- Defined the Core Competencies. Defined the Practice Standards. Defined the Core Clinical Practice. Defined the Core Practice Guidelines. Society of Interventional Radiology Standards of Practice. 2020.
- Defined the Core Competencies. Defined the Practice Standards. Defined the Core Clinical Practice. Defined the Core Practice Guidelines. Western Trauma Association Critical Decisions in Trauma. 2020.
- Defined the Core Practice Guidelines. Defined the Core Clinical Practice. EAST Practice Management Guidelines for Hemorrhage in Pelvic Fracture. 2021.
- Defined the Core Practice Guidelines. Defined the Core Clinical Practice. ACS Committee on Trauma: ATLS Guidelines. 10th ed. 2018.