Vascular trauma management

🚨 Signs of Trouble

• Hard Signs (→ Immediate OR)

  • Pulsatile external bleeding
  • Rapidly expanding hematoma
  • Palpable thrill or audible bruit
  • Absent distal pulses
  • Signs of distal ischemia (limb threat)
    • 📌 6 P's: Pain, Pallor, Pulselessness, Paresthesia, Paralysis, Poikilothermia

• Soft Signs (→ Further Investigation)

  • History of significant hemorrhage at scene
  • Diminished distal pulses (vs. absent)
  • Non-expanding hematoma
  • Bony injury (e.g., fracture/dislocation)
  • Neurologic deficit in an adjacent nerve

⭐ Hard signs mandate immediate surgical exploration. Soft signs or an Ankle-Brachial Index (ABI) < 0.9 prompt further diagnostic imaging, typically a CT Angiogram (CTA).

🩺 Diagnosis - Finding the Leak

• Initial Assessment: Ankle-Brachial Index (ABI) is a rapid, non-invasive screening tool.

  • Formula: $ABI = \frac{P_{ankle}}{P_{brachial}}$
  • An ABI < 0.9 is highly suggestive of arterial injury.

• Diagnostic Pathway:

• Definitive Imaging:
  • CT Angiography (CTA): The gold standard for hemodynamically stable patients. It's fast, widely available, and accurately identifies the injury (e.g., transection, pseudoaneurysm).
  • Conventional Angiography: Most accurate; reserved for equivocal CTA or planned endovascular intervention.

⭐ An ABI < 0.9 in a patient with extremity trauma is a critical threshold. It mandates further imaging (usually CTA) even if distal pulses are palpable.

🩹 Management - Plugging the Holes

• Initial Control:

  • Direct Pressure: First-line for external bleeding.
  • Tourniquet: For extremity exsanguination. Apply proximal; note time.
  • Damage Control: In unstable patients, use temporary shunts or ligation.

• Decision Pathway:

• Definitive Repair:
  • Primary Repair: Simple lacerations.
  • Patch Angioplasty: Vein patch for larger defects.
  • Interposition Graft: For segmental loss.
  • Ligation: Non-critical arteries or life-saving.
  • Endovascular: Stent-grafts, embolization.

⭐ Reversed saphenous vein is the ideal conduit for most extremity arterial repairs due to its resistance to infection and good size match.

💡 Consider prophylactic fasciotomy for significant ischemia-reperfusion to prevent compartment syndrome.

💥 Complications - The Aftermath

• Compartment Syndrome
  • 📌 6 P's: Pain out of proportion, Pallor, Paresthesias, Pulselessness (late), Paralysis (late), Poikilothermia.
  • Dx: Compartment pressure > 30 mmHg or Delta P (Diastolic BP - Compartment P) < 20-30 mmHg.
  • Tx: Emergent fasciotomy.
• Reperfusion Injury
  • Mechanism: ↑ Oxygen free radicals & inflammatory cascade post-revascularization.
  • Leads to: Rhabdomyolysis (↑ CK), hyperkalemia, metabolic acidosis, AKI.
• Other
  • Thrombosis/Embolism
  • Infection (especially with grafts)
  • Late: Pseudoaneurysm, Arteriovenous Fistula (AVF)

⭐ Pain out of proportion to injury is the earliest and most sensitive sign of compartment syndrome. Pulselessness is a very late and ominous finding.

⚡ Biggest Takeaways

• Hard signs (pulsatile bleed, expanding hematoma, bruit/thrill, absent pulses) mandate immediate surgical exploration.
• Soft signs (proximity injury, diminished pulses) or an ABI < 0.9 require further imaging, typically CTA.
• Always suspect popliteal artery injury with any posterior knee dislocation or complex knee injury; get an ABI/CTA.
• Compartment syndrome is a clinical diagnosis (pain out of proportion); requires emergent fasciotomy.
• Initial hemorrhage control is direct pressure; use a tourniquet for uncontrolled extremity bleeding.