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Acute Aortic Occlusion

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Acute Aortic Occlusion, Aortic Occlusion

  • See Also
  1. Abdominal Aortic Aneurysm
  2. Aortic Dissection
  • Definitions
  1. Acute Aortic Occlusion (AAO)
    1. Rare, life threatening, sudden Occlusion of the aorta, either by thrombosis or embolism
  • Epidemiology
  1. Rare
  2. Infrarenal Aortic Occlusion is most common
  • Risk Factors
  1. Thrombosis
    1. Atherosclerosis
    2. Low flow states (e.g. major surgery)
    3. Hypercoagulable state
    4. Tobacco Abuse
    5. Diabetes Mellitus
    6. Blunt Abdominal Trauma
      1. May result in injury to aortic intima layer, precipitating thrombosis
    7. Abdominal Aortic Aneurysm
    8. Male gender
    9. Prior aortic reconstruction surgery (e.g. endovascular aortic aneurysm repair)
  2. Embolism
    1. Valvular heart disease
    2. Female gender
    3. Atrial Fibrillation
  • Findings
  1. Background
    1. Presentating signs relate to level of obstruction
    2. Thrombotic Occlusions may be more subtle on presentation due to collateral circulation
  2. Torso
    1. Abdominal Pain or tenderness
    2. Back pain
  3. Bilateral Acute Limb Ischemia
    1. Acute pain or Paresthesias
    2. Leg paralysis or weakness
    3. Decreased lower extremity Deep Tendon Reflexes
    4. Leg mottling, pallor or coldness
    5. Decreased or absent peripheral pulses
  4. Renal Involvement (suprarenal Occlusion)
    1. Hypertensive Crisis
  • Causes
  1. Thrombosis (60 to 70% of cases)
    1. Most commonly infrarenal
  2. Occlusion of aortic reconstruction such as aorta graft or stent (10-20%)
  3. Saddle embolism (10 to 20%)
    1. Historically most common, but modern Anticoagulants have reduced Incidence of embolism
    2. Typically occurs as a large saddle embolism to the aortic bifurcation (to the iliac arteries)
  • Differential Diagnosis
  1. Cerebrovascular Accident
  2. Cauda Equina Syndrome
  3. Spinal Cord Syndrome
  4. Aortic Dissection
  5. Abdominal Aortic Aneurysm
  • Imaging
  1. Bedside Ultrasound
    1. Performed as part of initial exam
    2. FAST Scan
    3. Abdominal Aorta Ultrasound
      1. Observe for echogenic material within aorta, without color flow
    4. Common femoral artery Ultrasound
  2. CT Angiography of Aorta (Chest AbdomenPelvis CTA)
    1. First-line study
  • Management
  1. General Measures
    1. Opioid Analgesics
    2. Anticoagulation with weight-based Heparin
    3. ABC Management
  2. Emergent vascular surgery Consultation for operative intervention
    1. Thromboembolectomy
    2. Axillary-Bifemoral Bypass
    3. Aortic-Biilliac/Bifemoral Bypass
  3. Other therapeutic options
    1. Consider Thrombolysis (esp. distal lesions)
  • Complications
  1. Mortality: 34 to 52%
    1. Highest mortality with suprarenal Occlusion
  2. Acute Renal Failure: 50%
  3. Limb Amputation: 7 to 31%
  4. Fasciotomy: 20 to 33%
  5. Mesenteric Ischemia 10 o 14%
  6. Acute Myocardial Ischemia: 14%
  • References
  1. Adibi (2020) Acute Aortic Occlusion, EMdocs, accessed 1/1/2022
    1. http://www.emdocs.net/acute-aortic-occlusion/
  2. Crawford (2014) J Vasc Surg 59:1044-50 [PubMed]
  3. Grip (2019) Circulation 139:292-4 [PubMed]