CV

Aortoenteric Fistula

search

Aortoenteric Fistula, Aortic Graft-Enteric Fistula

  • Pathophysiology
  1. Fistula formation from aorta to adjacent bowel
  2. Complication of aortic repair (stenting, grafting)
    1. Infection of aortic graft material is cause in most cases
    2. Onset typically in first year after repair
  • Findings
  1. Gastrointestinal Bleeding (80%)
  2. Sepsis (44%)
  3. Abdominal Pain (30%)
  4. Back Pain (15%)
  • Imaging
  • CT Aorta Angiogram
  1. Intravenous Contrast only
    1. No Oral Contrast (obscures bleeding within bowel lumen)
  2. CT Aorta Angiogram with 3 phase protocol of Chest, Abdomen, Pelvis
    1. Noncontrast CT
    2. Arterial Phase CT with contrast injection
    3. Delayed Imaging CT at 80 sec
  3. Findings
    1. Active bleeding (e.g. into bowel lumen)
    2. Aortic wall discontinuity
    3. Focal bowel wall thickening
    4. Loss of fat between aorta and bowel wall
    5. Signs of infection
      1. Fat stranding
      2. Fluid collection (may be normal in first 3 months after surgery)
      3. Periaortic gas (may be normal up to 4 weeks after surgery)
    6. Differential diagnosis findings
  4. Efficacy
    1. Test Sensitivity: 40 to 90%
    2. Test Specificity: 33 to 100%
  • Management
  1. Broad spectrum Antibiotics
  2. Surgical repair including removal of infected graft material
  • References
  1. Broder (2021) Crit Dec Emerg Med 35(12): 14-5
  2. Vu (2009) Radiographics 29: 197-209 [PubMed]