Diagnosis

Aortoenteric fistula

Etiology

Cause [smc]

• Primary aortoenteric fistula:

  • Compression of abdominal aortic aneurysm into GI organs (most common)

  • Foreign body

  • Tumor

  • Radiation therapy

  • Infection (tuberculosis, syphilis, septic aortitis, mycotic aneurysm, salmonella)

• Secondary aortoenteric fistula:

  • Erosion of an aortic prosthetic graft into the gastrointestinal organs

  • Endovascular aneurysm repair (metal aortic stents)

  • The most frequent site of bowel connection is the duodenum.

Pathophysiology: Aortoenteric erosion --> fistula [4mz]

• Mechanical or inflammatory degradation of the aorta and bowels as they rub against each other due to pulsation and peristalsis

• Enteral bacteria translocate into the bloodstream and contaminate the graft leading to life-threatening fistula, sepsis, and graft infection

Epidemiology

Incidence per 100.000 [are][4mz]

Approach

• Blood test

• Blood gas

• Blood cultures

• Ultrasonography

• CT angiography

• Upper gastrointestinal endoscopy

• Colonoscopy

• MRI

Treatment

1. Resuscitation and hemodynamic support [4mz]

   • 1:1:1 transfusion ratio of packed red blood cells to platelets and fresh frozen plasma

2. Broad-spectrum antimicrobial therapy (after blood culture)

3. Endovascular repair: a bridging therapy to definitive surgical management

4. Open aortic repair:

   • Primary aortic repair using biologic vascular grafts and intestinal resection

   • Extra-anatomic bypass and aortic/GI-resection

Differential diagnoses

Abdominal aortic aneurysm, Angiodysplasia, Colorectal cancer, Crohn disease, Gastrointestinal hemorrhage, Hemorrhoids, Perforated ulcer, Ruptured aortic aneurysm, Septic aortitis, Ulcerative colitis, Ulcer disease, Vascular graft infection