aortoenteric fistula

Imaging of
the oesophagus: beyond cancer. Aortoesophageal Fistula. CT angiogram of the chest in soft tissue window in axial (a) and sagittal (b) planes demonstrates extravasation of contrast from the descending thoracic aorta into the oesophagus. Soft tissue attenuation material within the oesophagus is consistent with clotted blood
insightsimaging.springeropen.com • Open Access
Esophageal
emergencies: another important cause of acute chest pain. Esophageal fistulas. a Esophago-pleural fistula in a 61-year-old male with squamous cell carcinoma of mid esophagus, status post esophagectomy and gastric pull through presenting with fever. Axial CT image obtained 12 days after surgery shows a fistula (arrowheads) between the gastric tube and the right pleural space. Fluid collection with pleural enhancement and thickening (arrow) is suspicious for empyema. Reprinted with permission from Kim et al. Radiographics 2007; 27(2):409-429. b Aorto-esophageal fistula in a 70-year-old male patient with hypertension and regular alcohol use presenting with hematemesis and melena. Axial image of CT chest angiography shows type B aortic dissection with rupture, communication, and extravasation between aorta and esophagus (blue arrow) in the arterial phase. Reprinted from Kokatnur. Indian J Crit Care Med. 2015;19(2):119–121
insightsimaging.springeropen.com • CC-by-4.0
Radiopaedia • CC-by-nc-sa 3.0 • de

Aortoenteric fistulas are pathologic communications between the aorta (or aortoiliac tree) and the gastrointestinal tract and represent an uncommon cause of catastrophic gastrointestinal hemorrhage.

Aortic fistulas may be considered primary (associated with a complicated abdominal aortic aneurysm) or secondary (associated with graft repair).

Epidemiology

The annual incidence of primary aortoenteric fistulas is thought to be around 0.007 per million while that of secondary aortoenteric fistulas is about ~1% (range 0.6-2%) .

The incidence of secondary aortoenteric fistulas is found to be higher in patients following open aortic repair compared to patients with endovascular stent placement.

Clinical presentation

  • classically, aortoenteric fistula may initially present with minor "herald" gastrointestinal hemorrhage, followed by a later catastrophic life-threatening gastrointestinal hemorrhage
  • primary aortoenteric fistula may present with recurrent septicemia with enteric pathogens 

Pathology

A primary aortoenteric fistula forms when a large abdominal aortic aneurysm closely abuts bowel loops, usually the 3 or 4 parts of the duodenum. Similarly, in the chest, when a large thoracic aortic aneurysm compresses the esophagus. Due to long-standing pressure, the aneurysm slowly erodes into the bowel or esophageal wall. These are most commonly due to infected mycotic aneurysms.

Secondary aortoenteric fistulas are seen as a complication of aortic reconstructive surgery with or without the placement of an aortic stent-graft. Secondary fistulas that result from perigraft infection may occur between 2 weeks and 10 years after surgery.

Radiographic features

CT
Primary aortoenteric fistula

Direct signs include:

  • ectopic gas adjacent to or within the aorta
  • presence of vascular contrast within the gastrointestinal tract

Indirect signs include:

  • bowel/esophageal wall thickening overlying an aneurysm
  • disruption of the aortic fat cover
  • retroperitoneal/mediastinal hematoma or hematoma within the bowel wall or lumen
Secondary aortoenteric fistula
  • increased perigraft soft tissue
  • pseudoaneurysm formation
  • disruption of aneurysmal wrap
  • increased soft tissue between the graft and aneurysmal wrap

Treatment and prognosis

The only curative treatment is surgery. Without prompt surgical intervention, mortality approaches 100%. Operative mortality itself is as high as 50%.

Differential diagnosis

On imaging, consider:

History and etymology

First described by Sir Astley Cooper (1768-1841), a British surgeon in the early 19 century .

Siehe auch:
und weiter:
Assoziationen und Differentialdiagnosen zu aortoösophageale Fistel:
Bauchaortenaneurysma
 
Wikipedia • CC BY-SA 4.0