Aortoenteric fistula
Updates to Article Attributes
Aortoenteric fistula is an uncommon catastrophic cause of gastrointestinal haemorrhage. Aortic fistulas can be primary (associated with 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%) 1.
The incidence of secondary aortoenteric fistulas is found to be greater in patients following open aortic repair compared to patients with endovascular stent placement.
Clinical presentation
- initial presentation can be with a minor "herald" bleeding, which may be followed by a catastrophic, life-threatening gastrointestinal haemorrhage
- primary aortoenteric fistula: recurrent septicaemia with enteric pathogens
Pathology
A primary aortoenteric fistula forms when a large abdominal aortic aneurysm closely abuts bowel loops, usually the 3rd or 4th parts of the duodenum. Due to long-standing pressure, the aneurysm slowly erodes into the bowel 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.
Clinical features
initial presentation can be with a minor "herald" bleeding, which may be followed by a catastrophic, life-threatening gastrointestinal haemorrhageprimary aortoenteric fistula: recurrent septicaemia with enteric pathogens
Radiographic features
CT
Primary aortoenteric fistula
Direct signs include:
- ectopic gas adjacent to or within the aorta
- the presence of vascular contrast within the gastrointestinal tract
Indirect signs include:
- bowel wall thickening overlying an aneurysm
- disruption of the aortic fat cover
- retroperitoneal haematoma or haematoma 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
- perigraft infection without fistulisation
- retroperitoneal fibrosis
- infected (mycotic) aortic aneurysm
- infectious aortitis
-<p><strong>Aortoenteric fistula</strong> is an uncommon catastrophic cause of gastrointestinal haemorrhage. Aortic fistulas can be primary (associated with complicated <a href="/articles/abdominal-aortic-aneurysm">abdominal aortic aneurysm</a>) or secondary (associated with graft repair).</p><h4>Epidemiology</h4><p>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%) <sup>1. </sup></p><p>The incidence of secondary aortoenteric fistulas is found to be greater in patients following open aortic repair compared to patients with endovascular stent placement.</p><h4>Pathology</h4><p>A primary aortoenteric fistula forms when a large abdominal aortic aneurysm closely abuts bowel loops, usually the 3<sup>rd</sup> or 4<sup>th</sup> parts of the duodenum. Due to long-standing pressure, the aneurysm slowly erodes into the bowel wall. These are most commonly due to infected mycotic aneurysms.</p><p>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. </p><h4>Clinical features</h4><ul>- +<p><strong>Aortoenteric fistula</strong> is an uncommon catastrophic cause of gastrointestinal haemorrhage. Aortic fistulas can be primary (associated with complicated <a href="/articles/abdominal-aortic-aneurysm">abdominal aortic aneurysm</a>) or secondary (associated with graft repair).</p><h4>Epidemiology</h4><p>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%) <sup>1. </sup></p><p>The incidence of secondary aortoenteric fistulas is found to be greater in patients following open aortic repair compared to patients with <a title="EVAR" href="/articles/endovascular-aneurysm-repair">endovascular stent</a> placement.</p><h4>Clinical presentation</h4><ul>
-</ul><h4>Radiographic features</h4><h5>CT</h5><h6>Primary aortoenteric fistula</h6><p>Direct signs include:</p><ul>- +</ul><h4>Pathology</h4><p>A primary aortoenteric fistula forms when a large abdominal aortic aneurysm closely abuts bowel loops, usually the 3<sup>rd</sup> or 4<sup>th</sup> parts of the duodenum. Due to long-standing pressure, the aneurysm slowly erodes into the bowel wall. These are most commonly due to infected mycotic aneurysms.</p><p>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. </p><h4>Radiographic features</h4><h5>CT</h5><h6>Primary aortoenteric fistula</h6><p>Direct signs include:</p><ul>
Image 2 CT (C+ arterial phase) ( create )
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