Arecaidine

Aortoenteric Fistula

An aortoenteric fistula is an abnormal connection between the aorta and the gastrointestinal tract. This condition is a rare but serious complication that can lead to massive gastrointestinal bleeding and is often life-threatening. Aortoenteric fistulas can be classified as either primary or secondary.

Classification

Primary Aortoenteric Fistula

Primary aortoenteric fistulas occur spontaneously and are usually associated with abdominal aortic aneurysms. They are rare and often result from the erosion of an aortic aneurysm into the adjacent bowel, most commonly the duodenum.

Secondary Aortoenteric Fistula

Secondary aortoenteric fistulas are more common and occur as a complication of previous aortic surgery, particularly after aortic graft placement. These fistulas can develop due to infection, graft erosion, or mechanical stress on the graft leading to erosion into the bowel.

Pathophysiology

The pathophysiology of aortoenteric fistulas involves the erosion of the aortic wall or graft into the gastrointestinal tract. This erosion can be due to infection, mechanical stress, or inflammatory processes. Once the aorta or graft erodes into the bowel, it creates a direct communication between the vascular system and the gastrointestinal tract, leading to potential massive bleeding.

Clinical Presentation

Patients with aortoenteric fistulas typically present with symptoms of gastrointestinal bleeding, which can range from occult bleeding to massive hemorrhage. Common symptoms include:

• Melena
• Hematochezia
• Abdominal pain
• Hypotension
• Tachycardia

In some cases, a "herald bleed" may occur, which is a small initial bleed that precedes a massive hemorrhage.

Diagnosis

Diagnosing an aortoenteric fistula can be challenging due to its rarity and the nonspecific nature of its symptoms. Diagnostic methods include:

• Computed tomography angiography (CTA)
• Endoscopy
• Magnetic resonance imaging (MRI)

CTA is often the preferred initial diagnostic tool due to its ability to visualize both the aorta and the gastrointestinal tract.

Treatment

The treatment of aortoenteric fistulas is surgical. The goals of surgery are to control bleeding, repair the fistula, and prevent recurrence. Surgical options include:

• Resection of the affected bowel segment
• Repair or replacement of the aortic graft
• Use of endovascular stent grafts

In some cases, antibiotic therapy is also necessary, especially if infection is present.

Related Pages

• Abdominal aortic aneurysm
• Gastrointestinal bleeding
• Endovascular aneurysm repair

Gallery

• 
  Dissection of an aortoenteric fistula