Aortoenteric fistula

A rare but serious condition involving abnormal connection between the aorta and the gastrointestinal tract

Aortoenteric fistula

An aortoenteric fistula is an abnormal connection between the aorta and the gastrointestinal tract. This condition is a rare but potentially life-threatening cause of gastrointestinal bleeding. It can be classified into primary and secondary types, with secondary aortoenteric fistulas being more common.

Classification

Aortoenteric fistulas are classified into two main types:

Primary aortoenteric fistula

Primary aortoenteric fistulas occur spontaneously, without any prior surgical intervention. They are often associated with conditions such as abdominal aortic aneurysms, atherosclerosis, or inflammatory diseases like Crohn's disease.

Secondary aortoenteric fistula

Secondary aortoenteric fistulas are more common and occur as a complication of previous aortic surgery, particularly after aortic graft placement. The fistula typically forms between the aortic graft and the duodenum, the first part of the small intestine.

Pathophysiology

The development of an aortoenteric fistula involves the erosion of the aortic wall into the gastrointestinal tract. In secondary fistulas, this is often due to mechanical stress, infection, or graft material degradation. The resulting communication allows blood to enter the gastrointestinal tract, leading to potentially massive hemorrhage.

Clinical presentation

Patients with an aortoenteric fistula may present with a classic triad of symptoms:

• Gastrointestinal bleeding: This can range from occult bleeding to massive hemorrhage, often presenting as hematemesis or melena.
• Abdominal pain: Patients may experience severe, sudden-onset abdominal pain.
• Sepsis: Signs of infection or systemic inflammatory response may be present, especially in secondary fistulas.

Diagnosis

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

• Computed tomography angiography (CTA): This is the preferred imaging technique, providing detailed images of the aorta and surrounding structures.
• Endoscopy: May reveal active bleeding or erosion in the gastrointestinal tract.
• Magnetic resonance imaging (MRI): Can be used in certain cases to provide additional information.

Treatment

The treatment of aortoenteric fistulas is surgical. Options include:

• Endovascular repair: Minimally invasive approach using stent grafts to exclude the fistula.
• Open surgical repair: Involves resection of the affected aortic segment and repair of the gastrointestinal tract.

Both approaches aim to control bleeding, repair the fistula, and prevent recurrence.

Prognosis

The prognosis of aortoenteric fistulas depends on the promptness of diagnosis and treatment. Delayed treatment can lead to significant morbidity and mortality due to massive bleeding or infection.

Prevention

Preventive measures focus on reducing risk factors for aortic disease and careful monitoring of patients with aortic grafts. Regular follow-up and imaging studies can help detect potential complications early.

Related pages

• Aortic aneurysm
• Gastrointestinal bleeding
• Endovascular aneurysm repair

Aortoenteric fistula dissection mark