Aortoenteric fistula

Aortoenteric Fistula

An aortoenteric fistula is a rare but significant medical condition characterized by an abnormal connection (fistula) between the aorta, the largest artery in the body, and part of the gastrointestinal tract. This condition can lead to life-threatening bleeding and requires immediate medical attention.

Etiology

Aortoenteric fistulas can be classified into two main types based on their etiology: primary and secondary. A primary aortoenteric fistula is one that develops as a result of atherosclerosis, infection, or cancer eroding from the gastrointestinal tract into the aorta. A secondary aortoenteric fistula, on the other hand, is usually a complication of aortic surgery, particularly after the placement of an aortic aneurysm repair or aortic prosthetic graft.

Symptoms

The clinical presentation of an aortoenteric fistula can vary, but the hallmark symptom is gastrointestinal bleeding, which may be intermittent or massive. Other symptoms may include abdominal pain, fever, and signs of sepsis due to the infection. The classic triad of symptoms, known as Chiari's triad, includes gastrointestinal bleeding, abdominal pain, and a pulsatile abdominal mass, though it is rare.

Diagnosis

Diagnosing an aortoenteric fistula can be challenging due to its rare occurrence and nonspecific symptoms. Computed tomography angiography (CTA) is the preferred diagnostic modality as it can provide detailed images of the aorta and gastrointestinal tract, potentially identifying the site of the fistula. Endoscopy and angiography may also be used to aid in diagnosis.

Treatment

The treatment of an aortoenteric fistula is primarily surgical. The goals of surgery are to control the bleeding, repair the aorta, and address the defect in the gastrointestinal tract. This often involves removing the infected aortic graft (if present), repairing the aorta with a new graft, and repairing or resecting the affected portion of the gastrointestinal tract. In some cases, antibiotics are also administered to treat or prevent infection.

Prognosis

The prognosis for individuals with an aortoenteric fistula is generally poor, with high rates of morbidity and mortality. Early diagnosis and prompt surgical intervention are critical to improving outcomes.