Aortoenteric fistula: a diagnostic dilemma.

Area of Science:

• Radiology
• Gastroenterology
• Vascular Surgery

Background:

• Aortoenteric fistula (AEF) is a rare but life-threatening condition often presenting with gastrointestinal bleeding.
• Accurate and timely diagnosis of AEF is crucial for patient management and outcomes.

Purpose of the Study:

• To evaluate the diagnostic accuracy of computed tomography (CT) for aortoenteric fistula (AEF).
• To identify specific CT findings indicative of AEF.
• To determine the sensitivity and specificity of CT in diagnosing AEF.

Main Methods:

• Retrospective review of 22 cases (10 AEF, 12 controls) over 20 years.
• Two blinded readers assessed CT scans for six predefined radiological findings.
• Comparison of CT findings with laparotomy/autopsy diagnoses and other investigations.

Main Results:

• Peri-aortic ectopic gas after two weeks post-surgery, with GI bleeding, showed 100% specificity for AEF.
• CT demonstrated 100% specificity but only 50% sensitivity for AEF when peri-aortic infection and GI bleeding were considered.
• CT can suggest AEF but negative findings do not exclude the diagnosis.

Conclusions:

• CT is a valuable tool for ruling in AEF, particularly in patients with suspected AEF and GI bleeding.
• CT should be considered the initial imaging modality for stable patients with suspected AEF.
• Negative CT findings should be interpreted cautiously due to the limited sensitivity.