Primary aortoenteric fistula: pitfalls in the diagnosis of a rare condition.

Primary aortoenteric fistula is such a rare condition that even specialist vascular surgeons may not encounter one in their lifetime practice. Any hope of survival depends upon prompt diagnosis and surgical treatment. We present our experience of one such case, particularly the difficulties encountered in confirming the diagnosis, and go on to review the literature on the subject. Both our experience and that reported by previous authors would suggest that specialized investigations such as computed tomography, contrast angiography, radionuclide scintigraphy, and gastrointestinal endoscopy have only a limited contribution to make in confirming the diagnosis of primary aortoenteric fistula. The diagnosis should be considered in any patient with gastrointestinal blood loss and an abdominal aortic aneurysm. Specialized investigations should not be relied upon to confirm or refute the diagnosis. Any prospect of survival is dependant upon prompt diagnosis and surgical intervention. The latter is only achieved by a high index of clinical suspicion.