Primary Aortoduodenal Fistula – A Rare Clinical Entity

Abstract

Abdominal aortic aneurysm (AAA) is a very serious and rare communication between the lumen of the aorta and that of the duodenum. When such a fistula occurs in the absence of previous aortic aneurysm surgery, it is called a primary aortoduodenal fistula (PADF), a condition much less frequent than a secondary aortoduodenal fistula which occurs as a result of previous aortic aneurysm grafting. The diagnosis can be delayed due to the rare occurrence of the condition, non-specificity of abdominal signs, and frequent initial absence of records alerting the clinician to a known AAA, thereby resulting in increased morbidity and mortality. Salmon described the first case report of a PADF in 1843.1 Since then about 250 cases have been reported in literature.2–7 The incidence at autopsy is between 0.04% and 0.07%.4,7 The incidence of secondary aortoduodenal fistula is 0.5–2.3%.6 In this article we present a further case of PADF and discuss the pathophysiology, diagnosis and management of the condition, highlighting the fallibility of diagnostic investigations and the importance of having a high index of clinical suspicion.