Mycotic aortic aneurysm with unknown source and primary aortoenteric fistula: a case report

Mycotic aortic aneurysm represents an infrequent but life-threatening disease usually affecting old, male, and immunocompromised subjects with pre-existing aneurysms. We describe the case of a 69-year-old man with a history of cardiopathy and coagulopathy, admitted to our hospital due to intractable abdominal pain and marked hypotension. In the suspicion of aortic acute syndrome, the patient undergoes CT-angiography of the aorta, showing aneurysm of the infra-renal tract with thrombosis and peri-aortic soft tissue in contact with the third portion of the duodenum, raising suspicion for a mycotic aortic aneurysm with aorto-enteric fistula. The patient is thus in need of emergency vascular surgery, confirming CT findings. positivity of the infective tissue for Staphylococcus Aureus is seen; despite the good technical success, the patient dies due to the sequelae of shock. Early diagnosis is challenging because of non-specific clinical and laboratory findings, CT thus representing the gold standard for diagnosis, quantification of aortic disease, relationship with nearby organs, and potential sources of infection (unknown in 30% of cases). Mycotic aneurysms are prone to rupture, sometimes leading to fistulization with the duodenum, bronchi, or inferior vena cava, often associated with life-threatening hemorrhages. Treatment options are conventional open surgical or endovascular repair.