Clostridial Mycotic Aneurysm Leading to Emphysematous Aortitis

Mycotic aneurysms account for less than 5% of all aneurysms of the aorta, with most cases linked to infection with either Staphylococcus or Salmonella species. Emphysematous aortitis is a rare consequence of mycotic aneurysms and is associated with high morbidity and mortality. It typically occurs from infection superimposed on already damaged endothelium, which is commonly seen in conditions such as atherosclerosis. This report discusses the presentation and relevant imaging findings of a unique case of emphysematous aortitis from Clostridial infection of the thoracic aorta. The patient was a 66-year-old male with a past medical history of end-stage renal disease, arteriovenous fistula for dialysis, hypertension, and diabetes, who presented with tachycardia and tachypnea. Computed tomography of the chest showed inflammatory changes of the thoracic aorta with gas bubbles along the aortic wall, and post-mortem aortic tissue cultures were positive for Clostridium innocuum. Although emphysematous aortitis is rare, the radiographic findings are strikingly characteristic and should prompt immediate and aggressive management.