Rapidly Growing Aneurysm with Ulcer-like Projection Complicated with Bacteroides ovatus Bacteremia

Abstract

The incidence of anaerobic bacteremia has been increasing over the past several decades. Further, antibiotic resistance in Bacteroides is a pertinent issue. A 76-year-old man was brought to our hospital with complaints of fever, chills, and abdominal pain. Empiric antibiotics induced minimal relief. The blood culture was positive for multi-drug resistant Bacteroides ovatus. Our patient developed a periaortic abscess in the abdominal aorta and a thoracic aortic aneurysm with ulcer-like projection (ULP), which rapidly increased in size. He was transferred to the tertiary medical institution for surgical drainage. This case suggests that bacteremia can exacerbate aneurysms with ulcerative lesions. Anaerobic bacteremia is a possible differential diagnosis when periaortic abscess formation is present. Early surgical consultation and appropriate antibiotic selection are crucial in anaerobic bacteremia treatment.