Infected Iliac Artery Aneurysm Concomitant with Liver Abscess Caused by Fusobacterium nucleatum

We report a case of infected iliac artery aneurysm concomitant with liver abscesses caused by Fusobacterium nucleatum. A 58-year-old man developed an aneurysm of the right common iliac artery and liver abscesses. The aneurysm was resected and a femoro-femoral crossover bypass with a knitted Dacron graft was performed for impending rupture. Anaerobic cultures obtained from blood and intramural thrombus were positive for Fusobacterium nucleatum. With antibiotics, the liver abscesses disappeared without drainage. Iliopsoas abscesses developed after surgery, but it was controlled with antibiotics. The patient was free of infection 1 year after the surgery. The causative bacterium was suspected to originate in the oral cavity, because the patient had a notable history of poor chronic periodontal conditions. Clinically, infected aortoiliac aneurysm complicated by Fusobacterium is extremely rare relative to the prevalence of the pathogenic bacterium. However, it is noteworthy that Fusobacterium can cause this condition.