Mycotic Aortic Arch Aneurysm Caused by Clostridium perfringens.

We report a case of a 79-year-old man for a mycotic aortic arch aneurysm caused by Clostridium perfringens. The patient who had been hospitalized for cholangitis two months prior revisited the hospital for fever and left precordial pain. He was suspected of an infected aortic aneurysm in the distal arch due to emphysematous changes observed. After antibiotics treatment, the emphysematous changes disappeared. However, he underwent urgent total arch replacement due to a new ulcer-like projection and enlargement of the aortic aneurysm, which were observed at that time. Clostridium-infected infectious aneurysms require not only treatment for vascular lesions but also scrutiny of complications, such as cancer.