Clostridium septicum is a rare, highly virulent Gram-positive, spore-forming anaerobic bacterium that preferentially colonizes hypoxic and necrotic tissue and is associated with underlying malignancy, particularly gastrointestinal cancers. C. septicum-associated mycotic aortic aneurysm is an uncommon but highly lethal complication. We report a case of a 64-year-old man with a history of squamous cell carcinoma of the head and neck who presented with central chest pain and was found to have a 9.2 × 7.5 × 6.2 cm necrotic mediastinal mass inseparable from the aortic arch, C. septicum bacteremia, and a 6 cm mycotic aneurysm of the distal aortic arch. Open repair was declined by cardiothoracic surgery due to the patient's prohibitive medical condition, and thoracic endovascular aortic repair (TEVAR) was performed as the only available surgical option. The patient initially recovered but returned two months later with hematemesis from progressive aortic degeneration and aortoenteric fistula despite endograft revision, and he died shortly thereafter. This case expands the literature on C. septicum aortitis by documenting direct contiguous extension from an adjacent necrotic mass as a viable mechanism of aortic infection and demonstrates the inadequacy of TEVAR as a standalone therapy when open surgical repair is not feasible. Early recognition, definitive open aortic repair when possible, and a multidisciplinary approach integrating vascular surgery, infectious disease, and oncology are essential to optimizing outcomes in this rare but lethal disease.
Connor et al. (Sun,) studied this question.