Clostridium septicum-infected aortic aneurysm or graft is a deadly diagnosis.

Background: Clostridium septicum is an anaerobic, motile, spore-forming, toxin-producing gram-positive bacillus that can lead to rapidly progressive gas gangrene due to the release of alpha toxin. Aortic aneurysm secondary to C. septicum infection is a rare condition with 60 cases reported in the literature; however, we have recently treated several patients with the condition in our large tertiary care and aortic center.

Methods: Blood and tissue culture results collected between January 2005 and January 2018 and maintained in the microbiology laboratory database at the Cleveland Clinic were reviewed to identify those with C. septicum reported. Each was reviewed to determine radiographic or histopathologic correlation with aortic disease.

Results: Seven cases of C. septicum aortitis were reviewed. Underlying malignant disease was found in four cases and a history of remote malignant disease in one case. The most common location for infection was the infrarenal abdominal aorta. Vascular surgery had previously been performed in three of the cases. Five of the seven patients underwent operative repair. All patients were treated with β-lactam antibiotics. The two patients who did not undergo an operation died, which is consistent with the 100% mortality described in the literature. Of the five patients who underwent an operation, there was only one documented survivor and one was lost to follow-up.

Conclusions: In the largest reported case series, only a small percentage of patients with C. septicum-infected aortic aneurysms survived >1 year. In the patients described, those who did not receive an operation had 100% mortality. Earlier recognition and prompt operation with appropriate antimicrobial therapy are needed to improve the outcome of patients diagnosed with this rare infection.