A Surgical Case of Infected Popliteal Artery Aneurysm From Rare Bacteria, Eubacterium sp

A 79-year-old man presented to our hospital with complaints of a sudden worsening of swelling in the right popliteal fossa and fever persisting for a week. Upon close examination, an infected popliteal artery aneurysm (PAA) was identified. Given the risk of rupture, the patient was advised to undergo surgery. The surgical procedure involved resecting the infectious PAA using a lateral approach. Additionally, a bypass was performed from the superficial femoral artery to the below-knee artery, utilizing the great saphenous vein located at the posterior aspect of the knee. Surgical findings revealed a popliteal artery pseudoaneurysm. Preoperative blood cultures identified Eubacterium spp., and cultures of the inoperative aneurysm specimens confirmed the presence of the same bacteria. After surgery, inflammation quickly subsided, and the patient was discharged on postoperative day (POD) 41 after receiving transvenous antibiotic therapy. Although PAA accounts for approximately 80% of all peripheral arterial aneurysms, mycotic aneurysms are relatively rare. Eubacterium spp. is part of the human intestinal or oral flora, and very few reports of bacteremia have been published. The present case of bacteremia caused by Eubacterium sp. is very rare; to the best of our knowledge, no literature has been published on this topic.