Cutibacterium acnes as a cause of late prosthetic valve Endocarditis – A case report

Background Dehiscence of a composite graft following aortic valve and ascending aorta replacement represents a rare, potentially life-threatening, complication. The need for reoperation after a Bentall procedure usually is related to the development of an endocarditis, formation of (pseudo)aneurysms, or recurrent dissection. We report a rare case of late pseudoaneurysm formation due to Cutibacterium acnes (C. acnes) endocarditis. Case summary A 52-year-old man was admitted to the emergency department due to dizziness, diplopia, right-sided hemiparesis, and dysarthria. 5.5 years ago, the patient underwent a replacement of the aortic valve and entire ascending aorta due to a bicuspid aortic valve (AV) with combined valvular disease and ascending aortic aneurysm. Transthoracic echocardiography revealed a large, perfused posterior pseudoaneurysm caused by the dehiscence of the composite graft, while the mechanical valve remained well-functioning. After 8 days of incubation C. acnes was detected in blood cultures. The patient underwent reoperation, including replacement of the composite graft, reimplantation of the coronary ostia, and replacement of the hemiarch. The postoperative course was uneventful. Discussion The dehiscence of a composite graft is a rare but serious complication following aortic valve and aortic replacement with a high mortality. C. acnes is a slow-growing, biofilm forming bacterium, considered als typical pathogen in infective endocarditis (IE) in the presence of prosthetic material. Cardiac imaging is the cornerstone of IE diagnosic process, often requiring multimodality imaging aproach. The management of C. acnes endocarditis typically involves a combination of antibiotic therapy and frequently surgical intervention.