Cutibacterium acnes as a cause of late prosthetic valve endocarditis: a case report

Dehiscence of a composite graft following aortic valve (AV) and ascending aorta replacement represents a rare but potentially life-threatening complication. The need for re-operation after a Bentall procedure is usually 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.

A 52-year-old man was admitted to the emergency department due to dizziness, diplopia, right-sided hemiparesis, and dysarthria. Five and a half years ago, the patient underwent a replacement of the AV and entire ascending aorta due to a bicuspid 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 re-operation, including replacement of the composite graft, reimplantation of the coronary ostia, and replacement of the hemiarch. The post-operative course was uneventful.

The dehiscence of a composite graft is a rare but serious complication following AV and aortic replacement with a high mortality. Cutibacterium acnes is a slow-growing, biofilm-forming bacterium, considered a typical pathogen in infective endocarditis (IE) in the presence of prosthetic material. Cardiac imaging is the cornerstone of IE diagnostic process, often requiring multimodality imaging approach. The management of C. acnes endocarditis typically involves a combination of antibiotic therapy and frequently surgical intervention.