A 50-year-old man underwent total arch graft replacement surgery for life-threatening thoracic aortic dissection and then developed a postoperative graft infection with methicillin-resistant Staphylococcus aureus. The graft infection was treated by mediastinal lavage and high-pressure vacuum for 3 vessels with omentopexy. A year later, the patient became febrile and started taking oral and intravenous antibiotics at an outpatient clinic.
A few months later, he suddenly developed dysarthria and right hemiparesis and was emergently admitted to our stroke center. On laboratory examinations, the white blood cell count (18000/μL; to convert to ×109 per liter, multiply by 0.001) and the highly sensitive C-reactive protein level (150.5 mg/L; to convert to nanomoles per liter, multiply by 9.524) were elevated. Diffusion-weighted magnetic resonance imaging demonstrated fresh small infarcts scattered in both cerebral and both cerebellar hemispheres (Figure, A). Intracranial magnetic resonance angiography showed no vascular occlusion. Although the infected emboli from the arch graft were thought to have caused multiple embolic strokes, emergent transthoracic echocardiography and chest computed tomography showed no infected changes. On transesophageal echocardiography (TEE), a mobile, irregular-shaped isoechoic and hypoechoic mass, 5.9 × 7.4 mm in diameter, was delineated at the origin of the prosthetic left subclavian artery (Figure, B) (video), suggesting vegetation. Fluorine 18–labeled fluorodeoxyglucose (FDG) positron emission tomography (PET) demonstrated increased tracer uptake in the grafted ascending aorta and aortic arch (Figure, C). Intravenous linezolid administration was immediately started for the graft infection that was due to methicillin-resistant S aureus; the bacterium was later identified.