A Case of Mitral Stenosis and Recurrent Cerebral Infarction after Subclinical Infection for 5 Years after Artificial Mitral Ring Infection during the Perioperative Period of Mitral Valve Repair

Abstract

A 45-year-old man underwent mitral valve repair for degenerative mitral regurgitation and coronary artery bypass grafting for coronary artery stenosis at the age of 40 years. During this hospitalization, although he had methicillin-resistant Staphylococcus epidermidis(MRSE)sepsis, antibiotic treatment rapidly improved his condition. His improving condition was then reversed as his mitral stenosis gradually worsened. During surgical planning, it was elicited that he had had a stroke 4 years 8 months after his previous operation. Although it could have been cardiogenic cerebral infarction, further workup did not reveal any other embolic sources. He had two additional stroke episodes 4 months after the first stroke. Follow-up transthoracic echocardiography revealed vegetation-like lesions attached to the mitral annulus. Although there were no signs of inflammation, his blood culture was positive for MRSE, similar to his previous infection. Because these findings were consistent with the diagnosis of chronic infective endocarditis, the patient underwent open-heart surgery. Intraoperatively, the artificial mitral ring surface was not seen, as it was covered by pseudo-intima, excluding the three infected annular sutures. Furthermore, the mitral orifice was stenotic due to pannus formation seen to be continuous with the pseudo-intima. To address these, he underwent mitral valve replacement, tricuspid annuloplasty, and antibiotic therapy. The postoperative course was uneventful. The infection probably originated from the artificial mitral ring infection during the first surgery performed 5 years eariler.