多発肺塞栓を伴う孤立性肺動脈弁位感染性心内膜炎の1例

Isolated Pulmonary Valve Endocarditis Accompanying Multiple Pulmonary Embolisms：Report of a Case

はじめに　孤立性肺動脈弁位の感染性心内膜炎（IE）はIE全体の1.5～2.0％ときわめてまれである1）．われわれは多発肺塞栓を認めた孤立性肺動脈弁位IEに対して，肺動脈弁置換術（PVR）を行った1例を経験したので報告する．

Isolated pulmonary valve infective endocarditis is rare and accounts for only 1.5％ to 2.0％ of all cases of infective endocarditis. We present a case of isolated pulmonary valve endocarditis, which was successfully treated by pulmonary valve replacement. A 69-year-old man presented with fever and was diagnosed with active pulmonary valve infective endocarditis. He had no apparent predisposing factors. Blood cultures were positive for Streptococcus viridans, and transesophageal echocardiography showed mobile vegetation. His condition improved transiently with intravenous antibiotic therapy；however, high fever and reduced oxygen saturation recurred. Computed tomography showed multiple infiltrative shadows suggesting septic pulmonary embolisms. Urgent surgery was indicated because antibiotic treatment was ineffective. During the operation, we found that vegetation had destroyed all pulmonary leaflets. We performed pulmonary valve replacement with a stented bioprosthetic valve as well as enlargement of the right ventricular outflow tract with a bovine pericardial patch. The postoperative course was uneventful. Antibiotic therapy was continued for six weeks after surgery. For two years since surgery, the patient has experienced no recurrence of infection.