孤発性三尖弁位感染性心内膜炎に対する弁置換術

Tricuspid Valve Replacement for Isolated Tricuspid Valve Infective Endocarditis without Risk Factor

感染性心内膜炎（IE）の中でも，右心系IEは本邦では比較的まれな疾患であり，短絡を有する先天性心疾患や中心静脈カテーテル留置例，高齢者や人工透析などの免疫低下例で発症が報告されている．われわれは，このような基礎疾患のない孤発性三尖弁位IEに対し，弁置換術を行い良好な結果を得たため報告する．

A 78-year-old Japanese male with previous gastric cancer and untreated diabetes mellitus was admitted to hospital for persistent fever and leg edema. Blood culture was positive for Streptococcus anginosus, and echocardiography showed isolated tricuspid valve infective endocarditis. Infection was controlled with intravenous antibiotics, but surgery was indicated because of persistent severe regurgitation and large vegetation of 15 mm in size. As the tricuspid valve anterior leaflet was extensively damaged, he underwent valve replacement using a bioprosthetic valve. The patient was discharged 25 days postoperatively with additional antibiotics, and he has been free from recurrent endocarditis for 6 months.