早期生体弁機能不全を併発した人工弁感染性心内膜炎に対する大動脈弁再置換術の1例

Prosthetic Valve Endocarditis with Early Structural Valve Deterioration of Trifecta Aortic Bioprosthesis：Report of a Case

はじめに　近年，大動脈弁置換術（aortic valve replacement：AVR）は増加傾向にある．その中でもTrifecta弁（Abbott社）はウシ心膜がステント構造の外側に縫着されている外巻き弁であり，内巻き弁と比較して有効弁口面積が大きく，狭小弁輪の症例に対して有効であると考えられている．一方で早期人工弁機能不全（structural valve deterioration：SVD）の報告も散見される．われわれは，Trifecta GT弁の移植後早期に人工弁感染性心内膜炎（prosthetic valve endocarditis：PVE）およびSVDをきたし，再手術を施行した症例を経験したので，若干の文献的考察を加えて報告する．

We report a case of prosthetic valve endocarditis with bioprosthetic valve dysfunction of Trifecta valve. A 74-year-old female had undergone aortic valve replacement with Trifecta 21 mm four years ago. She was admitted to the emergency unit of our institution with fever and progressive dyspnea. Transthoracic echocardiography showed severe aortic regurgitation and stenosis due to structural valve deterioration. Blood culture yielded Streptococcal species. She was treated with antibiotics for 10 days, and redo aortic valve replacement using an Inspilis 19 mm was performed. Intraoperative findings revealed a large laceration in the right coronary cusp and no paravalvular abscess. Post-surgical intravenous antibiotics administration was continued for two weeks and then it was switched to an oral agent. Postoperative course was uneventful, and she was discharged on the 25th postoperative day.