ウシ心膜弁による三尖弁置換術14年後に石灰化による構造的弁破壊をきたした1例

Structural Deterioration of a Bovine Pericardial Valve in a Tricuspid Position 14 Years Postoperatively；Report of a Case

生体弁による三尖弁置換術（TVR）後，パンヌス形成や自己弁組織の付着による人工弁機能不全に関する報告は散見されるが，生体弁自体の石灰化や亀裂などによる構造的弁破壊（structural valve deterioration：SVD）はまれである．われわれはウシ心膜弁によるTVR 14年後にSVDをきたし，再手術を行った症例を経験したので報告する．

Although nonstructural dysfunction of a bioprosthesis caused by pannus formation or native valve attachment has been well described, structural valve deterioration （SVD） caused by calcification or tear of a bioprosthesis, especially a bovine pericardial valve, is very rare in the tricuspid position. We report a case of redo tricuspid valve surgery for SVD 14 years after tricuspid valve replacement （TVR） using a Carpentier-Edwards Perimount （CEP） pericardial valve. A 71-year-old woman was referred to our hospital because of exertional dyspnea and pre-syncope. She had undergone mitral valve replacement with a St. Jude Medical mechanical valve and TVR with a CEP pericardial valve 14 years previously. Transthoracic echocardiography revealed tricuspid valve stenosis with a mean trans-tricuspid valve pressure gradient （TVPG） of 7.3 mmHg. Redo TVR using a CEP Magna Mitral Ease valve was performed under cardiac arrest. Severe calcification was observed on the ventricular side of the leaflets of the explanted valve. The mean TVPG decreased to 3.2 mmHg after surgery, and the patient’s postoperative course was uneventful.