大動脈弁置換術後の生体弁機能不全に対する弁輪拡大術を伴う再弁置換術の1例

Valve Re-replacement Combined with Patch Enlargement of the Aortic Annulus for Bioprosthetic Valve Deterioration；Report of a Case

はじめに　再弁置換術時に前回人工弁を除去する際は，自己の弁輪と癒着した人工弁と，その周囲に増生したパンヌスが遺残すると，弁輪をさらに狭小化させる．この場合再挿入する弁は小さくなるため1），もともと狭小弁輪の症例では患者人工弁不適合（PPM）となる可能性が高くなる．われわれは生体弁による大動脈弁置換術（AVR）8年後に弁機能不全をきたし，再弁置換術に弁輪拡大術を同時施行した狭小弁輪の1例を経験した．特に人工弁除去のアプローチ法について，実際の生体弁（Magna Ease：Edwards Lifesciences社，Irvine）を用い，その構造的特徴を明らかにしながら検討したので報告する．

A 42-year-old woman had undergone aortic valve replacement with a 19 mm bioprosthetic valve for aortic stenosis due to a bicuspid valve 8 years before. She was admitted to our hospital for valve re-replacement owing to the prosthetic valve dysfunction. As the patient’s valve annulus was markedly thickened owing to pannus formation, we were unable to pass a 19 mm valve sizer through the annulus even after removal of the prosthetic valve and the tissue surrounding the annulus. Valve re-replacement combined with patch enlargement of the aortic annulus was performed to obtain maximally effective orifice area. Her postoperative course was uneventful, and echocardiography revealed no perivalvular leak. In valve re-replacement, it is important to remove the prosthetic valve and the tissue surrounding the annulus to the greatest extent possible and consider patch enlargement of the aortic annulus to avoid patient-prosthesis mismatch in a patient with a small aortic annulus.