メチシリン耐性黄色ブドウ球菌による三尖弁感染性心内膜炎に対して自己心膜を用いて三尖弁形成術を施行した1例

Tricuspid Valve Infective Endocarditis Treated with Autologous Pericardium：Report of a Case

はじめに　右心系感染性心内膜炎の頻度は感染性心内膜炎の中でも5〜10％程度と少なく，原因は卵円孔開存，心室中隔欠損症などの先天性心疾患やペースメーカリード感染などの続発性のものがある1，2）．われわれは膀胱瘻造設後の菌血症に続発した三尖弁心内膜炎（tricuspid valve endocarditis：TVE）および重度三尖弁閉鎖不全症（tricuspid regurgitation：TR）を呈した症例に対して，自己心膜を用いた三尖弁形成術で良好な結果を得た1例を経験したので報告する．

Right-sided infective endocarditis （IE） is rare, accounting for 5～10％ of all cases. Herein, we report a 70-year-old man who developed methicillin-resistant Staphylococcus aureus （MRSA） bacteremia and tricuspid valve endocarditis （TVE） with severe tricuspid regurgitation （TR） following bladder fistula placement. Echocardiography revealed a 17×14 mm vegetation on the septal leaflet. Despite antibiotic therapy, the symptoms of heart failure worsened and surgery was indicated. Under cardiopulmonary bypass, the infected anterior and septal leaflets were excised, and valve reconstruction was performed using glutaraldehyde-treated autologous pericardium. Postoperative echocardiography revealed mild TR. The patient underwent prolonged antibiotic therapy and was discharged in good condition. At two years follow-up, there was no recurrence of infection or worsening of TR. This case suggests that autologous pericardial patch repair is a useful strategy for MRSA-associated TVE, particularly in patients with a high reinfection risk, where prosthetic material should be avoided.