僧帽弁置換術，三尖弁輪縫縮術後に発生し，外科的に除去した右房血栓の1例

An Operative Case of Right Atrial Thrombus after Mitral Valve Replacement and Tricuspid Annuloplasty

　症例は49歳，フィリピン人女性．僧帽弁狭窄兼閉鎖不全症，三尖弁閉鎖不全症による両心不全で緊急僧帽弁置換術，三尖弁輪縫縮術を施行した．術後心不全，呼吸不全の治療に5日間のスワンガンツ・カテーテル，9日間の気管内挿管と中心静脈カテーテルの留置を必要とした．この間，トロンボテストは20％台で推移したが，術後7日目に心エコー図法で心房中隔に付着した右房血栓を認め，一部が三尖弁を越えて右室内へ陥入していた．血栓溶解療法に消失傾向がなく，術後10日目体外循環下に8.4gの赤色血栓を摘出した．その後の経過は良好で，患者は再手術後40日目に退院した．全経過を通じ左房血栓は認めなかった．心房細動と三尖弁逆流減少による血流停滞，心房中隔切開の影響，長期間のカテーテルの留置などが右房血栓の原因と考えられた．右房血栓は稀だが，肺梗塞の危険があり，内科的治療に抵抗する場合は外科的除去を考慮すべきである．

We report a case of right atrial thrombus after mitral valve replacement (MVR) and tricuspid annuloplasty (TAP) in a 49-year-old Philippine female. She was admitted to the hospital because of congestive heart failure and pulmonary hypertension secondary to severe mitral stenosis and regurgitation and tricuspid regur-gitation. She required mechanical ventilation and inva-sive monitoring including a central venous catheter and a pulmonary artery catheter for more than a week after MVR and TAP. Echocardiography on the 7th postoper-ative day revealed a right atrial thrombus protruding into the right ventricle. The administration of throm-bolytic therapy with heparin for 3 days was ineffective. Thus we performed right atrial thrombectomy on the 10th postoperative day without any complications. Right atrial thrombus should be treated by thrombolytic therapy or surgical therapy. We think that right atrial thrombectomy should be performed as soon as possible if the medical therapy fails.