左心耳切除後に発生した左房内巨大血栓の1例

Giant Left Atrium Thrombus after Left Atrial Appendectomy：Report of a Case

はじめに　心房細動はリモデリングによる心房収縮機能低下と左房拡大により血流うっ滞を起こし，特に左心耳内において血栓易形成の状態となる．一般的に心房細動患者の脳梗塞発生率は約4～7％/年，また全脳梗塞の20～30％が心房細動によるとされており，脳梗塞の大きな原因となっている1～3）．

A 78-years-old woman was admitted to our hospital due to recurrence of cerebral infarction. She had history of chronic atrial fibrillation, so we performed left atrium appendectomy for prevention of cardiogenic brain embolism. But a giant left atrium thrombus appeared in spite of left atrial appendage closure and anticoagulant therapy. Echo cardiogram showed severe spontaneous echo contrast in the large left atrium. The criteria of mitral valve stenosis were not met, but restriction of the mitral valve opening was suspected. So, we performed removal of left atrium thrombus and mitral valve replacement. The left atrium thrombus did not attach at the stump of the left atrial appendage, but at the junction of left pulmonary vein and left atrium. She was transferred without recurrence of left atrium thrombus. Severe left atrial blood stasis may cause thrombus in spite of left atrium appendectomy.