左心耳縫縮術後の遠隔期に指摘された左心耳瘤の1例

Left Atrium Appendage Aneurysm Late After Suture Exclusion：Report of a Case

はじめに　左心耳閉鎖術は心房細動を伴う患者の心内血栓予防目的に行われる手術で，本邦では『不整脈非薬物治療ガイドライン』のクラスⅡaで推奨され1），心臓手術の際に広く行われている手術手技である2～4）．当院では心房細動を伴った僧帽弁手術の際に，左房内からの縫合閉鎖術を積極的に行っている．われわれは，13年前に左心耳閉鎖術を行った患者の遠隔期に，左心耳が瘤化したため外科的治療を行った．左心耳閉鎖術後の左心耳瘤は文献的報告がなく非常にまれであり，その拡大した経緯を考察し報告する．

Left atrial appendage closure is widely performed in cardiac surgery to prevent intracardiac thrombus in patients with atrial fibrillation. Herein, we report the surgical case of an 80-year-old man whose left atrial appendage became aneurysmic long after undergoing suture exclusion. At the age of 67, he underwent mitral valve annuloplasty and left atrial appendage suture exclusion for mitral regurgitation and chronic atrial fibrillation at our institution. At the age of 76, a mass near the left atrial appendage that was difficult to distinguish from a tumor was observed. During follow-up, the mass increased in size, and blood flow was observed inside. Consequently, surgery was performed when he was 80 years old. The interior of the mass was nearly filled with thrombus, and some oozing was observed；however, no blood flow was noted from the left atrium. The diagnosis was a left atrial appendage aneurysm that has developed over a long-term period of following suture exclusion. However, it was suspected to be a rare condition involving various factors, including residual left atrial feeding vessels, chronic expanding hematoma, and continuous use of anticoagulants.