左房内血栓に対する抗凝固療法後に上腸間膜動脈塞栓症を発症し，緊急手術により救命し得た1例

An Emergent Operation Case of Acute Thrombotic Superior Mesenteric Ischemia Occurred After Initiation of Anticoagulant Therapy for a Left Atrial Thrombus

要旨　患者は82歳，女性．尿路感染症で入院中に胸痛発作を認め，経胸壁心エコー検査(transthoracic echocardiography;TTE)で左房内に可動性のない大きさ28.1×13.8mmの血栓を認めた．入院第6日目に一過性脳虚血発作を来したため，左房内血栓に対する抗凝固療法を開始した．入院第16日目に上腹部痛が出現し，腹部造影CT検査にて，小腸広範にイレウス像，骨盤内小腸の濃染不良，回腸動脈の完全閉塞所見を認め，上腸間膜動脈塞栓症と診断し，緊急手術が施行された．壊死を来した骨盤内小腸を約240cm切除した．本例は，左房内血栓に対する抗凝固療法開始後に，血栓が浮遊し，上腸間膜動脈塞栓症を発症したと考えられた．

　An 82-year-old woman complained of chest pain during her hospitalization for urinary tract infection. Transthoracic echocardiography showed an immobile thrombus of 28.1×13.8mm in the left atrium. Six days after admission,transient cerebral ischemic attack occurred, so anticoagulant therapy for the left atrial thrombus was initiated. Sixteen days after admission, she had upper abdominal pain. Contrast-enhanced CT at the level of the pelvis showed small bowel obstruction with poorly-enhanced bowel wall and total occlusion of the ileal artery. The patient was diagnosed as having acute thrombotic superior mesenteric ischemia. An emergent operation was performed and about 240 cm of gangrenous small bowel was resected. In this case, the occlusion of the mesenteric artery might have been caused by a mobile and floating thrombus originating in the left atrium after initiation of anticoagulant therapy.