寒冷凝集反応陽性患者に対する上行大動脈および大動脈弁置換術

Ascending Aortic Replacement and Aortic Valve Replacement in a Patient with Cold Agglutinins

寒冷凝集素（cold agglutinin：CA）は赤血球膜に存在する抗原に対する冷式自己抗体であり，ほとんどがIgMである．CAのほとんどは体温条件では無害であるが，一定の温度を下回ると赤血球膜表面にある抗原にCAが結合して補体が活性化し，血管外溶血および血管内溶血をきたす．またCAを介する赤血球凝集により，血管の閉塞や塞栓症を引き起こす．そのため低温で人工心肺管理を要する心臓血管外科手術において，CA陽性患者では術前精査，人工心肺の温度管理，心筋保護の選択や術式の選択で注意を要する．

Cold agglutinins are commonly found in healthy individuals. Cold agglutinins bind to red blood cells at low temperatures, such as during cardiovascular surgery. Agglutination leads to hemolysis and embolism. A 73-year-old man with cold agglutinins disease underwent ascending aortic replacement and aortic valve replacement. As there was no agglutination reaction at 34 degrees centigrade in preoperative testing, we performed the operation under cardiopulmonary bypass and cardioplegia at a temperature above 34 degrees centigrade. He was discharged without any complications.