急性大動脈解離術後に肺塞栓症を生じたプロテインC欠乏症の1例

A Case of Protein C Deficiency that Resulted in a Pulmonary Embolism after Operation for Acute Aortic Dissection

要旨　患者は68歳，男性．急性大動脈解離に対して，体外循環下に上行大動脈置換術を施行した．術後5日目に人工呼吸器より離脱したが，6日目に肺塞栓のため呼吸状態が悪化し，再挿管となった．プロテインC活性が26%と低下しており，先天性プロテインC欠乏症と診断した．ヘパリン・ワルファリンによる抗凝固療法により血栓は消失し，30日目に退院となった．プロテインC欠乏症は，先天性血栓性素因の一つで，外傷，手術，妊娠・分娩，感染症などが誘因となり，血栓症を生じる．術後に血栓症が生じた場合は，適切な治療を行うとともに，先天性血栓性素因を念頭に置くことが重要である．注意深い抗凝固療法が治療の中心となる．

　A 68-year-old male underwent ascending-aorta replacement under cardiopulmonary bypass for acute aortic dissection. He was extubated on postoperative day 5. However, his respiratory status worsened because of pulmonary embolism on day 7 and he was re-intubated. The patient was diagnosed as having protein C deficiency with an activity level of 26%. The thrombus disappeared under anticoagulant therapy using heparin and Warfarin. He was discharged on day 30. Protein C deficiency is one of the effects of congenital thrombophilia. It causes a thrombosis under the influence of various triggers, such as injury, surgery, pregnancy and/or delivery, an infectious disease and so on. When a thrombosis has occurred postoperatively, it is important to take congenital thrombophilia into consideration as a possible cause and careful anticoagulant therapy is required.