発熱を主訴とし喀血にて死亡した解離性大動脈瘤の1剖検例

An Autopsy Case of a Dissectmg Aneurysm in a Patient Complaining of Fever and Who Died of Hemoptysis

　経過中，胸痛なく発熱を主訴として入院し喀血にて死亡した解離性大動脈瘤のきわめて稀な剖検例を経験したので報告する．患者は67歳の男性で，不明熱の精査目的で入院した．入院時，脈拍，血圧に左右差があり，CRP 6.9 mg／dlと炎症所見を認め，胸部X線写真にて大動脈弓および縦隔陰影の拡大を認めた．入院5日目，誘因なく喀血し，胸部CTにて解離性大動脈瘤の切迫破裂と診断した．炎症所見が強く局所感染の可能性より緊急手術の適応とはならず保存的に治療したが，再度大量に喀血し死亡した．剖検にて下行大動脈部の解離腔から左肺上葉への穿通を認めた．解離性大動脈瘤で胸腔内出血を認めず喀血を来す例は稀であるが，本症例においては，拡張した動脈瘤による局所の圧迫および線維性癒着に二次感染が加わり動脈壁の脆弱化が起こり，気腫性病変部へ瘻孔を形成したことが原因と推察された．

We report a rare occurrence of a dissecting aneurysm in a patient who died of hemoptysis. A 67-year-old man was admitted to the Matsuyama Red Cross Hospital because of fever but he had no episodes of chest pain. Physical examination revealed the laterality of his radial pulse and blood pressure. Laboratory examina-tion showed the presence of inflammation and chest X-ray film showed enlargement of the aortic arch and the mediastinum. On the fifth day of his admission, he coughed up fresh blood. Chest CT disclosed the dissec-tion of a thoracic aortic aneurysm. An emergency opera-tion was unable to be carried out because of the possibil-ity of local infection. He died of repeated hemoptysis during conservative treatment.

An autopsy finding disclosed penetration from the dissecting lumen of the descending aorta to the upper lobe of the left lung. Although hemoptysis has rarely occurred in patients with dissecting aneurysms, it is thought that compression by the enlarged aneurysm had caused, in this case, adhesion, secondary infection, weakening of the arterial wall and finally penetration of the emphysematous lung.