渡邉 幸太郎¹, 三宅 仁¹, 松田 真太郎¹, 前西 文秋², 登尾 里紀², 榊原 由希², 登尾 薫², 佐藤 信浩², 山野 愛美², 大北 裕³

Kotaro WATANABE¹, Shinobu MIYAKE¹, Shintaro MATSUDA¹, Fumiaki MAENISHI², Riki NOBORIO², Yuki SAKAKIBARA², Kaoru NOBORIO², Nobuhiro SATO², Manami YAMANO², Yutaka OKITA³

¹西神戸医療センター循環器科, ²西神戸医療センター臨床検査部, ³神戸大学大学院医学研究科外科学講座心臓血管外科学

¹Department of Cardiovascular Medicine, Nisi-Kobe Medical Center, ²Clinical Laboratory, Nisi-Kobe Medical Center, ³Division of Cardiovascular Surgery, Kobe University Graduate School of Medicine

キーワード : acute severe aortic regurgitation, localized aortic dissection, 3D transesophageal echocardiography

患者は50歳の男性で，3日前よりの発熱，次第に増悪する呼吸困難を主訴に来院した．来院時，低酸素血症と胸部Ｘ線上で両肺野にうっ血像を認め，急性左心不全と診断した．入院後に呼吸補助と利尿薬投与を施行し，循環血行動態は安定し，心不全は軽快した．経胸壁心エコー図検査にて重症大動脈弁閉鎖不全症（aortic regurgitation，以下AR）を認め，これが心不全の原因であると考えた．経胸壁心エコー図検査及び心臓カテーテル検査ではいずれも急性重症ARの所見を呈していたが，経食道心エコー図検査を施行しても感染性心内膜炎などのARの原因疾患は特定出来なかった．その後，重症ARに対して手術適応と判断し，心不全発症後第40病日に他院にてARに対する根治術を施行したところ，大動脈弁左冠尖から右冠尖の直上に限局性大動脈解離を認め，今回のARの原因であると断定した．改めて術前の3D経食道心エコー図検査を解析したところ，右冠尖直上に存在するflapを確認し，限局性大動脈解離の広がりを再構築することが可能であった．限局性大動脈解離によるARは比較的稀な疾患であり，時として診断が困難である．病歴や経胸壁心エコー図検査から急性発症のARが疑われる場合には，早急な外科的治療が必要な疾患を検索するため，必要に応じて3D経食道心エコー図検査を使用すべきであると考えられた．

A 50-year-old male was admitted to our hospital with symptoms of fever and gradual development of dyspnea. At that time, he was in a state of acute left heart failure, hypoxic, and with bilateral congestion shadow on chest X ray. Respiratory assistance and infusion of diuretics rapidly improved the left heart failure. Transthoracic echocardiography and cardiac catheterization revealed acute severe aortic regurgitation, but transesophageal echocardiography could not identify the cause of the aortic regurgitation, such as infective endocarditis. We figured that this severe aortic regurgitation was a candidate for valve replacement surgery, so a radical operation for aortic regurgitation was undertaken on the 40^th day after the onset of left heart failure in another hospital. During the operation, a localized aortic dissection appeared to be above the left coronary cusp through the right coronary cusp of the aortic valve, so we judged that the cause of aortic regurgitation was this localized aortic dissection. We analyzed the preoperative 3D transesophageal echocardiography findings again, and we verified the presence of a flap lying directly on the right coronary cusp. In addition, we could rebuild the range of localized aortic dissection. Aortic regurgitation due to localized aortic dissection is a relatively rare disorder, and it is often difficult to make a diagnosis of this disorder. We concluded that in cases of acute aortic regurgitation with unidentified cause, suspected on the grounds of the clinical history and transthoracic echocardiography findings, 3D transesophageal echocardiography should be used to make a decision for the purpose of emergency opration.