Fibrous strandの断裂により急性発症した大動脈弁閉鎖不全症の1例

Acute Aortic Regurgitation Caused by Rupture of a Fibrous Strand: A case report

要旨　急性発症した大動脈弁閉鎖不全症の原因診断は非常に重要である．今回，稀な病態であるfibrous strandの断裂による急性大動脈弁閉鎖不全症例を経験したが，術前診断に苦慮した．患者は56歳，男性，急激な呼吸困難，胸部圧迫感出現．胸部X線検査，心臓エコー検査から大動脈弁は二尖で，その一つの弁尖の高度逸脱による大動脈弁閉鎖不全症，肺水腫と診断された．感染性心内膜炎などを疑い精査を行ったが，逸脱の原因は不明であった．心不全治療後，大動脈弁置換術を施行．術中所見で，二尖弁のrapheの先端にあたる大動脈弁尖と大動脈壁との間に存在したfibrous strandの断裂による逸脱と診断された．

　A 56-year-old male suddenly complained of chest discomfort and dyspnea. He was diagnosed as having marked pulmonary congestion due to severe aortic regurgitation. The aortic valve was bicuspid and one leaflet obviously prolapsed, but the cause of the prolapse was unclear. Blood culture yielded no microorganisms. The patient underwent aortic valve replacement after medical treatment for acute heart failure. Surgery disclosed a rupture of a fibrous strand between the tip of raphe of the bicuspid valve and the wall of the ascending aorta. It is very important to diagnose the etiology of aortic regurgitation preoperatively, and clinicians should be aware of this uncommon entity as a cause of serious acute aortic regurgitation.