Fibrous strandの断裂による大動脈弁閉鎖不全症の1例

Aortic Regurgitation due to Rupture of a Fibrous Strand in Fenestrated Aortic Valve：Report of a Case

はじめに　大動脈弁のfenestrationは大動脈弁と大動脈壁の間に線維組織が遺残した発生学上の先天異常である1）．この線維組織が索状となって遺残した場合に腱索様となり，これをfibrous strand（FS）と表記している報告があり2，3），まれにFSが断裂し，大動脈弁閉鎖不全症（AR）が生ずることがある．われわれは，大動脈弁FSの断裂により生じたARに対して人工弁置換術を施行したので報告する．

Fenestration of the aortic valve cusps rarely causes aortic regurgitation. A 54-year-old woman was diagnosed with aortic regurgitation secondary to a ruptured fibrous strand in a fenestrated aortic valve cusp. Diastolic murmur was pointed out during health checkup five months earlier, and transthoracic echocardiography revealed severe aortic valve regurgitation with a mobile mass attached to the aortic valve cusp. The patient underwent aortic valve replacement. Intraoperatively, we observed a ruptured fibrous strand attached to the non-coronary cusp and cusp laceration, both of which caused severe aortic regurgitation. Histopathological examination of the resected specimen showed myxomatous degeneration. The patient’s postoperative course was uneventful, and she was discharged in a stable condition on postoperative day 14.