NONINFLAMMATORY AORTIC ROOT DISEASE AND FLOPPY AORTIC-VALVE AS CAUSE OF ISOLATED REGURGITATION - A CLINICO-MORPHOLOGIC STUDY

A clinico-morphologic study was performed on 1120 patients who underwe nt aortic valve replacement at the Department of Medical and Surgical Cardiology, 2nd University Medical School of Naples, Naples, Italy, fr om January 1981 through December 1991. In 69 cases the aortic valve wa s incompetent due to a non-inflammatory aortic root disease such as my xomatous infiltration of the cusps and or aortic root dilatation. Amon g these patients males were prevalent (male/female ratio = 2.2). The m ean age was 37 +/- 7.5 years. A floppy mitral valve was diagnosed in 1 6 cases while in one a left atrial mixoma was found. The patients were divided into 3 groups: Group 1 - 29 patients with aortic root dilatat ion and normal cusps; Group 2 - 25 patients with aortic root dilatatio n and myxomatous infiltration of aortic cusps (floppy aortic valve); a nd Group 3 - 15 patients with floppy aortic valve and undilated aortic root. At the gross examination the cusps of the patients in Groups 2 and 3 were redundant, thin, soft and gelatinous. The histology showed myxomatous infiltration with disruption of the fibrous layer. In patie nts with aortic root dilatation the histology of the aortic root fragm ents showed a cystic medial necrosis. Deep correlation was found betwe en the root dilatation and the grade of aortic wall cystic medial necr osis. Cusp's diastasis was the cause of aortic regurgitation in patien ts with aortic root dilatation, while cusp prolapse caused aortic inco mpetence in presence of the floppy aortic valve and undilated aortic r oot. Aortic root dilatation, cystic medial necrosis and floppy aortic valve are related to the same degenerative disease which may involve t he cusps and or the aortic wall.