Surgical pathology of the common atrioventricular valve: a study of 11 cases.

Eleven patients (six females and five males) underwent partial or complete excision of common atrioventricular valves. Their ages ranged from 11 months to 23 years (mean, 8 years). Six patients had complex congenital heart disease: three with asplenia, two with polysplenia, and one with a hypoplastic left ventricle and severe pulmonary stenosis. Pure regurgitation characterized all 11 valves and was severe in eight. Neither active nor healed endocarditis was observed in any valve. Of the 11 valves, nine were thickened, and eight had features of floppy valves, including hooding deformity, inadequate chordal insertions, and disruption of the fibrosa by the spongiosa. In ten valves fibrous pads also involved the leaflet surfaces. These observations support the concept that floppy valves may result from congenital abnormalities in valvular development.