title: Surgical pathology and etiology of 278 surgically removed mitral valves with pure regurgitation in Thailand.
abstract: BACKGROUND
  There are multiple causes of mitral regurgitation. Its etiology includes floppy valve, postinflammatory disease, infective endocarditis, and other disorders. Recently, there has been an increased tendency to remove only portions of the mitral valve, causing difficulty in the determination of etiology. Our objective was to study the pathology and etiology of mitral regurgitation from surgically removed specimens.
  
  
  METHODS
  Native mitral valve specimens surgically excised due to mitral insufficiency were examined. Etiology was determined according to macroscopic, microscopic, clinical, and operative findings.
  
  
  RESULTS
  Among 278 mitral valve specimens, 43% were classified as floppy valve, 31% as postinflammatory disease (presumably associated with rheumatic fever), 12% as infective endocarditis, and 14% as miscellaneous group. In floppy valves, diffuse myxoid change and chordal rupture were the main findings. In postinflammatory disease, moderate neovascularization and chronic inflammatory cell infiltration were most commonly found. Aschoff bodies were found in two cases. In infective endocarditis, gram-positive cocci were found in 70% of cases. In the miscellaneous group, three cases were related to Marfan syndrome and one case was related to papillary muscle necrosis. In comparison with postinflammatory disease, the posterior leaflet in the floppy valve had a significantly longer basal free-edge length, a more frequent chordal rupture, and an higher mean age of patients. Among completely and partially excised specimens with postinflammatory disease, there were no significant differences in microscopic findings.
  
  
  CONCLUSIONS
  The three most common etiologies in mitral regurgitation were floppy valve, postinflammatory disease, and infective endocarditis. Macroscopic, microscopic, clinical, and operative findings are important in the evaluation of etiology, especially in partially excised specimens.
authors.affiliation: Department of Pathology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand. sipkf@mahidol.ac.th
authors.forename: Pornsuk
authors.initials: P
authors.lastname: Cheunsuchon
authors.forename: Tuenjai
authors.initials: T
authors.lastname: Chuangsuwanich
authors.forename: Norasate
authors.initials: N
authors.lastname: Samanthai
authors.forename: Malee
authors.initials: M
authors.lastname: Warnnissorn
authors.forename: Piyavadee
authors.initials: P
authors.lastname: Leksrisakul
authors.forename: Punnarerk
authors.initials: P
authors.lastname: Thongcharoen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D015897:Comorbidity; D004697:Endocarditis, Bacterial / Q000453:epidemiology / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000473:pathology* / Q000601:surgery; D008944:Mitral Valve Insufficiency / Q000453:epidemiology / Q000473:pathology* / Q000601:surgery; D008945:Mitral Valve Prolapse / Q000453:epidemiology / Q000473:pathology* / Q000601:surgery; D012214:Rheumatic Heart Disease / Q000453:epidemiology / Q000473:pathology* / Q000601:surgery; D013785:Thailand / Q000453:epidemiology