title: Redo mitral valve surgery: morphological features.
abstract: BACKGROUND
  Mitral valve (MV) repair is the surgery of choice in patients with mitral regurgitation. This study reviews the histological features of excised mitral leaflets and annuloplasty rings of patients who had previous MV repair or attempted repair.
  
  
  METHODS
  This study examines the morphological findings of 54 excised MV leaflets and 39 annuloplasty rings, excised over 15 years at one institution. Patients were separated into groups based on the time interval between surgeries: attempted repair, <30 days, 30-365 days, and >1 year.
  
  
  RESULTS
  The fifty-four patients had a mean age of 55.7+/-17.9 years at the time of surgery after failed repair or attempted repair, of the MV. Index surgery for all patients had been performed between 1973 and 2005. The interval between index surgery and readmission (n=49, 91%, excluding those with MV replacement following attempted repair) was 6.61+/-7.12 years. Myxomatous change and infective endocarditis (IE) were found in valves with failed attempted MV repair. Nonleaflet (ischemic, chordal rupture, and flow abnormalities) and acquired changes, degenerative, myxomatous, and IE were found in valves repaired in patients at <30 days postoperatively. Degenerative changes (myxomatous and RF) were the main underlying pathology found in valves repaired between 31 and 365 days previously. At over 1 year after original surgery, repairs were found to have congenital, degenerative (myxomatous, rheumatic valvular disease, and IE) and nonleaflet (ischemic and chordal rupture) changes.
  
  
  CONCLUSIONS
  Although MV repair is the preferred treatment for mitral regurgitation, failure of repair may occur in patients at the time of surgery or over varying periods after surgery. The pathological findings following repair include IE, fibrosis, calcification, and nodular thickening at and around the operative site, thickening and stiffening of the synthetic chordae tendinae due to tissue overgrowth, rupture of chordae tendinae, and progression of acquired degenerative disease.
authors.affiliation: Department of Pathology, Toronto General Hospital/University Health Network, and Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, ON, Canada.
authors.forename: Adriana
authors.initials: A
authors.lastname: Luk
authors.forename: Anusha
authors.initials: A
authors.lastname: Jegatheeswaran
authors.forename: Tirone E
authors.initials: TE
authors.lastname: David
authors.forename: Jagdish
authors.initials: J
authors.lastname: Butany
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006350:Heart Valve Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000601:surgery*; D011475:Prosthesis Failure; D012086:Reoperation; D012189:Retrospective Studies