title: Mitroflow pericardial bioprosthesis: structured failure at 4.5 years.
abstract: BACKGROUND
  Prosthetic heart valves are commonly used in the management of significant valvular disease. Although bioprostheses are increasingly popular, structural deterioration with cusp tears and calcification persists.
  
  
  METHODS
  We present a case of a Mitroflow pericardial bioprosthesis (Sorin Group Inc., Mitroflow Division, Vancouver, Canada) explanted after 4.5 years from a 78-year-old woman for bioprosthesis stenosis.
  
  
  RESULTS
  The morphological reasons for bioprosthesis failure include structural tissue deterioration with thickening of the pericardial cusps, cusp calcification, and parastent post tears resulting in significant valvular dysfunction.
  
  
  CONCLUSIONS
  To the best of our knowledge, this is the first detailed morphological description of the failure modes of a surgically explanted Mitroflow (A12) pericardial bioprosthesis.
authors.affiliation: Department of Pathology, Toronto General Hospital/University Health Network, Toronto, Canada. jagdish.butany@uhn.on.ca
authors.forename: Jagdish
authors.initials: J
authors.lastname: Butany
authors.forename: Tianshu
authors.initials: T
authors.lastname: Feng
authors.forename: Rahul
authors.initials: R
authors.lastname: Suri
authors.forename: Kelsey
authors.initials: K
authors.lastname: Law
authors.forename: George
authors.initials: G
authors.lastname: Christakis
mesh_terms: D000368:Aged; D001021:Aortic Valve / Q000601:surgery; D001022:Aortic Valve Insufficiency / Q000601:surgery; D001024:Aortic Valve Stenosis / Q000601:surgery; D001705:Bioprosthesis; D002114:Calcinosis / Q000473:pathology; D020878:Device Removal; D019544:Equipment Failure Analysis; D005260:Female; D006350:Heart Valve Prosthesis / Q000009:adverse effects*; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects*; D006801:Humans; D011474:Prosthesis Design; D011475:Prosthesis Failure; D013997:Time Factors; D016896:Treatment Outcome