title: Pulmonary valve-in-valve implants: how long do they prolong reintervention and what causes them to fail?
abstract: BACKGROUND
  The valve-in-valve (VinV) procedure is a minimally invasive, transcatheter, off-pump, alternative to conventional valve replacement, which uses a failing bioprosthesis to anchor a second transcatheter-delivered prosthesis. This technique appears effective for prolonging freedom from reintervention and treating early device failure. However, it is unknown as to how long reintervention can be avoided.
  
  
  METHODS
  We present the pathological findings of a VinV explanted after 47 months, as well as the failure modes of these devices.
  
  
  RESULTS
  The VinV approach in our case ultimately failed, likely due to the proximity of the host's tissues to the prosthetic device, resulting in a combination of pannus, calcification, and a cusp tear.
  
  
  CONCLUSIONS
  Additional long-term follow-up of pulmonary VinV implantations is needed in order to determine the life span of VinVs and what causes them to fail.
authors.affiliation: Department of Pathology, Toronto General Hospital/University Health Network, Toronto, Canada M5G 2C4.
authors.forename: Kelsey B
authors.initials: KB
authors.lastname: Law
authors.forename: Katharine R B
authors.initials: KR
authors.lastname: Phillips
authors.forename: Jagdish
authors.initials: J
authors.lastname: Butany
mesh_terms: D001705:Bioprosthesis; D002114:Calcinosis / Q000473:pathology; D020878:Device Removal; D019544:Equipment Failure Analysis; D006350:Heart Valve Prosthesis / Q000009:adverse effects*; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D007223:Infant; D008297:Male; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011666:Pulmonary Valve Stenosis / Q000209:etiology / Q000473:pathology / Q000601:surgery; D013771:Tetralogy of Fallot / Q000150:complications / Q000473:pathology / Q000601:surgery; D013997:Time Factors