title: Histopathologic comparison of a pulmonary autograft and pulmonary homograft in a patient 17 months after a Ross procedure: an autopsy study.
abstract: OBJECTIVE
  The Ross operation has become very popular during the last decade. However little is known about the cellular behaviour of a normally functioning pulmonary autograft.
  
  
  METHODS
  This case report deals with a 14-year-old female who died from a non-valve-related cause 17 months after a Ross-Konno operation using a cryop-reserved viable pulmonary homograft for the right outflow tract. Comparison is made between the homologous and autologous pulmonary valves by macroscopic description, histology and immunohistochemistry.
  
  
  RESULTS
  The autograft kept its cellular population-except for the dendritic cells which have disappeared, and developed a jet lesion on the ventricular aspect of one cusp as a likely adaptation to a transvalvular gradient. The homograft was extensively devitalized, its cusps being partially covered with a fibrous sheath of recipient origin; few inflammatory cells, consisting of macrophages and rare T lymphocytes were present.
  
  
  CONCLUSIONS
  The most puzzling observation, which needs confirmation, is the selective disappearance of the dendritic cells from the viable autograft. It is disappointing that a viable cryopreserved homograft valve has devitalized in the midterm. This phenomenon seems to result from a clinically silent immune reactions.
authors.affiliation: European Homograft Bank International Association, Brussels, Belgium.
authors.forename: Y A
authors.initials: YA
authors.lastname: Goffin
authors.forename: K R
authors.initials: KR
authors.lastname: Narine
authors.forename: J P
authors.initials: JP
authors.lastname: Alexander
authors.forename: J
authors.initials: J
authors.lastname: Van Goethem
authors.forename: W J
authors.initials: WJ
authors.lastname: Daenen
mesh_terms: D000293:Adolescent; D001021:Aortic Valve / Q000601:surgery*; D015925:Cryopreservation; D003713:Dendritic Cells / Q000473:pathology; D005260:Female; D006330:Heart Defects, Congenital / Q000473:pathology / Q000601:surgery*; D006801:Humans; D011664:Pulmonary Valve / Q000473:pathology* / Q000637:transplantation*; D013997:Time Factors; D014182:Transplantation, Autologous; D014184:Transplantation, Homologous