title: First experience with heterotopic thoracic pig-to-baboon cardiac xenotransplantation.
abstract: BACKGROUND
  Heterotopic thoracic heart transplantation may be an alternative to the established heterotopic abdominal or orthotopic cardiac xenotransplantation model as it combines the safety of heterotopic transplantation with the benefit of a working heart model.
  
  
  METHODS
  In a first series of two animals, we tested the surgical feasibility of this procedure with non-transgenic pig hearts transplanted into pre-sensitized baboons (killed after weaning from cardiopulmonary bypass). In a second group (n = 2), double-transgenic alpha(1,3)galactosyl-transferase knock out/hCD46 pig hearts were transplanted into naïve baboons after immunoadsorption. The immunosuppressive regimen consisted of anti-CD20-mAb, tacrolimus, sirolimus, MMF and steroids.
  
  
  RESULTS
  The first baboon was successfully transplanted, but died of an air embolism, while in the second animal graft survival was 50 days with the recipient in good physical condition. One rejection reaction was successfully treated by immunoadsorption, ATG and the proteasome inhibitor bortezomib. Post-mortem histopathology showed no evidence for humoral or cellular rejection of the cardiac xenograft.
  
  
  CONCLUSIONS
  This is the first description of a heterotopic thoracic pig-to-baboon heart transplantation. The procedure combines the advantages of a working heart model with the safety of heterotopic transplantation. In contrast to orthotopic transplantation, the recipient heart can assist the donor heart during episodes of rejection. We believe that the heterotopic thoracic model may accelerate the progress into the clinical application of cardiac xenotransplantation. However, successful combination of this heterotopic transplantation with an experimental model of cardiac failure may be needed before this technique can be promoted to clinical trials.
authors.affiliation: Department of Anaesthesiology, Ludwig Maximilian University Munich, Munich, Germany. andreas.bauer@med.uni-muenchen.de
authors.forename: Andreas
authors.initials: A
authors.lastname: Bauer
authors.forename: Johannes
authors.initials: J
authors.lastname: Postrach
authors.forename: Michael
authors.initials: M
authors.lastname: Thormann
authors.forename: Stefanie
authors.initials: S
authors.lastname: Blanck
authors.forename: Claudius
authors.initials: C
authors.lastname: Faber
authors.forename: Bernd
authors.initials: B
authors.lastname: Wintersperger
authors.forename: Sebastian
authors.initials: S
authors.lastname: Michel
authors.forename: Jan-Michael
authors.initials: JM
authors.lastname: Abicht
authors.forename: Frank
authors.initials: F
authors.lastname: Christ
authors.forename: Christoph
authors.initials: C
authors.lastname: Schmitz
authors.forename: Michael
authors.initials: M
authors.lastname: Schmoeckel
authors.forename: Bruno
authors.initials: B
authors.lastname: Reichart
authors.forename: Paolo
authors.initials: P
authors.lastname: Brenner
mesh_terms: D000818:Animals; D055785:Gene Knockdown Techniques; D006084:Graft Rejection / Q000188:drug therapy* / Q000473:pathology; D006085:Graft Survival; D016027:Heart Transplantation / Q000379:methods* / Q000473:pathology; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D051916:Membrane Cofactor Protein / Q000235:genetics; D009206:Myocardium / Q000473:pathology; D010215:Papio; D013552:Swine; D014183:Transplantation, Heterologous / Q000379:methods* / Q000473:pathology
chemical_list: D007166:Immunosuppressive Agents; D051916:Membrane Cofactor Protein