title: Performance and morphology of decellularized pulmonary valves implanted in juvenile sheep.
abstract: BACKGROUND
  Because of cryopreserved heart valve-mediated immune responses, decellularized allograft valves are an attractive option in children and young adults. The objective of this study was to investigate the performance and morphologic features of decellularized pulmonary valves implanted in the right ventricular outflow tract of juvenile sheep.
  
  
  METHODS
  Right ventricular outflow tract reconstructions in juvenile sheep (160±9 days) using cryopreserved pulmonary allografts (n=6), porcine aortic root bioprostheses (n=4), or detergent/enzyme-decellularized pulmonary allografts (n=8) were performed. Valve performance (echocardiography) and morphologic features (gross, radiographic, and histologic examination) were evaluated 20 weeks after implantation.
  
  
  RESULTS
  Decellularization reduced DNA in valve cusps by 99.3%. Bioprosthetic valves had the largest peak and mean gradients versus decellularized valves (p=0.03; p<0.001) and cryopreserved valves (p=0.01; p=0.001), which were similar (p=0.45; p=0.40). Regurgitation was minimal and similar for all groups (p=0.16). No cusp calcification was observed in any valve type. Arterial wall calcification was present in cryopreserved and bioprosthetic grafts but not in decellularized valves. No autologous recellularization or inflammation occurred in bioprostheses, whereas cellularity progressively decreased in cryopreserved grafts. Autologous recellularization was present in decellularized arterial walls and variably extending into the cusps.
  
  
  CONCLUSIONS
  Cryopreserved and decellularized graft hemodynamic performance was comparable. Autologous recellularization of the decellularized pulmonary arterial wall was consistently observed, with variable cusp recellularization. As demonstrated in this study, decellularized allograft valves have the potential for autologous recellularization.
authors: Cardiac Surgery Research Laboratories of the Ward Center for Congenital Heart Disease of The Children's Mercy Hospital, Kansas City, Missouri 64108, USA. rwquinn@cmh.edu
authors: Rachael W
authors: RW
authors: Quinn
authors: Stephen L
authors: SL
authors: Hilbert
authors: Arthur A
authors: AA
authors: Bert
authors: Bill W
authors: BW
authors: Drake
authors: Julie A
authors: JA
authors: Bustamante
authors: Jason E
authors: JE
authors: Fenton
authors: Sara J
authors: SJ
authors: Moriarty
authors: Stacy L
authors: SL
authors: Neighbors
authors: Gary K
authors: GK
authors: Lofland
authors: Richard A
authors: RA
authors: Hopkins
mesh_terms: D000818:Animals; D001705:Bioprosthesis; D002302:Cardiac Output; D006348:Cardiac Surgical Procedures / Q000009:adverse effects / Q000379:methods* / Q000401:mortality; D015925:Cryopreservation / Q000379:methods*; D004195:Disease Models, Animal; D017548:Echocardiography, Transesophageal; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D007150:Immunohistochemistry; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000503:physiopathology; D019919:Prosthesis Implantation / Q000379:methods; D011664:Pulmonary Valve / Q000473:pathology* / Q000601:surgery / Q000637:transplantation*; D011897:Random Allocation; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012756:Sheep; D034561:Sheep, Domestic; D015996:Survival Rate; D014184:Transplantation, Homologous; D016896:Treatment Outcome; D014694:Ventricular Outflow Obstruction / Q000000981:diagnostic imaging / Q000601:surgery