title: New-generation valved conduit: an experimental study.
abstract: OBJECTIVE
  An ideal valved conduit to repair complex congenital heart defects is yet to be developed. In this study we have evaluated the merits of our newly developed calcification-free biologic valve incorporated in a compatible conduit of biologic origin in an animal model.
  
  
  METHODS
  Porcine aortic valves and main pulmonary arteries were cross-linked in glutaraldehyde, followed by coupling to partially degraded heparin through an intermediate surface-bound substrate containing amino groups. Because commercially available valves are treated only with glutaraldehyde, control aortic valves and main pulmonary arteries were cross-linked in 0.625% glutaraldehyde. Valved conduits were fabricated from main pulmonary arteries, which were sewn to the aortic and ventricular ends of aortic valves. Valved conduits were examined for calcification and other pathologic changes after being implanted in the descending thoracic aorta in juvenile sheep for 5 months.
  
  
  RESULTS
  Severe calcification was noticed in all layers of cusps (calcium, 231.86 +/- 17.90 mg/gm) and aortic wall (calcium, 123.24 +/- 24.72 mg/gm) of aortic valves and main pulmonary arteries (calcium, 135.43 +/- 26.63 mg/gm) of valved conduits treated with 0.625% glutaraldehyde. Cusps (calcium, 1.28 +/- 0.22 mg/gm) of the aortic valve of heparin-bonded conduits did not calcify at all. Only sparse calcific deposits were noticed in the medial layer of the aortic wall (calcium, 25.90 +/- 22.79 mg/gm) of aortic valves and main pulmonary arteries (calcium, 9.64 +/- 10.79 mg/gm) of the valved conduits coupled to heparin.
  
  
  CONCLUSIONS
  Heparin coupling is effective in preventing calcification of glutaraldehyde cross-linked valved conduits implanted in the systemic circulation of juvenile sheep.
authors.affiliation: Department of Cardiovascular Surgery, Akita University School of Medicine, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Chanda
authors.forename: R
authors.initials: R
authors.lastname: Kuribayashi
authors.forename: T
authors.initials: T
authors.lastname: Abe
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000601:surgery; D001021:Aortic Valve / Q000473:pathology / Q000601:surgery; D001705:Bioprosthesis / Q000379:methods*; D001807:Blood Vessel Prosthesis / Q000379:methods*; D002114:Calcinosis / Q000517:prevention & control; D003432:Cross-Linking Reagents; D004195:Disease Models, Animal; D005976:Glutaral; D006350:Heart Valve Prosthesis / Q000379:methods*; D006493:Heparin; D011651:Pulmonary Artery / Q000473:pathology / Q000601:surgery; D012756:Sheep; D013552:Swine
chemical_list: D003432:Cross-Linking Reagents; D006493:Heparin; D005976:Glutaral