title: In vivo remodeling potential of a novel bioprosthetic tricuspid valve in an ovine model.
abstract: OBJECTIVE
  A novel bioprosthetic tricuspid valve was constructed from an acellular extracellular matrix (ECM) bioscaffold. The valve's mechanical functionality and potential for histologic regeneration was evaluated in an ovine model.
  
  
  METHODS
  The native tricuspid valves of 4 domestic sheep were excised and replaced with bioprosthetic valves constructed from the ECM bioscaffold material shaped into the form of a tube. In vivo function was assessed over time by transthoracic echocardiography. Animals were euthanized at 3, 5, 8, and 12 months after valve implantation, and explanted valves were examined for gross morphology and by qualitative histopathologic analysis.
  
  
  RESULTS
  All 4 sheep survived until the specified date. Forward flow by echocardiography was normal with trivial to mild regurgitation. Annular morphology and mobility of the leaflets appeared normal with excellent leaflet coaptation. Explanted valves were grossly normal at all time points and showed evidence of progressive tissue remodeling and integration at the host-tissue interface. Histopathologic analysis demonstrated massive host-cell infiltration, structural reorganization of the ECM bioscaffold, elastin generation at the annulus by 3 months, and increased collagen organization and glycosaminoglycan presence in the leaflets by 5 months, with no evidence of foreign body response.
  
  
  CONCLUSIONS
  When implanted in the form of a tubular valve, the acellular ECM bioscaffold demonstrates feasibility as a biomechanically sound bioprosthetic tricuspid valve replacement with evidence of progressive endothelialization and constructive tissue remodeling.
authors.affiliation: CorMatrix Cardiovascular, Inc, Roswell, Ga. Electronic address: afallon@cormatrix.com.
authors.forename: Anna M
authors.initials: AM
authors.lastname: Fallon
authors.affiliation: Saint Joseph's Translational Research Institute, Atlanta, Ga.
authors.forename: Traci T
authors.initials: TT
authors.lastname: Goodchild
authors.affiliation: Washington University, St Louis, Mo.
authors.forename: James L
authors.initials: JL
authors.lastname: Cox
authors.affiliation: CorMatrix Cardiovascular, Inc, Roswell, Ga.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Matheny
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001705:Bioprosthesis; D018618:Echocardiography, Doppler, Color; D005240:Feasibility Studies; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation*; D008944:Mitral Valve Insufficiency / Q000209:etiology; D023421:Models, Animal; D011474:Prosthesis Design; D034561:Sheep, Domestic; D013997:Time Factors; D054457:Tissue Scaffolds; D014261:Tricuspid Valve / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology / Q000601:surgery*
chemical_list: D015415:Biomarkers