title: Early failure of freehand aortic stentless xenograft valves.
authors.forename: M F
authors.initials: MF
authors.lastname: O'Brien
mesh_terms: D000818:Animals; D001021:Aortic Valve / Q000637:transplantation*; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D011475:Prosthesis Failure; D013552:Swine; D013997:Time Factors; D014183:Transplantation, Heterologous