title: New polyurethane valves in new soft artificial hearts.
abstract: This article describes new bistable valves, and introduces a new soft heart that is easy to implant. Earlier, five polyurethane (PU) valves were implanted in the mitral position in sheep. All five survived for 1 year or more, and the valves, although calcified, were intact. Since the opening resistance was somewhat high, valves that are bistable were developed, which means they may be open or closed. These valves have lower opening resistance, and regurgitation is similar to that of mechanical valves. Eight calves have been implanted with a new, soft total artificial heart (TAH). Seven had bistable leaflet valves; the eighth had mechanical (Bicer) valves in the inflow position. Four of the calves were sacrificed after 22 to 43 days. At autopsy, the number of thromboemboli found, particularly in the kidneys, was low compared with previous experiments. None of these animals received anticoagulants other than the heparin given during heart/lung bypass.
authors.affiliation: Department of Surgery, University of Utah, Salt Lake City 84112.
authors.forename: L S
authors.initials: LS
authors.lastname: Yu
authors.forename: B
authors.initials: B
authors.lastname: Yuan
authors.forename: D
authors.initials: D
authors.lastname: Bishop
authors.forename: S
authors.initials: S
authors.lastname: Topaz
authors.forename: J
authors.initials: J
authors.lastname: van Griensven
authors.forename: S
authors.initials: S
authors.lastname: Hofma
authors.forename: P
authors.initials: P
authors.lastname: Swier
authors.forename: J
authors.initials: J
authors.lastname: Klinkmann
authors.forename: J
authors.initials: J
authors.lastname: Kolff
authors.forename: W J
authors.initials: WJ
authors.lastname: Kolff
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity; D001794:Blood Pressure; D002417:Cattle; D006350:Heart Valve Prosthesis; D006354:Heart, Artificial; D008955:Models, Cardiovascular; D011140:Polyurethanes; D011474:Prosthesis Design; D013927:Thrombosis / Q000209:etiology
chemical_list: D011140:Polyurethanes