title: The value of the stentless biovalve prosthesis. An experimental study.
abstract: Clinical use of the stentless bioprosthesis has not yet been accepted world-wide. Experimental studies are scarce. In a study in growing pigs, 23 aortic valve replacements were performed (7 stented bioprostheses (STB), 10 stentless bioprostheses (SLB) and 6 cryopreserved homografts (CAH)). Valves were studied macroscopically and microscopically after explantation. Five animals died between 1.5 and 4 months after implantation. Two STBs showed extreme calcific degeneration. A third STB animal died suddenly: this STB showed only minimal leaflet calcification. One SLB was stenosed with a large fibrin deposit in one cusp, a second SLB showed slight cusp calcification and three were paracommissural tears in one cusp. In all other animals the valves were explanted after 5 to 6.5 months. All STBs showed severe calcific degeneration. Five SLBs showed mild calcific degeneration, while three others were unaltered after 6 months. All CAHs were free of calcific degeneration, three were perfect, two had a tear in a commisure and another was prolapsed with a fibrin degeneration. The speed and extent of valve degeneration were less than in the STB group. The stentless design is an important contribution which may result in a higher durability of bioprosthetic valves.
authors.affiliation: Department of Cardiothoracic Surgery, University Hospital, Leiden, The Netherlands.
authors.forename: M G
authors.initials: MG
authors.lastname: Hazekamp
authors.forename: Y A
authors.initials: YA
authors.lastname: Goffin
authors.forename: H A
authors.initials: HA
authors.lastname: Huysmans
mesh_terms: D000818:Animals; D001021:Aortic Valve / Q000637:transplantation; D001705:Bioprosthesis; D002114:Calcinosis; D015925:Cryopreservation; D004868:Equipment Failure; D006350:Heart Valve Prosthesis; D015607:Stents; D013552:Swine; D014184:Transplantation, Homologous