title: A new equine pericardial stentless valve.
abstract: OBJECTIVE
  Small aortic valve replacement remains a challenging hemodynamic problem. A new bioprosthesis (3F Therapeutics, Lake Forest, Calif) was designed to further improve the hemodynamic performance currently achieved with stentless bioprostheses. This valve consists of a tubular structure assembled from 3 equal sections of equine pericardial material, with virtually no foreign material except for a thin polyester ring. Its hemodynamic performance was compared with that of a commercially available stentless prosthesis in a bovine model.
  
  
  METHODS
  Twelve calves (55 +/- 2.8 kg) received a 19-mm 3F valve (3F group, n = 6) or a 19-mm stentless control valve (control group, n = 6). The animals were fully equipped for hemodynamic monitoring and transvalvular gradient measurements. After implantation, dopamine was infused in increasing doses, and the hemodynamic values were recorded at each step of 100-microg/min increase. Linear regression analysis was applied for group comparison of each variable.
  
  
  RESULTS
  The mean transvalvular gradient at 4.5 L/min was 3.48 +/- 0.14 mm Hg (95% confidence interval) in the 3F group and 5.72 +/- 0.28 mm Hg in the control group (P <.0001) and at 6.5 L/min, 7.4 +/- 1.55 mm Hg, and 11.13 +/- 0.18 mm Hg, respectively (P <.0001). The effective orifice area at 4.5 L/min was 2.4 +/- 0.03 cm(2) in the 3F group and 1.86 +/- 0.02 cm(2) in the control group (P <.0001) and at 6.5 L/min, 2.41 +/- 0.04 cm(2), and 1.96 +/- 0.02 cm(2), respectively (P <.0001).
  
  
  CONCLUSIONS
  This new bioprosthesis without a stent and without a supporting wall that has its commissures fixed directly to the aorta outperforms in vivo standard stentless prostheses in the immediate postimplant period.
authors.affiliation: Department of Cardio-vascular Surgery, Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, Quebec, Canada. xavier.mueller@usherbrooke.ca
authors.forename: Xavier M
authors.initials: XM
authors.lastname: Mueller
authors.forename: Ludwig K
authors.initials: LK
authors.lastname: von Segesser
mesh_terms: D000818:Animals; D001021:Aortic Valve; D001705:Bioprosthesis; D002417:Cattle; D006350:Heart Valve Prosthesis; D006439:Hemodynamics; D011474:Prosthesis Design