title: Valve replacement with a stentless bioprosthesis: versatility of the porcine aortic root.
abstract: OBJECTIVE
  Stentless valves convey important hemodynamic benefits but are used selectively depending on aortic root structure. The Freestyle valve (Medtronic, Inc, Minneapolis, Minn) is a versatile device that can be implanted by different methods depending on operating conditions. We aimed to demonstrate that a stentless valve could be used in every patient without increased risk of morbidity or mortality. We documented the effects of this valve on clinical outcome and left ventricular mechanics.
  
  
  METHODS
  The Freestyle valve was implanted by the modified subcoronary method into 200 consecutive unselected patients who received a tissue valve in the aortic position and by root replacement in 2. Forty-three percent were older than 75 years. Forty percent underwent coronary bypass. Detailed clinical and echocardiographic follow-up (Food and Drug Administration protocol) was used out to 3 years.
  
  
  RESULTS
  Mean ischemic time was 43+/-6 minutes for isolated aortic valve replacement and 63+/-14 minutes with concomitant procedures. Thirty-day mortality was 6%, none of the deaths being valve related. Hemodynamic function improved progressively with falling valve gradients and increased effective orifice areas. Left ventricular mass fell within normal limits over 2 years, but at 3 years there was a non-valve-related upswing. No instances of valve thrombosis, hemolysis, or paravalvular leak were noted. Less than 5% had mild to moderate aortic regurgitation.
  
  
  CONCLUSIONS
  The Freestyle valve can be used in virtually every patient with aortic valve disease and provides superlative hemodynamic outcome. Hospital mortality and morbidity are similar to those reported for stented valves in an elderly population.
authors.affiliation: Department of Cardiac Surgery, Oxford Heart Centre, The John Radcliffe Hospital, United Kingdom.
authors.forename: S
authors.initials: S
authors.lastname: Westaby
authors.forename: X Y
authors.initials: XY
authors.lastname: Jin
authors.forename: T
authors.initials: T
authors.lastname: Katsumata
authors.forename: A
authors.initials: A
authors.lastname: Arifi
authors.forename: P
authors.initials: P
authors.lastname: Braidley
mesh_terms: D000368:Aged; D001021:Aortic Valve; D001022:Aortic Valve Insufficiency / Q000401:mortality / Q000601:surgery*; D001024:Aortic Valve Stenosis / Q000401:mortality / Q000601:surgery*; D001705:Bioprosthesis; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000379:methods* / Q000401:mortality; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D011474:Prosthesis Design; D013997:Time Factors; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000502:physiology