title: Freestyle valve experience: technical considerations and mid-term results.
abstract: BACKGROUND
  Many studies have demonstrated the superior hemodynamics of stentless porcine aortic valves compared to stented valves. This article describes the operative techniques and reviews our 5-year experience with the Medtronic Freestyle stentless valve.
  
  
  METHODS
  Between January 1993 and November 1997, 95 patients underwent implantation of the Medtronic Freestyle valve at a mean age of 76 years. All patients were seen at 6 months, 1 year, and annually thereafter for clinical assessment and Doppler echocardiography.
  
  
  RESULTS
  There were three operative and ten late deaths (two cardiac and eight noncardiac). Three strokes and four transient ischemic attacks occurred in the follow-up period. Four patients had bacteremia that was treated successfully with antibiotics. No patient required reoperation for valve-related problems. Serial echocardiograms revealed a decrease in mean systolic gradients across the valve during the first year and an increase in effective orifice areas. Ninety-one percent of patients had no, or trace, aortic insufficiency at the time of discharge and this has not increased over time.
  
  
  CONCLUSIONS
  The Medtronic Freestyle valve has excellent hemodynamics and good clinical results. In our experience, no patient has required reoperation in a 5-year follow-up.
authors.affiliation: Department of Cardiac Surgery, Kaiser Permanente Medical Center, Los Angeles, California, USA.
authors.forename: C F
authors.initials: CF
authors.lastname: Sintek
authors.forename: T A
authors.initials: TA
authors.lastname: Pfeffer
authors.forename: G S
authors.initials: GS
authors.lastname: Kochamba
authors.forename: K L
authors.initials: KL
authors.lastname: Yun
authors.forename: A D
authors.initials: AD
authors.lastname: Fletcher
authors.forename: S
authors.initials: S
authors.lastname: Khonsari
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000601:surgery; D001705:Bioprosthesis; D020099:Coated Materials, Biocompatible; D015150:Echocardiography, Doppler; D005260:Female; D005500:Follow-Up Studies; D006349:Heart Valve Diseases / Q000503:physiopathology / Q000601:surgery*; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000295:instrumentation* / Q000401:mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D009829:Oleic Acids; D011093:Polyethylene Terephthalates; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome
chemical_list: D020099:Coated Materials, Biocompatible; D009829:Oleic Acids; D011093:Polyethylene Terephthalates; C088318:2-(amino)oleic acid