title: Freestyle stentless bioprosthesis for aortic valve therapy: 17-year clinical results.
abstract: BACKGROUND
  Aortic valve replacement with stentless bioprostheses has been shown to produce lower aortic gradients than stented bioprostheses, thus facilitating left ventricular mass regression and preventing heart failure. We sought to determine the long-term results of stentless biological aortic valve replacement over a 17-year follow-up.
  
  
  METHODS
  Between 1996 and 2012, 2551 patients underwent isolated aortic valve replacement with a stentless prosthesis (Medtronic Freestyle) at a single center. The mean patient age was 72 ± 10 years, 55% were male, 24.1% were in New York Heart Association class I and II, 9.6% had undergone previous surgery, 18.1% had coronary artery disease, and 23.1% had diabetes. For the long-term follow-up, patients were contacted in writing and by telephone; follow-up was 96.3% complete, resulting in 11,546 patient-years.
  
  
  RESULTS
  At 30 days, mortality (5.4%), renal failure (3.9%), myocardial infarction (0.7%), and stroke (1.4%) rates were acceptable. During long-term follow-up of 1-17 years, the bleeding rate (2.9%) was higher than the thromboembolic event rate (0.7%) despite 18.1% of patients being on oral anticoagulants. New pacemaker implantation (4.5%; 0.87 events/100 patient-years), neurological disorders (5%; 0.52 events/100 patient-years), valve insufficiency (0.7%; 0.16 events/100 patient-years), paravalvular leakage (0.4%; 0.09 events/100 patient-years) and reoperation due to valvular complications (0.7%; 0.38 events/100 patient-years) were rare. Long-term survival was 41.8% ± 1.6 after 10 years, 21.3% ± 2.3 after 15 years, and 12.1% ± 3.9 after 17 years.
  
  
  CONCLUSIONS
  Long-term results after aortic valve replacement with stentless biological prostheses compare favorably with those obtained with stented bioprostheses.
authors.affiliation: Heart Center, Helios Hospital Siegburg Germany.|Faculty of Medicine, Witten-Herdecke University, Witten, Germany.
authors.forename: Juergen
authors.initials: J
authors.lastname: Ennker
authors.affiliation: Institute of Medical Statistics, Justus-Liebig University Giessen, Giessen, Germany.|Department of Cardiovascular Surgery, Justus-Liebig University Giessen, Giessen, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Meilwes
authors.affiliation: Institute of Medical Statistics, Justus-Liebig University Giessen, Giessen, Germany.
authors.forename: Joern
authors.initials: J
authors.lastname: Pons-Kuehnemann
authors.affiliation: Department of Cardiovascular Surgery, Justus-Liebig University Giessen, Giessen, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Niemann
authors.affiliation: Department of Cardiovascular Surgery, Justus-Liebig University Giessen, Giessen, Germany.
authors.forename: Philippe
authors.initials: P
authors.lastname: Grieshaber
authors.affiliation: Hannover Medical School, Department of Plastic and Reconstructive Surgery, Hannover, Germany.
authors.forename: Ina C
authors.initials: IC
authors.lastname: Ennker
authors.affiliation: Department of Cardiovascular Surgery, Justus-Liebig University Giessen, Giessen, Germany andreas.boening@chiru.med.uni-giessen.de.
authors.forename: Andreas
authors.initials: A
authors.lastname: Boening
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000503:physiopathology / Q000601:surgery*; D001705:Bioprosthesis; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D005858:Germany; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation* / Q000401:mortality; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology / Q000401:mortality / Q000628:therapy; D011474:Prosthesis Design; D012086:Reoperation; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome
keywords: Aortic valve; Bioprosthesis; Heart valve prosthesis; Heart valve prosthesis implantation; Treatment outcome