title: Aortic valve replacement with the Cryolife-O'Brien stentless aortic bioprosthesis: five-year experience.
abstract: OBJECTIVE
  Improved hemodynamics with stentless bioprosthesis compared to stented valves have been well documented. It has been suggested that a simplified implant model, the Cryolife-O'Brien, offers less satisfactory outcomes compared with standard stentless models. This study was conducted to prospectively evaluate the midterm results after aortic valve replacement with the Cryolife-O'Brien stentless bioprosthesis.
  
  
  METHODS
  In 1996, the prospective clinical trial using different stentless valves was initiated in our center. From September 1996 through August 2001, 132 consecutive patients with a mean age of 72.5 years underwent aortic valve replacement with the Cryolife-O'Brien porcine stentless bioprosthesis by the same surgeon. The predominant aortic valve lesion was stenosis in 110 cases and insufficiency in 22 cases. Patients have been followed-up from 2 to 60 months, mean 28 months. Echocardiography was performed by the same echocardiographer preoperatively, intraoperatively, postoperatively at discharge, 2 to 6 months later and annually thereafter.
  
  
  RESULTS
  Sixty-five percent of patients received a valve 25 mm in diameter or larger, 42% had concomitant coronary bypass grafting. The 30-day operative mortality rate was 6.8 %. Nine late deaths, none related to the valve, have occurred. Severe aortic insufficiency caused by oversizing led to early reoperation in 3 patients. The peak and mean systolic gradients decreased significantly during the first 12 months after implantation (p<0.001) and the effective valve areas increased significantly during this time interval (p<0.001). Eleven patients have aortic insufficiency, trivial in 7 and mild in 4. The actuarial survival at 5 years was 86+/-3%. The rate for freedom from endocarditis was 100% and for freedom from thromboembolic events 92%.
  
  
  CONCLUSIONS
  The Cryolife-OBrien stentless bioprosthesis has superior hemodynamics and a low rate of valve-related complications thus representing a very good alternative to conventional stented bioprosthesis. The midterm results are encouraging but further follow-up is needed to determine the valve's durability.
authors.affiliation: Department of Cardiovascular Surgery, Klinikum Krefeld, Am Oberend 11, 47809 Krefeld, Germany. IvoMartino@aol.com
authors.forename: I
authors.initials: I
authors.lastname: Martinovic
authors.forename: I
authors.initials: I
authors.lastname: Farah
authors.forename: M
authors.initials: M
authors.lastname: Everlien
authors.forename: I
authors.initials: I
authors.lastname: Knez
authors.forename: H P
authors.initials: HP
authors.lastname: Greve
authors.forename: P
authors.initials: P
authors.lastname: Vogt
mesh_terms: D000368:Aged; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000601:surgery*; D001705:Bioprosthesis; D019544:Equipment Failure Analysis; D005260:Female; D005500:Follow-Up Studies; D006349:Heart Valve Diseases / Q000000981:diagnostic imaging / Q000401:mortality / Q000601:surgery*; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D008297:Male; D011446:Prospective Studies; D015996:Survival Rate; D016896:Treatment Outcome; D014463:Ultrasonography