title: Comparison of three different types of stentless valves: full root or subcoronary.
abstract: BACKGROUND
  It is believed that, compared with stented valves, stentless bioprostheses at the aortic position offer a larger orifice area.
  
  
  METHODS
  During the past 45 months, we have implanted 211 various types of aortic prostheses in our clinic. In the subcoronary position, we have used the Medtronic Freestyle, Toronto SPV, and Cryolife O'Brien prostheses, and as an aortic root replacement, the Medtronic Freestyle. There were no special indications for selection of each prosthesis except in 8 patients suffering from a disease of the ascending aorta in addition or in a redo procedure because of endocarditis or valve degeneration in which we implanted the full root Freestyle prosthesis. All patients had echocardiographic examinations postoperatively and after 1 year.
  
  
  RESULTS
  Although the implantations took significantly longer time initially, recently the complication rate has shown itself to be no greater than in comparable patients with stented prostheses. The hemodynamic results are very good with the exception of the Freestyle prosthesis implanted in the subcoronary position. The gradients of the remaining three prosthesis after 1 year are between 5 mm Hg and 10 mm Hg, and the effective valve orifice is between 2 and 3 cm2 depending on valve size.
  
  
  CONCLUSIONS
  The use of stentless tissue valves offers better hemodynamic results than that of stented valves with essentially no increased operative risk.
authors.affiliation: Department of Cardiothoracic Surgery, Klinikum Krefeld, Germany. HC@Klinikum-Krefeld.de
authors.forename: H H
authors.initials: HH
authors.lastname: Greve
authors.forename: I
authors.initials: I
authors.lastname: Farah
authors.forename: M
authors.initials: M
authors.lastname: Everlien
mesh_terms: D000368:Aged; D001021:Aortic Valve / Q000601:surgery*; D001705:Bioprosthesis; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis; D006801:Humans; D008297:Male; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000401:mortality; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012086:Reoperation; D015607:Stents; D015996:Survival Rate