Se stárnutím populace přibývá nemocných s aortální stenózou indikovaných k náhradě chlopně. Stále častěji jsou implantovány bioprotézy. Dlouhodobá funkce bez nutnosti antikoagulační léčby, vyvážená kratší životností je výhodná zvláště pro nemocné starší 65 let.The number of patients indicated for aortic valve replacement increases as the population ages. Also the number of bioprostheses used is increasing. The main advantage of bioprostheses is long term function without anticoagulation treatment. Between March 2002 and December 2006, a total of 296 bioprostheses were implanted at our institution. Bioprostheses used were as follows: Edwards Lifesciences, Irvine, U.S.A. (type 2650, 2900, 3000), Sorin Biomedica, Saluggia, Italy (type More, Soprano), St. Jude Medical, St. Paul, U.S.A. (type Epic) and Medtronic, Minneapolis, U.S.A. (type Mosaic). We measured flow gradients through native valve and diastolic thickness of septum and back wall of left ventricle before surgery. During surgery before valve implantation we measured the inner and outer diameter of the bioprostheses ring. Later on we measured flow gradients, effective orifice area and left ventricle wall thickness postoperatively. Examinations were done before patient discharge and then on outpatient basis three months, six months, one year and two years postoperatively.