[Evaluation of the 21 mm Björk-Shiley aortic valve prosthesis].
D000328:Adult; D001021:Aortic Valve / Q000601:surgery; D001022:Aortic Valve Insufficiency / Q000503:physiopathology / Q000601:surgery*; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis; D006439:Hemodynamics; D006801:Humans; D008875:Middle Aged