title: Transcatheter aortic valve implantation: time to expand?
abstract: OBJECTIVE
  Transcatheter aortic valve implantation is a new, emerging technique that has been performed in elderly and higher-risk patients suffering severe, symptomatic aortic stenosis.
  
  
  RESULTS
  Initial clinical results are promising. Important technological progress, i.e. the development of two stent-based aortic valve xenografts (the CoreValve prosthesis with a nitinol frame and the Edwards Sapien prosthesis with a steel stent), has allowed these achievements. Both prostheses can be crimped to small diameters, allowing for implantation by either a transfemoral or a transapical approach. Recently, CE mark approval has been obtained for both prostheses for transfemoral implantation. This will likely lead to an increased number of implantations. Current clinical studies are of prospective design with observational character. No prospectively randomized clinical trials have been reported so far; however, one randomized trial is under way.
  
  
  CONCLUSIONS
  Transcatheter aortic valve implantation has become a clinical reality and will be performed more frequently in the future. Patient selection is critical and current indications include only higher-risk patients suffering severe aortic stenosis. When selecting the optimal therapy for individual patients, the advantages and disadvantages of this novel approach must be carefully weighed against the excellent results achieved with conventional surgery.
authors.affiliation: Herzzentrum, Klinik für Herzchirurgie und Kardiologie, Universität Leipzig, Leipzig, Germany. walt@medizin.uni-leipzig.de
authors.forename: Thomas
authors.initials: T
authors.lastname: Walther
authors.forename: Michael W A
authors.initials: MW
authors.lastname: Chu
authors.forename: Friedrich W
authors.initials: FW
authors.lastname: Mohr
mesh_terms: D001021:Aortic Valve; D001024:Aortic Valve Stenosis / Q000601:surgery*; D002404:Catheterization; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D006801:Humans