title: Assessment of aortic annulus dimensions for Edwards SAPIEN Transapical Heart Valve implantation by computed tomography: calculating average diameter using a virtual ring method.
abstract: OBJECTIVE
  Accurate preoperative assessment of the aortic annulus dimensions is critical in patients undergoing transcatheter aortic valve implantation (TAVI) for severe AS. Using multislice computed tomography (MSCT), we evaluated a novel approach to quantify aortic annulus dimensions using cross-sectional area (CSA) assessment and average diameter calculation compared with the commonly applied electronic caliper measurements in patients undergoing transapical implantation of the Edwards SAPIEN Transcatheter Heart Valve.
  
  
  METHODS
  Seventy-one patients underwent pre-TAVI MSCT with the following dimensions assessed at the level of the most basal attachment points of all three aortic cusps joined by a virtual ring: CSA, calculated average annulus diameter (CAAD), and minimal, maximum, sagittal and coronal diameters. Measurements were compared with post-TAVI MSCT data sets at the level of the ventricular stent ending in 24 patients. Pre-TAVI measurements were compared to those taken post-TAVI. Eligibility to balloon-expandable TAVI was evaluated based on the different measurements.
  
  
  RESULTS
  The Edwards SAPIEN valve (23 mm, n=8; 26 mm, n=16) was implanted 2.1±1.1 mm below the non-coronary sinus. Pre-TAVI CAAD was 23.0±1.6 mm; post-TAVI CAAD was 23.0±1.1 mm. Post-TAVI CSA was circular in 18 patients (75%) and ovoid in six (25%). Pre- and post-TAVI assessment showed strong correlation for CSA and CAAD (r=0.835, p<0.001; r=0.841, p<0.001, respectively). Minimal, maximum, coronal and sagittal dimension correlated weakly between pre- and post-TAVI measurements (r=0.435-0.632, p=0.001-0.034).
  
  
  CONCLUSIONS
  Pre-TAVI CSA assessment and average diameter calculation using a virtual ring method is able to predict the post-interventional configuration of the annulus after balloon-expandable TAVI. We regard this approach as the best-available method to select the appropriate prosthesis size for balloon-expandable TAVI. Specific MSCT-based sizing recommendations should be developed.
authors.affiliation: Department of Diagnostic Radiology, University Hospital Freiburg, Hugstetter Str. 55, 79104 Freiburg, Germany. philipp.blanke@uniklinik-freiburg.de
authors.forename: Philipp
authors.initials: P
authors.lastname: Blanke
authors.forename: Matthias
authors.initials: M
authors.lastname: Siepe
authors.forename: Jochen
authors.initials: J
authors.lastname: Reinöhl
authors.forename: Manfred
authors.initials: M
authors.lastname: Zehender
authors.forename: Friedhelm
authors.initials: F
authors.lastname: Beyersdorf
authors.forename: Christian
authors.initials: C
authors.lastname: Schlensak
authors.forename: Mathias
authors.initials: M
authors.lastname: Langer
authors.forename: Gregor
authors.initials: G
authors.lastname: Pache
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000473:pathology; D001022:Aortic Valve Insufficiency / Q000209:etiology; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D017548:Echocardiography, Transesophageal / Q000379:methods; D005260:Female; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D006801:Humans; D008297:Male; D015588:Observer Variation; D011474:Prosthesis Design; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods