title: Discrepancies between sizer and valve dimensions: implications for small aortic root.
abstract: BACKGROUND
  Precise labeling of sizer and valve diameters is crucial for optimal valve selection especially in the small aortic root. This study examines the accuracy of manufacturers' markings on small aortic prostheses and sizers.
  
  
  METHODS
  Sizer and valve dimensions of 22 different mechanical aortic prostheses (19 to 23 mm) were evaluated by caliper micrometer measurements.
  
  
  RESULTS
  Nearly all sizers exceeded their marked dimensions by up to 1.0 mm. Measured tissue annulus diameters for 19-mm-labeled valves varied between 18.3 and 19.6 mm, for 21-mm valves from 20.5 to 21.6 mm, and for 23-mm valves from 22.4 to 23.5 mm, respectively. The orifice areas ranged from 1.5 to 2.06 cm2 for 19-mm valves, from 2.0 to 2.55 cm2 for 21-mm valves, and from 2.4 to 3.09 cm2 for 23-mm valves, respectively.
  
  
  CONCLUSIONS
  Actual sizer dimensions and tissue annulus diameters of various small mechanical aortic prostheses varied considerably from their marked diameters. These differences should be considered to ensure the optimal prosthesis selection for each patient.
authors.affiliation: Department of Cardiac Surgery, Medical University of Lübeck, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Bartels
authors.forename: R G
authors.initials: RG
authors.lastname: Leyh
authors.forename: J F
authors.initials: JF
authors.lastname: Matthias Bechtel
authors.forename: E
authors.initials: E
authors.lastname: Joubert-Hübner
authors.forename: H H
authors.initials: HH
authors.lastname: Sievers
mesh_terms: D001021:Aortic Valve; D002138:Calibration; D005069:Evaluation Studies as Topic; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000295:instrumentation*; D006801:Humans; D011474:Prosthesis Design; D013499:Surface Properties