title: Hemodynamic performance of small aortic valve bioprostheses: is there a difference?
abstract: BACKGROUND
  There is the potential for left ventricular outflow obstruction when small aortic valve bioprostheses are employed in normal-sized or large adults. It has been hoped that bovine pericardial valves would improve hemodynamic performance in the smaller tissue valve sizes.
  
  
  METHODS
  To determine in vivo hemodynamic performance of heterograft aortic valve prostheses, we analyzed echocardiographic data from patients receiving 21- or 23-mm Carpentier-Edwards pericardial, Medtronic Intact, and Carpentier-Edwards porcine bioprostheses. In addition, data from 19-mm Carpentier-Edwards pericardial valves were included for comparison of hemodynamic performance between valve sizes. Doppler echocardiography was performed in 151 patients within 2 weeks of operation. Left ventricular outflow gradient was derived from continuous Doppler measurements of flow velocity, and effective orifice area was calculated by the continuity equation.
  
  
  RESULTS
  There were statistically significant differences in hemodynamic performance of different sized prostheses for each valve type (effective orifice area, p < 0.01; valvular gradient, p < 0.03). There were, however, no significant differences in effective orifice area or mean gradient for different valve types within each size category.
  
  
  CONCLUSIONS
  The in vivo hemodynamic performance of these three different aortic valve heterograft bioprostheses is similar. Patient-prosthesis mismatch with heterograft prostheses, as demonstrated by the indexed effective orifice area can be avoided by appropriate sizing and use of annular enlarging techniques when necessary.
authors.affiliation: Section of Cardiovascular Surgery, Mayo Clinic and Foundation, Rochester, Minnesota 55905, USA.
authors.forename: M L
authors.initials: ML
authors.lastname: McDonald
authors.forename: R C
authors.initials: RC
authors.lastname: Daly
authors.forename: H V
authors.initials: HV
authors.lastname: Schaff
authors.forename: C J
authors.initials: CJ
authors.lastname: Mullany
authors.forename: F A
authors.initials: FA
authors.lastname: Miller
authors.forename: J J
authors.initials: JJ
authors.lastname: Morris
authors.forename: T A
authors.initials: TA
authors.lastname: Orszulak
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve; D001705:Bioprosthesis; D015150:Echocardiography, Doppler; D005069:Evaluation Studies as Topic; D005260:Female; D006350:Heart Valve Prosthesis; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period