title: The CarboMedics supraannular top hat valve improves prosthesis size in the aortic root.
abstract: OBJECTIVE
  Aortic valve replacement can result in patient-valve mismatch and attenuated left ventricular remodeling. Using CarboMedics mechanical valves, we examined if the supraannular Top Hat prosthesis provided a size advantage over the intraannular valve.
  
  
  METHODS
  Seventeen patients with aortic stenosis and aortic root < or = 23 mm were randomized to receive a CarboMedics supraannular Top Hat valve (n = 7) or an intraannular valve (n = 10). Doppler echocardiography was performed preoperatively, and after three months.
  
  
  RESULTS
  There was no difference in aortic annulus size, but mean prosthesis size was significantly larger in the Top Hat group than in the intraannular group (25.00 mm versus 21.60 mm); the mean size improvement for Top Hat patients was 3.14 mm. After three months, all patients had excellent functional improvement and low transvalvular pressure gradients, with slightly higher effective valve opening area in the Top Hat group.
  
  
  CONCLUSIONS
  The supraannular Top Hat valve provides an advantage of one to two sizes over the intraannular valve, and improves the effective valve opening area. Both valves offer favorable hemodynamic performance and functional improvement.
authors: Department of Cardiothoracic Surgery, Ullevål University Hospital, Oslo, Norway.
authors: R
authors: R
authors: Lundblad
authors: O M
authors: OM
authors: Hagen
authors: G
authors: G
authors: Smith
authors: K
authors: K
authors: Kvernebo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D015150:Echocardiography, Doppler; D005260:Female; D006350:Heart Valve Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies