title: Mitral valve replacement with small-sized tilting-disc mechanical prostheses may lead to moderate stenosis.
abstract: BACKGROUND
  Analyzing the hemodynamics of small-sized tilting-disc mechanical prostheses implanted in the mitral position.
  
  
  METHODS
  
  
  
  METHODS
  this is a retrospective study. The mean follow-up of patients was 114+/-27 months (range 68-152 months).
  
  
  METHODS
  departments of Cardiovascular Surgery and Cardiology in a general community hospital Patients: this study includes 9 survivors of 17 patients undergoing mitral valve replacement with this type of device between May, 1982 and July, 1991.
  
  
  METHODS
  all subjects underwent mitral valve replacement with size 25 mm Sorin tilting-disc mechanical prostheses.
  
  
  METHODS
  all patients underwent transthoracic echocardiography. Five consenting patients also underwent transoesophageal echocardiography. The following parameters were measured: peak gradient, mean gradient, peak velocity, mean velocity, pressure half-time and Doppler area.
  
  
  RESULTS
  The ejection fraction was 50% or more in all patients. The following mean results were obtained: peak gradient: 17.4+/-2.5 mmHg; mean gradient: 8.2+/-0.6 mmHg; peak velocity: 2.1+/-0.1 m/sec; mean velocity: 1.43+/-0.06 m/sec; pressure half-time: 135.9+/-29.7 msec; Doppler area: 1.7+/-0.3 cm2.
  
  
  CONCLUSIONS
  Valve replacement with Sorin 25 mm tilting-disc mechanical prostheses appears to originate a moderate degree of mitral stenosis and, therefore, we do not recommend their use if at all possible.
authors.affiliation: Department of Cardiovascular Surgery, Hospital N.S. del Pino, Las Palmas de Gran Canaria, Canary Islands, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Hurlè
authors.forename: F
authors.initials: F
authors.lastname: Wangüemert
authors.forename: J J
authors.initials: JJ
authors.lastname: Feijóo
authors.forename: A
authors.initials: A
authors.lastname: Medina
mesh_terms: D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity; D000075202:Contraindications; D015150:Echocardiography, Doppler; D017548:Echocardiography, Transesophageal; D005260:Female; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects* / Q000295:instrumentation; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery; D008944:Mitral Valve Insufficiency / Q000601:surgery; D008946:Mitral Valve Stenosis / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D011379:Prognosis; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012189:Retrospective Studies; D012214:Rheumatic Heart Disease / Q000601:surgery; D013318:Stroke Volume