title: Mechanical valves in the pulmonary position: a reappraisal.
abstract: OBJECTIVE
  To evaluate midterm results of mechanical valves in pulmonary position in patients with pulmonary regurgitation and right ventricular dysfunction as an alternative to bioprostheses.
  
  
  METHODS
  Mechanical valves (six tilting disc valves and two bileaflet valves) were implanted in eight patients previously operated on for tetralogy of Fallot (n = 7) and truncus arteriosus (n = 1), with severe right ventricular dysfunction caused by massive pulmonary regurgitation.
  
  
  RESULTS
  All patients survived prosthesis implantation and are currently well. At follow-up (3 months to 9 years), they do not show signs of valve failure, and right ventricular function has dramatically improved in all but one, who still shows moderate ventricular hypokinesia.
  
  
  CONCLUSIONS
  After operative correction of congenital heart defects in selected patients who show severe dysfunction of the right ventricle caused by pulmonary regurgitation/stenosis, mechanical valves may represent an alternative to bioprosthetic valves. The selection of the valve type is still a matter of debate. However, according to literature data, complications seem to have occurred only in patients with bileaflet mechanical valves in the pulmonary position, whereas no thromboembolic episodes or valve failure is reported in subjects with tilting disc valves in the right ventricular outflow. Tilting disc valves might perform better in the right ventricular outflow than bileaflet valves.
authors.affiliation: Department of Pediatric Cardiology/Cardiac Surgery, San Donato Hospital, San Donato Milanese, Milan, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Rosti
authors.forename: B
authors.initials: B
authors.lastname: Murzi
authors.forename: A M
authors.initials: AM
authors.lastname: Colli
authors.forename: P
authors.initials: P
authors.lastname: Festa
authors.forename: S
authors.initials: S
authors.lastname: Redaelli
authors.forename: L
authors.initials: L
authors.lastname: Havelova
authors.forename: L
authors.initials: L
authors.lastname: Menicanti
authors.forename: A
authors.initials: A
authors.lastname: Frigiola
mesh_terms: D000293:Adolescent; D001783:Blood Flow Velocity; D002648:Child; D015150:Echocardiography, Doppler; D015716:Electrocardiography, Ambulatory; D005260:Female; D005500:Follow-Up Studies; D006330:Heart Defects, Congenital / Q000150:complications / Q000601:surgery; D006350:Heart Valve Prosthesis; D006801:Humans; D008297:Male; D011183:Postoperative Complications / Q000503:physiopathology / Q000601:surgery; D011664:Pulmonary Valve / Q000000981:diagnostic imaging / Q000601:surgery; D011665:Pulmonary Valve Insufficiency / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D012189:Retrospective Studies; D018497:Ventricular Dysfunction, Right / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D017725:Ventricular Pressure