title: Mechanical valve replacement in congenital heart disease.
abstract: OBJECTIVE
  Mechanical valves are the prosthesis of choice in valve replacement in children. However, the problem of somatic growth leading to patient-valve mismatch remains present, and the appropriate anticoagulation regimen remains controversial. We present our experience of valve replacement in a young population over 20 years.
  
  
  METHODS
  Between 1972 and 1992, 48 patients (34 males and 14 females), mean age 11.2 years (range 0.4-27.4 years), underwent mechanical valve replacement at our institution. Aortic valve replacement was performed in 28 patients (58.3%), mitral valve replacement in 13 (27.1%), tricuspid valve replacement in six (12.5%) and pulmonary valve replacement in one patient (2.1%). The prostheses used were: St. Jude Medical (n = 2), Björk-Shiley (n = 14), Medtronic Hall (n = 16), Duromedics (n = 2) and CarboMedics (n = 14). Early mortality was 14.3%, 10.7% for aortic valve replacement and 30.8% for mitral valve replacement. Mean follow up for all patients was 8.3 years (range 0-22 years), with a total of 398 patient-years.
  
  
  RESULTS
  Seven patients died during the follow up (17.1%). Survival after 10 years, including operative mortality, was 81% for aortic valve replacement, 33% for mitral valve replacement, 83% for tricuspid valve replacement and 100% for pulmonary valve replacement. All patients were anticoagulated with warfarin. In eight patients (16.7%) an antiplatelet drug (aspirin or dipyridamole) was added. Major events included paravalvular leak in six patients (1.5%/pty), valve thrombosis in five (mitral position in two, tricuspid in three) (1.3%/pty) and endocarditis in one patient (0.3%/pty). Minor thromboembolic events occurred in three patients (0.8%/pty) and minor hemorrhagic events in three (0.8%/pty). No patients developed hemolytic anemia and there was no case of structural failure.
  
  
  CONCLUSIONS
  In our experience, mechanical prostheses in congenital heart disease were associated with significant morbidity and mortality, however long term survival after aortic valve replacement was good (81% at 10 years). Thromboembolic and hemorrhagic events were of minor significance. Atrio-ventricular valve replacement carried the highest risk of valve thrombosis and we now give warfarin and an antiplatelet drug to children undergoing mechanical valve implantation in this position.
authors.affiliation: Department of Cardiothoraclc Surgery, Rikshospitalet, University of Oslo, Norway.
authors.forename: A E
authors.initials: AE
authors.lastname: Fiane
authors.forename: H L
authors.initials: HL
authors.lastname: Lindberg
authors.forename: K
authors.initials: K
authors.lastname: Saatvedt
authors.forename: J L
authors.initials: JL
authors.lastname: Svennevig
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D004651:Employment; D005260:Female; D005500:Follow-Up Studies; D006330:Heart Defects, Congenital / Q000401:mortality / Q000534:rehabilitation / Q000601:surgery*; D006350:Heart Valve Prosthesis; D006351:Heart Valves / Q000601:surgery*; D006801:Humans; D007223:Infant; D008297:Male; D011183:Postoperative Complications / Q000401:mortality; D011788:Quality of Life; D012189:Retrospective Studies; D015996:Survival Rate