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Mechanical aortic valve replacement: long-term outcomes in children.

BACKGROUND AND AIM OF THE STUDY
Early and late outcomes following mechanical aortic valve replacement (AVR) in children were analyzed.


METHODS
Between January 1980 and December 2003, 55 patients underwent mechanical AVR at the authors' institution. Of these patients, 12 had aortic regurgitation (AR), 31 had aortic stenosis (AS), and 12 had mixed disease. Preoperatively, 25 patients (45.5%) were in NYHA classes III and IV. Among patients, 22 had a previous valvotomy and 19 had associated cardiac defects. Isolated AVR was performed in 37 cases. Twelve patients required root enlargement procedures, two had aortic root replacement, three had a double valve replacement, and one patient had a concurrent mitral annuloplasty. The mean prosthesis size was 22.6 mm (range: 16-31 mm). Mean follow up was 12.28 +/- 6 years (range: 1-23 years); total follow up was 665 patient-years (pt-yr).


RESULTS
There was one late death. Actuarial survival at 20 years was 98 +/- 2%. Event-free survival at one, five and 20 years was 96 +/- 3%, 92 +/- 4% and 88 +/- 5%, respectively. Four patients required reoperation (two for valve outgrowth, one each for paravalvular leak and prosthetic valve endocarditis (PVE)). Freedom from reintervention at one, five and 20 years was 98 +/- 2%, 96 +/- 3% and 92 +/- 4%, respectively. There was one event of anticoagulation-related hemorrhage. Freedom from anticoagulant-related hemorrhage at 20 years was 98 +/- 2%, and freedom from PVE at five and 20 years was 98 +/- 2% and 96 +/- 3%, respectively. There were no instances of thromboembolism or structural valve dysfunction. Linearized rates of bleeding and endocarditis were 0.15 and 0.3% per pt-yr, respectively. At follow up, 54 children were in NYHA classes I or II.


CONCLUSION
Mechanical AVR, with aortic root enlargement if necessary, is associated with low mortality and morbidity, and is an excellent treatment option in children. Late embolic and hemorrhagic complications are infrequent in the current era.