Evolution of aortic valve replacement in children: a single center experience.

BACKGROUND: The availability of an ideal prosthesis for aortic valve replacement (AVR) in children remains controversial due to an early degeneration of xenografts and the potential risks related to anticoagulation with mechanical prostheses. This has led many surgeons to the Ross procedure. This study outlines the evolution of our 30-year experience with AVR in children.

METHODS: One hundred and forty-seven children, aged 10 days to 18 years (mean 11.9+/-5.7 years), underwent AVR between 1974 and June 2005. Preoperative diagnosis included aortic insufficiency (n=39), aortic stenosis (n=14), combined aortic stenosis with insufficiency (n=78), and complex left ventricular outflow tract obstruction (n=16). Xenografts (n=11) and mechanical prostheses (n=47) were used in 58 patients. The remaining 89 patients had placement of homografts (n=8) or underwent a Ross procedure (n=81). Of the 147 patients, 87 (59%) had previous procedures.

RESULTS: Overall early and late mortality was 7.5% (11/147 pts). Overall survival estimated by the Kaplan-Meier method, including early mortality, was 94% at 1 year, and 93% at 5, 10, and 20 years. Univariate and multivariate analysis identified date of operation (before 1980) as a risk factor for death (p=0.002). Follow-up was complete in 136 patients (5 lost to follow-up), with a total follow-up of 2433.72 patient-years. The overall study group aortic valve-related reoperation rate was 20% (20/138 pts), the reoperation rate was highest in xenograft group (60%); followed by mechanical valves group (16%), homograft group (14%), and the Ross procedure group (9%). Ross patients showed significant increase of the annulus diameter (p=0.002) and the aortic sinus diameter (p=0.01) at the last follow-up. The actuarial rate for freedom from aortic valve-related reoperation was 99% at 1 year, 94% at 5 years, 88% at 10 years, and 85% at 20 years. Univariate and multivariate analysis identified the presence of a xenograft as a risk factor for aortic valve-related reoperation (p=0.001).

CONCLUSION: AVR in children can be performed with acceptable mortality and minimal mid-term morbidity. The Ross procedure, although more complicated, has the advantage of not requiring anticoagulation. Pulmonary autograft, in our series, has demonstrated growth with no structural degeneration. The potential for development of significant autograft insufficiency and ascending aortic aneurysmal dilatation is small but warrants annual follow-up. Our data supports that the Ross procedure is the AVR of choice in children.