Mechanical valves versus the Ross procedure for aortic valve replacement in children: Propensity-adjusted comparison of long-term outcomes

Objective: We aimed to identify characteristics differentiating children undergoing aortic valve replacement by using mechanical prostheses versus the Ross procedure and to compare survival and the need for aortic valve reoperation after each procedure. Methods: From 1983 to 2004, 346 children underwent aortic valve replacement (215 underwent the Ross procedure and 131 underwent placement of a mechanical prosthesis). Factors associated with procedure choice were used to construct a propensity score for use as a covariate in regression models to adjust for potential confounding by indication. Results: Patients undergoing the Ross procedure were younger, more likely to have a congenital cause, and less likely to have a rheumatic or connective tissue cause. They had a lower frequency of regurgitation, required more annular enlargement, and had less concomitant cardiac surgery. Competing-risk analysis showed that 16 years after aortic valve replacement, 20% of patients had died without subsequent aortic valve replacement, 25% underwent second aortic valve replacement, and 55% remained alive without further replacement. After propensity adjustment, factors associated with early-phase death included mechanical valves and a nonrheumatic cause. Mechanical valves were also associated with constant-phase mortality. Repeated aortic valve replacement was associated with the Ross procedure and a rheumatic cause. Both factors were also associated with all-cause cardiac reoperation. In children receiving mechanical prostheses, younger age and smaller valve size were significant risk factors for death. Freedom from homograft replacement after the Ross procedure was 82% at 16 years of follow-up. Conclusion: Results from this study showed good outcomes and an acceptable complication rate with both valve choices. Given the significantly increased risk of early and late death in younger children receiving smaller mechanical valves, the Ross procedure confers survival advantage in this age group at the expense of increased reoperation risk, especially in patients with a rheumatic cause.