Long-term tricuspid valve function after Norwood operation

Abstract

Long-term functional outcomes after Norwood palliation are likely to depend on tricuspid valve performance in the systemic role. We therefore aimed to characterize features associated with tricuspid valve intervention. All 219 children (1990-2007) who underwent Norwood stage 1 palliation resulting in a systemic rightventricle were investigated. In parametric competing risks analyses, primary end points included surgical tricuspid valve intervention (repair=27, replacement=3) and death (N=105). All 2705 echocardiogram reports were included in time-related analyses of outcome adjusted for repeated measures. Variable selection used bootstrapping. Approximately 25% of survivors underwent tricuspid valve repair at some point, especially in children with mitral atresia (P=.04, 53% reliability), longer myocardial ischemic time during Norwood (P=.02, 50%), and moderate/severe tricuspid regurgitation immediately post-Norwood (P=.006, 86%). Risk of tricuspid valve intervention was mainly early, but a late risk emerged 10 to 15 years after Norwood. Tricuspid valve intervention was successful in restoring functional natural history to that of the remainder of the cohort. Tricuspid valve intervention did not compromise survival (82% ± 2% 5 years after tricuspid valve intervention), and right ventricular function was not worse in patients requiring tricuspid valve intervention. Repeat tricuspid valve interventions were undertaken in 6 patients (3 repairs, 3 replacements). At latest follow-up, the degree of tricuspid valve regurgitation was not different between those who did and did not receive intervention. Tricuspid valve surgery is common after single ventricle palliation for hypoplastic left heart syndrome, necessary in up to 25% of survivors. Mitral atresia and lengthy myocardial ischemic times during Norwood surgery are prominent risks. Right ventricular function was preserved by tricuspid repair. However, the emerging late hazard for tricuspid valve intervention may have implications for long-term outcome and should be explored further.