Norwood procedure for hypoplastic left heart syndrome: a 14-year national experience, temporal trends, and implications for management in a middle-income country

Hypoplastic left heart syndrome (HLHS) is a severe congenital cardiac defect associated with substantial neonatal morbidity and mortality. The Norwood procedure, the initial palliative operation for HLHS, is a technically demanding surgery that requires highly specialized centers and an experienced multidisciplinary team. In middle-income countries, outcome data following the Norwood procedure remains limited. To identify factors associated with in-hospital mortality and major postoperative complications and to report temporal trends in outcomes among neonates with HLHS undergoing the Norwood procedure between 2009 and 2023 at a single center in a Latin American country. A retrospective cohort study was conducted including all neonates with confirmed HLHS who underwent the Norwood procedure. Patients were excluded only for significant comorbidities precluding surgical candidacy (prematurity < 36 weeks, chromosomal abnormalities, heterotaxy syndrome, intact atrial septum, or anomalous pulmonary venous connection). The primary outcome was in-hospital mortality. Secondary outcomes included occurrence of at least one major postoperative complication (per STS criteria), postoperative length of stay, and complication-specific mortality. Crude ORs with 95%CIs were estimated using univariable logistic regression. Multivariable analysis was performed using Firth penalized logistic regression. A total of 81 patients were included. In-hospital mortality was 35.8%, with a 19% reduction observed between the periods 2009–2014 and 2015–2023. Preoperative mechanical ventilation (aOR, 0.27; 95% CI, 0.07–0.97) and higher weight at the time of surgery were protective factors. In contrast, intraoperative ECMO use (aOR, 5.49; 95% CI, 1.36–22.1) and the occurrence of major postoperative complications (aOR, 4.46; 95% CI, 1.11–17.8) were associated with increased mortality. The most frequent complication was the need for unplanned reintervention (37%).Conclusion: In this cohort of neonates undergoing the Norwood procedure in a middle-income setting, in-hospital mortality decreased over time but remained higher than that reported in high-income countries. Higher surgical weight was protective, whereas ECMO use and major postoperative complications were associated with worse outcomes. What is Known: • The Norwood procedure remains a high-risk surgical intervention for neonates with hypoplastic left heart syndrome, associated with substantial postoperative morbidity and mortality. • The management of hypoplastic left heart syndrome remains particularly challenging in low-income populations and resource-limited healthcare systems, where access to surgical palliation is often restricted. What is New: • In this 14-year single-center cohort from Colombia, in-hospital mortality decreased from 44.4% to 25.0%, accompanied by a statistically signifi cant reduction in major postoperative complications. • Higher weight at surgery and preoperative mechanical ventilation were associated with lower in-hospital mortality, whereas intraoperative ECMO use and major postoperative complications were associated with increased mortality. Graphical Abstract A graphical abstract summarizing the main findings is provided.