Infants less than or equal to 2.5 kg have increased mortality and worse motor neurodevelopmental outcomes at 2 years of age after Norwood–Sano palliation

OBJECTIVES: In infants with single-ventricle congenital heart disease, prematurity and low weight at the time of the Norwood operation are risk factors for mortality. Reports assessing outcomes (including neurodevelopment) post Norwood palliation in infants ≤2.5 kg are limited. METHODS: All infants who underwent a Norwood–Sano procedure between 2004 and 2019 were identified. Infants ≤2.5 kg at the time of the operation (cases) were matched 3:1 with infants >3.0 kg (comparisons) for year of surgery and cardiac diagnosis. Demographic and perioperative characteristics, survival, and functional and neurodevelopmental outcomes were compared. RESULTS: Twenty-seven cases (mean ± standard deviation: weight 2.2 ± 0.3 kg and age 15.6 ± 14.1 days at surgery) and 81 comparisons (3.5 ± 0.4 kg and age 10.9 ± 7.9 days at surgery) were identified. Post-Norwood, cases had a longer time to lactate ≤2 mmol/L (33.1 ± 27.5 vs 17.9 ± 12.2 hours, P < .001), longer duration of ventilation (30.5 ± 24.5 vs 18.6 ± 17.5 days, P = .005), greater need for dialysis (48.1% vs 19.8%, P = .007), and greater need for extracorporeal membrane oxygenation support (29.6% vs 12.3%, P = .004). Cases had significantly greater postoperative (in-hospital) (25.9% vs 1.2%, P < .001) and 2-year (59.2% vs 11.1%, P < .001) mortality. Neurodevelopmental assessment showed the following for cases versus comparisons, respectively: cognitive delay (18.2% vs 7.9%, P = .272), language delay (18.2% vs 11.1%, P = .505), and motor delay (27.3% vs 14.3%, P = .013). CONCLUSIONS: Infants ≤2.5 kg at Norwood–Sano palliation have significantly increased postoperative morbidity and mortality up to 2-year follow-up. Neurodevelopmental motor outcomes were worse in these infants. Additional studies are warranted to assess the outcome of alternative medical and interventional treatment plans in this patient population.