Comparison of Necrotizing Enterocolitis After Surgical Norwood versus Hybrid Stage 1 Palliation

Hybrid stage 1 palliation (HS1P) is used as an alternative to the surgical Norwood for single ventricle patients and specific other conditions. Necrotizing enterocolitis (NEC) occurs in 5%-18% of infants after surgical Norwood, contributing to significant morbidity. We sought to compare the NEC incidences in HS1P versus Norwood patients. A single-center retrospective cohort study of all infants undergoing HS1P or Norwood over a 12-year period. Demographics, underlying cardiac diagnosis, surgical details, and NEC episodes were queried for each patient. The cumulative incidences of NEC between HS1P and Norwood patients were compared. A total of 305 infants were included; 200 Norwood and 105 HS1P. HS1P infants were more often premature (gestational age < 37 weeks; 23.8% vs 1.5%) and had lower birth weight (mean 2.8 ± 0.66 kg versus 3.3 ± 0.47 kg) than their Norwood counterparts. Most infants who underwent the Norwood procedure had hypoplastic left heart syndrome (79.5%), with variable underlying cardiac diagnosis for those who underwent HS1P. Incidence of NEC was significantly higher in the HS1P group (53.3% versus 37.0%, p = 0.01), with increased risk independent of birth weight or underlying cardiac diagnosis (adjusted odds ratio 1.8, p = 0.03). Infants after HS1P had a median of 2 episodes of NEC (interquartile range [IQR] 1-3) versus 1 episode in the Norwood group (IQR 1-2). Infants after HS1P are at higher risk of NEC in comparison to infants after the Norwood procedure. More studies are needed to help predict which infants after HS1P are at highest risk for NEC.