Characteristics, progression, management, and outcomes of NEC: a retrospective cohort study.

Background: Necrotising enterocolitis (NEC) in preterm infants is associated with high morbidity and mortality. In most neonates, it is a progressive disease from medical NEC (mNEC) to surgical NEC (sNEC); however, in some, it presents as sNEC from onset.

Objective: To evaluate the rate, the timing of progression, different surgical approaches, and outcomes of mNEC and sNEC in preterm neonates.

Design: A retrospective cohort study of preterm infants with diagnosis of NEC between 2010 and 2020 was conducted. Data on clinical presentation, NEC progression, treatment received, different surgical approaches, resource utilization, and outcomes were abstracted. Infants were classified into 3 groups: mNEC, mNEC that progressed to sNEC, and sNEC at presentation.

Results: Among 208 included infants with NEC, 109 (52%) were mNEC, 66 (32%) progressed from mNEC to sNEC, and 33 (16%) presented with sNEC. Gestational age, birth weight, and postnatal age at NEC were inversely associated with the development of sNEC. mNEC progressed to sNEC occurred after a median of 2.5 (IQR 1-4.25) days. Ninety (91%) of sNEC patients underwent interventions: peritoneal drain only in 19 (21%), laparotomy in 59 (66%), or both in 12 (13%). In comparison with mNEC, those with sNEC infants had longer duration on antibiotics, inotropes, respiratory support, length of stay, and time to reaching full enteral feeds; and were more likely to have recurrent NEC episodes, BPD, and mortality.

Conclusion: There is a high burden of illness for sNEC cases. Insight into the expected clinical course of sNEC patients can facilitate anticipatory management and provide a window of opportunity for timely interventions that may ameliorate the course of sNEC.