Abstract
Background: To investigate the association between the timing of surgery from the day of NEC/SIP diagnosis and clinical outcomes in preterm infants. Study Design: A retrospective cohort study comparing clinical outcomes of infants undergoing laparotomy at three clinically relevant time points (less and more than 48 hours, 96 hours, and 168 hours [7 days]) following NEC/SIP diagnosis. Results: Infants with NEC/SIP (N = 97) receiving surgical invention >96 hours (34/97) had significantly lower gestational age (25.5 weeks [24.0; 26.9] vs 27.0 [25.0; 31.3]; p = 0.006), had lower birth weight (687 grams [600; 902] vs 940 [710; 1495]; p<0.001), had pneumoperitoneum less often on the abdominal x-ray (29.4% vs 57.1%, p = 0.017), had hemorrhagic (p = 0.04) and reparative (p = 0.003) lesions more often on intestinal histopathology, had PDA diagnosed more often (76.5% vs 50.8%, p = 0.02), required assisted ventilation more frequently (p = 0.013), and received parenteral nutrition for longer duration (112 days [76.5; 145] vs 65.0 [23.0; 112], p = 0.004) following surgery compared to the infants receiving surgical intervention before 96 hours (n = 63/97). In NEC-only sub-cohort, infants receiving laparotomy >48 hours (n = 29/75) had lower median gestational age, lower birth weight, less pneumoperitoneum, and higher acute kidney injury than those receiving surgery <48 hours. On logistic regression, the odds of death were not significantly different (OR 0.65 [0.28, 1.54], p = 0.32) for infants receiving laparotomy ≤48 hours following NEC/SIP compared to subjects undergoing surgery >48 hours. The odds of intestinal failure (>60 days of parenteral nutrition) were 4.5 times (CI 1.56, 14.3), p = 0.005) higher for those having surgery >96 hours from NEC/SIP diagnosis. Conclusion: There was no significant difference in death among infants receiving surgery within 48 hours following surgical NEC/SIP diagnosis compared to those receiving surgery at ≥ 48 hours of diagnosis. However, infants receiving surgery >96 hours were more likely to receive parenteral nutrition for longer time. A prospective study is needed to understand the continuous relationship between time to surgery and outcomes.