Risk Factors for 30-day Mortality in Patients with Surgically Treated Necrotizing Enterocolitis: A Multicenter Retrospective Cohort Study

Purpose Necrotizing enterocolitis (NEC) is a leading cause of death in very preterm born infants. The most severe variant is NEC totalis (NEC-T), where necrosis of the small intestines is so extensive that curative care is often withdrawn. Mortality and NEC-T are difficult to predict before surgery, complicating counseling and decision-making. This study's aim was to identify preoperative risk factors for overall 30-day mortality and NEC-T in preterm born infants with surgical NEC. Methods This multicenter retrospective cohort study included preterm born infants (<35 weeks) surgically treated for NEC between 2008 and 2022. NEC-T was defined as necrosis of the majority of small intestine, leading to a surgical open-close procedure without curative treatment. Preoperative risk factors for 30-day postoperative mortality, NEC-T, and mortality without NEC-T were assessed using multivariable logistic regression analyses. Results Among the 401 patients included, the 30-day mortality rate was 34.2% (137/401), of which 18.7% (75/401) involved NEC-T. Significant risk factors for mortality were male sex (odds ratio [OR]: 2.53; 95% confidence interval [CI]: 1.54-4.16), lower birthweight (OR: 0.91; 95% CI: 0.86-0.96/100 g), portal venous gas (PVG) on abdominal radiograph (OR: 1.89; 95% CI: 1.11-3.20), need for cardiovascular support between NEC diagnosis and surgery (OR: 3.26; 95% CI: 2.02-5.24), and shorter time between diagnosis and surgery (OR: 0.74; 95% CI: 0.65-0.84). Similar risk factors were found for NEC-T. In patients without NEC-T, the need for cardiovascular support (OR: 2.33; 95% CI: 1.33-4.09) and time between diagnosis and surgery (OR: 0.77; 95% CI: 0.64-0.91) were significant. Conclusion Male sex, lower birthweight, PVG, cardiovascular support, and a short interval between NEC diagnosis and surgery are preoperative risk factors for 30-day mortality and NEC-T. Preoperative cardiovascular support and a shorter time interval between diagnosis and surgery are also risk factors for mortality without NEC-T.