Mortality and management of surgical necrotizing enterocolitis in very low birth weight neonates: a prospective cohort study

Background: Necrotizing enterocolitis (NEC) is a leading cause of death in very low birth weight (VLBW) neonates. The overall mortality of NEC is well documented. However, those requiring surgery appear to have increased mortality compared with those managed medically. The objective of this study was to establish national birth-weight-based benchmarks for the mortality of surgical NEC and describe the use and mortality of laparotomy vs peritoneal drainage.

Study design: There were 655 US centers that prospectively evaluated 188,703 VLBW neonates (401 to 1,500 g) between 2006 and 2010. Survival was defined as living in-hospital at 1-year or hospital discharge.

Results: There were 17,159 (9%) patients who had NEC, with mortality of 28%; 8,224 patients did not receive operations (medical NEC, mortality 21%) and 8,935 were operated on (mortality 35%). On multivariable regression, lower birth weight, laparotomy, and peritoneal drainage were independent predictors of mortality (p < 0.0001). In surgical NEC, a plateau mortality of around 30% persisted despite birth weights >750 g; medical NEC mortality fell consistently with increasing birth weight. For example, in neonates weighing 1,251 to 1,500 g, mortality was 27% in surgical vs 6% in medical NEC (odds ratio [OR] 6.10, 95% CI 4.58 to 8.12). Of those treated surgically, 6,131 (69%) underwent laparotomy only (mortality 31%), 1,283 received peritoneal drainage and a laparotomy (mortality 34%), and 1,521 had peritoneal drainage alone (mortality 50%).

Conclusions: Fifty-two percent of VLBW neonates with NEC underwent surgery, which was accompanied by a substantial increase in mortality. Regardless of birth weight, surgical NEC showed a plateau in mortality at approximately 30%. Laparotomy was the more frequent method of treatment (69%) and of those managed by drainage, 46% also had a laparotomy. The laparotomy alone and drainage with laparotomy groups had similar mortalities, while the drainage alone treatment cohort was associated with the highest mortality.