The purposes of this study were: 1) to compare mortality and postoperative morbidities in extremely low birth weight (ELBW) infants who underwent initial laparotomy or drainage for necrotizing enterocolitis (NEC) or isolated intestinal perforation (IP); 2) to determine the ability to distinguish NEC from IP preoperatively and the importance of this distinction on outcome measures; and 3) to evaluate the association between extent of intestinal disease determined at operation and outcome measures. All ELBW infants born at participating NRN centers were screened for the presence of NEC or IP that was thought by the pediatric surgeon and neonatologist to require surgical intervention. Data were collected enrolled infants, including: intraoperative findings recorded by the surgeon and specific post-operative complications. Neurodevelopmental examinations were conducted on surviving infants at 18-22 months corrected age.

Necrotizing enterocolitis (NEC) is a condition, generally affecting premature infants, in which the intestines become ischemic (lack oxygen and/or blood flow). NEC occurs in up to 5-15% of extremely low birth weight (ELBW) infants. Isolated or focal intestinal perforation (IP) is a less common condition, affecting an estimated 4% of ELBWs, in which a hole develops in the intestines leaking fluid into the abdomin. The outcomes for infants with NEC or IP are poor: 49% die and half of the surviving infants are neurodevelopmentally impaired.

Surgical options for NEC and IP include two possible procedures: peritoneal drainage, in which a tube is placed in the abdominal cavity through a small incision for fluid to drain out; or laparotomy, in which an incision is made in the abdomen and diseased intestine is removed. Infants treated with an initial drainage sometimes go on to need a laparotomy. Most surgeons now believe that a diagnosis of the intestinal perforation (IP) may actually be either true NEC or a different and distinct pathology, termed isolated intestinal perforation. The ability to distinguish these 2 conditions preoperatively, based on perinatal characteristics, physical examination findings, and findings on abdominal plain film imaging, remains unknown. If these 2 entities can be distinguished preoperatively, the intervention chosen and outcomes may be different. From the two available surgical options, tt is not known whether initial laparotomy or peritoneal drain placement is more effective for either NEC or IP.

This study was a prospective, multicenter observational study to describe the surgical outcomes (mortality, post-operative intestinal stricture, intra-abdominal abscess formation, etc.) in ELBW infants with either NEC or IP who underwent initial laparotomy or peritoneal drainage. We also evaluated the ability of surgeons to distinguish NEC and IP pre-operatively and the relevance of this distinction on outcome. Finally, an analysis of the impact of extent of intestinal involvement with NEC on outcome measures is reported.

All ELBW infants born at participating NRN centers were screened for the presence of NEC or IP that was thought by the pediatric surgeon and neonatologist to require surgical intervention. Data were collected enrolled infants, including: intraoperative findings recorded by the surgeon and specific post-operative complications.

Neurodevelopmental examinations were conducted on surviving infants at 18-22 months corrected age.

Inclusion Criteria:

• Infants born 401-1,000 grams at birth enrolled in the NRN Generic Database
• Sage III NEC or isolated intestinal perforation
• Pediatric surgeon decision to perform surgery for suspected NEC or IP

Exclusion Criteria:

• Decision not to treat

Extremely Low Birth Weight (ELBW) infants (those with birth weights <1000 g) born at participating NRN Centers diagnosed by a pediatric surgeon and neonatologist as having either necrotizing enterocolitis (NEC) or intestinal perforation (IP) requiring surgical intervention.