In this study, we found the most frequent stoma related complication was fluid/electronic imbalance, which was normally caused by postoperative diarrhea. Diarrhea in NEC patients is associated with antibiotics use and enterostomy effluent . Antibiotic-associated diarrhea (AAD) can vary nuisance loose to watery stool, even severe diarrhea, which relates to antibiotics destroying normal intestinal microbial flora [11, 12]. Lactoferrin, a human breastmilk protein, has both anti-bacterial and anti-inflammatory effect. Moreover, this protein dose not impact normal gut microbiota in intestine . In 1978, Chandra and colleague performed a cohort study in 70 infants, which 35 were fed with human breastmilk and 35 were fed with formula milk. The results showed a human breastmilk can significantly protect infants against diarrhea . In 2018, Doherty and colleague published a meta-analysis, which demonstrated human breastmilk feeding can reduce diarrhea incidence in infancy . Enterostomy includes ileostomy and colostomy. Kennedy and colleagues reported the patients with ileostomy had higher risk of fluid/electronic imbalance than the ones with colostomy in their study . However, in our study, no significant difference of complication rate was found between the two groups (P = 0.0631); instead, the formula milk feeding patients had the higher. According to this conflict, more studies should be exploited about reintroduction of feeding and relevant complications on infants with enterostomy, especially for NEC patients.
The other two stoma related complications, found in this study, were prolapse and stenosis. Stoma prolapse is a full-thickness telescope of the bowel, which locates out of a stoma. Five prolapse cases were found in this study and all of them had a reoperation, and three of them were because of increased intra-abdominal pressure associated with diarrhea. According to previous publication, the risk factors of prolapse formation are obesity, abdominal wall laxity, a large fascial opening, and other conditions which could increase intra-abdominal pressure . In 2018, Wolf and colleagues published a retrospective 10-year cohort study. They reported 51 patients had primary enterostomy and stoma formation for NEC; 22 prolapse cases were observed among them . Compared to their findings, the prolapse rate in our study was lower. This is because a lower incidence of diarrhea was found in the human breastmilk feeding patients, which reduced the chance of increasing intra-abdominal pressure in our patients.
Stoma stenosis can occur in any postoperative period. The most common symptom is a noise from stoma when the flatus passes though, and stoma stenosis is rare to present as an acute intestinal obstruction . Therefore, most of stenotic stoma cases are not problematic and can be treated by local procedure. In our study, the five stomas stenosis cases were managed by serial gentile dilation and none of them required a reoperation. However, in 2019, Baelum and colleagues published a chart review study about enterostomy complications in NEC patients, and the results showed the most frequent stoma related complication in the reoperation group was stenosis .
To determine the risk factors of stoma related complications in NEC patients after primary operation. We performed a binary logistical multivariable analysis in this study, and the results showed two risk factors, GA (OR: 0.793) and formula milk feeding (OR: 8.345), were associated. It also demonstrated that younger GA and formula milk feeding after primary surgery could increase the risk of stoma relevant complications. In 2009, Aguayo and colleagues published a similar retrospective study. 73 NEC patients were included and younger GA and low preoperative body weight were identified to increase risk of stoma related complications . However, more researches are still needed in the field, especially a multicentre perspective study.