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420 Necrotising Enterocolitis

results in loss of intestinal length at the time of stoma closure. For Late Complications
this reason, a second-look laparotomy after proximal diversion has Late, or postdischarge, complications of NEC are often chronic in
been proposed as an alternative to initial extensive resection. Weber nature. Infants with stage II or greater NEC are reported to have a
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and Lewis reported their results of 32 infants with acute NEC who significantly higher risk of long-term neurodevelopmental impairment
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underwent operative intervention with resection of only frankly compared to similar infants without NEC. Additionally, surgery for
necrotic bowel and proximal diversion. Survival of the 14 infants who NEC has been shown to be an independent risk factor for physical, psy-
met criteria and underwent a second-look surgery was similar to that of chomotor, and neurodevelopmental impairment compared to VLBW
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the infants who underwent only one procedure. The authors concluded infants without NEC. Although the reason for this increased risk of
that a second-look strategy results in survival rates similar to a single- neurodevelopmental delay is not entirely clear, some studies suggest
stage procedure while potentially sparing intestinal length. that increased duration of parenteral nutrition may render the neonate
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Surgical Indications in Developing Nations particularly susceptible to this issue. Due to the high risk of preterm
Much of the success over the years in the treatment of NEC has been infants with NEC developing neurodevelopmental disability, most
afforded by supportive care and sophisticated ICUs and therefore has units now recommend close follow-up for all ≤1,250-gram infants who
not been manifest in segments of the developing world. Banieghbal develop stage II or III (clinical) NEC.
and colleagues have suggested the institution of more aggressive Prevention Strategies
surgical protocols in developing nations that do not have modernised Treatment strategies to reduce the incidence of NEC have targeted
intensive care unit capabilities may lead to improved survival in those some of the perinatal insults believed to contribute to its pathogenesis,
17
regions. In their prospective study, conducted at a single institution in such as bacterial colonisation, immaturity of the neonatal defense sys-
Johannesburg, South Africa, 450 neonates with NEC were treated with tem, and formula feeding. Some approaches include (1) administra-
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a more aggressive surgical protocol, and results were compared to prior tion of prophylactic oral antibiotics to decontaminate the gut 63–65 ; (2)
data collected using the more classic criteria described by Kosloske. administration of glucocorticoids to accelerate epithelial cell matura-
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The aggressive surgical protocol consisted of: tion; 66–68 and (3) administration of human (breast) milk, which is replete
1. Laparotomy is undertaken in all patients with radiological with substances that are both immunologically active as well as trophic
perforation within 8 hours. for the intestinal mucosa. 69,70
2. Any neonate with peritonitis on clinical exam is actively resuscitated Oral Antibiotics
and re-examined in 4–6 hours. Continuing peritonitis is an indication The use of prophylactic oral antibiotics for the prevention of NEC has
for laparotomy within 4 hours. met with mixed results. The theory behind the proposed efficacy of
3. If the main area of disease is found to be in the ileocolic region, antibiotic treatment is that gut decontamination may prevent potential
extended colonic resection for all macroscopic disease is performed pathogens from invading the bowel wall after mucosal breakdown.
with ileostomy creation. Indeed, results of one trial suggested early introduction of such anti-
biotics as gentamicin and amoxicillin in cases of suspected NEC have
4. In the cases of multiple areas of perforation/necrosis, only the most 71
obvious necrotic/perforated bowel is excised with anastomosis or been shown to have a protective effect. However, subsequent trials
enterostomy, and a second-look laparotomy is performed in 3–4 days. failed to demonstrate a reduced incidence of NEC in patients receiving
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The authors reported an overall decrease in mortality rate from 82% prophylactic antibiotics. As such, the issue of prophylactic antibiot-
to 48%, with the institution of the more aggressive surgical protocol. ics in the prevention of NEC remains controversial and is not com-
Infants with active disease involving a limited length of the terminal monly practiced due to the inherent risks of antibiotic resistance and
ileum and/or colon derived the greatest benefit from the more pseudomembraneous colitis. A new area of study that is being actively
aggressive protocol. Each individual hospital/region must decide researched is administering probiotic bacteria in an effort to prevent
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whether this protocol or one using primary peritoneal drainage is pathogenic bacteria from colonising the intestine.
suitable for the local resources available. Corticosteroids
A large multicentred trial reported a decreased incidence of NEC in
Postoperative Complications infants of mothers who received prenatal steroids. Similarly, a 12-day
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The overall mortality rate for NEC is 15–30%. Smaller infants, infants course of postnatal steroids reduced the incidence of NEC in newborn
with a larger proportion of diseased intestine, and infants undergoing infants with respiratory distress syndrome. These results, however,
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surgery have the highest mortality rates. With improvements in support- are called into question as a meta-analysis performed by the Cochrane
ive care and monitoring, the survival rate for patients with NEC has been Database of 15 randomised trials of postnatal steroids demonstrated no
increasing, calling attention to the issue of postoperative complications benefit in the prevention of NEC. Thus, the question of whether steroids
in those survivors. Overall, infants <28 weeks gestation had a signifi- should be used in the prevention of NEC remains unresolved. 75
cantly higher complication rate (47%) compared to those further along Human Breast Milk
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in gestation (29%). Complications of NEC can be separated into early
or predischarge complications and late, usually chronic, complications. Studies have shown that neonates fed with human breast milk are 10
times less likely to develop NEC, although the exact mechanism of this
Early Complications protective affect is unknown. 76,77 Possible protective factors present in
A multiinstitutional observational study reported that 39% of NEC breast milk include macrophages, neutrophils, lymphocytes, lactoferrin,
patients who underwent surgery had some type of stomal or wound oligosaccharides, growth factors, and immunoglobulins. In a land-
60
complication. One multicentred prospective cohort study reported the mark study by Eibl et al., supplementation of standard formula with
57
78
overall incidence of postoperative intestinal stricture at 10.3% and an IgA and IgG reduced the incidence of NEC in a cohort of premature
intraabdominal abscess occurred in 5.8%, with no difference between infants. Subsequent trials using monomeric IgG supplementation alone
58
the initial laparotomy versus the initial drainage group. Laparotomy showed conflicting results. 79,80 Ultimately, the question regarding the
was found to have a 7.9% incidence of wound dehiscence as compared mechanism by which breast milk exerts its protective effect is yet to
to a 1.3% incidence in the initial drainage group. The overall rate of be elucidated.
prolonged parental nutrition, defined as lasting >85 days, is 11% and
was similar for the drainage and laparotomy groups.