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Necrotising Enterocolitis 419

tered. Currently, the recommended antibiotic therapy regimen includes laparotomy 43,44 and therefore primary laparotomy would minimise the
ampicillin, gentamicin, and clindamycin or metronidazole to cover number of surgical interventions in these patients. A recent multicen-
gram-positive, gram-negative, and anaerobic bacteria, respectively. In tred, prospective randomised trial comparing laparotomy to primary
a series reported by Chan et al., several gram-negative bacteria resistant peritoneal drainage in patients weighing less than 1,500 g with perfo-
38
to ampicillin or gentamicin were isolated. Thus, depending on the rated NEC showed no significant difference in survival, dependence
43
antimicrobial profile of the institution, different antibiotic strategies on parenteral nutrition, or length of hospital stay. It has also been
may be required to treat the emerging strains of bacteria. suggested that peritoneal drainage may be particularly suited to the
In addition to clinical exams and continued haemodynamic treatment of infants less than 26 weeks gestational age or who weigh
monitoring, disease progression should be monitored by using serial less than 1,000 g because isolated intestinal perforations are more fre-
44
abdominal radiographs, ideally obtained every 6 to 8 hours. Daily quently encountered in this patient population. In regions with scarce
and as-needed x-rays may be sufficient, however, if that is all the resources and a shortage of skilled personnel, primary peritoneal drain-
resources will allow. Imaging protocols should include both vertical age may be the best initial option for all NEC patients who meet the
and horizontal beam radiographs to ensure adequate sensitivity for criteria for surgical intervention.
signs of disease progression. Many institutions use supine abdominal Extent of Surgical Intervention
images along with cross table lateral images, which allow the Most authors agree that the extent of surgical intervention should be
infants to remain supine, thereby minimising repositioning of the determined by the degree of bowel involvement encountered at lapa-
24
unstable patients. Alternatively, decubitus films often more clearly rotomy. Approximately 50% of infants with acute NEC present with
demonstrate pneumoperitoneum. If repeat radiographs display an focal disease, and the other 50% present with multiple areas of involve-
unchanged or improving pattern of pneumatosis intestinalis, then ment. Nearly 20% of infants treated surgically for NEC are found
43
expectant management may be continued, provided that the infant to have pan-involvement, which is defined as disease encompassing
remains haemodynamically stable. 34
greater than 75% of the total intestine.
Acute Medical Management Summary Focal Perforation
In the absence of surgical indications, acute medical management of Exploratory laparotomy with limited resection and creation of an enter-
patients with suspected NEC includes the following: ostomy remains the standard of care for infants with NEC found to have
1. Resuscitation: intravenous fluids, nasogastric decompression, a focal perforation. Recently, some authors have advocated intestinal
careful control of acid-base balance, and correction of electrolyte resection with primary anastomosis as an alternative to enterostomy,
abnormalities. citing the high morbidity associated with enterostomies in the newborn
2. Cessation of oral feeds and medications. population. 43,45,46 Additionally, they argue, primary anastomosis affords
the possibility of avoiding a second surgery. Advocates of resection
3. Broad-spectrum antibiotics: guided by cultures and local
microbiological profile. and enterostomy creation maintain that the majority of stomal com-
47
plications are minor and easily managed. Additionally, early ostomy
4. Management of thrombocytopaenia and abnormal clotting profile; closure has been shown to be well-tolerated in this patient population
48
important due to the potential for cerebral bleeds. and therefore does not justify the added risk inherent in primary anasto-
5. High index of suspicion for complications: frequent monitoring and mosis. Cooper et al. reported their experience with primary anastomosis
reassessment as well as x-ray monitoring in the acute patient to look as compared to resection and diversion at the Children’s Hospital of
for pneumoperitoneum (6 to 8 hourly or as clinically indicated). Philadelphia. They reported that overall survival for infants who
49
6. Early surgical consultation. underwent intestinal diversion was 72%, compared to only 48% for
Surgical Indications patients with primary anastomosis. Postmortem examination of 7 out of
the 14 patients who died after primary anastomosis revealed two anas-
Indications for surgical intervention focus on signs of perforation or tomotic leaks and a gangrenous anastomosis that was easily disrupted
impending perforation. Development of pneumoperitoneum on abdom- during the postmortem exam. The authors of that study concluded that
inal radiograph is considered an absolute indication for surgical inter- primary anastomosis is not comparable, much less superior, to intestinal
vention. Other signs, such as a fixed loop on abdominal radiographs, diversion.
an abdominal mass or erythema of the abdominal wall on physical
exam, positive paracentesis, or little to no clinical improvement despite Principles of Surgery
50
optimal medical management, are considered relative indications. NEC with pan-involvement carries the highest mortality rates; infants
Some authors argue that portal venous air on radiography should also who survive often develop short-bowel syndrome and long-term TPN
mandate surgical intervention due to its associated poor prognosis (70% dependence with associated complications. 1,33 As such, surgical strate-
mortality in some series), although this is not a universally accepted gies have focused on minimising the extent of bowel resection without
view. 39,40 With the exception of evidence of pneumoperitoneum, the compromising patient outcome. One such strategy is primary peritoneal
timing and method of surgical intervention must be made based on drainage as a temporising measure to allow the infant time to regain
individual cases. haemodynamic stability and perfuse viable bowel, thus saving bowel
that may have been resected with initial laparotomy. Some surgeons
51
Exploratory Laparotomy versus Primary Peritoneal
Drainage even suggest that peritoneal drainage may, in fact, serve a definitive
Although there is a general consensus regarding the factors and relative therapy for some cases of NEC, particularly for VLBW (<1,000 g)
52,53
Nevertheless, the majority of infants treated with peritoneal
infants.
indications for surgical intervention, in the setting of acute NEC, con- drainage require subsequent laparotomy in some series. Currently,
54
troversy persists regarding the optimal surgical strategy. Some authors peritoneal drainage is considered by many as an initial approach in
have advocated primary peritoneal drainage alone as definitive therapy haemodynamically unstable VLBW infants with NEC to allow resusci-
for advanced NEC. 41,42 Primary peritoneal drainage is performed by tation and stabilisation prior to definitive laparotomy. 46
using a 0.5–1–cm incision to evacuate the peritoneum of all faecal When initial laparotomy is employed, the overriding consideration
and purulent content followed by aggressive irrigation and placement is to spare as much bowel as possible to prevent short bowel syndrome.
of a drain. Advocates of primary laparotomy argue that many patients Aggressive resection of all diseased segments leads to sacrifice of
with NEC treated initially with peritoneal drainage require subsequent
intestine with borderline viability, and creation of multiple ostomies