In necrotizing enterocolitis (NEC) the integrity of the bowel wall is compromised by ischemia and inflammation.
The cause of NEC is still elusive, but the condition is seen primarily in infants who are born prematurely, and in those who are formula-fed. Infants born weighing less than 1000 g are at particularly increased risk.
Affected infants present within two weeks of birth with abdominal swelling and bloating, as well as poor feeding tolerance, fever and lethargy. These infants may also have green vomit, bloody stools and may, in severe cases, develop shock.
Prompt identification and treatment of NEC is crucial to ensuring a favorable clinical outcome. The mainstay of diagnosis is abdominal X-rays in conjunction with physical examination.
X-rays show the presence of gas within the intestinal wall, and if there is perforation, then air will also be seen in the abdominal cavity.
Depending on disease severity and the overall health of the infant, treatment may vary. However, it involves both medical and surgical techniques.
Medical therapy involves resting the bowels with the use of intravenous feeding tubes, broad spectrum antibiotics, gastric aspiration, and other supportive measures, while surgery entails removing sections of necrotic bowel.
Notwithstanding great strides in medical and surgical treatment over the past 60 years or so, NEC still has a very high mortality.
This is especially seen in infants who have an extremely low birth weight. However, NEC mortality is also high in infants who have minimal bowel involvement.
Infants who survive are at a high risk for developing complications due to intestinal and/or systemic damage.
Morbidities associated with the condition include recurrent NEC, intestinal strictures, and failure as well as disabilities with regards to neurodevelopment.
In many cases NEC is treated non-surgically, and when successful has a good outlook that allows many affected infants to go on and live normal lives.
In severe cases, for example when there is perforation or no response to resting the bowel, surgery is required and is performed under general anesthesia.
Following surgery, babies may be hospitalized for a period of time, especially due to other complications that may have arisen because of their premature birth.
The outlook for infants with NEC depends largely on how prematurely the baby was born. About 1 in every 10 infants who were treated surgically may experience a recurrent episode of NEC and this may lead to a dependence on long-term parenteral nutrition.
In addition to this, approximately 25% of those treated surgically develop intestinal strictures that require further surgical resection.
Prevention and Novel Therapies
There are several studies that have shown that probiotics may be safely and effectively used prophylactically in infants with very low birth weight to prevent NEC.
These studies demonstrate that the probiotics greatly reduce the incidence of NEC and its associated mortality.
Research notes that prebiotics and synbiotics may also be used as NEC-preventative strategies.
Novel therapies against NEC tested in experimental models include captopril, erythropoietin and stem cell therapy. These have all so far shown some promising results that could pave the way towards better NEC therapy.
Reviewed by Liji Thomas, MD