Surgical management of acute necrotizing enterocolitis in infancy

Necrotizing enterocolitis totalis: High mortality in the absence of an aggressive surgical approach

BACKGROUND

Necrotizing enterocolitis is the leading case of gastrointestinal-related morbidity in premature infants. Necrotizing enterocolitis totalis is an aggressive form of necrotizing enterocolitis, which has traditionally been managed with comfort care. Recent advances in management of short bowel syndrome have resulted in some reported long-term survival.

METHODS

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, studies that reported outcomes in children with necrotizing enterocolitis totalis were identified. The definition of necrotizing enterocolitis totalis was captured along with length of follow-up, patient demographics, and outcomes.

RESULTS

A total of 766 articles were screened, of which 166 were selected for full article review. Of these, 32 articles included data on 414 patients with necrotizing enterocolitis totalis. In the majority of studies (52%), necrotizing enterocolitis totalis was not defined. Aggressive surgical therapy (defined as bowel resection or fecal diversion) was undertaken in 32 patients (7.7%), with a mortality rate of 68.8%. In contrast, nonaggressive surgical therapy was undertaken in 382 patients (92.3%), and the mortality in these patients was 95%. Long-term outcomes for necrotizing enterocolitis totalis survivors, such as length of time on parenteral nutrition, progression to liver and/or small bowel transplant, and quality of life, were not reported.

CONCLUSION

We found that there is no accepted definition of necrotizing enterocolitis totalis. Aggressive surgical therapy is rarely pursued, which likely drives the overall high mortality rate. This study underscores the importance of standardizing the definition of necrotizing enterocolitis totalis and capturing short and long-term outcomes prospectively. With more aggressive surgical therapy, more infants are likely to survive this abdominal catastrophe, which was once thought to be uniformly fatal.

Enteric nervous system abnormalities are present in human necrotizing enterocolitis: potential neurotransplantation therapy

Introduction

Intestinal dysmotility following human necrotizing enterocolitis suggests that the enteric nervous system is injured during the disease. We examined human intestinal specimens to characterize the enteric nervous system injury that occurs in necrotizing enterocolitis, and then used an animal model of experimental necrotizing enterocolitis to determine whether transplantation of neural stem cells can protect the enteric nervous system from injury.

Methods

Human intestinal specimens resected from patients with necrotizing enterocolitis (n = 18), from control patients with bowel atresia (n = 8), and from necrotizing enterocolitis and control patients undergoing stoma closure several months later (n = 14 and n = 6 respectively) were subjected to histologic examination, immunohistochemistry, and real-time reverse-transcription polymerase chain reaction to examine the myenteric plexus structure and neurotransmitter expression. In addition, experimental necrotizing enterocolitis was induced in newborn rat pups and neurotransplantation was performed by administration of fluorescently labeled neural stem cells, with subsequent visualization of transplanted cells and determination of intestinal integrity and intestinal motility.

Results

There was significant enteric nervous system damage with increased enteric nervous system apoptosis, and decreased neuronal nitric oxide synthase expression in myenteric ganglia from human intestine resected for necrotizing enterocolitis compared with control intestine. Structural and functional abnormalities persisted months later at the time of stoma closure. Similar abnormalities were identified in rat pups exposed to experimental necrotizing enterocolitis. Pups receiving neural stem cell transplantation had improved enteric nervous system and intestinal integrity, differentiation of transplanted neural stem cells into functional neurons, significantly improved intestinal transit, and significantly decreased mortality compared with control pups.

Conclusions

Significant injury to the enteric nervous system occurs in both human and experimental necrotizing enterocolitis. Neural stem cell transplantation may represent a novel future therapy for patients with necrotizing enterocolitis.

Is pneumoperitoneum an absolute indication for surgery in necrotizing enterocolitis?

BACKGROUND

Necrotizing enterocolitis (NEC) is the most common gastrointestinal medical/surgical emergency in neonates. Non-operative support is needed in 70% of NEC cases, and surgical intervention in the rest 30%. Historically, pneumoperitoneum has been considered as an absolute indication for laparotomy. In the present study we emphasize that pneumoperitoneum is not an absolute indication for exploratory laparotomy in NEC cases.

METHODS

We prospectively studied 58 patients with severe NEC having pneumoperitoneum on abdominal X-ray in the last 5 years. At the time of admission, the patients were given intravenous fluid, total parental nutrition, blood transfusion and broad spectrum antibiotics followed by abdominal tapping (paracentesis). All the patients with pneumoperitoneum were closely monitored for 48 hours if abdominal tapping was repeated. When the disease seemed to worsen clinically, radiologically and laboratorially, the patient was subjected to exploratory laparotomy.

RESULTS

Of the 58 patients, 40 were treated conservatively whereas 18 underwent surgical intervention. The overall mortality in the present study was 12.1%, including 5% of the patients managed conservatively and 27% of the patients undergoing surgery.

CONCLUSIONS

Pneumoperitoneum is not an absolute indication for surgery in cases of neonatal NEC. Most of the patients can be treated conservatively.

Necrotizing enterocolitis: laboratory indicators of surgical disease

The timely distinction between infants with necrotizing enterocolitis (NEC) who need surgery and those who are likely to recover with medical management is important, but it may be difficult clinically. Because pneumoperitoneum is not always present, additional markers of bowel gangrene are needed. Among 73 babies managed for NEC over the study period, 49 (67%) met the study criteria of Bell's stage > 1, and their records were reviewed to determine the usefulness of common laboratory tests in predicting outcome. The patients were divided into three groups based on management. Group 1 (7 patients) required surgery at the time of initial presentation because of pneumoperitoneum. The remaining 42 patients were initially managed medically, 19 of whom (group 2) recovered successfully; the other 23 (group 3) required surgery. The combination of certain laboratory tests, ie, white blood cell count (WBC), immature:total neutrophil ratio (I:T), platelet count (PLT), and base excess (BE), was of significance in distinguishing between infants who would need surgery and those who would recover with medical therapy (group 3 v group 2) 4 to 12 hours or 12 to 24 hours after the diagnosis of NEC was established. A scoring scale was developed, with a point for each of the following: WBC < 9,000/mm3, I:T > .5, PLT < 200,000/mm3, and BE < or = -2. A score of > or = 3 during 4 to 12 hours after diagnosis of NEC strongly predicted the presence of surgical disease (positive predictive value, 100%; negative predictive value, 76%; specificity, 100%; sensitivity, 64%).(ABSTRACT TRUNCATED AT 250 WORDS)

Indications for operation in necrotizing enterocolitis revisited

Operation for necrotizing enterocolitis (NEC) is reserved for infants with intestinal gangrene or perforation. It should not be undertaken until gangrene is present, but ideally should be performed before intestinal perforation occurs. To characterize the onset of intestinal gangrene, data were analyzed for 147 infants with documented NEC, 94 of whom had gangrene. Twelve criteria were evaluated as predictors of intestinal gangrene, using standard epidemiological measures for diagnostic tests. Sensitivity, specificity, positive predictive value, negative predictive value, and prevalence were calculated for each of the proposed operative criteria. The best indications were those whose specificity and positive predictive value approached 100%, and whose prevalence was greater than 10%. These were pneumoperitoneum, positive paracentesis, and portal venous gas. Good indications were those whose specificity and positive predictive value approached 100%, but whose prevalence was less than 10%. These were fixed intestinal loop noted on x-ray, erythema of the abdominal wall, and a palpable abdominal mass. A fair indication for operation--with 91% specificity, 94% positive predictive value, and prevalence of 20%--was "severe" pneumatosis intestinalis, graded by a radiographic system. Poorer indications for operation (and their predictive value for the presence of gangrene) were clinical deterioration (78%), platelet count below 100,000/mm3 (73%), abdominal tenderness (58%), severe gastrointestinal hemorrhage (50%), and gasless abdomen with ascites (0%). No test had a high sensitivity for intestinal gangrene. Portal venous gas should be acknowledged as an indication for operation. Probability analysis may provide a more scientific basis for clinical decision-making.

Alimentary absorption of gentamicin in preterm infants

Fifty-two preterm neonates receiving oral gentamicin from birth, as prophylaxis against necrotizing enterocolitis (NEC), had serum gentamicin levels measured on the second day of life (52 infants) and on the seventh to tenth days (43 infants). The serum gentamicin concentrations on the second day were 0.5 microgram/ml or less in 21 percent, 0.6 to 1.0 microgram/ml in 15 percent, 1.1 to 2 micrograms/ml in 34 percent, 2.1 to 5 micrograms/ml in 25 percent, and 5 to 7.1 micrograms/ml in 4 percent of the infants. Paired serum gentamicin levels were significantly lower (p less than 0.001) on the seventh to tenth day as compared to the second day. We conclude that preterm infants in the first few days of life absorb orally administered gentamicin. Concomitant use of systemic gentamicin under such circumstances may potentially lead to toxic serum gentamicin concentration.

Surgical therapy for necrotizing enterocolitis

Fifty-one infants were treated surgically for necrotizing enterocolitis utilizing a uniform protocol from July 1980 through July 1983. The indications for surgery were pneumoperitoneum or a paracentesis indicative of bowel infarction. Segmental intestinal resection and exteriorization of the bowel ends through the upper abdominal transverse incision was the usual procedure. Intestinal continuity was reestablished when the patient reached 10 pounds, or sooner if he was failing to thrive with his ileostomy. The overall survival was 72.5%, and it was 82% for those patients have a definitive surgical procedure. This survival rate was not adversely affected by the patient's weight or age at the time of operation, nor by the presence of bowel perforation. The 37 survivors endured multiple postoperative complications. The most significant long-term sequela was short-gut syndrome, which occurred in 11% of survivors.

Long-term assessment of growth, nutritional status, and gastrointestinal function in survivors of necrotizing enterocolitis

The long-term effect of necrotizing enterocolitis on growth, nutritional status, and gastrointestinal function was assessed in premature infants at the age of 1 year. Of the 22 of 40 infants who developed NEC, 18 were given medical treatment and four required surgical treatment consisting of intestinal resection of less than one fourth of the small bowel. Eighteen infants who did not develop NEC served as controls. At 1 year follow-up, NEC survivors and controls had normal and comparable anthropometric measurements, biochemical values (serum iron, albumin, prealbumin, retinol binding protein, liver function studies) and gastrointestinal tract function (vitamin E absorption, fasting serum bile acids concentration, lactose breath test). This study demonstrates that, in the absence of short bowel syndrome, there is no detectable long-term effect on growth, nutritional status, and gastrointestinal tract function in premature infants who had NEC in the newborn period.

A new look at the neonatal bowel-contrast studies with metrizamide (Amipaque)

Metrizamide is the first water-soluble radiographic contrast agent which, because it is nonionic, can be used in isotonic solution and gives good visualization of the desired body structure. Its only major disadvantage is that it is very expensive. Metrizamide can be used to study the neonatal bowel in clinical situations where all the other existing contrast agents are contraindicated. The results of 55 metrizamide studies of the bowel in infants are reviewed. In necrotizing enterocolitis metrizamide aids in confirming or rejecting the diagnosis, identifying patients for surgery, and in evaluating the response to surgery. Metrizamide can identify the etiology in unusual cases of bowel obstruction. Metrizamide correctly identified a thoracic origin of free peritoneal air in four cases and a bowel origin in two cases. It identified bowel perforation in two patients in the absence of pneumoperitoneum. In six patients, the metrizamide study identified the cause for a gasless abdomen. It is concluded that metrizamide has a valuable role to play in evaluating a variety of neonatal bowel disorders.

Use of high jejunostomy in extensive NEC

Use of a stoma above involved bowel has been suggested as an option in the infant found to have NEC of an extent which precludes resection. This achieves total decompression and places the involved bowel at rest. A 1-mo-old infant developed NEC after a week of diarrhea. Pneumoperitoneum prompted exploration and involvement of the entire small bowel with a perforation of the ileum was present. The perforation was sutured and a jejunostomy performed within 6 in of the duodenum. Recovery was smooth. After 3 wk of central IV alimentation weight gain was steady and a contrast study ruled out stenosis of the colon. The stoma was resected and bowel continuity restored. Subsequent growth and development have been normal. This approach offers promise in extensive NEC and should be considered early in a patient who fails to improve promptly with intensive medical management.

Early operation with intestinal diversion for necrotizing enterocolitis

Necrotizing enterocolitis (NEC) remains a highly lethal disorder despite significant advances in management during the past decade. Increased mortality with perforation and the frequent finding of massive intestinal necrosis have hampered efforts to improve survival. A recent experience with early operation and intestinal diversion in selected patients with clinical features suggesting impending intestinal gangrene suggests a place in the management of infants with rapidly progressive NEC.

Mild hypothermia: its effect on cardiac output and regional perfusion in the neonatal piglet

Cardiac output and regional perfusion was measured in neonatal piglets using radionuclide labeled microspheres. Measurements made at normal core body temperature (38-39.5 degrees C) were compared to those obtained after a 4-5 degrees C reduction in temperature. There is a significant reduction in cardiac output and in the myocardial, renal, pancreatic, and adrenal blood flow. The separated layers of the gastrointestinal tract wall are subject to varying decreases in blood flow. The mucosa of the distal small intestine demonstrated the most significant decreases in blood flow during mild hypothermia.

Peritoneal drainage under local anesthesia for necrotizing enterocolitis (NEC) perforation: a second look

Between 1974 and 1979, 15 extremely ill neonates with necrotizing enterocolitis (NEC) were initially treated with peritoneal drainage under local anesthesia for intestinal perforation. They weighed 600 to 3040 g with half less than 1000 g. Most had other serious illnesses (RDS, PDA, jaundice, CNS abnormalities). There were no immediate complications such as hemorrhage or bowel evisceration from the local drainage procedures. Seven of the 15 (46%) survived. Three (20%) died because of unrelated problems (CNS, liver failure) with an intact gastrointestinal tract, while another 8 (34%) died from intestinal sepsis. Seven (87%) of the neonates weighing less than 1000 g had an adequately functioning GI tract after this drainage procedure. Half of the neonates requiring additional surgery within 24 hr of initial peritoneal drainage survived and half of the neonates requiring subsequent surgery survived. Five of 15 infants developed strictures one died before excision. This technique is contrary to standard practice and was employed in less than 10% of the neonates with NEC treated at our institution. These results indicate that this method is effective in possibly temporizing the very ill neonate with NEC. An added bonus, however, is that 40% of the neonates treated in this fashion had complete resolution of their disease without residual scarring of the gastrointestinal tract requiring further surgery. It is our continued conclusion that this form of peritoneal drainage under local anesthesia is warranted in certain carefully selected instances.

Prospective application of an index of neonatal necrotizing enterocolitis

Fifty-five patients were scored 1 to 3 according to the criteria: the character of stools, abdominal findings on palpation, x-ray evidence of pneumatosis intestinalis, the development of pulmonary insufficiency, and the duration of symptoms to positive x-rays. Fifteen patients with scores of less than five were considered to have subclinical NEC with one late death. Twenty-nine of 30 patients with scores of 5-10 responded to medical management with 2 deaths related to recurrent bouts of sepsis without recurrent NEC. Eleven patients required surgery with index scores of 10-14 with 6 deaths occurring uniformly in those patients with scores of 12 or more. Two patients were scored inappropriately low due to the lack of the passage of a stool for analysis. One patient with a score of 4 did not pass a stool but had the other diagnostic criteria for the single false negative of the series. This index correctly determined the severity of NEC of 53 of 55 patients, identified the patients who required surgical intervention and predicted survival.

Nectotizing enterocolitis: is there a place for resection and primary anatomosis?

While most situations of peritonitis, perforation and compromised blood flow in necrotizing enterocolitis are best handled by resection and stoma formation, primary resection and anastomosis should be considered in selected cases. Nine premature infants with NEC underwent bowel resection with primary anastomosis in the face of localized perforation and peritonitis. Eight survived and had no problems when oral alimentation was started. One patient with small bowel involvement underwent two anastomoses rather than a high jejunostomy; the proximal anastomosis leaked and led to the death of the patient.

Neonatal necrotizing enterocolitis. Therapeutic decisions based upon clinical staging

A method of clinical staging for infants with necrotizing enterocolitis (NEC) is proposed. On the basis of assigned stage at the time of diagnosis, 48 infants were treated with graded intervention. For Stage I infants, vigorous diagnostic and supportive measures are appropriate. Stage II infants are treated medically, including parenteral and gavage aminoglycoside antibiotic, and Stage III patients require operation. All Stage I patients survived, and 32 of 38 Stage II and III patients (85%) survived the acute episode of NEC. Bacteriologic evaluation of the gastrointestinal microflora in these neonates has revealed a wide range of enteric organisms including anaerobes. Enteric organisms were cultured from the blood of four infants dying of NEC. Sequential cultures of enteric organisms reveal an alteration of flora during gavage antibiotic therapy. These studies support the use of combination antimicrobial therapy in the treatment of infants with NEC.

Peritoneal drainage under local anesthesia for perforations from necrotizing enterocolitis

During 1974 and 1975, five newborn infants weighing between 760 and 1600 g developed severe intraabdominal complications of NEC due to necrotic bowel with perforation and peritonitis. Because these tiny neonates were very ill with sepsis and other severe medical problems, no attempt at laparotomy under general anesthesia was carried out. Instead, using local anesthesia, the contaminated peritoneal cavity was drained via a small incision, usually in the right lower quadrant. This permitted evacuation of air, pus, and stool. In all babies there was improvement evident in the abdomen within one wk, although two of the five newborns died from other causes. The three survivors are well and have normally functioning intestinal tracts 1-2 yr following surgery. One of these surviving babies developed a bowel stricture which subsequently required resection. We feel this method is preferable in the handling of the tiny sick neonate with a bowel perforation from NEC.

Intestinal anastomoses in neonatal surgery

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Necrotizing enterocolitis in low-birth-weight infants fed an elemental formula

The incidence of necrotizing enterocolitis in the newborn infant has increased within the same time period that increasing emphasis has been placed on oral alimentation of very small infants. A prospective investigation was conducted to determine the nutritional efficacy as well as the incidence of necrotizing enterocolitis of a standard cow milk formula compared with an elemental formula. Sixteen infants who weighed less than 1,200 gm were randomized and fed one of the two formulas. The clinical status of the two groups was similar. Seven of eight (87.5%) infants fed the elemental formula and two of eitht (25%) fed the standard cow milk formula developed necrotizing enterocolitis (p less than 0.02). The hypertonicity of the elemental diet may have contributed to the increased incidence of necrotizing enterocolitis in infants fed this formula.