Routine contrast enemas for diagnosing and managing strictures following nonoperative treatment of necrotizing enterocolitis

Conservative Management of Necrotizing Enterocolitis in Newborns: Incidence and Management of Intestinal Strictures

BACKGROUND

 Necrotizing enterocolitis (NEC) is one of the main causes of acute abdomen in neonates. Surgical treatment entails important morbidity and mortality and conservative management, when possible, offers better outcomes. Post-NEC intestinal strictures are one of the main complications.

METHODS

Retrospective analysis from June 2011 to November 2022 of post-NEC strictures (PNS) after conservative management of neonates diagnosed with NEC (modified Bell stage IIA or higher) at a tertiary neonatal surgery center.

RESULTS

 Out of 219 NEC, 126 received initial conservative management (57.5%), 24 (19%) of which eventually underwent surgery for PNS. Average gestational age and weight at birth of our cohort were 31.3 ± 4.9 weeks and 1,694 ± 1,009 g.PNS diagnosis was made 38.4 ± 16.5 days after the NEC episode. 6/24 (25%) were asymptomatic and diagnosed by screening enema, 11 (46%) presented signs of intestinal obstruction before the enema could be performed and 7 (29%) after a normal previous protocol study.Median age at PNS surgery was 56 ± 17.9 days. A total of 2/3 strictures were found in cecum, ascendent, and transverse colon. Primary resection and anastomosis were performed in all cases. Feeds were restarted on postoperative day 4.3 ± 2.9. Two cases presented anastomotic complications (1 dehiscence and 1 stenosis), and no deaths were recorded.

CONCLUSIONS

 PNS is a frequent complication after conservative management. Deffered surgical treatment after the acute NEC episode is resolved allows for safer surgeries (since patients have reached hemodynamical stability and overcome septic shock), shorter resections, and favorable postoperative outcomes.

Long Term Outcome of Infants with NEC

Necrotizing enterocolitis (NEC) is an important complication for premature newborns. Infants who survive NEC have a greater possibility of poor long-term physiological and neurodevelopmental growth. The objective of this paper is to give a comprehensive description of the long-term consequences of NEC. Despite the rise in incidence of NEC there is a scarcity of data regarding long-term outcomes of these infants that can be divided into two groups. The first group includes gastrointestinal complications that could occur in relation to the bowel disease, the surgical treatment and quality of the residual bowel. These complications are strictures and short bowel syndrome (SBS). Intestinal strictures are a common occurance after recovery from NEC that should be investigated with a contrast study in case of suspicious clinical findings of bowel obstruction or before reversal ostomy. After this diagnostic investigation, if a stricture is detected in a symptomatic patient, resection of the affected loop of bowel with anastomosis is required. SBS is the result of a massive intestinal resection or of a dysfunctional residual bowel and it can occur in a fourth of patients affected by NEC. The second group includes neurodevelopmental impairment and growth. Neurodevelopmental outcomes of patients after NEC recovery have not been widely reported. Infants with NEC is a population of patients at high risk for adverse neurodevelopmental outcomes whose cause can be multifactorial and linked to perinatal events, severity of disease, surgical treatment and its complications and hospitalization. Understanding the morbidity of NEC with a longterm follow-up would aid neonatologists and pediatric surgeons to make informed decisions in providing care for these patients. Further research on this topic is needed.

Surgical considerations for neonates with necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a potentially devastating condition that preferentially affects premature and low birth weight infants, with approximately half requiring acute surgical intervention. Surgical consult should be considered early on, and deterioration despite maximal medical therapy or the finding of pneumoperitoneum are the strongest indications for emergent surgical intervention. There is no clear consensus on the optimal surgical approach between peritoneal drainage and laparotomy; the best course of action likely depends on the infant's comorbidities, hemodynamic status, size, disease involvement, and available resources. Patients who develop surgical NEC are at a significant risk for morbidity and mortality, with long-term complications including short bowel syndrome, growth failure, and neurodevelopmental impairment. Further research into strategies that optimize outcomes following surgery for NEC in the neonatal intensive care unit and long-term are paramount.

The value of contrast studies in the evaluation of bowel strictures after necrotising enterocolitis

PURPOSE

Strictures of the bowel are a frequent complication post-necrotising enterocolitis (NEC). Contrast studies are routinely performed prior to stoma closure following NEC. The aim of this study was to evaluate the ability of these studies to detect strictures and also directly compare them to operative and histological findings.

METHODS

Two hundred and fourteen neonates who had a diagnosis of NEC (Bell stage 2 or greater) in a single unit (2007-2011) were analysed. Their case notes, radiology, and histology were reviewed.

RESULTS

One hundred and sixteen neonates underwent an emergency laparotomy and 77 had stomas fashioned. Sixty-six patients had a contrast study prior to stoma closure (distal loopogram 18, contrast enema 37, both studies 11). Colonic strictures were reported in 18 patients and small bowel strictures were reported in two patients. Fourteen of these colonic strictures were confirmed at operation and on histology but three colonic strictures were missed on contrast studies; one patient had had both contrast studies and the other two only a distal loopogram. Two small bowel strictures reported were confirmed and an additional small bowel stricture missed on distal loopogram was also detected at the time of operation. The incidence of post-op strictures was 19 out of 68 patients (27.9 %) and 16 (84.2 %) of these strictures were found in the colon. Contrast enemas had a much higher sensitivity for detecting post-NEC colonic strictures than distal loopograms; 93 versus 50 %, respectively; however, they are more likely to give a false positive result and therefore their specificity is lower; 88 versus 95 %, respectively.

CONCLUSION

Colon is the commonest site for post-NEC stricture and contrast enema is the study of choice for detecting these strictures prior to stoma closure.

Utility of gastrointestinal fluoroscopic studies in detecting stricture after neonatal necrotizing enterocolitis

OBJECTIVES

We report our institution's 5-year experience with upper gastrointestinal study with small bowel follow-through (UGI-SBFT) and contrast enema (CE) for the diagnosis of a post-necrotizing enterocolitis (NEC) stricture. We hypothesized that sensitivity and specificity of UGI-SBFT and CE were <85% in diagnosing a post-NEC stricture.

METHODS

A retrospective observational cohort study was performed. Included patients were neonates diagnosed as having Bell's modified stage 2 or 3 NEC who had undergone UGI-SBFT and/or CE to evaluate for a stricture. Exploratory laparotomy was used to definitively determine the stricture presence, which was confirmed by pathology. An infant was categorized as having no stricture if no surgical intervention occurred or if no stricture was reported on pathology following surgical resection.

RESULTS

A total of 56 patients met inclusion criteria, with 51 UGI-SBFT and 85 CE performed. A total of 25 patients were diagnosed as having a stricture. For small bowel (SB) strictures, CE compared with UGI-SBFT has a higher sensitivity (0.667 vs 0.00) and a similar specificity (0.857 vs 0.833). For SB and/or colonic strictures, CE has a sensitivity of 0.667 and a specificity of 0.951. Strictures were more likely to be found on imaging in symptomatic infants compared with those in asymptomatic infants (28% vs 8%, P = 0.002).

CONCLUSIONS

CE should be the initial study in the diagnostic workup for a post-NEC stricture because this test has a higher likelihood of detecting a stricture if it is present. As a result of low sensitivity of UGI-SBFT and/or CE in the diagnosis of a post-NEC stricture, a negative study should not rule out the diagnosis of a stricture in persistently symptomatic patients.

Necrotizing enterocolitis (NEC) and the risk of intestinal stricture: the value of C-reactive protein

Necrotizing enterocolitis (NEC) is a severe complication frequently seen during the neonatal period associated with high mortality rate and severe and prolonged morbidity including Post-NEC intestinal stricture. The aim of this study is to define the incidence and risk factors of these post-NEC strictures, in order to better orient their medicosurgical care. Sixty cases of NEC were retrospectively reviewed from a single tertiary center with identical treatment protocols throughout the period under study, including systematic X-ray contrast study. This study reports a high rate of post-NEC intestinal stricture (n = 27/48; 57% of survivors), either in cases treated surgically (91%) and after the medical treatment of NEC (47%). A colonic localization of the strictures was more frequent in medically-treated patients than in those with NEC treated surgically (87% vs. 50%). The length of the strictures was significantly shorter in case of NEC treated medically. No deaths were attributable to the presence of post-NEC stricture. The mean hospitalization time in NICU and the median age at discontinuation of parenteral nutrition were longer in the group with stricture, but this difference was not significant. The median age at discharge was significantly higher in the group with stricture (p = 0.02). The occurrence of post-NEC stricture was significantly associated with the presence of parietal signs of inflammation and thrombopenia (<100 000 platelets/mm³). The mean maximum CRP concentration during acute phase was significantly higher in infants who developed stricture (p<0.001), as was the mean duration of the elevation of CRP levels (p<0.001). The negative predictive value of CRP levels continually <10 mg/dL for the appearance of stricture was 100% in our study. In conclusion, this retrospective and monocentric study demonstrates the correlation between the intensity of the inflammatory syndrome and the risk of secondary intestinal stricture, when systematic contrast study is performed following NEC.

Neonatal necrotizing enterocolitis

Necrotizing enterocolitis (NEC) remains a major cause of morbidity and death in neonates. The 30% to 50% mortality rate for NEC with perforation has not changed appreciably in the past 30 years. The critical relevant outcomes following NEC include survival, gastrointestinal function, and neurodevelopmental status. In each of these areas, initial anecdotal and case-series analysis has been followed by studies using more sophisticated methods of analysis. The single most important predictor of outcome, besides gestational age, is whether or not the disease has progressed to the point requiring surgical intervention. Patients with NEC requiring operation have a high mortality. Moreover, the vast majority of morbidity following NEC occurs in the patients who survive following operation. The purpose of this review is to examine the evolution of evidence regarding outcomes for patients with NEC and to provide an update on our current state of knowledge.

Preoperative distal loop contrast radiograph before closure of an enterostomy in paediatric surgical patients. How much does it affect the procedure or predict early postoperative complications?

Before the closure of an enterostomy, a distal loop contrast radiograph (DLCR) is widely used to disclose pathology which may affect the performance of the procedure. We studied whether DLCR of paediatric patients caused actual alterations in the surgical plan and whether it predicted postoperative complications. Between 1991 and 2006, 105 patients (small bowel enterostomy, SBE; n = 51), (colostomy, CO; n = 54) underwent closure of an enterostomy. All 105 patients had preoperative DLCR. The indications for enterostomy included anorectal malformation (n = 38), neonatal intestinal perforation (n = 25), J-Pouch ileoanal anastomosis (n = 20), anorectal trauma (n = 5), and miscellaneous (n = 17). We recorded sensitivity, specificity, and positive and negative predictive value (PPV and NPV) of DLCR for complications within 6 postoperative weeks. DLCR was considered complete and interpreted as normal in 94 (90%) and abnormal (incomplete n = 3 or pathological n = 8) in 11 (10%) patients. None of the 11 abnormal findings caused cancellation of surgery, but in three (27%) patients it was possible to surgically correct a stricture seen in DLCR. The frequency of surgical complications was 17/105 (16%), SBE (15/51,29%) and CO (2/54, 4%), (P < 0.05). Most common complications (9/17, 53%) were those associated with the intestinal anastomosis. For postoperative complications DLCR had sensitivity, specificity, and PPV and NPV of 47, 97, 73 and 90% (SBE and 47, 97, 88 and 81%), (CO 50, 96, 33 and 98%). The pathology seen in DLCR, however, seldom directly hinted the complications which actually occurred. Abnormal DLCR changed the surgical plan in less than one-fifth of the cases. For surgical complications DLCR had poor sensitivity, good specificity and NPV, and moderate PPV. The pathology suggested by DLCR, however, correlated poorly with the actual complications. Poor sensitivity reflects the high frequency of anastomotic complications, which are practically unpredictable by preoperative radiographs.

[Intestinal stenosis during ulceronecrotizing enterocolitis]

BACKGROUND

Intestinal stenosis following necrotizing enterocolitis (NE) occurred both in surgically-treated neonates after perforation, distal to an enterostomy and in medically-treated patients developing symptoms of obstruction. It has been proposed to detect stenosis by contrast enema before refeeding in those medically-treated patients. The aim of this study was to compare delay, clinical and pathological characteristics of surgical and medical patients, both after occlusion and prospective contrast studies.

PATIENTS AND METHODS

Fifteen patients out of 50 with NE observed from 1984 to 1994 developed one or several intestinal stenosis. Diagnosis of NE was based on usual clinical signs, X-ray pneumatosis (43 to 50) and/or perforation in 16 cases. Among these 16 surgical patients, 12 survived the initial perforation. Among the 34 medical patients, 11 were seen before 1989 and did not have contrast studies before refeeding; 23 seen after 1989 had a contrast enema before.

RESULTS

One or several stenosis occurred in four out of 12 surgical patients, four out of 11 medical patients without prospective contrast studies (one of them died from sepsis) and seven out of the 23 of the prospective group. On the whole, 26 stenosis occurred in 15 neonates: ten to the right colon, five to the transverse and 11 to the left colon. One ileal stenosis followed enterostomy. Delay of stenosis development was comparable in the three groups (between 3 weeks and 3 months). Pathologic examination showed similar lesions in the three groups (fibrosis 15, edema nine to 15 and chronic inflammation 12 to 15).

CONCLUSION

Among 46 neonates who survived the initial period, 15 developed stenosis, a 30% proportion similar in patients operated on for perforation or in medically-treated patients whose diagnosis was made after occlusion or after contrast enema as well. These results suggest that systematic stenosis detection by contrast enema may avoid complications and permit programmed one-stage surgery.

Late intestinal strictures following successful treatment of necrotizing enterocolitis

Between 1975 and 1992, in 16 infants (14%) out of 113 neonates with previous necrotizing enterocolitis (NEC) a total of 25 intestinal strictures had to be treated. Four (16%) were found in the ileum and 21 (84%) in the colon, and in 50% multiple strictures were present. In these 16 patients initial treatment for acute NEC included conservative treatment in 5, primary resection and enterostomies in 6 and proximal diverting enterostomies in 5. Therefore, the incidence of late strictures was 11% after conservative therapy, 11% after primary resection and 55% after primary proximal diverting enterostomies. An average of 49 days elapses between the recovery from NEC and the diagnosis of late strictures in conservatively treated patients. After initial surgical treatment, late strictures were detected on contrast studies on an average of 80 days. In pathologic specimens, marked fibrosis in the submucosa was consistently present in all strictures, whereas inflammatory changes in the mucosa, disruption or hypertrophy of the muscle layers or absence of ganglion cells were seen less frequently. All strictures were resected and primary end-to-end anastomosis was performed. But despite the development of late intestinal strictures, bowel preservation was improved after initial restrictive surgical therapy and aggressive medical treatment.

Colonic strictures following successful medical management of necrotizing enterocolitis: a prospective study evaluating early gastrointestinal contrast studies

This is a prospective study of 50 patients with neonatal necrotizing enterocolitis (NEC) treated successfully by medical means. They were all screened with an upper gastrointestinal (GI) contrast study after 14 days of healing and prior to establishment of feeding. Thirty-six patients (72%) with normal upper GI examinations responded well to a graduated increase in feeding. Another 5 (10%) with questionable areas on their upper GI examination had a normal follow-up contrast enema. Feeding was successfully established in this group of infants also. The remaining 9 patients (18%) had demonstrable strictures in both contrast studies. After elective resection of strictures with restoration of intestinal continuity, they were also fed successfully. No delayed strictures were seen in any of the patients. We propose that this method of evaluation is safe, efficient and reliable in the diagnosis of strictures that develop in patients recovering from NEC.

A scoring system in predicting the risk of intestinal stricture in necrotizing enterocolitis

Of 46 infants with a diagnosis of necrotizing enterocolitis (NEC) admitted to the neonatal intensive care unit over the period 1981-1985, 40 have been followed from 2 to 6 years after the acute episode. A contrast enema (CE) to look for intestinal strictures (IS) was performed either during the first months in surgically managed patients, or between 2 and 6 years in asymptomatic patients. Clinical, laboratory and radiology parameters collected during the 7 days following NEC were used to establish a score which was correlated with radiological data obtained after CE. Of the 40 infants, 17 developed symptomatic or asymptomatic IS and 16 of these 17 infants has a score greater than or equal to 7. Nineteen of the 23 patients without IS had a score less than 7. We conclude that the proposed score established on day 8 after onset of NEC helps to identify infants at higher risk of developing IS and for whom closer follow up appears necessary.

Necrotizing enterocolitis of the neonate

Necrotizing enterocolitis is the most common gastrointestinal emergency in the newborn. The syndrome strikes premature infants during the first 2 weeks of life. Abdominal distention, lethargy, and feeding intolerance are early signs of NEC that may progress to gastrointestinal bleeding and hemodynamic instability. The radiographic hallmark of NEC is pneumatosis intestinalis (air in the bowel wall). The ileum and colon are the usual sites of crepitant intestinal necrosis, leading frequently to perforation. In spite of appropriate medical therapy, about half of the infants with NEC develop intestinal gangrene or perforation and require surgery, consisting of bowel resection and enterostomy formation. The most common late complication, intestinal stricture, occurs in 15 to 35 per cent of recovered infants. Overall mortality from NEC ranges from 20 to 40 per cent. The etiology of NEC is poorly understood and is considered to be multifactorial, related to ischemia, bacterial colonization, and formula feedings in a susceptible infant. Future progress in the treatment of NEC may be achieved by earlier detection of necrosis, modification of gastrointestinal flora, or by bolstering the deficient gastrointestinal immune mechanisms of the premature neonate.