A UK wide cohort study describing management and outcomes for infants with surgical Necrotising Enterocolitis

UK neonatal stoma practice: a population study

OBJECTIVE

The optimal time for neonatal stoma closure is unclear and there have been calls for a trial to compare early and late surgery. The feasibility of such a trial will depend on the population of eligible infants and acceptability to families and health professionals. In this study, we aimed to determine current UK practice and characteristics of those undergoing stoma surgery.

DESIGN

A retrospective cohort study of neonates who had undergone stoma surgery (excluding anorectal malformations and Hirschsprung's disease) using three national databases: the National Neonatal Research Database (NNRD, 2012-2019), British Association of Paediatric Surgeons Congenital Anomalies Surveillance System (BAPS-CASS, 2013-2014) and Hospital Episode Statistics-Admitted Patient Care (HES-APC, 2011-2018).

RESULTS

1830 eligible neonates were identified from NNRD, 163 from BAPS-CASS, 2477 from HES-APC. Median (IQR) duration of stoma in days was 57 (36-80) in NNRD, 63 (41-130) in BAPS-CASS and 78 (55-122) for neonates identified from HES-APC. At the time of closure, there were low rates of invasive ventilation (13%), inotrope use (5%) and recent steroids use (4%). Infants who underwent earlier closure (<9 weeks) were less preterm (median 28 weeks vs 25 weeks), have higher birth weight (median 986 g vs 764 g) and more likely to have stoma complications (29% vs 5%).

CONCLUSION

There are sufficient UK neonates undergoing stoma formation for a trial. Stoma closure is performed at around 2 months, with clinical stability, gestation, weight and stoma complications appearing to influence timing. The variation in practice we document indicates there is opportunity to optimise practice through a trial.

Methods of identifying surgical Necrotizing Enterocolitis-a systematic review and meta-analysis

BACKGROUND

Current data suggests potential benefit of earlier surgery for necrotizing enterocolitis (NEC) however this requires accurate prognostication early in the disease course. This study aims to identify and determine the effectiveness of previously reported methods or tests for the identification of surgical NEC.

METHODS

Systematic review and meta-analysis with registration on PROSPERO including articles describing a method of identifying surgical NEC. Outcomes of interest were effectiveness and repeatability of index test.

RESULTS

Of the 190 full-text articles screened, 90 studies were included which contained 114 methods of identifying surgical NEC in 9546 infants. Of these methods, 44 were a scoring system, 37 a single biomarker, 24 an imaging method, and 9 an invasive method. Sensitivity and specificity ranged from 12.8-100% to 13-100%, respectively. Some methods (9.6%) provided insufficient methods for repeatability within clinical practice or research. Meta-analyses were possible for only 2 methods, the metabolic derangement 7 score and abdominal ultrasound.

CONCLUSIONS

A range of methods for identifying surgical NEC have been identified with varying overall performance and uncertainties about reproducibility and superiority of any method. External validation in large multicentre datasets should allow direct comparison of accuracy and prospective study should evaluate impact on clinical outcomes.

IMPACT

Earlier identification of need for surgery in necrotizing enterocolitis (NEC) has the potential to improve the unfavourable outcomes in this condition. As such, many methods have been developed and reported to allow earlier identification of surgical NEC. This study is the first synthesis of the literature which identifies previously reported methods and the effectiveness of these. Many methods, including scoring systems and biomarkers, appear effective for prognostication in NEC and external validation is now required in multicentre datasets prior to clinical utility.

Factors affecting neurodevelopmental outcome following surgical necrotising enterocolitis: a systematic review

Surgically treated necrotising enterocolitis (sNEC) is associated with significantly worse neurodevelopmental outcomes than that seen in premature infants without NEC. We aim to review the association between factors involved in the surgical treatment of NEC and subsequent neurodevelopmental outcomes to identify potential areas for improvement. The PubMed and Embase databases were interrogated for articles reporting neurodevelopmental outcomes in babies treated surgically for NEC using key terms including: "Infant", "Necrotising enterocolitis", "Surgical", "Neurodevelopmental" and "Outcomes". The search strategy yielded 1170 articles and after applying inclusion and exclusion criteria 22 studies remained and formed the review. A diverse range of neurodevelopmental outcomes were reported. Extreme prematurity and lower birth weight were associated with worse neurodevelopmental outcomes. The use of peritoneal drains and enterostomies were associated with worse outcomes. Modifications to surgical strategies in NEC may improve neurodevelopmental outcomes but the effect of confounding factors remains unclear. Further large scale studies are required to define the optimum strategies for treating NEC surgically and to develop a core outcome set for research into NEC.

Recent advances in our understanding of NEC diagnosis, prognosis and surgical approach

Necrotising enterocolitis (NEC) remains a devasting condition that has seen limited improvement in outcomes in recent years. The incidence of the disease is increasing as more extremely premature infants survive. NEC is responsible for 1 in 10 neonatal deaths and up to 61% of survivors have significant neurodevelopmental delay. The aim of this review is to highlight recent advances in diagnosis, prognosis and surgical approach in this condition. Many recent studies have reported novel methods of diagnosis of NEC with the aim of earlier and more accurate identification. These include imaging and machine learning techniques. Prognostication of NEC is particularly important to allow earlier escalation of therapy. Around 25% of infants with NEC will require surgery and recent data has shown that time from disease onset to surgery is greater in infants whose indication for surgery is failed medical management, rather than pneumoperitoneum. This indication was also associated with worse outcomes compared to pneumoperitoneum. Ongoing research has highlighted several new methods of disease prognostication which includes differentiating surgical from medical NEC. Finally, recent randomised controlled trials in surgical technique are discussed along with the implications of these for practice. Further, high quality research utilising multi-centre collaborations and high fidelity data from electronic patient records is needed to address the issues discussed and ultimately improve outcomes in NEC.

Application of abdominal ultrasonography in surgical necrotizing enterocolitis: a retrospective study

Background

Necrotizing enterocolitis (NEC) is a severe inflammatory bowel disease that may lead to perforation, causing high morbidity and mortality in preterm infants. Abdominal ultrasound (AUS) has been shown to provide benefits in diagnosing and managing NEC in recent years.

Objective

This study focused on the utility of AUS in the diagnosis and evaluation of surgical NEC.

Patients and methods

In this retrospective study, available data of the patients diagnosed from January 2019 to June 2022 were reviewed. The sensitivity and specificity of AUS in diagnosing a perforation were analyzed. Typical cases for the application of AUS in monitoring and evaluating the progression, complications, and sequela of NEC were described.

Results

There were 69 neonates diagnosed with NEC and examined by AUS, of whom eight patients developed a perforation. AUS was used for diagnosing a perforation in eight patients with key features of pneumoperitoneum and/or complex ascites, allowing us to find four locations of perforation, with a sensitivity and specificity of 100%.

Conclusion

AUS plays an important role in diagnosing and evaluating surgical NEC in newborn infants, with good sensitivity and specificity.

Association between timing of re-introduction of enteral feeding and short-term outcomes following laparotomy for necrotising enterocolitis

PURPOSE

To investigate the relationship between timing of re-introduction of feeds following surgery for Necrotising Enterocolitis (NEC) and important early outcomes.

METHODS

Secondary analysis of prospectively collected data from paediatric surgical units in UK/Ireland of infants who underwent laparotomy for NEC between 01/03/2013 and 28/02/2014. Multivariable logistic regression analysis was used to compare the relationship of early (≤ 7 days) and later (8-27 days) re-introduction of feeding after surgery on death or need for PN at 28 days, correcting for known cofounders.

RESULTS

41/143 infants (29%) received early and 102/143 infants (71%) had delayed reintroduction of feeding. Infants in the early feeding group had a higher gestational age at birth, higher proportion of growth restriction, lower inotrope requirement, and weremore likely to have undergone primary anastomosis. Following adjustment there was no statistically significant difference detected in the rate of death or need for PN at 28 days, adjusted OR 0.4 (95% CI 0.2-1.1), noting the limited statistical power of this comparison.

CONCLUSIONS

There is no evidence from this study to support a minimum period of 7 days nil by mouth post laparotomy for infants with NEC. Early feed reintroduction following laparotomy for NEC is safe in appropriate cases.

LEVEL OF EVIDENCE

Level II - Treatment Study Group; Prospective comparative study.

NIRS as a biomarker of bowel ischaemia & surgical pathology: A meta-analysis of studies in newborns

OBJECTIVE

We performed a meta-analysis on Near-infrared Spectroscopy (NIRS) as a biomarker of bowel ischaemia.

SUMMARY BACKGROUND DATA

NIRS allows non-invasive assessment of gastrointestinal regional oxygen saturation (GrSO₂). Studies to date have focused on the feasibility of NIRS in clinical practice and its reproducibility. GrSO₂ can be used alone, or in conjunction with cerebral NIRS to give a Cerebral Splanchnic Oxygenation Ratio (CSOR). We assess published data on abdominal NIRS as a marker of bowel ischaemia.

METHODS

A literature review was conducted using the PRISMA method. Data on GrSO₂ and CSOR in controls and patients with confirmed ischaemia was included in a meta-analysis, and used to identify a diagnostic threshold.

RESULTS

14 studies were identified. Meta-analysis demonstrated that GrSO₂ (p < 0.01) and CSOR (p < 0.01) were significantly lower in neonates with bowel pathology associated with ischaemia than controls. Area under the curve for GrSO₂ was 0.80, with Youden's index highest (0.52) at a GrSO₂ of 42% (specificity 91% and sensitivity 62%). For CSOR, area under the curve is 0.89, with Youden's index highest (0.69) at 0.76 (specificity of 80%, sensitivity 90%).

CONCLUSIONS

Splanchnic NIRS correlates with bowel ischaemia. Low GrSO₂ is consistently associated with ischaemia, although a specific cut off level in each patient is hard to define. However, values below 42% correlate strongly with ischaemia while values above 52% are more suggestive of patients without bowel pathology. CSOR of below 0.76 is strongly suggestive of ischaemia. Trends within individuals are likely to be able to provide even more clinically correlatable and diagnostic data.

Surgical necrotizing enterocolitis: Association between surgical indication, timing, and outcomes

BACKGROUND/PURPOSE

Despite improvements in neonatal care the outcomes of Necrotizing Enterocolitis (NEC) remain unchanged over previous decades. The study aims to explore whether different indications for surgical intervention in NEC are associated with timing of surgery and outcomes.

METHODS

Population-based, prospective, observational study of all 27 paediatric surgical centres in the United Kingdom and Ireland identified using the British Association of Paediatric Surgeons Congenital Anomalies Surveillance System from 1st February 2013 to 28th February 2014. Infants were included if they had NEC and underwent first surgical intervention within 7 days of diagnosis. Primary outcomes were death, parenteral nutrition requirement or a composite outcome of death or PN requirement at 28 days post surgery.

RESULTS

There were 133 infants meeting inclusion criteria. Indications for surgery were bowel perforation (n = 67), suspected necrotic bowel without bowel perforation and not deemed to have failed medical management (n = 20), those who had failed medical management (n = 42) and a palpable mass without any other indication (n = 4). Failed medical treatment as an indication for surgery was associated with an increased time to surgery of 30.28 (95% CI 13.46-47.10) hours from those whose indication was perforation and was also the strongest predictor of PN requirement or death at 28 days post-surgery (OR 4.54 [1.59-13.0]).

CONCLUSIONS

Failed medical treatment as an indication for surgery for NEC is associated with poor outcome. Earlier intervention in these infants represents a potential opportunity to improve outcomes in this population.

C-reactive protein/albumin ratio is a prognostic indicator for predicting surgical intervention and mortality in neonates with necrotizing enterocolitis

PURPOSE

The role of hypoalbuminemia and raised C-reactive protein (CRP) levels in predicting critical prognosis has been described extensively in adult literature. However, there are limited studies in pediatrics, particularly neonates. The CRP/albumin (CRP/ALB) ratio is often associated with higher mortality, organ failure and prolonged hospital stay. We hypothesized that the serum CRP/ALB ratio has a prognostic value in predicting surgery and mortality in neonates with necrotizing enterocolitis (NEC).

METHODS

Retrospective review of all neonates with clinical and radiological evidence of non-perforated NEC that were treated in a tertiary-level referral hospital between 2009 and 2018. General patient demographics, laboratory parameters and outcomes were recorded. Receiver operating characteristics analysis was performed to evaluated optimal cut-offs and area under the curve (AUC) with 95% confidence intervals (CI).

RESULTS

A total of 191 neonates were identified. Of these, 103 (53.9%) were born at ≤ 28 weeks of gestation and 101 (52.9%) had a birth weight of ≤ 1000 g. Eighty-four (44.0%) patients underwent surgical intervention for NEC. The overall survival rate was 161/191 (84.3%). A CRP/ALB ratio of ≥ 3 on day 2 of NEC diagnosis was associated with a statistically significant higher likelihood for surgery [AUC 0.71 (95% CI 0.63-0.79); p < 0.0001] and mortality [AUC 0.66 (95% CI 0.54-0.77); p = 0.0150], respectively.

CONCLUSIONS

A CRP/ALB ratio of ≥ 3 on day 2 is indicative of a critical pathway in neonates with radiologically confirmed, non-perforated NEC. This could be used as an additional criterion to guide parental counselling in NEC for surgical intervention and mortality.

Necrotising enterocolitis-A 15-year outcome report from a UK specialist centre

AIMS

Necrotising enterocolitis (NEC) is a disease associated with high mortality and morbidity, low birthweight and prematurity are risk factors. This study reports outcomes of babies having emergency laparotomy for NEC, examining institutional trends and exploring impact of multiple variables on mortality at 30 days and 1 year post-operatively.

METHODS

Case records of babies with ICD coding for NEC were examined from 2000 to 2015. After exclusions, 243 cases were identified-confirmed by operative findings and histology. Cohort demographics and trends in mortality were investigated, and the relationship of common variables to mortality was modelled with univariate and multivariate logistic regression to generate a mortality prediction tool.

RESULTS

Mean gestational age was 28 + 4 weeks. A 30-day mortality was 18.9%. Gestation, birthweight and area of bowel affected were significant of outcome (mortality), and the presence of pre-operative pneumoperitoneum was strongly correlated. Year of surgery and congenital cardiac pathology requiring intervention were not significant. Using multivariate regression modelling, a mortality outcome prediction tool has been developed.

CONCLUSION

Good survival following operation for NEC (>70%) is feasible, even in those babies born extremely premature (<28 weeks) and post-operatively re-located to tertiary NICUs. With increasing gestational age (>32 weeks), mortality is uncommon.

One-year Outcomes of Congenital Duodenal Obstruction: A Population-based Study

OBJECTIVES

Congenital duodenal obstruction (CDO) occurs in 1.2 per 10,000 live births and is frequently associated with other anomalies, most commonly cardiac. The aim of this study was to report important outcomes to 1 year following surgical repair.

METHODS

This was a prospective population-based study using the British Association of Paediatric Surgeons Congenital Anomaly Surveillance System. Cases were identified at specialist pediatric surgical centres in the United Kingdom during a 12-month period starting in March 2016. Outcomes were recorded at 1 year following surgical repair.

RESULTS

There were 100 infants with possible follow-up at 1 year and follow-up was achieved in 80 of these (80%) of whom 76 were alive at 1 year. The remainder had been discharged home, although one remained on parenteral nutrition. Five (6.1%) infants underwent repeat surgery for reasons related to CDO and overall 23 (23%) experienced at least 1 central venous catheter-related complication within 1 year. Overall mortality either before repair or within 1 year following surgical repair was 8.4% (95% CI 2.5%-14.4%), no deaths were related to CDO.

CONCLUSIONS

One year outcomes for CDO are generally very good with poor outcomes typically related to comorbidities. These data are useful for national benchmarking and parental counselling.

Contemporary Outcomes for Infants with Necrotizing Enterocolitis-A Systematic Review

OBJECTIVE

To develop an accurate understanding of outcomes for necrotizing enterocolitis (NEC) to inform parental counseling, clinical care, and research agendas.

STUDY DESIGN

A systematic review of recent (January 2010-January 2018) large cohort studies reporting outcomes of infants who developed NEC. Only studies reporting national, regional, or multicenter outcomes of NEC in high income countries were included. Outcomes assessed were mortality, neurodevelopmental outcome, and intestinal failure. Meta-analyses were used to generate summary statistics for these outcomes.

RESULTS

Of 1375 abstracts, 38 articles were included. Overall mortality was 23.5% in all neonates with confirmed NEC (Bell stage 2a+) (95% CI 18.5%-28.8%), 34.5% (30.1%-39.2%) for neonates that underwent surgery for NEC, 40.5% (37.2%-43.8%) for extremely low birthweight infants (<1000 g), and 50.9% (38.1%-63.5%) for extremely low birthweight infants with surgical NEC. Studies examining causes of neonatal mortality showed NEC is responsible for around 1 in 10 of all neonatal deaths. Neurodevelopmental disability was reported in 4 studies at between 24.8% and 61.1% (1209 total NEC cases). Three studies reported intestinal failure with an incidence of 15.2%-35.0% (n = 1370). The main limitation of this review is the lack of an agreed definition for diagnosing NEC and the differences in the way that outcomes are reported.

CONCLUSIONS

Mortality following NEC remains high. These contemporary data inform clinical care and justify ongoing research efforts. All infants with NEC should have long-term neurodevelopmental assessment. Data on the long-term risk of intestinal failure are limited.

TRIAL REGISTRATION

CRD42018094791.

Abdominal ultrasound should become part of standard care for early diagnosis and management of necrotising enterocolitis: a narrative review

Necrotising enterocolitis (NEC) is a leading cause of death and disability in preterm newborns. Early diagnosis through non-invasive investigations is a crucial strategy that can significantly improve outcomes. Hence, this review gives particular attention to the emerging role of abdominal ultrasound (AUS) in the early diagnosis of NEC, its performance against abdominal radiograph and the benefits of AUS use in daily practice. AUS has been used in the diagnosis and management of NEC for a couple of decades. However, its first-line use has been minimal, despite growing evidence demonstrating AUS can be a critical tool in the early diagnosis and management of NEC. In 2018, the NEC group of the International Neonatal Consortium recommended using AUS to detect pneumatosis and/or portal air in preterm NEC as part of the 'Two out of three' model. To facilitate widespread adoption, and future improvement in practice and outcomes, collaboration between neonatologists, surgeons and radiologists is needed to generate standard operating procedures and indications for use for AUS. The pace and scale of the benefit generated by use of AUS can be amplified through use of computer-aided detection and artificial intelligence.

Does the initial surgery for necrotizing enterocolitis matter? Comparative outcomes for laparotomy vs. peritoneal drain as initial surgery for necrotizing enterocolitis in infants <1000 g birth weight

PURPOSE

Quantify short-term outcomes associated with initial surgery [laparotomy (LAP) vs. peritoneal drain (PD)] for necrotizing enterocolitis (NEC) in extremely-low-birth-weight (ELBW) infants.

METHODS

Using the Children's Hospitals Neonatal Database, we identified ELBW infants <32 weeks' gestation with surgical NEC (sNEC). Unadjusted and multivariable regression analyses were used to estimate the associations between LAP (or PD) and death/short bowel syndrome (SBS) and length of stay (LOS).

RESULTS

LAP was the more common initial procedure for sNEC (n = 359/528, 68%). Infants receiving LAP were older and heavier. Initial procedure was unrelated to death/SBS in both bivariate (LAP: 43% vs PD: 46%, p = 0.573) and multivariable analyses (OR = 0.89, 95% CI = 0.57, 1.38, p = 0.6). LAP was inversely related to mortality (29% vs. 41%, p < 0.007) in bivariate analysis, but not significant in multivariable analysis accounting for markers of preoperative illness severity. However, the association between LAP and SBS (14% vs. 5%, p = 0.012) remained significant in multivariable analyses (adjusted OR = 2.25, p = 0.039). LOS among survivors was unrelated to the first surgical procedure in multivariable analysis.

CONCLUSION

ELBW infants who undergo LAP as the initial operative procedure for sNEC may be at higher risk for SBS without a clear in-hospital survival advantage or shorter hospitalization.

LEVEL OF EVIDENCE

Level II.

One-year outcomes following surgery for necrotising enterocolitis: a UK-wide cohort study

OBJECTIVE

The objective was to describe outcomes and investigate factors affecting prognosis at 1 year post intervention for infants with surgical necrotising enterocolitis (NEC).

DESIGN

Using the British Association of Paediatric Surgeons Congenital Anomalies Surveillance System, we conducted a prospective, multicentre cohort study of every infant reported to require surgical intervention for NEC in the UK and Ireland between 1 March 2013 and 28 February 2014. Association of independent variables with 1-year mortality was investigated using multivariable logistic regression analysis.

SETTING

All 28 paediatric surgical centres in the UK and Ireland.

PATIENTS

Infants were eligible for inclusion if they were diagnosed with NEC and deemed to require surgical intervention, regardless of whether that intervention was delivered.

OUTCOMES

Primary outcome was mortality within 1 year of the decision to intervene surgically.

RESULTS

236 infants were included in the study. 208 (88%) infants had 1-year follow-up. 59 of the 203 infants with known survival status (29%, 95% CI 23% to 36%) died within 1 year of the decision to intervene surgically. Following adjustment, key factors associated with reduced 1-year mortality included older gestational age at birth (adjusted OR (aOR) 0.87, 95% CI 0.78 to 0.96). Being small for gestational age (SGA) (aOR 3.6, 95% CI 1.4 to 9.5) and requiring parenteral nutrition at 28 days post-decision to intervene surgically (aOR 3.5, 95% CI 1.1 to 11.03) were associated with increased 1-year mortality.

CONCLUSIONS

Parents of infants undergoing surgery for NEC should be counselled that there is approximately a 1:3 risk of death in the first post-operative year but that the risk is lower for infants who are of greater gestational age at birth, who are not SGA and who do not require parenteral nutrition at 28 days post-intervention.

Advances in paediatric gastroenterology

Recent developments in paediatric gastrointestinal surgery have focused on minimally invasive surgery, the accumulation of high-quality clinical evidence, and scientific research. The benefits of minimally invasive surgery for common disorders like appendicitis and hypertrophic pyloric stenosis are all supported by good clinical evidence. Although minimally invasive surgery has been extended to neonatal surgery, it is difficult to establish its role for neonatal disorders such as oesophageal atresia and biliary atresia through clinical trials because of the rarity of these disorders. Advances in treatments for biliary atresia and necrotising enterocolitis have been achieved through specialisation, multidisciplinary management, and multicentre collaboration in research; similarly robust clinical evidence for other rare gastrointestinal disorders is needed. As more neonates with gastrointestinal diseases survive into adulthood, their long-term sequelae will also need evidence-based multidisciplinary care. Identifying cures for long-term problems of a complex developmental anomaly such as Hirschsprung's disease will rely on unravelling its pathogenesis through genetics and the development of stem-cell therapy.

Current Research on the Epidemiology, Pathogenesis, and Management of Necrotizing Enterocolitis

Despite decades of research on necrotizing enterocolitis, we still do not fully understand the pathogenesis of the disease, or how to prevent or how to treat it. However, as a result of recent significant advances in the microbiology, molecular biology, and cell biology of the intestine of preterm infants and infants with necrotizing enterocolitis, there is some hope that research into this devastating disease will yield some important translation into effective prevention, more rapid diagnosis, and novel therapies.