Value of abdominal ultrasound in management of necrotizing enterocolitis: a systematic review and meta-analysis

Point-of-care abdominal ultrasound in pediatric and neonatal intensive care units

A spectrum of critical abdominal pathological conditions that might occur in neonates and children warrants real-time point-of-care abdominal ultrasound (abdominal POCUS) assessment. Abdominal radiographs have limited value with low sensitivity and specificity in many cases and have no value in assessing abdominal organ perfusion and microcirculation (Rehan et al. in Clin Pediatr (Phila) 38(11):637-643, 1999). The advantages of abdominal POCUS include that it is non-invasive, easily available, can provide information in real-time, and can guide therapeutic intervention (such as paracentesis and urinary bladder catheterization), making it a crucial tool for use in pediatric and neonatal abdominal emergencies (Martínez Biarge et al. in J Perinat Med 32(2):190-194, 2004) and (Alexander et al. in Arch Dis Child Fetal Neonatal Ed 106(1):F96-103, 2021).  Conclusion: Abdominal POCUS is a dynamic assessment with many ultrasound markers of gut injury by two dimensions (2-D) and color Doppler (CD) compared to the abdominal X-ray; the current evidence supports the superiority of abdominal POCUS over an abdominal X-ray in emergency situations. However, it should still be considered an adjunct rather than replacing abdominal X-rays due to its limitations and operator constraints (Alexander et al. in Arch Dis Child Fetal Neonatal Ed 106(1):F96-103, 2021). What is Known: • Ultrasound is an important modality for the assessment of abdominal pathologies. What is New: • The evidence supports the superiority of abdominal POCUS over an abdominal X-ray in emergency abdominal situations in the neonatal and pediatric intensive care units.

A Novel Integrated Clinical-Biochemical-Radiological and Sonographic Classification of Necrotizing Enterocolitis

OBJECTIVE

 To evaluate the sensitivity and specificity of clinical, laboratory, and radiological markers and the neonatologist-performed intestinal ultrasound (NP-IUS) for treatment interventions in preterm neonates who developed necrotizing enterocolitis (NEC).

STUDY DESIGN

 This was a case-control study of preterm neonates < 35 weeks with a diagnostic workup for NEC. The diagnostic workup included NP-IUS performed by trained neonatologists using a standard protocol, abdominal roentgenogram (AXR), and laboratory investigations. Intestinal ultrasound (IUS) performed by two neonatologists was standardized to detect 11 injury markers. AXRs were read independently by experienced pediatric radiologists. The investigators who retrospectively interpreted the IUS were blinded to the clinical and treatment outcomes.

RESULTS

 A total of 111 neonates were assessed. Fifty-four did not require intervention and formed the control group. Twenty cases were treated medically, 21 cases were treated with late surgery for stricture or adhesions, and 16 were treated with early surgery. The integrated model of cumulative severity of ultrasound markers, respiratory and hemodynamic instability, abdominal wall cellulitis, and C- reactive protein > 16 mg/L had an area under the curve (AUC) of 0.89 (95% confidence interval [CI]: 0.83-0.94%, p < 0.0001) for diagnosing NEC requiring surgical intervention. We also investigated the utility of Bell's classification to diagnose either the need for surgery or death, and it had an AUC of 0.74 (95% CI: 0.65-0.83%, p < 0.0001).

CONCLUSION

 In this cohort, a combination of specific IUS markers and clinical signs of instability, abdominal wall cellulitis, plus laboratory markers were diagnostic of NEC requiring interventions.

KEY POINTS

· The diagnosis of necrotizing enterocolitis requires a combination of markers.. · The combination of specific ultrasound markers, clinical signs, and laboratory markers were diagnostic of NEC requiring intervention.. · The intestinal ultrasound performed by a trained neonatologist was the most sensitive diagnostic marker of NEC requiring surgical intervention..

The role of an abbreviated ultrasound in the evaluation of necrotizing enterocolitis

BACKGROUND

Bowel ultrasound is a useful diagnostic tool in the diagnosis and management of necrotizing enterocolitis (NEC) but can be time-consuming and requires technical expertise, particularly for assessing pneumatosis. Previous literature on sonographic evaluation of NEC has focused on a full bowel ultrasound protocol, but the utility of an abbreviated protocol primarily aimed at identifying high-risk sonographic findings without focused bowel assessment has not been well studied.

OBJECTIVE

This study aims to describe the diagnostic accuracy of an abbreviated ultrasound protocol for identifying high-risk NEC findings.

MATERIALS AND METHODS

This is a retrospective, institutional review board-approved study. We identified all abbreviated NEC ultrasounds performed between January 2014 and August 2022 at our institution. Exams were reviewed for the presence of high-risk findings including pneumoperitoneum, fluid collections, and complex free fluid. Clinical outcome was categorized as poor or good depending on if emergent surgical intervention or death related to NEC occurred. The frequency of follow-up NEC ultrasounds was reviewed to determine if new findings affected outcome. Sensitivity, specificity, and positive and negative predictive values were generated to assess the performance of the abbreviated ultrasounds to identify high-risk findings.

RESULTS

A total of 84 abbreviated abdominal ultrasounds were performed on 73 children. Median age at the time of ultrasound was 41 days (interquartile range (IQR) 53 days) and median gestational age was 35 weeks and 3 days (IQR 80 days), and 44/73 (60%) were male. Thirteen ultrasounds had at least one high-risk finding with nine (69%) resulting in a poor outcome, including seven surgical interventions and four deaths. Two patients had surgical intervention and died as a result of necrotizing enterocolitis. Ultrasounds without high-risk findings were not associated with poor clinical outcomes. Sensitivity, specificity, positive predictive value, and negative predictive value of the abbreviated NEC ultrasound were 100% (95% CI 60-100%), 95% (95% CI 86-98%), 69% (95% CI 39-90%), and 100% (95% CI 94-100%), respectively. Twelve abbreviated ultrasounds were followed by a second NEC ultrasound within 5 days. Five follow-up ultrasounds demonstrated new high- or low-risk findings, but the new findings did not correlate with a change in outcome as predicted by the initial ultrasound.

CONCLUSION

An abbreviated NEC ultrasound can be of clinical utility in predicting poor outcomes, particularly during non-business hours when resources are limited.

Association of new sonographic features with outcome in neonates with necrotizing enterocolitis

BACKGROUND

We have recently noted some sonographic features in necrotizing enterocolitis that have received little or no attention in the current literature. These include thickening of the mesentery, hyperechogenicity of intraluminal intestinal contents, abnormalities of the abdominal wall, and poor definition of the intestinal wall. It has been our impression that the above four sonographic findings are generally seen in neonates with more severe necrotizing enterocolitis and may be useful in predicting outcome.

OBJECTIVES

The aim of this study is, firstly, to review a large series of neonates, known to have clinical NEC, to document how frequently the above four sonographic features occur in neonates with necrotizing enterocolitis and, secondly, to determine whether they are predictive of outcome.

MATERIALS AND METHODS

We retrospectively analyzed the clinical, radiographic, sonographic, and surgical findings in neonates with necrotizing enterocolitis between 2018 and 2021. The neonates were categorized into two groups based on outcome. Group A included neonates with a favorable outcome defined as successful medical treatment with no surgical intervention. Group B included neonates with an unfavorable outcome defined as failed medical treatment requiring surgery (for acute complications or late strictures) or death because of necrotizing enterocolitis. The sonographic examinations were reviewed with attention to the features of mesenteric thickening, hyperechogenicity of intraluminal intestinal contents, abnormalities of the abdominal wall, and poor definition of the intestinal wall. We then determined the association of these four findings with the two groups.

RESULTS

We included 102 neonates with clinical necrotizing enterocolitis: 45 in group A and 57 in group B. Neonates in group B were born at a significantly earlier gestational age (median 25 weeks, range 22-38 weeks) and had a significantly lower birth weight (median 715.5 g, range 404-3120 g) than those in group A (median age 32 weeks, range 22-39 weeks, p = 0.003; median weight 1190 g, range 480-4500 g, p = 0.002). The four sonographic features were present in both study groups but with different frequency. More importantly, all four were statistically significantly more frequently present in neonates in group B compared to group A: (i) mesenteric thickening, A = 31 (69%), B = 52 (91%), p = 0.007; (ii) hyperechogenicity of intestinal contents, A = 16 (36%), B = 41 (72%), p = 0.0005; (iii) abnormalities of the abdominal wall, A = 11 (24%), B = 35 (61%), p = 0.0004; and (iv) poor definition of the intestinal wall, A = 7 (16%), B = 25 (44%), p = 0.005. Furthermore, the proportion of neonates with more than two signs was greater in group B compared to group A (Z test, p < 0.0001, 95% CI = 0.22-0.61).

CONCLUSION

The four new sonographic features described were found to occur statistically significantly more frequently in those neonates with an unfavorable outcome (group B) than in those with a favorable outcome (group A). The presence or absence of these signs should be included in the sonographic report to convey the radiologists concern regarding the severity of the disease in every neonate, suspected or known to have necrotizing enterocolitis, as the findings may impact further medical or surgical management.

Point-of-care Ultrasound to Diagnose and Monitor the Course of Necrotizing Enterocolitis

Context

Neonatal gut ultrasound (US) is an emerging clinical tool for quick diagnosis and prognosis in various abdominal pathologies. In this review, we summarize normal gut US findings and concentrate on the specifications of diagnosing necrotizing enterocolitis.

Evidence

A comprehensive literature search was conducted across numerous sources with relevant keywords along with the specified age group of 0-28 days of life.

Findings

This review describes the normal gut US picture with the basic technicalities needed to master the art of point-of-care (POC) abdominal US. This modality is gaining importance due to its accuracy, applicability, safety, and affordability. Key findings include altered bowel perfusion, decreased peristalsis, and bowel wall thickening with better precision compared to abdominal X-ray (AXR). Many meta-analyses and narrative reviews have already demonstrated their usefulness. The high specificity and positive predictive value could make this tool a guide for early identification and prompt surgical intervention in the dreaded diagnosis of necrotizing enterocolitis.

Conclusion

Emerging evidence and expertise in the field of abdominal US will make it a valuable tool for early diagnosis and prognosis of necrotizing enterocolitis.

Clinical Outcome of Ultrasound-Detected Perforated Necrotizing Enterocolitis without Radiographic Pneumoperitoneum in Very Preterm Infants

OBJECTIVES

To investigate the clinical outcomes of ultrasound (US)-detected perforated necrotizing enterocolitis (NEC) without radiographic pneumoperitoneum in very preterm infants.

METHODS

In this single-center retrospective study, very preterm infants who underwent a laparotomy for perforated NEC during their neonatal intensive care unit stay were classified into two groups according to the absence or presence of pneumoperitoneum on radiographs (the case versus the control groups). The primary outcome was death before discharge, and the secondary outcomes included major morbidities and body weight at 36 weeks postmenstrual age (PMA).

RESULTS

Of the 57 infants with perforated NEC, 12 (21%) had no pneumoperitoneum on the radiographs and were diagnosed with perforated NEC on the US. In the multivariable analyses, the primary outcome of death before discharge was significantly lower in infants with perforated NEC without radiographic pneumoperitoneum than in those with perforated NEC and radiographic pneumoperitoneum (8% [1/12] vs. 44% [20/45]; adjusted odds ratio [OR], 0.02; 95% confidence interval [CI], 0.00-0.61; p = 0.025). The secondary outcomes (short bowel syndrome, total parenteral nutrition dependence for 3 months or more, the length of their hospital stay, a bowel stricture requiring surgery, sepsis after the laparotomy, acute kidney injury after the laparotomy, and body weight at 36 weeks PMA) did not differ significantly between the two groups.

CONCLUSIONS

Very preterm infants with US-detected perforated NEC without radiographic pneumoperitoneum had a lower risk of death before discharge than those with perforated NEC and radiographic pneumoperitoneum. Bowel USs may have a potential role in surgical decision-making in infants with advanced NEC.

IS -94INS/DELATTG POLYMORPHISM IN THE NUCLEAR FACTOR KAPPA-B1 GENE (NFKB1) ASSOCIATED WITH NECROTIZING ENTEROCOLITIS?

BACKGROUND

Abnormalities in the different stages of the intestinal maturation process cause metabolic and molecular changes. Among the genetic alterations associated with necrotizing enterocolitis, the -94ins/delATTG polymorphism in NFKB1 gene leads to unregulated activation of the NFKB protein due to an increase in the inherent pro-inflammatory state of the premature intestine.

AIMS

To determine the prevalence of the -94ins/delATTG polymorphism in NFKB1 gene in neonates with and without necrotizing enterocolitis.

METHODS

This is a case-control study, in which 25 neonates were evaluated as the case group and 50 neonates as the control group, of both genders. DNA was extracted from peripheral blood leukocytes, and the site encompassing the polymorphism was amplified by molecular techniques (polymerase chain reaction/polymorphism in restriction fragment length).

RESULTS

Necrotizing enterocolitis was diagnosed in 25 (33%) neonates and, of these, 3 (12%) died. Male gender was more prevalent in both groups (p=0.1613): cases (52%) and controls (62%). Moderate and extreme preterm newborns were predominant in both groups: cases (80%) and controls (88%) (p=0.3036). Low birth weight and extremely low birth weight newborns were the most prevalent in cases (78%), and very low birth weight and extremely low birth weight were the most prevalent in controls (81%) (p=0.1073). Clinical treatment was successful in 72%, and hospital discharge was achieved in 88% of newborns with NEC. The -94ins/delATTG polymorphism in NFKB1 gene was not identified in all the 150 alleles analyzed (100%).

CONCLUSIONS

The absence of the -94ins/delATTG polymorphism in NFKB1 gene in newborns with and without necrotizing enterocolitis does not rule out the possibility of alterations in this and/or in other genes in newborns with this condition, which reinforces the need for further research.

Ultrasound for necrotizing enterocolitis: how can we optimize imaging and what are the most critical findings?

Necrotizing enterocolitis (NEC) is a common condition in the neonatal intensive care unit that continues to present challenges in terms of diagnosis and management. Traditionally NEC has been diagnosed and managed by clinical and radiographic findings, but US has shown promise in characterizing and prognosticating NEC. In this manuscript we review the abdominal US technique for NEC, the clinical significance of individual sonographic findings of NEC, and how US can be integrated in the clinical decision process for diagnosing and managing NEC. We also discuss the potential value-added role of a limited abdominal US protocol that focuses on the sonographic findings most indicative of a poor prognosis to include pneumoperitoneum, complex free fluid and focal fluid collections.

Pneumatosis coli in preterm neonates: Can they be managed more conservatively to maintain the intestinal milieu?

Necrotising enterocolitis (NEC) is a severe gastrointestinal disease mostly in premature infants due to intestinal necrosis. The aetiology of NEC is multifactorial and includes gut immaturity, intestinal dysbiosis and exaggerated intestinal mucosal reactivity to microbial ligands. Radiographic evidence of pneumatosis intestinalis has been a critical feature for diagnosing NEC Bell stage ≥IIA and recommended treatment includes prolonged antibiotics (7-14 days) while off enteral feeds. Pneumatosis coli (Pcoli), a mild or benign form of NEC, is characterised by pneumatosis limited to the colon in an infant having haematochezia, negative septic screening and no systemic signs. We report two healthy preterm infants with haematochezia and colonic pneumatosis while on breast milk feeds. The sepsis screen was negative. A brief period of antibiotics and gut rest led to the spontaneous resolution of haematochezia and colonic pneumatosis, facilitating early enteral feeds. This case report emphasises the need to differentiate NEC from benign Pcoli.

Abdominal Ultrasound Assists the Diagnosis and Management of Necrotizing Enterocolitis

BACKGROUND

Abdominal x-ray (KUB) routinely aids in detecting necrotizing enterocolitis (NEC), one of the most serious neonatal intestinal diseases. However, a KUB may miss up to 50% of the early signs of NEC. Recent advances in abdominal ultrasound (AUS) can expedite this diagnosis and improve clinical management.

PURPOSES

To illustrate AUS findings that suggest NEC through 3 case examples. To review current literature regarding advantages and limitations of AUS compared with KUB.

RESULTS

The added visualization of intra-abdominal structures with AUS compared with KUB improves the diagnosis and management of NEC. Some AUS features are highly suggestive of impending bowel perforation, while others can confirm bowel perforation despite a negative radiograph.

IMPLICATIONS FOR PRACTICE

AUS expedites time to diagnosis of NEC and helps to stratify patients who may fail medical management and require surgical intervention.

IMPLICATIONS FOR RESEARCH

More quality improvement studies are needed to validate an AUS protocol for the management of NEC. Advances in technology, such as contrast-enhanced ultrasound, may improve NEC detection with AUS in the future.Video Abstract available athttps://journals.lww.com/advancesinneonatalcare/Pages/videogallery.aspx.

Clinical Presentation and Multifactorial Pathogenesis of Necrotizing Enterocolitis in the Preterm Infant

BACKGROUND

Necrotizing enterocolitis (NEC) is a serious infection of the bowel wall induced by multiple pathological factors, which include inflammation and tissue invasion with bacteria known to cause severe infections. NEC is now understood to be several disease processes under one umbrella. The most common form occurs in premature infants and can exert significant impacts to preterm morbidity and mortality.

PURPOSE

This narrative review describes current knowledge of the clinical presentation and pathophysiology of NEC in premature infants.

METHODS/SEARCH STRATEGY

A review of literature was conducted using key words in PubMed and CINAHL with preference for years 2015 to 2020.

FINDINGS/RESULTS

Several converging and interrelated factors including characteristics of the premature intestinal mucosa, gut ischemia, dysregulation of the microbiome, enteral feeding, and genetics create an environment where NEC is more likely to occur.

IMPLICATIONS FOR PRACTICE

To recognize and diagnose NEC in preterm infants, an understanding of underlying factors that create an optimal environment for disease acquisition in premature infants is essential.

IMPLICATIONS FOR RESEARCH

Prevention of NEC remains the most important strategy for decreasing morbidity and mortality. Multiple areas of potential study exist for NEC pathophysiology including those that consider how the factors discussed in this review are interrelated and how each particular pathway can be optimized to prevent the onset of NEC.

Low-dose cyclooxygenase-2 (COX-2) inhibitor celecoxib plays a protective role in the rat model of neonatal necrotizing enterocolitis

This study aims to investigate the effects of the cyclooxygenase-2 (COX-2) inhibitor celecoxib on neonatal necrotizing enterocolitis (NEC) in rats. After treatment with a low dose of celecoxib (0.5, 1, or 1.5 mg/kg), pathological changes in the ileum and the levels of oxidative stress and inflammatory factors in NEC rats were compared. Enzyme-linked immunosorbent assay (ELISA) was employed to detect inflammatory factors, terminal deoxyribonucleotidyl transferase (TdT)-mediated biotin-16-dUTP nick-end labeling (TUNEL) staining was employed to assess apoptotic epithelial cells in the ileum, and real-time quantitative polymerase chain reaction (qRT-PCR) and Western blotting were used to quantify gene and protein expression, respectively. The incidences of NEC rats in the 0.5, 1 and 1.5 mg/kg celecoxib groups were lower than in the model group (100%). Celecoxib improved the histopathology of the ileum in NEC rats. Moreover, low doses of celecoxib relieved oxidative stress and inflammation in NEC rats, as evidenced by decreased tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), total oxidation state (TOS), malondialdehyde (MDA) and oxidative stress index (OSI), as well as increased interleukin-10 (IL-10), total antioxidant status (TAS), superoxide dismutase (SOD) and glutathione peroxidase (GPx). With increasing celecoxib doses (0.5, 1, or 1.5 mg/kg), the amount of apoptotic epithelial cells in the ileum of NEC rats gradually declined and Caspase-3 expression was reduced. The low dose of the COX-2 inhibitor celecoxib ameliorated the histopathologic conditions of the ileum, alleviated oxidative stress and inflammation, and reduced apoptotic epithelial cells in NEC rats, thereby making it a potential therapy for NEC.

Doppler ultrasound assessment of splanchnic perfusion and heart rate for the detection of necrotizing enterocolitis

PURPOSE

Monitoring disease progression is crucial to improve the outcome of necrotizing enterocolitis (NEC). A previous study indicates that intestinal wall flow velocity was reduced in NEC pups from the initial stages of the disease. This study aims to investigate whether splanchnic perfusion via the superior mesenteric artery (SMA) (i) is altered during NEC development and (ii) can be used as a monitoring tool to assess disease progression.

METHODS

NEC was induced in C57BL/6 mice via gavage feeding of formula, hypoxia, and oral lipopolysaccharide, from postnatal day 5 (P5) to P9 (AUP: 32,238). Breastfed littermates served as controls. Doppler ultrasound (U/S) of bowel loops was performed daily. Intestinal wall perfusion was calculated as average flow velocity (mm/s) of multiple abdominal regions. Groups were compared using one-way ANOVA.

RESULTS

The SMA flow velocity was not altered during the initial stage of NEC development, but become significantly reduced at P8 when the intestinal disease was more advanced. These changes occurred concomitantly with an increase in heart rate.

CONCLUSIONS

NEC is associated with intestinal hypo-perfusion at the periphery and flow in the SMA is reduced during the later stages of disease indicating the presence of intestinal epithelium damage. This study contributes to understanding NEC pathophysiology and illustrates the value of Doppler U/S in monitoring disease progression.

[Clinical guidelines for the diagnosis and treatment of neonatal necrotizing enterocolitis (2020)]

Necrotizing enterocolitis (NEC) is a devastating gastrointestinal disease of neonates, especially of preterm infants, with high morbidity and mortality. The surviving infants may have digestive tract and neurological sequelae. Therefore, the prevention and treatment of NEC are of great significance in improving survival rate and survival quality of neonates. To provide evidence-based recommendations for management of NEC, the guidelines were developed based on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) and the current domestic and overseas studies.

Implementation of bowel ultrasound practice for the diagnosis and management of necrotising enterocolitis

Necrotising enterocolitis (NEC) is a serious inflammatory bowel disease of prematurity with potentially devastating complications and remains a leading cause of morbidity and mortality among premature infants. In recent years, there has been accumulating data regarding benefits of using bowel ultrasound (BUS) in the diagnosis and management of NEC. Despite this, adoption of robust BUS programmes into clinical practice has been slow. As BUS is a relatively new technique, many barriers to implementation exist, namely lack of education and training for sonographers and radiologists, low case volume and unfamiliarity by clinicians regarding how to use the information provided. The aim of this manuscript is to provide a framework and a roadmap for units to implement BUS in day-to-day practice for NEC diagnosis and management.

Efficacy of abdominal ultrasound inspection in the diagnosis and prognosis of neonatal necrotizing enterocolitis

OBJECTIVE

This study aimed to identify the most useful ultrasound (US) features associated with definite neonatal necrotizing enterocolitis (NEC) and their prognostic values, particularly the calculated markers combined with important features.

METHODS

A total of 213 suspected NEC cases were collected from the neonatal department of our hospital from January 2015 to August 2017. Each infant received both X-ray and US examinations.

RESULTS

No differences were found in sex composition and delivery modes between groups. NEC-positive neonates had poorer prognosis compared to negative ones. The NEC group showed a higher frequency of abnormal signals. US showed higher NEC-related frequencies in different parameters. A variable (named predictor in US [PUS]) with five features was constructed. For NEC diagnosis, this variable provided a much higher area under the curve Q2 (AUC) (0.965) than other parameters. In this model, PUS had a cutoff value of 0.376 with a 0.900 sensitivity and 0.922 specificity. In prognosis, the closest factors were selected to draw a receiver operating characteristic curve, as well as a novel calculated variable US prognostic (USPro) marker. USPro had a much higher AUC (0.86) than other single features and showed a cutoff value of 0.18145, with 0.75 sensitivity and 0.84 specificity. This variable had a weaker power in prognosis when compared with PUS in diagnosis.

CONCLUSIONS

The application of abdominal color Doppler US can provide high accuracy and sensitivity in NEC diagnosis and also contribute to its prognosis, without induction of radiation. Suspected neonates should be examined using this technique as early as possible.

New Strategies for Necrotizing Enterocolitis Diagnosis and Prevention in Newborns

Necrotizing enterocolitis is one of the most frequent and severe gastrointestinal diseases that affect preterm newborns in Neonatal Intensive Care Units. It was firstly described in 1960s, but this clinical entity was not widely recognized until the advent of modern neonatal intensive care. The disease is characterized by submucosal edema, infiltration of intestinal wall by immune cells, specifically neutrophils and, in severe forms, wall necrosis that leads to intestinal perforation. Its incidence is inversely associated to birth weight and gestational age. Necrotizing enterocolitis has been responsible for high rates of morbidity and mortality (15-30%), despite improvements made in neonatal care in the last decades. The challenge is to optimize strategies for early diagnosis, define the best medical and surgical treatments and standardize preventive measures. Several biomarkers have been proposed for the early prediction of necrotizing enterocolitis onset in preterm newborns and can be useful not only for diagnostic purposes but also for prediction of disease progression and severity. The purpose of this paper is to illustrate the most recent evidence regarding the diagnosis and prevention of necrotizing enterocolitis. This manuscript contributes to clinical decision-making in preterm neonates at high risk of developing necrotizing enterocolitis.

Predictive Indicators for Necrotizing Enterocolitis With the Presence of Portal Venous Gas and Outcomes of Surgical Interventions

Objectives: Portal venous gas (PVG) was an important clinical sign in stage II or III necrotizing enterocolitis (NEC) in preterm neonates. Not a proper predictive indicator was found to predict the diseases (NEC with the presence of PVG) up to now. There is a need to put forward predictive indicators and compare the predictive effects among them. Methods: We conducted a retrospective study of preterm neonates with NEC-PVG (n = 61) or NEC-non PVG (n = 62) from 2014 to 2021. Predictive indicators were put forward and determined by receiver operating characteristic curve analysis. An analysis of the surgical interventions and their outcomes was performed. Results: The incidence rate of NEC among preterm neonates was 4.99%; surgical and conservative interventions accounted for 20.47 and 75.07%, and the mortality rate was 0.03%. The composition ratio of shock in the NEC-PVG group increased 13.2% (P = 0.029). C-reactive protein, fibrinogen degradation product, and blood glucose had better predictive effects in the predictive indicators (P < 0.05). Intestinal necrosis and subependymal hemorrhage in the outcomes of surgical interventions had a strong relationship with the presence of PVG in NEC II/III (P < 0.05). Conclusion: Early and reasonable use of antibiotics, improvement of coagulation function, rectification of acidosis, and decreased blood glucose could cut down the occurrence of the disease (NEC with the presence of PVG). Except for subependymal hemorrhage and intestinal necrosis, NEC with the presence of PVG did not increase the occurrence of other outcomes after surgery.

Imaging of the Intestinal Microcirculation during Acute and Chronic Inflammation

Because of its unique microvascular anatomy, the intestine is particularly vulnerable to microcirculatory disturbances. During inflammation, pathological changes in blood flow, vessel integrity and capillary density result in impaired tissue oxygenation. In severe cases, these changes can progress to multiorgan failure and possibly death. Microcirculation may be evaluated in superficial tissues in patients using video microscopy devices, but these techniques do not allow the assessment of intestinal microcirculation. The gold standard for the experimental evaluation of intestinal microcirculation is intravital microscopy, a technique that allows for the in vivo examination of many pathophysiological processes including leukocyte-endothelial interactions and capillary blood flow. This review provides an overview of changes in the intestinal microcirculation in various acute and chronic inflammatory conditions. Acute conditions discussed include local infections, severe acute pancreatitis, necrotizing enterocolitis and sepsis. Inflammatory bowel disease and irritable bowel syndrome are included as examples of chronic conditions of the intestine.

Defining necrotizing enterocolitis: current difficulties and future opportunities

Necrotizing enterocolitis (NEC) is a leading cause of morbidity and mortality in hospitalized infants. First classified through Bell staging in 1978, a number of additional definitions of NEC have been proposed in the subsequent decades. In this review, we summarize eight current definitions of NEC, and explore similarities and differences in clinical signs and radiographic features included within these definitions, as well as their limitations. We highlight the importance of a global consensus on defining NEC to improve NEC research and outcomes, incorporating input from participants at an international NEC conference. We also highlight the important role of patient-families in helping to redefine NEC.

[Prevention, diagnosis and treatment of necrotising enterocolitis in newborns less than 32 weeks at birth in Spain]

OBJECTIVES

To describe preventive, diagnostic and therapeutic strategies regarding necrotising enterocolitis in Spain and to identify the strengths, areas of further improvement, and future research lines.

METHODS

Two questionnaires on the management of preterm infants less than 32 weeks, at risk of, or with diagnosed necrotising enterocolitis, were distributed among selected representatives of the surgeons and neonatologists of the Spanish Neonatal Network (SEN1500) participant hospitals with a Paediatric Surgery Department.

RESULTS

Percentage of response was 77.1% of contacted surgeons and 88.6% of neonatologists. There is a written protocol on the diagnosis and medical management of necrotising enterocolitis in 52% of the hospitals, and as regards surgical treatment in 33%. There is wide access to donor bank milk and to staff dedicated to breastfeeding promotion (87%). On the contrary, only 52% of the centres perform delayed cord clamping, and probiotics are used in just 23%. The use of abdominal ultrasound is increasing. There are no large differences as regards duration of antibiotic use and bowel rest, whereas there was as regards antibiotic selection, surgical indication, and type of intervention.

CONCLUSIONS

As regards prevention, delayed cord clamping and extended access to donor milk are two possible aspects of further improvement. The observed discrepancies noted in diagnostic and therapeutic aspects are common in precisely the areas where evidence in the literature is weakest.

Portal venous gas by ultrasound in advance of impending necrotizing enterocolitis of a very low birth weight infant

Necrotizing enterocolitis (NEC) is a serious complication of premature infants, portal venous gas (PVG) under X-ray, and ultrasound is a typical manifestation of this disease. We report a case of a very low birth weight (VLBW) infant with PVG unexpectedly detected by ultrasound before the onset of NEC. After positive ultrasound result, clinical manifestations, X-ray, and lab tests confirmed the diagnosis of NEC. This is the first report of a similar case, demonstrating the value of ultrasonography in prediction or early diagnosis of NEC, which may change our understanding of the disease and the timing of examination.

Necrotizing Enterocolitis: The Future

Progress in our understanding of the pathophysiology, prevention and treatment of necrotizing enterocolitis (NEC) has been hampered for many reasons. Included among these is the fact that what we are calling "NEC" is likely to represent different disease processes, which need to be delineated before evaluating individual pathogenic mechanisms and attempting to develop predictive and diagnostic biomarkers. Treatment is also likely to be hampered because not all of the different entities called "NEC" will respond to the same regimen. In this review, some of these entities will be discussed in more detail, with suggestions for refining our approach toward improving methods for their diagnosis, prevention and treatment.

Biomarker Discovery and Utility in Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a devastating disease of prematurity, with no current method for early diagnosis. Diagnosis is particularly challenging, frequently occurring after the disease has progressed to the point of significant and often irreversible intestinal damage. Biomarker research has tremendous potential to advance clinical management of NEC and our understanding of its pathogenesis. This review discusses the need for novel biomarkers in NEC management, evaluates studies investigating such biomarkers, and explains the difficulties associated with translating biomarker discovery into clinical use.

Recent advances in understanding necrotizing enterocolitis

Necrotizing enterocolitis is a devastating intestinal disease affecting preterm infants. In spite of ongoing research and advancement in neonatal care, mortality remains high, especially in infants with advanced disease. The mechanism of disease development, the progression of intestinal injury, and management remain areas of ongoing research and controversy. In this review, we examine our current understanding of the disease, its epidemiology, the risk factors associated with the development of the disease, and its pathophysiology. We also describe current management and new emerging research highlighting potential future directions.

Intestinal microcirculation and necrotizing enterocolitis: The vascular endothelial growth factor system

Necrotizing enterocolitis (NEC), a leading cause of morbidity and mortality in preterm neonates, is a devastating disease characterized by intestinal tissue inflammation and necrosis. NEC pathogenesis is multifactorial but remains unclear. Translocation of bacteria and/or bacterial products across a weak intestinal barrier in the setting of impaired mucosal immunity leads to an exaggerated inflammatory response and secondary mucosal epithelial injury. In addition to prematurity, other risk factors for NEC include congenital heart disease, maternal pre-eclampsia with placental vascular insufficiency, severe anemia and blood transfusion - all conditions that predispose the intestine to ischemia. We recently found that maldevelopment of the intestinal microvasculature plays an important role in NEC pathogenesis. Here we review the evidence supporting a role for defective development of the intestinal mucosal microvasculature and perturbations of intestinal blood flow in NEC, emphasizing the importance of vascular endothelial growth factor (VEGF) and the VEGF receptor-2 signaling pathway.