Value of abdominal ultrasonography in predicting intestinal resection for premature infants with necrotizing enterocolitis

Surgery for intestinal injuries in very preterm infants: a Norwegian population-based study with a new approach to disease classification

OBJECTIVE

To evaluate population-based data on very preterm infants (<32 weeks gestation) operated for intestinal injuries, focusing on necrotising enterocolitis (NEC) and focal intestinal perforation (FIP).

DESIGN

Nationwide, population-based registry cohort study.

SETTING

All 21 neonatal units in Norway.

PARTICIPANTS

All very preterm infants born from 2014 through 2021 and admitted to a neonatal unit.

MAIN OUTCOME MEASURES

Incidence of surgery for subgroups of intestinal injuries, medical record data on laboratory-radiology results, anatomical location of affected bowel, length of resections, number of re-operations, morbidities of prematurity and/or death before discharge.

RESULTS

Abdominal surgery was performed in 124/4009 (3.1%) very preterm infants and in 97/1300 (7.5%) extremely preterm infants <28 weeks. The main intestinal injuries operated were NEC (85/124; 69%), FIP (26/124; 21%) and 'other abdominal pathologies' (13/124; 10%). NEC cases were divided in (i) acute NEC, extensive disease (n=18), (ii) non-extensive disease (n=53) and (iii) NEC with surgery >3 days after disease onset (n=14). High lactate values immediately prior to surgery was predominantly seen in acute NEC-extensive disease and associated with high mortality. Other laboratory values could not discriminate between acute NEC and FIP. Timing of surgery for acute NEC and FIP overlapped. Radiological absence of portal venous gas was typical in FIP. Most infants (62.5%) underwent a stoma formation at initial surgery. The overall survival rate was 67% for NEC and 77% for FIP.

CONCLUSION

NEC cases have different presentation and prognosis depending on the extent of bowel affected. Revised classifications for intestinal injuries in preterm infants may improve prognostication and better guide therapy.

Surgical prediction of neonatal necrotizing enterocolitis based on radiomics and clinical information

PURPOSE

To assess the predictive value of radiomics for surgical decision-making in neonatal necrotizing enterocolitis (NEC) when abdominal radiographs (ARs) do not suggest an absolute surgical indication for free pneumoperitoneum.

METHODS

In this retrospective study, we finally included 171 newborns with NEC and obtained their ARs and clinical data. The dataset was randomly divided into a training set (70%) and a test set (30%). We developed machine learning models for predicting surgical treatment using clinical features and radiomic features, respectively, and combined these features to build joint models. We assessed predictive performance of the different models by receiver operating characteristic curve (ROC) analysis and compared area under curve (AUC) using the Delong test. Decision curve analysis (DCA) was used to assess the potential clinical benefit of the models to patients.

RESULTS

There was no significant difference in AUC between the clinical model and the four radiomic models (P > 0.05). The XGBoost joint model had better predictive efficacy and stability (AUC, training set: 0.988, test set: 0.959). Its AUC in the test set was significantly higher than that of the clinical model (P < 0.05). DCA showed that the XGBoost joint model achieved higher net clinical benefit compared to the clinical model in the threshold probability range (0.2-0.6).

CONCLUSION

Radiomic features based on AR are objective and reproducible. The joint model combining radiomic features and clinical signs has good surgical predictive efficacy and may be an important method to help primary neonatal surgeons assess the surgical risk of NEC neonates.

Values of serum intestinal fatty acid-binding protein, fecal calprotectin, and fecal human β-defensin 2 for predicting necrotizing enterocolitis

BACKGROUND

This study aimed to assess the diagnostic potential of serum intestinal fatty acid-binding protein (I-FABP), fecal calprotectin (FC), and fecal human β-defensin 2 (hBD2) in predicting necrotizing enterocolitis (NEC) in preterm infants.

METHODS

A prospective cohort of neonates with a gestational age < 32 weeks, suspected of NEC, was enrolled between June 2021 and December 2022. Serum I-FABP, FC, and fecal hBD2 levels were measured upon NEC suspicion, and diagnosis was confirmed through radiological examination or surgical intervention. Diagnostic precision of serum I-FABP, FC, and fecal hBD2 was assessed using a logistic regression model with multiple variables.

RESULTS

The study included 70 neonates (45 males, 25 females), with 30 developing NEC (40% Stage III, n = 12; 60% Stage II, n = 18) and 40 in the control group. NEC patients exhibited significantly higher serum I-FABP and FC levels (4.76 ng/mL and 521.56 µg/g feces, respectively) than those with other diagnoses (1.38 ng/mL and 213.34 µg/g feces, respectively; p ˂ 0.05 for both biomarkers). Stage II NEC neonates showed elevated fecal hBD2 levels (376.44 ng/g feces) than Stage III NEC neonates and controls (336.87 ng/g and 339.86 ng/g feces, respectively; p ˂ 0.05). No such increase was observed in infants progressing to Stage III NEC. Using a serum I-FABP threshold of > 2.54 ng/mL yielded 76.7% sensitivity, 87.5% specificity, 82.1% positive predictive value (PPV), and 83.3% negative predictive value (NPV). For FC (cutoff > 428.99 µg/g feces), corresponding values were 76.7% sensitivity, 67.5% specificity, 63.9% PPV, and 79.4% NPV.

CONCLUSION

Serum I-FABP and FC levels are valuable for early NEC detection and provide insights into disease severity. Low fecal hBD2 levels suggest an inadequate response to luminal bacteria, potentially rendering these infants more susceptible to NEC development or exacerbation.

[ROC curves: general characteristics and their usefulness in clinical practice]

The use of diagnostic tests to determine the presence or absence of a disease is essential in clinical practice. The results of a diagnostic test may correspond to numerical estimates that require quantitative reference parameters to be transferred to a dichotomous interpretation as normal or abnormal and thus implement actions for the care of a condition or disease. For example, in the diagnosis of anemia it is necessary to define a cut-off point for the hemoglobin variable and create two categories that distinguish the presence or absence of anemia. The method used for this process is the preparation of diagnostic performance curves, better known by their acronym in English as ROC (Receiver Operating Characteristic). The ROC curve is also useful as a prognostic marker, since it allows defining the cut-off point of a quantitative variable that is associated with greater mortality or risk of complications. They have been used in different prognostic markers in COVID-19, such as the neutrophil/lymphocyte ratio and D-dimer, in which cut-off points associated with mortality and/or risk of mechanical ventilation were identified. The ROC curve is used to evaluate the diagnostic performance of a test in isolation, but it can also be used to compare the performance of two or more diagnostic tests and define which one is more accurate. This article describes the basic concepts for the use and interpretation of the ROC curve, the interpretation of an area under the curve (AUC) and the comparison of two or more diagnostic tests.

A Nomogram for Predicting Surgical Timing in Neonates with Necrotizing Enterocolitis

OBJECTIVE

To explore the surgical risk variables in patients with necrotizing enterocolitis (NEC) and develop a nomogram model for predicting the surgical intervention timing of NEC.

METHODS

Infants diagnosed with NEC were enrolled in our study. We gathered information from clinical data, laboratory examinations, and radiological manifestations. Using LASSO (least absolute shrinkage and selection operator) regression analysis and multivariate logistic regression analysis, a clinical prediction model based on the logistic nomogram was developed. The performance of the nomogram model was evaluated using the receiver operating characteristic (ROC) curve, calibration curves, and decision curve analysis (DCA).

RESULTS

A surgical intervention risk nomogram based on hypothermia, absent bowel sounds, WBC > 20 × 10⁹/L or < 5 × 10⁹/L, CRP > 50 mg/L, pneumatosis intestinalis, and ascites was practical, had a moderate predictive value (AUC > 0.8), improved calibration, and enhanced clinical benefit.

CONCLUSIONS

This simple and reliable clinical prediction nomogram model can help physicians evaluate children with NEC in a fast and effective manner, enabling the early identification and diagnosis of children at risk for surgery. It offers clinical revolutionary value for the development of medical or surgical treatment plans for children with NEC.

Neonatologist-performed point-of-care abdominal ultrasound: What have we learned so far?

This review describes the sonographic appearances of the neonatal bowel in Necrotising enterocolitis. It compares these findings to those seen in midgut-Volvulus, obstructive intestinal conditions such as milk-curd obstruction, and slow gut motility in preterm infants on continuous positive airway pressure (CPAP)-CPAP belly syndrome. Point-of-care bowel ultrasound is also helpful in ruling out severe and active intestinal conditions, reassuring clinicians when the diagnosis is unclear in a non-specific clinical presentation where NEC cannot be excluded. As NEC is a severe disease, it is often over-diagnosed, mainly due to a lack of reliable biomarkers and clinical presentation similar to sepsis in neonates. Thus, the assessment of the bowel in real-time would allow clinicians to determine the timing of re-initiation of feeds and would also be reassuring based on specific typical bowel characteristics visualised on the ultrasound.