Ultrasonographic assessment of mediastinal shift angle (MSA) in isolated left congenital diaphragmatic hernia for the prediction of postnatal survival

Prenatal diagnosis and risk stratification of congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a rare heterogenous disorder with varying degrees of severity. Infant survival rates in high-income countries are approaching 80% in isolated CDH; however, over 50% will have long-term morbidities. Advanced antenatal imaging, including ultrasound and magnetic resonance imaging, has made it possible to prognosticate severity of CDH and to stratify risk when counseling expectant parents. Risk stratification can also better prepare healthcare teams to enable optimal neonatal management, and provide options for fetal intervention or, where legally permitted, pregnancy termination. Factors that may affect the immediate and long-term prognosis for CDH include prenatal diagnosis, gestational age at detection and delivery, side of the defect, presence of additional structural or genetic abnormalities, defect size, estimation of fetal lung volume, the extent of visceral herniation, and the delivery center's experience in caring for neonates with CDH. Optimizing the outcome for families and infants begins with an early prenatal diagnosis followed by referral to a diverse and inclusive multidisciplinary center with CDH expertise. Prediction of disease severity is supported by accurate fetal imaging and comprehensive genetic testing, and allows the care team to provide realistic outcome expectations during the counseling of expectant parents of all racial and ethnic backgrounds.

Mediastinal Shift Index: A Novel Postnatal Measurement of Mediastinal Movement that Predicts Survival in Neonates With Congenital Diaphragmatic Hernia on Extracorporeal Membrane Oxygenation

PURPOSE

Mediastinal position varies in neonates with congenital diaphragmatic hernia (CDH), reflecting contralateral shift due to mass effect. We aimed to create and validate a postnatal measurement of mediastinal positioning using chest radiographs in neonates with CDH who require extracorporeal membrane oxygenation.

METHODS

Chart review identified neonates with CDH who required veno-arterial extracorporeal membrane oxygenation between 2017 and 2022. Mediastinal shift index (MSI) is the ratio of the distance between the venous cannula tip and the contralateral chest wall divided by the total width of the contralateral hemithorax. Three raters completed MSI measurements at designated timepoints: after cannulation, post- CDH repair, and immediately before decannulation. Intraclass correlation coefficients (ICC) assessed inter-rater agreement. Initial MSI and observed/expected lung head ratio (O/E LHR) were correlated and compared between survivors and non-survivors. Receiver operative characteristic (ROC) curve analysis evaluated the ability of MSI and O/E LHR to predict survival.

RESULTS

38 neonates were included. MSI demonstrated excellent agreement (ICC>0.98) amongst raters. Initial MSI and O/E LHR had a moderate positive correlation (Spearman correlation = 0.47, p = 0.014). Initial MSI differed significantly between survivors and non-survivors (0.52 vs. 0.33, p = 0.035) as did O/E LHR (0.36 vs. 0.26, p = 0.036). ROC analysis revealed initial MSI >0.35 was predictive of survival with 73% sensitivity and 70% specificity.

CONCLUSION

Mediastinal shift index is reliable and predicted survival with a higher specificity than O/E LHR. Future studies will elucidate the role of trending MSI over a patient's course to inform interventions to optimize mediastinal position.

LEVEL OF EVIDENCE: 3

Ultrasonographic measurement of mediastinal shift angle for the prediction of postnatal survival in fetuses with isolated left congenital diaphragmatic hernia

OBJECTIVE

The main objective of the study was to determine if ultrasonographic measurement of mediastinal shift angle (MSA) can predict postnatal survival in fetuses with isolated left congenital diaphragmatic hernia (CDH). This relatively new technique may be used to enhance antenatal prediction of survival in fetuses with CDH.

METHODS

A retrospective cross-sectional study was conducted at the Philippine Children's Medical Center involving 16 cases with prenatally diagnosed isolated left CDH and 60 controls with normal fetuses. The cases with prenatally diagnosed isolated left CDH were allocated into two groups: Group A (survivors) and group B (non-survivors). For all fetuses (study and control groups), MSA was determined independently by two operators. The diagnostic capacity of MSA was assessed using the receiver operating characteristic curve.

RESULTS

The mean MSA for the control group was 17.18°. Among CDH cases, the mean MSA was 33.04° and 37.57° for survivors and non-survivors, respectively. Results showed that MSA significantly predicted the probability of neonatal survival status (OR = 0.46, P = 0.021). The best cutoff score of MSA based on the receiver operating characteristic curve was 33.80° with 87.50% sensitivity and specificity.

CONCLUSION

MSA has the potential to enhance antenatal prediction of survival in fetuses with CDH and may serve as a guide in prenatal counseling and evaluation of the need for in-utero treatment or postnatal procedures.

Assessment of mediastinal shift angles in congenital pulmonary airway malformation: a new fetal magnetic resonance imaging indicator of congenital lung disease

BACKGROUND

The mediastinal shift angle is a new fetal magnetic resonance imaging (MRI) index that is reportedly correlated with postnatal survival in fetuses with congenital diaphragmatic hernia. However, its correlation in patients with congenital pulmonary airway malformation (CPAM) has not been assessed.

OBJECTIVE

This study aimed to establish a normal range for the right/left mediastinal shift angles, to evaluate the mediastinal shift angle in fetuses with CPAM, to compare the mediastinal shift angle with the CPAM volume ratio, and to evaluate the predictive value of the mediastinal shift angle measurements.

MATERIALS AND METHODS

To establish the normal range, we measured the mediastinal shift angle bilaterally in 124 fetuses without any lung abnormality (the control group). Subsequently, the mediastinal shift angle was measured in 32 fetuses pathologically diagnosed with CPAM. Moreover, the mediastinal shift angle and CPAM volume ratio were compared using fetal MRI.

RESULTS

The mean values for the right/left mediastinal shift angles were 18.6°/26.3° and 39.2°/35.9° for control fetuses and fetuses with CPAM, respectively. The mediastinal shift angle and the CPAM volume ratio showed a positive statistical correlation. The area under the curve demonstrated high discriminatory accuracy for the mediastinal shift angle (0.76).

CONCLUSION

The mediastinal shift angle has potential to replace the CPAM volume ratio for evaluating the severity of CPAM in fetal MRI.

Mediastinal shift angle (MSA) measurement with MRI: a simple and effective tool for prenatal risk stratification in fetuses with congenital diaphragmatic hernia

OBJECTIVES

To investigate the predictive value of mediastinal shift angle (MSA) in congenital diaphragmatic hernia (CDH).

METHODS

A retrospective analysis was performed on 87 fetuses with prenatally diagnosed left-sided CDH (LCDH) and 88 controls. MSA was measured on magnetic resonance imaging (MRI). Lung area to head circumference ratio (LHR), ratio of the observed/expected LHR (O/E LHR), total fetal lung volume (TFLV), and observed/expected total fetal lung volume (O/E TFLV) were also measured. Correlation of MSA with pulmonary hypertension (PH), extracorporeal membrane oxygenation (ECMO) use, duration of hospitalization and survival in neonates with CDH was analyzed. Performance of MSA in prediction of postnatal outcomes was compared with LHR, O/E LHR, TFLV, and O/E TFLV.

RESULTS

There were significant differences in MSA values not only between the CDH group and the control group but also in CDH patients with different survival outcomes. MSA was inversely correlated with O/E LHR, O/E TFLV, and TFLV. MSA, LHR, O/E LHR, TFLV, and O/E TFLV could all be used to predict survival of CDH patients. In addition, the receiver operating characteristic (ROC) curve showed that the test performance of MSA was similar to that of TFLV, O/E TFLV, and O/E LHR, but superior to that of LHR. MSA was also correlated with PH, need for ECMO support, and duration of hospitalization.

CONCLUSION

MRI measurement of MSA can provide various prognostic information for prenatally diagnosed LCDH, in addition to postnatal survival. The test performance of MSA is similar to TFLV, O/E TFLV, and O/E LHR.

KEY POINTS

• Mediastinal shift angle (MSA) can be measured quickly and reproducibly on MRI images. • MSA could provide more prognostic information other than postnatal survival for LCDH with good test performance. • MSA should be incorporated into prenatal risk stratification for LCDH to improve planning of postnatal management.

The role of magnetic resonance imaging in the diagnosis and prognostic evaluation of fetuses with congenital diaphragmatic hernia

In recent years, magnetic resonance imaging (MRI) has largely increased our knowledge and predictive accuracy of congenital diaphragmatic hernia (CDH) in the fetus. Thanks to its technical advantages, better anatomical definition, and superiority in fetal lung volume estimation, fetal MRI has been demonstrated to be superior to 2D and 3D ultrasound alone in CDH diagnosis and outcome prediction. This is of crucial importance for prenatal counseling, risk stratification, and decision-making approach. Furthermore, several quantitative and qualitative parameters can be evaluated simultaneously, which have been associated with survival, postnatal course severity, and long-term morbidity.

CONCLUSION

Fetal MRI will further strengthen its role in the near future, but it is necessary to reach a consensus on indications, methodology, and data interpretation. In addition, it is required data integration from different imaging modalities and clinical courses, especially for predicting postnatal pulmonary hypertension. This would lead to a comprehensive prognostic assessment.

WHAT IS KNOWN

• MRI plays a key role in evaluating the fetal lung in patients with CDH. • Prognostic assessment of CDH is challenging, and advanced imaging is crucial for a complete prenatal assessment and counseling.

WHAT IS NEW

• Fetal MRI has strengthened its role over ultrasound due to its technical advantages, better anatomical definition, superior fetal lung volume estimation, and outcome prediction. • Imaging and clinical data integration is the most desirable strategy and may provide new MRI applications and future research opportunities.

Fetal MRI mediastinal shift angle and respiratory and cardiovascular pharmacological support in newborns with congenital diaphragmatic hernia

In newborns with congenital diaphragmatic hernia (CDH), the mediastinal shift caused by the herniated organs negatively affects lung development. Assessment of the fetal magnetic resonance imaging (MRI) mediastinal shift angle (MSA) was shown to have an inverse correlation with the total fetal lung volume (TFLV), being associated with neonatal survival. However, a possible association with postnatal morbidity has never been investigated. We hypothesize that the degree of the mediastinal shift could be associated with higher respiratory and cardiocirculatory impairment, requiring intensive treatments and extended hospitalization in survivors. We retrospectively consider a cohort of isolated, left-sided CDH, for whom we calculated the MSA and the observed/expected (O/E) TFLV at fetal MRI. We performed a data collection regarding inotropic or vasoactive support, treatment with pulmonary vasodilators, mechanical ventilation, and length of stay. General linear models were performed. The MSA and O/E TFLV were inversely correlated (Pearson's coefficient - 0.65, p < 0.001), and deceased patients showed higher MSA values then survivors (p = 0.011). Among survivors, an increase in MSA was associated with longer pharmacological treatments (dobutamine: p = 0.016; dopamine: p = 0.049; hydrocortisone: p = 0.003; nitric oxide: p = 0.002; sildenafil: p = 0.039; milrinone: p = 0.039; oxygen: p = 0.066), and mechanical ventilation (p = 0.005), with an increasing trend in the length of hospitalization (p = 0.089).Conclusion: The MSA indirectly reflects lung hypoplasia and is associated with a higher neonatal intensity of cares. However, further studies are needed to consolidate the results.Trial registration: The study is an exploratory post hoc analysis of the registered NeoAPACHE protocol at ClinicalTrials.gov with the identifier NCT04396028. What is Known: • In congenital diaphragmatic hernia, the lung size, liver position, and defect side are the most common prenatal prognostic parameters used in clinical practice for morbidity and mortality prediction. • Lung hypoplasia, strictly associated with lung size, is estimated by observed/expected lung to head ratio and observed/expected total fetal lung volume with prenatal ultrasound and fetal magnetic resonance imaging, respectively. What is New: • A new, faster, more straightforward, and less operator-dependent tool to assess CDH severity could be the mediastinal shift angle calculation with fetal magnetic resonance imaging. • Postnatal clinical severity, considered as a postnatal cardiovascular and respiratory impairment that indirectly reflects lung hypoplasia, is associated with an increased mediastinal shift angle calculation.

Unsolved problems in CDH follow-up

In patients affected by CDH, survival beyond the neonatal period continues to increase thanks to technological and pharmacological improvements. Conversely, patients, families and caregivers are more and more frequently facing "new" complex late comorbidities, including chronic pulmonary and cardiac dysfunctions, neurodevelopmental challenges, and specific nutritional requirements, that often require ongoing long-term medical or surgical care. Therefore, late morbidity is now a key focus in clinical care of CDH. The aims of this paper are to stress some of the most important "unsolved problems" for CDH patients at long-term follow-up.

A maChine and deep Learning Approach to predict pulmoNary hyperteNsIon in newbornS with congenital diaphragmatic Hernia (CLANNISH): Protocol for a retrospective study

INTRODUCTION

Outcome predictions of patients with congenital diaphragmatic hernia (CDH) still have some limitations in the prenatal estimate of postnatal pulmonary hypertension (PH). We propose applying Machine Learning (ML), and Deep Learning (DL) approaches to fetuses and newborns with CDH to develop forecasting models in prenatal epoch, based on the integrated analysis of clinical data, to provide neonatal PH as the first outcome and, possibly: favorable response to fetal endoscopic tracheal occlusion (FETO), need for Extracorporeal Membrane Oxygenation (ECMO), survival to ECMO, and death. Moreover, we plan to produce a (semi)automatic fetus lung segmentation system in Magnetic Resonance Imaging (MRI), which will be useful during project implementation but will also be an important tool itself to standardize lung volume measures for CDH fetuses.

METHODS AND ANALYTICS

Patients with isolated CDH from singleton pregnancies will be enrolled, whose prenatal checks were performed at the Fetal Surgery Unit of the Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico (Milan, Italy) from the 30th week of gestation. A retrospective data collection of clinical and radiological variables from newborns' and mothers' clinical records will be performed for eligible patients born between 01/01/2012 and 31/12/2020. The native sequences from fetal magnetic resonance imaging (MRI) will be collected. Data from different sources will be integrated and analyzed using ML and DL, and forecasting algorithms will be developed for each outcome. Methods of data augmentation and dimensionality reduction (feature selection and extraction) will be employed to increase sample size and avoid overfitting. A software system for automatic fetal lung volume segmentation in MRI based on the DL 3D U-NET approach will also be developed.

ETHICS AND DISSEMINATION

This retrospective study received approval from the local ethics committee (Milan Area 2, Italy). The development of predictive models in CDH outcomes will provide a key contribution in disease prediction, early targeted interventions, and personalized management, with an overall improvement in care quality, resource allocation, healthcare, and family savings. Our findings will be validated in a future prospective multicenter cohort study.

REGISTRATION

The study was registered at ClinicalTrials.gov with the identifier NCT04609163.

Comparison of mediastinal shift angles obtained with ultrasound and magnetic resonance imaging in fetuses with isolated left sided congenital diaphragmatic hernia

Objectives: To compare ultrasound (US) and magnetic resonance imaging (MRI) in the assessment of mediastinal shift angles (MSAs) in fetuses affected by isolated left congenital diaphragmatic hernia (CDH). The use of MRI-MSA and US-MSA as prognostic factor for postnatal survival in fetal left CDH was also explored.Methods: This was an observational study of 29 fetuses with prenatally diagnosed isolated left CDH, assessed with both US and MRI examinations between January 2015 and December 2018. The US-MSA measurements performed within 2 weeks from the MRI assessment were considered for the analysis. The primary outcome was the postnatal survival rate.Results: No significant difference between US and MRI MSAs was detected (p = .419). Among the 29 cases, there were 21 alive infants, for an overall postnatal survival rate of 72.41%. After stratifying for postnatal survival, the best cutoffs with the highest discriminatory power in terms of sensibility and specificity were 42.1° for the US-MSA and 39.1° for the MRI-MSA. The performance of MRI-MSA in predicting postnatal survival was close to that of US-MSA in terms of sensitivity (62.5 versus 50.0%), specificity (80.9 versus 90.5%), positive predictive value (55.6 versus 66.7%), negative predictive value (85.0 versus 82.6%) and accuracy (75.9 versus 79.3%). There was no statistically significant difference between the two modalities (p > .05 for all).Conclusions: MRI and US can be interchangeably used for the assessment of MSA in prenatally diagnosed isolated left CDH. Moreover, MSA measured by both US and MRI was confirmed to be correlated with perinatal outcome in terms of survival.

Fetal MRI assessment of mediastinal shift angle in isolated left congenital diaphragmatic hernia: A new postnatal survival predictive tool?

OBJECTIVE

To quantify the mediastinal shift angle (MSA) in fetuses with isolated left congenital diaphragmatic hernia (CDH) by magnetic resonance imaging and evaluate survival.

METHOD

Fetuses from singleton pregnancies with isolated left CDH were matched for gestational age with controls without thoracic malformations. For all fetuses the MSA was determined by two operators and inter-operator variability and differences between cases and controls were investigated. For all cases total fetal lung volume (TFLV) was calculated and the correlation between MSA and TFLV was assessed, and its predictive value towards survival was determined.

RESULTS

Thirty-four fetuses were included as cases and 42 as controls. The mean gestational age for assessment of CDH fetuses was 32 weeks (range 27-38). Twenty-four fetuses survived until discharge and 10 did not. There was an excellent inter-operator reliability for measuring the MSA and a significant difference between MSA in cases and controls. There was an inverse correlation between MSA values and survival, a correlation between TFLV and survival and an inverse correlation between MSA and TFLV. The area under the ROC curve for MSA in predicting survival was 0.931 (95% CI 0.851-1.000).

CONCLUSION

The MSA measured late in gestation correlates with postnatal survival in patients with isolated left CDH.