Abnormal Shape and Size of the Cardiac Ventricles Are Associated with a Higher Risk of Neonatal Death in Fetuses with Isolated Left Congenital Diaphragmatic Hernia

INTRODUCTION

The objective of this study was to evaluate the association between fetal cardiac deformation analysis (CDA) and cardiac function with severe adverse perinatal outcomes in fetuses with isolated left congenital diaphragmatic hernia (CDH).

METHODS

CDA in each ventricle (contractility, size, and shape), evaluated by speckle tracking and novel FetalHQ software, and markers of cardiac function (E/A ratios, pulmonary and aortic peak systolic velocities, and sigmoid annular valve diameters), were evaluated in fetuses with isolated left CDH. Two evaluations were performed: at referral (CDA and function) and within 3 weeks of delivery (CDA). Severe adverse neonatal outcomes were considered neonatal death (ND) or survival with CDH-associated pulmonary hypertension (CDH-PH). Differences and associations between CDA, cardiac function, and severe adverse outcomes were estimated.

RESULTS

Fifty fetuses were included, and seventeen (34%) had severe adverse neonatal outcomes (11 ND and 6 survivors with CDH-PH). At first evaluation, the prevalence of a small left ventricle was 34% (17/50) with a higher prevalence among neonates presenting severe adverse outcomes (58.8 [10/17] vs. 21.2% [7/33]; p = 0.01; OR, 5.03 [1.4-19.1; p = 0.01]) and among those presenting with neonatal mortality (8/11 [72.7] vs. 9/39 [23.0%]; p = 0.03; OR, 8.9 [1.9-40.7; p = 0.005]). No differences in cardiac function or strain were noted between fetuses with or without severe adverse outcomes. Within 3 weeks of delivery, the prevalence of small left ventricle was higher (19/34; 55.8%) with a more globular shape (reduced transverse/longitudinal ratio). A globular right ventricle was significantly associated with ND or survival with CDH-PH (OR, 14.2 [1.5-138.3]; p = 0.02).

CONCLUSION

Fetuses with isolated CDH at risk of perinatal death or survival with CDH-PH had a higher prevalence of a small left ventricle and abnormal shape of the right ventricle.

Does Prediction of Neonatal Mortality by the Observed/Expected Lung-To-Head Ratio Change during Pregnancy in Fetuses with Left Congenital Diaphragmatic Hernia?

INTRODUCTION

The aim of this study was to evaluate prediction of neonatal mortality in fetuses with isolated left congenital diaphragmatic hernia (CDH) when the observed/expected lung-to-head ratio (O/E LHR) was estimated at two different gestational time points during pregnancy.

METHODS

Forty-four (44) fetuses with isolated left CDH were included. O/E LHR was estimated at the time of referral (first scan) and before delivery (last scan). The main outcome was neonatal death due to respiratory complications.

RESULTS

There were 10/44 (22.7%) perinatal deaths. The areas under (AU) the ROC curves were: first scan, 0.76, best O/E LHR cut-off 35.5% with 76% sensitivity and 70% specificity; last scan, AU-ROC 0.79, best O/E LHR cut-off 35.2%, with 79.0% sensitivity and 80% specificity. Considering an O/E LHR cut-off ≤35% to define high-risk fetuses at any examination, prediction for perinatal mortality showed: 80% sensitivity, 73.5% specificity, 47.1% positive and 92.6% negative predictive values, and 3.02 (95% CI 1.59-5.73) positive and 0.27 (95% CI 0.08-0.96) negative likelihood ratios. Prediction was similar in the two evaluations as 16/21 (76.2%) of fetuses considered at risk had an O/E LHR ≤35% in the two examinations; in the remaining 5 cases, two were identified only in the first and three only in the last scan.

CONCLUSION

The O/E LHR is a good predictor of perinatal death in fetuses with left isolated CDH. Approximately 80% of fetuses at risk of perinatal death can be identified with an O/E LHR ≤35%, and 90% of them will have similar O/E LHR values at the first and at the last ultrasound examinations prior to delivery. In general, 88.6% of all CDH fetuses have a similar severity classification based on the O/E LHR at the first diagnostic ultrasound or at the ultrasound examination prior to delivery.

Fetal Lung Volume Appears to Predict Respiratory Morbidity in Congenital Diaphragmatic Hernia

Congenital diaphragmatic hernia (CDH) is associated with pulmonary hypoplasia and respiratory morbidity. To assess whether respiratory morbidity during the first 2 years of life in infants with left-sided CDH is associated with fetal lung volume (FLV) evaluated by the observed-to-expected FLV ratio (o/e FLV) on antenatal magnetic resonance imaging (MRI). In this retrospective study, o/e FLV measures were collected. Respiratory morbidity in the first 2 years of life was studied according to two endpoints: treatment with inhaled corticosteroids for >3 consecutive months and hospitalization for any acute respiratory disease. The primary outcome was a favorable progression defined by the absence of either endpoint. Forty-seven patients were included. The median o/e FLV was 39% (interquartile range, 33-49). Sixteen (34%) infants were treated with inhaled corticosteroids and 13 (28%) were hospitalized. The most efficient threshold for a favorable outcome was an o/e FLV ≥ 44% with a sensitivity of 57%, specificity of 79%, negative predictive value of 56%, and positive predictive value of 80%. An o/e FLV ≥ 44% was associated with a favorable outcome in 80% of cases. These data suggest that lung volume measurement on fetal MRI may help to identify children at lower respiratory risk and improve information during pregnancy, patient characterization, decisions about treatment strategy and research, and personalized follow-up.

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.

Cost-effective fetal lung volumetry for assessment of congenital diaphragmatic hernia

OBJECTIVES

(1) To investigate the reproducibility of total fetal lung volume (TFLV) measurements using a free 3D modeling software (3DSlicer); (2) To correlate these measurements with lung-to-head ratio (LHR) or TFLV measured using PACS and; (3) To determine the role of 3DSlicer in predicting perinatal outcomes in cases with congenital diaphragmatic hernia (CDH) who had fetal tracheal occlusion (FETO).

METHODS

Retrospective cohort study between 2012 and 2017 at Texas Children's Hospital (2011-2017), including all patients who underwent FETO for CDH. LHR was measured by ultrasound and TFLV was measured by MRI at the time of referral and 6 weeks after FETO using 3DSlicer and PACS. We evaluated intra- and inter-rater reliability of TFLV measurement using 3DSlicer, infant survival to 1 year, need for ECMO and pulmonary hypertension.

RESULTS

The intra- and inter-rater reliability of TFLV measured with 3DSlicer was excellent before and after FETO (Intra-class correlation coefficient: 0.98-0.99 and 0.94-0.99, respectively). There was a good correlation between TFLV measured with PACS and with 3DSlicer before and after FETO (r = 0.78 and r = 0.99, respectively). Similarly, there was a good correlation between TFLV measurements using PACS or 3DSlicer and LHR after FETO (r = 0.86 and r = 0.88, respectively). Infants who survived to 1 year had a significantly higher TFLV evaluated with 3DSlicer before FETO compared to non-surviving infants (OR = 1.16[1.1-1.3], p = 0.03) as well as a significantly higher TFLV evaluated by 3DSlicer after FETO (OR = 1.2[1-1.4], p = 0.04).

CONCLUSION

Lung volume measurements using free 3DSlicer in infants with severe CDH who underwent FETO are reproducible and reliable, and have comparable predictive capability for survival as those measured using conventional software.

Update on Congenital Diaphragmatic Hernia

Congenital diaphragmatic hernia (CDH) is a rare developmental defect of the diaphragm, characterized by herniation of abdominal contents into the chest that results in varying degrees of pulmonary hypoplasia and pulmonary hypertension (PH). Significant advances in the prenatal diagnosis and identification of prognostic factors have resulted in the continued refinement of the approach to fetal therapies for CDH. Postnatally, protocolized approaches to lung-protective ventilation, nutrition, prevention of infection, and early aggressive management of PH have led to improved outcomes in infants with CDH. Advances in our understanding of the associated left ventricular (LV) hypoplasia and myocardial dysfunction in infants with severe CDH have allowed for the optimization of hemodynamics and management of PH. This article provides a comprehensive review of CDH for the anesthesiologist, focusing on the complex pathophysiology, advances in prenatal diagnosis, fetal interventions, and optimal postnatal management of CDH.

Prediction tools in congenital diaphragmatic hernia

Because congenital diaphragmatic hernia (CDH) is characterized by a spectrum of severity, risk stratification is an essential component of care. In both the prenatal and postnatal periods, accurate prediction of outcomes may inform clinical decision-making, care planning, and resource allocation. This review examines the history and utility of the most well-established risk prediction tools currently available, and provides recommendations for their optimal use in the management of CDH patients.

Calculating Observed-to-Expected Total Fetal Lung Volume in CDH Fetuses in Twin Gestation: Is There a Better Way?

BACKGROUND

Congenital diaphragmatic hernia (CDH) is a potentially lethal birth defect, and identifying prenatal predictors of outcome is important. Observed-to-expected total fetal lung volume (o/e TFLV) has been shown to be a predictor of severity and useful in risk stratification but is variable due to different TFLV formulas.

OBJECTIVES

To calculate o/e TFLV for CDH patients part of a twin gestation using the unaffected sibling as an internal control and comparing these values to those calculated using published formulas for TFLV.

METHODS

Seven twin gestations with one fetus affected by CDH were identified between 2006 and 2017. The lung volume for each twin was calculated using magnetic resonance imaging (MRI), and o/e TFLV was calculated using the unaffected twin's TFLV. This percentage was then compared to the o/e TFLV calculated using published formulas.

RESULTS

Lung volumes in the unaffected twins were within normal ranges at the lower end of the spectrum. No single TFLV formula was found to correlate perfectly. Intraclass correlation coefficient estimate was most consistent for o/e TFLV calculated with the Meyers formula and supported by Bland-Altman plots.

CONCLUSIONS

O/e TFLV measured in CDH/non-CDH twin gestations using the unaffected sibling demonstrated agreement with o/e TFLV calculated using the Meyers formula. We urge the fetal community to standardize the method, use, and interpretation of fetal MRI in the prenatal evaluation of CDH.

Neonatal lung growth in congenital diaphragmatic hernia: evaluation of lung density and mass by pulmonary MRI

BACKGROUND

Outcomes of infants with congenital diaphragmatic hernia (CDH) are primarily dependent on the severity of pulmonary hypoplasia. It is previously unknown whether postnatal lung growth in infants with CDH represents true parenchymal lung growth or merely an expansion in volume of the existing tissue. We hypothesized that lung volume growth in CDH infants will be accompanied by an increase in lung mass and that CDH infants will demonstrate accelerated catch-up growth of the more hypoplastic lung.

METHODS

We used fetal and post-CDH repair MRI of 12 infants to measure lung volume and density, which was used to calculate lung mass.

RESULTS

The average increase in right lung mass was 1.1 ± 1.1 g/week (p = 0.003) and the average increase in left lung mass was 1.8 ± 0.7 g/week (p < 0.001). When the ratio of left-to-right lung mass of the prenatal MRI was compared to post-repair MRI, the ratio significantly increased in all infants with average prenatal and post-repair ratios of 0.30 and 0.73, respectively (p = 0.002).

CONCLUSION

Lung growth in infants with CDH is indeed growth in lung mass (i.e. parenchyma), and the lungs demonstrate catch-up growth (i.e., increased rate of growth in the more hypoplastic ipsilateral lung).

Timing of Prenatal Magnetic Resonance Imaging in the Assessment of Congenital Diaphragmatic Hernia

INTRODUCTION

Fetal magnetic resonance imaging (MRI) has been used to stratify severity of congenital diaphragmatic hernia (CDH) after ultrasound diagnosis. The purpose of this study was to determine if timing of MRI influenced prediction of severity of outcome in CDH.

METHODS

A single institution retrospective review of all CDH referred to our institution from February 2004 to May 2017 was performed. Patients were included if they underwent at least 2 fetal MRIs prior to delivery. Prenatal MRI indices including observed-to-expected total fetal lung volume (o/e TFLV) were evaluated. Indices were categorized by trimester, either 2nd (20-27 weeks gestation) or 3rd trimester (>28 weeks gestation) and further analyzed for outcome predictability. Primary outcomes were survival, extracorporeal membrane oxygenation (ECMO), and pulmonary hypertension (PAH). Student t test and logistic and linear regression were used for data analyses.

RESULTS

Of 256 fetuses evaluated for CDH, 197 were further characterized by MRI with 57 having both an MRI in the 2nd and 3rd trimesters. There was an average of 9.95 weeks (±4.3) between the 1st and 2nd MRI. Second trimester o/e TFLV was the only independent predictor of survival by logistic regression (OR 0.890, p < 0.01). Third trimester MRI derived lung volumes were associated with, and independent predictors of, severity of PAH and need for ECMO. Interval TFLV growth was a strong predictor of PAH postnatally (OR 0.361, p < 0.01). Overall cohort survival was 79%.

CONCLUSION

Accuracy of MRI lung volumes to predict outcomes is dependent on the -gestational age at the time of exam. While MRI lung volumes at either the 2nd or 3rd trimester are predictive of morbidity, 2nd trimester lung volumes strongly correlated with mortality.

Early Postnatal Ventricular Dysfunction Is Associated with Disease Severity in Patients with Congenital Diaphragmatic Hernia

OBJECTIVE

To assess patterns of postnatal ventricular function and their relationship to prenatal and postnatal markers of disease severity in infants with congenital diaphragmatic hernia (CDH).

STUDY DESIGN

In this observational case-control study of cardiac function in infants with CDH in the first 5 days of life, systolic and diastolic function in the right ventricle (RV) and left ventricle (LV) were assessed using speckle tracking echocardiography-derived global strain and tissue Doppler imaging. Correlation between cardiac function and prenatal observed:expected total fetal lung volume (TFLV), oxygenation index (OI), duration of intubation, and hospital length of stay were assessed.

RESULTS

All measures of systolic and diastolic function were significantly reduced in the CDH group (n = 25) compared with controls (n = 20) at <48 hours, and were improved by 72-120 hours. LV global systolic longitudinal strain (GLS) correlated with prenatal TFLV (R² = 0.32; P = .03), OI (R² = 0.35; P < .001), duration of intubation (R² = 0.24; P = .04), and length of stay (R² = 0.4; P = .006). Mean (SD) LV GLS at <48 hours was significantly lower in infants with CDH who did not survive and/or required ECMO compared with those who did not: -11.5 (5.3)% vs -16.9 (5.3)% (P = .02).

CONCLUSIONS

RV and LV function are impaired in the transitional period in infants with CDH. Early LV systolic function correlates with prenatal and postnatal markers of clinical disease severity and may be an important determinant of disease severity and therapeutic target in CDH. These findings support regular assessment of cardiac function in CDH and investigational trials of targeted cardiovascular therapies.

Prenatal Diagnosis of Congenital Diaphragmatic Hernia: Does Laterality Predict Perinatal Outcomes?

OBJECTIVE

The objective of this study was to examine laterality as a predictor of outcomes among fetuses with prenatally diagnosed congenital diaphragmatic hernia (CDH).

METHODS

This is a retrospective cohort study of pregnancies with CDH evaluated at our center from 2008 to 2016 compared cases with right-sided CDH (RCDH) versus left-sided CDH (LCDH). The primary outcome was survival to discharge. Secondary outcomes included ultrasound predictors of poor prognosis (liver herniation, stomach herniation, lung area-to-head circumference ratio [LHR]), concurrent anomalies, hydrops, stillbirth, preterm birth, mode of delivery, small for gestational age, use of extracorporeal membrane oxygenation, and length of stay. Terminations and stillbirths were excluded from analyses of neonatal outcomes.

RESULTS

In this study, 157 (83%) LCDH and 32 (17%) RCDH cases were identified. Survival to discharge was similar (64 vs. 66.4%, p = 0.49) with regard to laterality. RCDH had higher rates of liver herniation (90.6 vs. 72%, p = 0.03), hydrops fetalis (15.6 vs. 1.3%, p < 0.01), and lower LHR (0.87 vs. 0.99, p = 0.04). LCDH had higher rates of stomach herniation (69.4 vs. 12.5%, p < 0.01). Rates of other outcomes were similar in univariate analyses. Adjusting for microarray abnormalities, the odds for survival to discharge for RCDH compared with LCDH was 0.93 (0.38-2.30, p = 0.88).

CONCLUSION

Compared with LCDH, fetuses with RCDH had higher rates of adverse ultrasound predictors, but equivalent survival.

Fetal Lung Volumes by MRI: Normal Weekly Values From 18 Through 38 Weeks' Gestation

OBJECTIVE

The purpose of this study is to establish normal total fetal lung volume reference ranges from 18 to 38 weeks' gestation at 1-week intervals.

MATERIALS AND METHODS

A retrospective analysis of 665 patients who underwent fetal MRI at two tertiary fetal centers from 2001 to 2013 was performed. Total fetal lung volume was measured in at least two planes, either manually or using a 3D workstation. The mean, median, SD, minimum, maximum, and lower and upper quartiles for total fetal lung volume were determined per gestational week. A t test was used to compare our values to previously reported values. A new formula to calculate total fetal lung volume derived from our data was created using a regression model. Comparisons between total fetal lung volume obtained by different imaging planes and manual versus semiautomatic calculation were also performed.

RESULTS

The mean normal total fetal lung volume showed a weekly increase from 18 through 35 weeks' gestation. Means were compared with the expected total fetal lung volume generated by the Rypens formula, showing statistically significant lower mean total fetal lung volume from week 19 to week 22 (p < 0.05). Comparison between our data-derived total fetal lung volume formula and the Rypens formula showed very similar values at every gestational age. No difference in total fetal lung volume was seen when comparing imaging planes or manual versus semiautomatic methods.

CONCLUSION

Measured mean total fetal lung volume values at 19-22 weeks are significantly lower than those predicted by the Rypens formula. Therefore, we propose preferential use of our values for prenatal counseling and delivery planning.

Prenatal Factors Associated with Postnatal Brain Injury in Infants with Congenital Diaphragmatic Hernia

BACKGROUND AND PURPOSE

Approximately 60% of infants with congenital diaphragmatic hernia have evidence of brain injury on postnatal MR imaging. It is unclear whether any brain injury is present before birth. In this study, we evaluated fetal MR imaging findings of brain injury and the association of congenital diaphragmatic hernia severity with postnatal brain injury.

MATERIALS AND METHODS

Fetal MR imaging and postnatal brain MR imaging were retrospectively evaluated in 36 cases of congenital diaphragmatic hernia (from 2009 to 2014) by 2 pediatric neuroradiologists. Brain injury on postnatal MR imaging and brain injury and congenital diaphragmatic hernia severity on fetal MR imaging were recorded. Correlations between brain abnormalities on fetal and postnatal brain MR imaging were analyzed. Postnatal brain injury findings correlating with the severity of congenital diaphragmatic hernia were also assessed.

RESULTS

On fetal MR imaging, enlarged extra-axial spaces (61%), venous sinus distention (21%), and ventriculomegaly (6%) were identified. No maturational delay, intracranial hemorrhage, or brain parenchymal injury was identified on fetal MR imaging. On postnatal MR imaging, 67% of infants had evidence of abnormality, commonly, enlarged extra-axial spaces (44%). Right-sided congenital diaphragmatic hernia was associated with a greater postnatal brain injury score (P = .05). Low observed-to-expected lung volume was associated with postnatal white matter injury (P = .005) and a greater postnatal brain injury score (P = .008). Lack of liver herniation was associated with normal postnatal brain MR imaging findings (P = .03).

CONCLUSIONS

Fetal lung hypoplasia is associated with postnatal brain injury in congenital diaphragmatic hernia, suggesting that the severity of lung disease and associated treatments affect brain health as well. We found no evidence of prenatal brain parenchymal injury or maturational delay.

Evaluation of Neonatal Lung Volume Growth by Pulmonary Magnetic Resonance Imaging in Patients with Congenital Diaphragmatic Hernia

OBJECTIVE

To evaluate postnatal lung volume in infants with congenital diaphragmatic hernia (CDH) and determine if a compensatory increase in lung volume occurs during the postnatal period.

STUDY DESIGN

Using a novel pulmonary magnetic resonance imaging method for imaging neonatal lungs, the postnatal lung volumes in infants with CDH were determined and compared with prenatal lung volumes obtained via late gestation magnetic resonance imaging.

RESULTS

Infants with left-sided CDH (2 mild, 9 moderate, and 1 severe) were evaluated. The total lung volume increased in all infants, with the contralateral lung increasing faster than the ipsilateral lung (mean ± SD: 4.9 ± 3.0 mL/week vs 3.4 ± 2.1 mL/week, P = .005). In contrast to prenatal studies, the volume of lungs of infants with more severe CDH grew faster than the lungs of infants with more mild CDH (Spearman's ρ=-0.086, P = .01). Although the contralateral lung volume grew faster in both mild and moderate groups, the majority of total lung volume growth in moderate CDH came from increased volume of the ipsilateral lung (42% of total lung volume increase in the moderate group vs 32% of total lung volume increase in the mild group, P = .09). Analysis of multiple clinical variables suggests that increased weight gain was associated with increased compensatory ipsilateral lung volume growth (ρ = 0.57, P = .05).

CONCLUSIONS

These results suggest a potential for postnatal catch-up growth in infants with pulmonary hypoplasia and suggest that weight gain may increase the volume growth of the more severely affected lung.

Percent predicted lung volume changes on fetal magnetic resonance imaging throughout gestation in congenital diaphragmatic hernia

PURPOSE

Percent predicted lung volume (PPLV)<15% on fetal MRI predicts high-risk CDH. Potential changes in PPLV throughout gestation and impact on risk stratification are unknown. We reviewed CDH patients with serial fetal MRIs to follow PPLV and determine correlation with postnatal outcomes.

METHODS

CDH patients with serial fetal MRIs from 2005 to 2015 were included. We recorded prenatal MRI gestational age (GA) and PPLV, postnatal ECMO use, and survival. Data were analyzed by logistic regression and Fisher's exact test.

RESULTS

57 patients had 127 fetal MRI studies. PPLV decreased from mean 25.4% to 19.6% between GA 22.1 and 32.6weeks. A steeper decline in PPLV, regardless of final PPLV, was independently predictive of higher ECMO use (p=0.046) and death (p=0.045). All patients with first PPLV<15% remained high-risk with poor outcomes. Of those with first PPLV>15%, 31% dropped below 15%, having similar ECMO use as the high-risk cohort, but trending toward greater survival (p=0.09). Those with first and final PPLV>15% had significantly less ECMO use (p=0.015) and greater survival (p<0.001) than the high-risk cohort.

CONCLUSIONS

On average, PPLV decreases throughout gestation in fetuses with CDH. Serial MRI is recommended for those with initial PPLV>15%, as clinical outcomes tend to mirror the lowest PPLV.

TYPE OF STUDY

Treatment study LEVEL OF EVIDENCE: III.

Fetal imaging and therapy for CDH-Current status

In congenital diaphragmatic hernia (CDH), herniation of the abdominal organs into the fetal chest causes pulmonary hypoplasia and pulmonary hypertension, the main causes of neonatal mortality. As antenatal ultrasound screening improves, the risk of postnatal death can now be better predicted, allowing for the identification of fetuses that might most benefit from a prenatal intervention. Fetoscopic tracheal occlusion is being evaluated in a large international randomized controlled trial. We present the antenatal imaging approaches that can help identify fetuses that might benefit from antenatal therapy, and review the evolution of fetal surgery for CDH to date.

Separate Evaluation of the Ipsilateral and Contralateral MR Fetal Lung Volume in Patients With Congenital Diaphragmatic Hernia

OBJECTIVE

Our study had two objectives. First, we separately evaluated observed-to-expected MR fetal lung volume (FLV) of lungs ipsilateral and contralateral to a congenital diaphragmatic hernia (CDH). Second, we compared the prognostic value of observed-to-expected MR FLV of the ipsilateral and contralateral lungs with that of observed-to-expected MR FLV of both lungs with respect to survival, need for extracorporeal membrane oxygenation (ECMO), and development of chronic lung disease (CLD).

MATERIALS AND METHODS

We evaluated observed-to-expected MR FLV of the lung ipsilateral to the diaphragmatic defect as well as in the contralateral lung in 107 fetuses with isolated CDH. ROC analysis and logistic regression analysis were performed to assess the prognostic value of the observed-to-expected MR FLV for association with outcome.

RESULTS

In all fetuses with CDH, values in the ipsilateral (mean observed-to-expected MR FLV ± SD, 9.4% ± 9.6%) and the contralateral lung (mean observed-to-expected MR FLV, 48.9% ± 18.5%; p < 0.0001) were significantly lower than values measured in healthy fetuses. Observed-to-expected MR FLV of both lungs and of the contralateral and ipsilateral lung revealed significant differences regarding survival (p < 0.0001, p < 0.0001, and p = 0.0170, respectively), need for ECMO (p < 0.0001, p < 0.0001, and p = 0.0051, respectively), and development of CLD (p = 0.0004, p = 0.0002, and p = 0.0460, respectively). Compared with the observed-to-expected MR FLV of both lungs, the observed-to-expected MR FLV of the contralateral lung showed a slightly higher prognostic accuracy regarding survival (AUC = 0.859 vs 0.825) and development of CLD (AUC = 0.734 vs 0.732) and a similar prognostic accuracy regarding need for ECMO (AUC = 0.805 vs 0.826). Observed-to-expected MR FLV of the ipsilateral lung did not show good prognostic value regarding survival (AUC = 0.617), need for ECMO (AUC = 0.673), and development of CLD (AUC = 0.636). These AUCs were significantly smaller than the AUCs resulting from the observed-to-expected MR FLV of both lungs (each p < 0.05) and considerably smaller than the AUCs of the observed-to-expected MR FLV of the contralateral lung (each p < 0.10).

CONCLUSION

Patients with CDH showed a substantially lower observed-to-expected MR FLV of both lungs compared with healthy fetuses. The observed-to-expected MR FLV of both lungs as well as of the lung contralateral to the CDH were reliable prenatal predictors of survival, need for ECMO, and development of CLD.

Predictive Value of MRI Findings for the Identification of a Hernia Sac in Fetuses With Congenital Diaphragmatic Hernia

OBJECTIVE

The purpose of this study was to identify MRI features of diaphragmatic hernia sac, as well as to assess the accuracy of diagnosing a sac prenatally.

MATERIALS AND METHODS

All fetal MRI examinations performed for intrapleural congenital diaphragmatic hernia (CDH) from 2004 to 2013 were retrospectively reviewed by two pediatric radiologists blinded to the hernia sac status (defined intraoperatively or at autopsy). Reviewers noted whether a sac was present on the basis of identification of the following four MRI findings: 1, meniscus of lung posterior or apical to the hernia contents; 2, encapsulated appearance of hernia contents, exerting less than expected mass effect on the heart and mediastinum; 3, presence of pleural fluid outlining a sac from above; and 4, presence of ascites outlining a sac from below. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for each finding and for various combinations. Contingency tables, chi-square testing, and logistic regression were applied to calculate the probability of a sac.

RESULTS

Ninety patients were included: 21 with and 69 without a sac. The first three MRI findings correlated with the presence of a sac. Logistic regression yielded high predicted probability of a sac when one finding was identified (finding 1, 94.4%; finding 2, 96.2%). Adding a second and a third finding improved the probability to 99.7% and 99.9%, respectively. Sensitivity and specificity for the presence of a sac were 0.43 and 0.97, respectively. PPV and NPV were 83.8% and 80%, respectively.

CONCLUSION

On fetal MRI, presence of a hernia sac in CDH can be diagnosed with high specificity when indicative findings are present.

Correlation of Observed-to-Expected MRI Fetal Lung Volume and Ultrasound Lung-to-Head Ratio at Different Gestational Times in Fetuses With Congenital Diaphragmatic Hernia

OBJECTIVE

The purpose of this study is to compare the observed-to-expected MRI fetal lung volume and the observed-to-expected ultrasound lung-to-head ratio intraindividually for prediction of survival, the need for extracorporeal membrane oxygenation (ECMO) therapy, and the development of chronic lung disease (CLD) at different times of gestation (< 28, 28-32, and > 32 weeks) in fetuses with congenital diaphragmatic hernia (CDH), and to analyze the intraindividual correlation of observed-to-expected MRI fetal lung volume and observed-to-expected ultrasound lung-to-head ratio.

MATERIALS AND METHODS

Two hundred one fetuses were included in our study. Observed-to-expected MRI fetal lung volume and observed-to-expected ultrasound lung-to-head ratio were calculated for 270 MRI and ultrasound examinations performed within 72 hours of each other. The prognostic accuracy of observed-to-expected MRI fetal lung volume and observed-to-expected ultrasound lung-to-head ratio was assessed by performing ROC analysis. Correlation was determined using linear regression analysis.

RESULTS

The results revealed statistically significant differences between the observed-to-expected MRI fetal lung volume and observed-to-expected ultrasound lung-to-head ratio for the prediction of survival, the need for ECMO therapy, and the development of CLD in fetuses with left-sided CDH (p ≤ 0.0444), with the highest prognostic accuracy for survival (AUC = 0.863). Observed-to-expected MRI fetal lung volume and observed-to-expected ultrasound lung-to-head ratio correlated statistically significantly (p < 0.0001) for left-sided CDH with correlation coefficients (r) of 0.71, 0.71, and 0.56 for early, intermediate, and late times of gestation, respectively. The correlation was not statistically significant at any time for right-sided CDH (p ≥ 0.3947; r ≤ 0.26).

CONCLUSION

Observed-to-expected MRI fetal lung volume and observed-to-expected ultrasound lung-to-head ratio are valuable prognostic parameters for prenatal prediction of survival, the need for ECMO therapy, and the development of CLD in fetuses with left-sided CDH at all times of gestation. Observed-to-expected MRI fetal lung volume and observed-to-expected ultrasound lung-to-head ratio correlate statistically significantly for left-sided CDH, and the correlation is best before 32 weeks' gestation, but they do not correlate statistically significantly for right-sided CDH.

Prenatal MR imaging of congenital diaphragmatic hernias: association of MR fetal lung volume with the need for postnatal prosthetic patch repair

OBJECTIVE

To assess whether the need for postnatal prosthetic patch repair of the diaphragmatic defect in neonates with a congenital diaphragmatic hernia (CDH) is associated with the antenatal measured observed-to-expected magnetic resonance fetal lung volume (o/e MR-FLV).

METHODS

The o/e MR-FLV was calculated in 247 fetuses with isolated CDH. Logistic regression analysis was used to assess the prognostic value of the individual o/e MR-FLV for association with the need for postnatal patch repair.

RESULTS

Seventy-seven percent (77%) of patients with a CDH (190/247) required prosthetic patch repair and the defect was closed primarily in 23% (57/247). Patients requiring a patch had a significantly lower o/e MR-FLV (27.7 ± 10.2%) than patients with primary repair (40.8 ± 13.8%, p < 0.001, AUC = 0.786). With an o/e MR-FLV of 20%, 92% of the patients required patch repair, compared to only 24% with an o/e MR-FLV of 60%. The need for a prosthetic patch was further influenced by the fetal liver position (herniation/no herniation) as determined by magnetic resonance imaging (MRI; p < 0.001). Fetal liver position, in addition to the o/e MR-FLV, improves prognostic accuracy (AUC = 0.827).

CONCLUSION

Logistic regression analysis based on the o/e MR-FLV is useful for prenatal estimation of the prosthetic patch requirement in patients with a CDH. In addition to the o/e MR-FLV, the position of the liver as determined by fetal MRI helps improve prognostic accuracy.

KEY POINTS

• The o/e MR-FLV is associated with the need for postnatal patch repair in CDH. • The need for a patch is associated with a significantly lower o/e MR-FLV (p < 0.001). • The patch requirement is also influenced by fetal liver position. • Fetal liver position, in addition to the o/e MR-FLV, improves prognostic accuracy. • CDH-fetuses with a high probability for patch requirement can be identified prenatally.

MRI-based ratio of fetal lung volume to fetal body volume as a new prognostic marker in congenital diaphragmatic hernia

OBJECTIVE

The objective of our study was to evaluate the prognostic accuracy of the MRI-based ratio of fetal lung volume (FLV) to fetal body volume (FBV) for predicting survival and the need for extracorporeal membrane oxygenation (ECMO) therapy in fetuses with congenital diaphragmatic hernia (CDH).

MATERIALS AND METHODS

MRI was performed in 96 fetuses (34 females and 62 males; mean gestational age, 33 ± 5 [SD] weeks; range, 23-39 weeks) with CDH and 44 healthy control subjects. FLV and FBV were measured for each fetus by one of three investigators, and we calculated the FLV/FBV ratio. Additionally, a subgroup analysis of growth-restricted fetuses was performed. Logistic regression analysis was used to model the dependence of survival and ECMO requirement on the FLV/FBV ratio. Prognostic accuracy was evaluated by applying the area under the curve (AUC).

RESULTS

Seventy-eight of the 96 (81%) fetuses survived and 35 (36%) neonates needed ECMO therapy. The FLV/FBV ratio was significantly higher in fetuses who survived (p < 0.0001; AUC = 0.829). Neonates who received ECMO therapy showed a significantly lower prenatal FLV/FBV ratio (p = 0.0001; AUC = 0.811) than neonates who did not need ECMO therapy. A subgroup analysis (n = 13) showed a trend toward a higher FLV/FBV ratio of survivors in comparison with nonsurvivors (p = 0.065; AUC = 0.875).

CONCLUSION

In our study, the MRI-based FLV/FBV ratio was able to predict neonatal survival and ECMO requirement in children with CDH with high accuracy. Unlike other prognostic parameters, FLV/FBV ratio is independent of a reference to a control group and may enhance prognostic accuracy particularly in growth-restricted neonatal patients.

Prenatal MRI fetal lung volumes and percent liver herniation predict pulmonary morbidity in congenital diaphragmatic hernia (CDH)

PURPOSE

The purpose of this study was to determine whether prenatal imaging parameters are predictive of postnatal CDH-associated pulmonary morbidity.

METHODS

The records of all neonates with CDH treated from 2004 to 2012 were reviewed. Patients requiring supplemental oxygen at 30 days of life (DOL) were classified as having chronic lung disease (CLD). Fetal MRI-measured observed/expected total fetal lung volume (O/E-TFLV) and percent liver herniation (%LH) were recorded. Receiver operating characteristic (ROC) curves and multivariate regression were applied to assess the prognostic value of O/E-TFLV and %LH for development of CLD.

RESULTS

Of 172 neonates with CDH, 108 had fetal MRIs, and survival was 76%. 82% (89/108) were alive at DOL 30, 46 (52%) of whom had CLD. Neonates with CLD had lower mean O/E-TFLV (30 vs.42%; p=0.001) and higher %LH (21.3±2.8 vs.7.1±1.8%; p<0.001) compared to neonates without CLD. Using ROC analysis, the best cutoffs in predicting CLD were an O/E-TFLV<35% (AUC=0.74; p<0.001) and %LH>20% (AUC=0.78; p<0.001). On logistic regression, O/E-TFLV<35% and a %LH>20% were highly associated with indicators of long-term pulmonary sequelae. On multivariate analysis, %LH was the strongest predictor of CLD in patients with CDH (OR: 10.96, 95%CI: 2.5-48.9, p=0.002).

CONCLUSION

Prenatal measurement of O/E-TFLV and %LH is predictive of CDH pulmonary morbidity and can aid in establishing parental expectations of postnatal outcomes.

Periodic MRI lung volume assessment in fetuses with congenital diaphragmatic hernia: prediction of survival, need for ECMO, and development of chronic lung disease

OBJECTIVE

The purpose of the study was to investigate the ability to predict survival, need for extracorporeal membrane oxygenation (ECMO), and incidence of chronic lung disease in patients with congenital diaphragmatic hernia in the context of a classification into three different times of gestation (< 28, 28-32, and > 32 weeks) by assessing the ratio between observed and expected MRI fetal lung volume.

MATERIALS AND METHODS

The data analysis included 226 fetuses with congenital diaphragmatic hernia. MRI was performed at different times of gestation with a T2-weighted HASTE sequence. Receiver operating characteristic curve analysis was performed to investigate the prognostic value of assessment of the ratio between observed and expected MRI fetal lung volumes at different stages of fetal growth.

RESULTS

For all reviewed times of gestation, the ratio between observed and expected MRI fetal lung volumes had almost equivalent statistically significant differences for neonatal survival (p ≤ 0.0029), need for ECMO therapy (p ≤ 0.0195), and development of chronic lung disease (p ≤ 0.0064). Results with high prognostic accuracy for early and for medium and late times in gestation also were obtained. Receiver operating characteristic analysis showed the highest area under the curve (≥ 0.819) for neonatal survival.

CONCLUSION

In patients with congenital diaphragmatic hernia, the relation between observed and expected MRI fetal lung volume is a valuable prognostic parameter for predicting neonatal mortality, morbidity represented by the development of chronic lung disease, and the need for ECMO therapy in early gestation (< 28 weeks) as well as later gestation with no statistically significant differences.

Prediction of mortality and the need for neonatal extracorporeal membrane oxygenation therapy by 3-dimensional sonography and magnetic resonance imaging in fetuses with congenital diaphragmatic hernias

OBJECTIVES

To compare different rotation angles for assessment of fetal lung volume by 3-dimensional (3D) sonography with magnetic resonance imaging (MRI) regarding prediction of mortality and the need for neonatal extracorporeal membrane oxygenation (ECMO) therapy in fetuses with congenital diaphragmatic hernias.

METHODS

One hundred patients with fetal congenital diaphragmatic hernias between 22 and 39 weeks' gestation were examined by 3D sonography and MRI. Sonographic contralateral fetal lung volumes were assessed by the rotational technique (virtual organ computer-aided analysis) at 3 different rotation angles: 6°, 15°, and 30°. The MRI fetal lung volumes were calculated based on multiplanar T2-weighted MRI. To eliminate the influence of gestational age, the observed to expected contralateral fetal lung volume on sonography and the observed to expected fetal lung volume on MRI were calculated. Receiver operating characteristic (ROC) curves were calculated for the statistical prediction of survival and need for ECMO therapy by the observed to expected contralateral fetal lung volume (sonography) and observed to expected fetal lung volume (MRI).

RESULTS

One hundred cases were assessed for survival and 89 for ECMO necessity (11 neonates were not eligible for ECMO). For prediction of postpartum survival and ECMO necessity, the areas under the ROC curves (AUCs) showed very similar results for MRI and 3D sonography: observed to expected fetal lung volume by MRI, 0.819 (95% confidence interval, 0.730-0.909) and 0.835 (0.748-0.922), respectively; 6° sonography, 0.765 (0.647-0.883) and 0.820 (0.734-0.905); 15° sonography, 0.784 (0.672-0.896) and 0.811 (0.719-0.903); and 30° sonography, 0.732 (0.609-0.855) and 0.772 (0.671-0.872). Comparisons between the AUCs revealed no statistical differences.

CONCLUSIONS

We have shown the good prognostic value of 3D sonography in fetuses with congenital diaphragmatic hernias compared with MRI, particularly when using small rotation angles. Therefore, it can be an appropriate diagnostic tool when counseling patients for congenital diaphragmatic hernias.

The presence of a hernia sac in congenital diaphragmatic hernia is associated with better fetal lung growth and outcomes

PURPOSE

The purpose of this study was to evaluate the relationship between the presence of a hernia sac and fetal lung growth and outcomes in infants with Congenital, Diaphragmatic Hernia (CDH).

METHODS

The medical records of all neonates with CDH treated in our institution between 2004 and 2011 were reviewed. The presence of a hernia sac was confirmed at the time of surgical repair or at autopsy. Data were analyzed using parametric and non-parametric tests where appropriate. Multivariable regression and survival analyses were applied.

RESULTS

Of 148 neonates treated for CDH, 107 (72%) had isolated CDH and 30 (20%) had a hernia sac. Infants with a hernia sac had significantly lower need for ECMO, patch repair, supplemental oxygen at 30 days of life, and shorter duration of mechanical ventilation and hospital stay. Ninety-three patients had prenatal imaging. The mean observed-to-expected total fetal lung volume in the sac group was higher throughout gestation. Although a greater percentage of sac patients had liver herniation as a dichotomous variable, the amount of herniated liver (%LH and LiTR) was significantly lower in the presence of a hernia sac.

CONCLUSION

The presence of a hernia sac in Congenital Diaphragmatic Hernia is associated with less visceral herniation, greater fetal lung growth, and better post-natal outcomes.

[Radiology and pregnancy : Part 2: clinical recommendations]

In spite of a growing number of radiological scans in pregnant women there is still a high level of uncertainty concerning radiation exposure to the fetus. At the same time, the risk of fetal radiation injury is frequently overestimated. This entails an avoidable fear in the pregnant patient and may delay urgently required imaging and thus lead to an increased risk for maternal and fetal health. As a consequence, radiological scans in pregnant patients do not only require a thorough medical check but also a careful estimate of the specific radiation exposure to the fetus. The previous first part of the article described the legal requirements in Germany, the technical exposure and pharmacological risks for the pregnant woman and the fetus. The current second article focuses on the risk analysis for examinations with ionizing radiation and will provide recommendations for typical indications for maternal and fetal imaging.

Risk adjustment for neonatal surgery: a method for comparison of in-hospital mortality

OBJECTIVE

To develop a risk-adjustment method for evaluation of in-hospital mortality after noncardiac neonatal surgery regardless of gestational age.

METHODS

Infants ≤ 30 days old undergoing noncardiac surgical procedures were identified by using the Kids' Inpatient Database (KID) 2000 + 2003. Neonates were included regardless of gestational age. International Classification of Disease, Ninth Revision, Clinical Modification codes were used to assign procedures to 1 of 4 previously derived risk categories. Prematurity and other clinical variables were assessed in logistic regression analysis. The final multivariable model was validated in 3 independent data sets: KID 2006, Pediatric Health Information System (PHIS) 2001-2003, and PHIS 2006-2008. The model was applied to generate standardized mortality ratios for institutions within PHIS 2006-2008.

RESULTS

Among 18437 eligible cases in KID 2000 + 2003, 15278 (83%) had 1 of 66 procedure codes assigned to a risk category and were eligible for analysis. In-hospital mortality for premature infants was 10.5% compared with 2.0% for full-term neonates. In addition to risk category, the clinical variables improving prediction of in-hospital death were prematurity, serious respiratory conditions, necrotizing enterocolitis, neonatal sepsis, and congenital heart disease. Area under the receiver-operator characteristic curve for the final model was 0.90. The model also showed excellent discrimination in the 3 validation data sets (0.90, 0.89, and 0.89). Within 41 institutions in PHIS, standardized mortality ratios ranged from 0.37 to 1.91.

CONCLUSIONS

This validated method provides a tool for risk adjustment of neonates undergoing noncardiac surgery to allow comparative analyses of in-hospital mortality.

Tracheobronchomegaly following intrauterine tracheal occlusion for congenital diaphragmatic hernia

BACKGROUND

Fetuses with severe congenital diaphragmatic hernia (CDH) and pulmonary hypoplasia may benefit from fetal endoluminal tracheal occlusion (FETO). Enlargement of the main bronchi and trachea appears to be a common complication of FETO.

OBJECTIVE

To retrospectively evaluate the trachea and main bronchi of infants who underwent FETO for CDH and compare diameters with age-matched references.

MATERIAL AND METHODS

Postnatal and follow-up chest radiographs were performed in seven children with unilateral CDH treated by FETO. Additional CT was performed in six of these (one neonate died before CT could be performed). Images were acquired from 3 days to 23 months of age. For each child, radiographs and CT images with optimal visualisation of the airways were selected for retrospective analysis. Tracheal and bronchial morphology was assessed by two experienced paediatric radiologists, and the diameters of these structures measured and compared with age-matched references.

RESULTS

Mean diameters of the trachea and main bronchi were above the age-matched normal range in all patients, regardless of the side of the hernia or the degree of lung hypoplasia.

CONCLUSION

Enlargement of the trachea and main bronchi appears following FETO and persists at least to the age of 5 years.

Quantitative pulmonary perfusion imaging at 3.0 T of 2-year-old children after congenital diaphragmatic hernia repair: initial results

OBJECTIVE

To investigate whether dynamic contrast-enhanced MR imaging of the lung following congenital diaphragmatic hernia repair is feasible at 3.0 T in 2-year-old children and whether associated lung hypoplasia (reflected in reduced pulmonary microcirculation) can be demonstrated in MRI.

METHODS

Twelve children with a mean age 2.0 ± 0.2 years after hernia repair underwent DCE-MRI at 3.0 T using a time-resolved angiography with stochastic trajectories sequence. Quantification of lung perfusion was performed using a pixel-by-pixel deconvolution approach. Six regions of interest were placed (upper, middle and lower parts of right and left lung) to assess differences in pulmonary blood flow (PBF), pulmonary blood volume (PBV) and mean transit time (MTT) while avoiding the inclusion of larger pulmonary arteries and veins.

RESULTS

The difference in PBF and PBV between ipsilateral and contralateral lung was significant (P < 0.5). No significant differences could be detected for the MTT (P = 0.5).

CONCLUSION

DCE-MRI in 2-year-old patients is feasible at 3.0 T. Reduced perfusion in the ipsilateral lung is reflected by significantly lower PBF values compared with the contralateral lung. DCE-MRI of the lung in congenital diaphragmatic hernia can help to characterise lung hypoplasia initially and in the long-term follow-up of children after diaphragmatic repair.

KEY POINTS

Congenital diaphragmatic hernia often leads to lung hypoplasia and secondary pulmonary hypertension. Dynamic contrast-enhanced 3-T magnetic resonance can assess these complications in 2-year-olds. The affected ipsilateral lung shows reduced perfusion and lower pulmonary blood flow. Thoracic DCE-MRI helps characterise lung hypoplasia in children after hernia repair.

Recent advances in the management of congenital diaphragmatic hernia

PURPOSE OF REVIEW

Congenital diaphragmatic hernia (CDH) is a rare developmental defect resulting in variable degrees of lung and pulmonary vasculature hypoplasia. Whereas many high-volume centers have recently reported increased survival rates, this has not been the collective trend. One potential explanation for this is inconsistent perinatal care among centers.

RECENT FINDINGS

Significant efforts have been made to identify prenatally those fetuses that will be most severely affected. A number of radiologic features have shown promise for achieving this goal as well as identifying fetuses that may benefit from prenatal intervention. When CDH is antenatally diagnosed, early referral to a tertiary center is recommended. Centers that routinely use postnatal management protocols have demonstrated improved overall survival rates including increased survival in high-risk CDH patients.

SUMMARY

As a result of advancements in perinatal care, more severely affected newborns with CDH are now surviving. These patients may experience a number of associated morbidities which affect not only their health but overall quality of life. A multidisciplinary approach to the long-term care of these patients will allow early identification and management of these morbidities.

Right- versus left-sided congenital diaphragmatic hernia: postnatal outcome at a specialized tertiary care center

OBJECTIVE

To systematically investigate the impact of the location of the defect in congenital diaphragmatic hernia on neonatal mortality and morbidity with a special focus on survival at discharge, extracorporeal membrane oxygenation requirement, and the development of chronic lung disease.

DESIGN

Retrospective tertiary care center study with a matched-pair analysis of all fetuses that were treated for congenital diaphragmatic hernia between 2004 and 2009.

SETTING

A specialized tertiary care center for fetuses with congenital diaphragmatic hernia.

PATIENTS

Complete sets of data were available for 106 patients with congenital diaphragmatic hernia. For 17 of 18 infants with right-sided congenital diaphragmatic hernia we were able to allocate infants with left-sided congenital diaphragmatic hernia with no relevant difference in previously described prognostic factors, such as pulmonary hypoplasia and liver herniation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

There was a strong trend toward better survival in infants with right-sided congenital diaphragmatic hernia than with left-sided congenital diaphragmatic hernia (94% vs. 70%; p = .07). More neonates with left-sided congenital diaphragmatic hernia died of severe pulmonary hypertension despite extracorporeal membrane oxygenation. Fewer neonates with right-sided congenital diaphragmatic hernia died, yet higher degrees of pulmonary hypoplasia and oxygen requirement were observed despite extracorporeal membrane oxygenation.

CONCLUSIONS

In congenital diaphragmatic hernia, the location of the defect has a substantial impact on postnatal survival and the development of chronic lung disease. In left-sided congenital diaphragmatic hernia, pulmonary hypertension resistant to therapeutic management, including extracorporeal membrane oxygenation, is more common and is associated with a higher rate of neonatal demise. Right-sided congenital diaphragmatic hernia infants have an increased benefit from extracorporeal membrane oxygenation but the better survival entails a higher rate of chronic lung disease.

Current advances in prenatal imaging of congenital diaphragmatic [corrected] hernia

Congenital diaphragmatic hernia, despite advances in therapy, remains a complex condition with significant morbidity and mortality. The etiology of the disorder is still incompletely understood, though the pulmonary hypoplasia and pulmonary hypertension that develop secondarily must be overcome to improve survival. Prenatal US and fetal MRI have helped in the development of a greater understanding of this disease. Also with these modalities, measurement techniques have been developed in an attempt to provide prognosticators for the development of pulmonary hypoplasia and pulmonary hypertension. There is a broad range of approaches for performing these measurements, and variability among imaging centers is noted. Despite inconsistent approaches, these techniques have become the foundation for counseling and prenatal and postnatal therapy. It is hoped that with further research with prenatal US and fetal MRI and the development of innovative medical and surgical therapies that the morbidity and mortality of children with congenital diaphragmatic hernias can be significantly reduced.

Correlation between US and MRI for prenatal lung volumetry in diaphragmatic hernia, and use of Doppler to identify the ipsilateral lung cap

BACKGROUND

Pulmonary hypoplasia is a common cause of neonatal death.

OBJECTIVE

To describe the correlation between relative fetal lung volume (RFLV) and lung-to-head ratio (LHR) in fetuses with unilateral diaphragmatic hernia. Additionally, to describe identification of the ipsilateral lung cap by power Doppler.

MATERIALS AND METHODS

Single-institution study of consecutive fetuses with diaphragmatic hernia. LHR (by US) and RFLV (by MRI) were correlated in fetuses with and without an ipsilateral lung cap seen at MRI. In four, color/power Doppler was used to follow the pulmonary artery of the ipsilateral lung to identify the compressed cap.

RESULTS

The study included 48 fetuses of 20-38 weeks' gestational age (mean, 26 weeks). Mean LHR was 1.52 (range, 0.6-3) in fetuses with a lung cap and 1.15 (range, 0.6-2.58) in fetuses without (P = 0.043). Mean RFLV was 47.4% (range, 18-80%) in fetuses with and 32.9% (range, 14-57%) in fetuses without a lung cap (P = 0.005). RFLV and LHR correlated (r = 0.41, P = 0.01 in those with a cap; r = 0.50, P = 0.05 in those without). Power Doppler identified the ipsilateral lung cap and pulsed Doppler confirmed pulmonary vascularization in four of four fetuses.

CONCLUSION

LHR underestimates lung volume in fetuses with an ipsilateral lung cap. Power Doppler may be useful for identifying the cap.

Assessment of lung volume by 3-dimensional sonography and magnetic resonance imaging in fetuses with congenital diaphragmatic hernias

OBJECTIVES

The purpose of this study was to evaluate the influence of different rotation angles in assessment of the contralateral lung volume by 3-dimensional (3D) sonography in comparison to magnetic resonance imaging (MRI) in fetuses with congenital diaphragmatic hernias.

METHODS

A total of 126 measurements by 3D sonography and MRI were conducted in 81 patients between 18 and 39 weeks' gestation. The 3D sonographic volumes of the contralateral fetal lung were calculated by the rotational technique (virtual organ computer-aided analysis) with rotation angles of 6°, 15°, and 30°. Transverse multiplanar T2-weighted MRI was performed for the MRI measurements. To compare the accuracy of 3D sonographic volumetry using different rotation angles, MRI assessment was taken as the reference method, and percentage errors and limits of agreement were calculated for each angle.

RESULTS

Three-dimensional sonographic volume measurements showed a high correlation with MRI (6° angle, R(2) = 0.86; 15° angle, R(2) = 0.78; 30° angle, R(2) = 0.68). The mean percentage error showed no systematic error. With regard to random error, the 6° step had significantly lower values than the larger angles 30° step (R = 0.472) and the narrowest limits of agreement.

CONCLUSIONS

Especially when using a small rotation angle, assessment of the contralateral fetal lung volume by 3D sonography in congenital diaphragmatic hernias is a reliable alternative to MRI.

Jugular vein hypoplasia can preclude extracorporeal membrane oxygenation cannulation in the neonate with congenital diaphragmatic hernia: potential identification of the neonate at risk by fetal magnetic resonance imaging

Magnetic resonance imaging (MRI) is used routinely in many fetal care centers for the evaluation of the fetus with congenital diaphragmatic hernia (CDH). Current MRI strategies focus on identifying the type of hernia and its contents, as well as calculating fetal lung volumes, in order to plan appropriately for neonatal support, including the use of extracorporeal membrane oxygenation (ECMO). Single-shot fast spin-echo T(2)-weighted sequences are fundamental, with additional sequences used variably as indicated. We report the case of a fetus with CDH in whom ECMO cannulation was attempted as a neonate but was unsuccessful because of variant anatomy of the internal jugular vein. A retrospective review of gradient echo sequences obtained through the fetal neck and chest showed the abnormality could have been anticipated. During multidisciplinary assessment of the fetus with CDH, consideration should be given to imaging evaluation of the neck to evaluate the cervical vascular anatomy, particularly in cases with poorer prognosis in whom it is anticipated that neonatal ECMO may be an option.

In vitro models of the fetal lung: comparison of lung volume measurements with 3-dimensional sonography and magnetic resonance imaging

OBJECTIVES

Three-dimensional (3D) sonography is an established volumetric method in gynecology and obstetrics. The aim of this study was to investigate the variability of 3D sonographic measurements and their accuracy in comparison with magnetic resonance imaging (MRI) for assessing fetal lung volume using in vitro lung models.

METHODS

Twenty-three in vitro lung models with randomly defined volumes ranging from 1 to 60 mL were made from gelatin with plastic sheaths, manually molded into the shape of fetal lungs. The models were measured using 3D sonography and MRI. The 3D sonographic volumes were calculated using the rotational technique with angles of 6° and 30°. Multiplanar T2-weighted sequences were used for the MRI measurements. The percentage error and absolute percentage error were calculated for each method, and intraobserver and interobserver variability in 3D sonographic measurements was assessed with intraclass correlation coefficients (ICCs). Agreement between calculated and real volumes using the limits of agreement method was also evaluated.

RESULTS

The ICCs for the rotation angles indicated very good intraobserver and interobserver variability (6°, 0.995 and 0.996; 30°, 0.997 and 0.985). No systematic errors were observed in the mean percentage errors for 3D sonographic measurements or MRI volumetry. The lowest median absolute percentage error (1.76) was obtained with MRI volumetry, significantly lower than the values for sonography (6°, 5.00; P < .001; 30°, 5.49; P < .001). There were no significant differences in absolute percentage errors between the rotation angles (P = .82) and no significant differences in limits of agreement between 3D sonography and MRI (6°, P = .76; 30°, P = .39).

CONCLUSIONS

Three-dimensional sonographic volumetry was almost as accurate as MRI in this in vitro model and can be regarded as a good alternative method. Further research is needed to confirm these findings in vivo and to assess the prognostic value in fetuses with lung hypoplasia (eg, congenital diaphragmatic hernias).

Congenital diaphragmatic hernia: lung-to-head ratio and lung volume for prediction of outcome

OBJECTIVE

The purpose of this study was to evaluate observed/expected (O/E) lung-to-head ratio (LHR) by ultrasound (US) and total fetal lung volume (TFLV) by magnetic resonance imaging as neonatal outcome predictors in isolated fetal congenital diaphragmatic hernia (CDH).

STUDY DESIGN

We conducted a retrospective study of 72 fetuses with isolated CDH, in whom O/E LHR and TFLV were evaluated as survival predictors.

RESULTS

O/E LHR on US and O/E TFLV by magnetic resonance imaging were significantly lower in newborn infants with isolated CDH who died compared with survivors (30.3 ± 8.3 vs 44.2 ± 14.2; P < .0001 for O/E LHR; 21.9 ± 6.3 vs 41.5 ± 17.6; P = .001 for O/E TFLV). Area under receiver-operator characteristics curve for survival for O/E LHR was 0.80 (95% confidence interval, 0.70-0.90). On multivariate analysis, O/E LHR predicted survival, whereas hernia side and first neonatal pH did not. For each unit increase in O/E LHR, mortality odds decreased by 11% (95% confidence interval, 4-17%).

CONCLUSION

In fetuses with isolated CDH, O/E LHR (US) independently predicts survival and may predict severity, allowing management to be optimized.

Influence of different rotation angles in assessment of lung volumes by 3-dimensional sonography in comparison to magnetic resonance imaging in healthy fetuses

OBJECTIVES

Three-dimensional (3D) sonographic volumetry is established in gynecology and obstetrics. Assessment of the fetal lung volume by magnetic resonance imaging (MRI) in congenital diaphragmatic hernias has become a routine examination. In vitro studies have shown a good correlation between 3D sonographic measurements and MRI. The aim of this study was to compare the lung volumes of healthy fetuses assessed by 3D sonography to MRI measurements and to investigate the impact of different rotation angles.

METHODS

A total of 126 fetuses between 20 and 40 weeks' gestation were measured by 3D sonography, and 27 of them were also assessed by MRI. The sonographic volumes were calculated by the rotational technique (virtual organ computer-aided analysis) with rotation angles of 6° and 30°. To evaluate the accuracy of 3D sonographic volumetry, percentage error and absolute percentage error values were calculated using MRI volumes as reference points. Formulas to calculate total, right, and left fetal lung volumes according to gestational age and biometric parameters were derived by stepwise regression analysis.

RESULTS

Three-dimensional sonographic volumetry showed a high correlation compared to MRI (6° angle, R(2) = 0.971; 30° angle, R(2) = 0.917) with no systematic error for the 6° angle. Moreover, using the 6° rotation angle, the median absolute percentage error was significantly lower compared to the 30° angle (P < .001). The new formulas to calculate total lung volume in healthy fetuses only included gestational age and no biometric parameters (R(2) = 0.853).

CONCLUSIONS

Three-dimensional sonographic volumetry of lung volumes in healthy fetuses showed a good correlation with MRI. We recommend using an angle of 6° because it assessed the lung volume more accurately. The specifically designed equations help estimate lung volumes in healthy fetuses.