Percent predicted lung volumes as measured on fetal magnetic resonance imaging: a useful biometric parameter for risk stratification in congenital diaphragmatic hernia

Congenital Chest Lesions and Interventions

Anomalies of the fetal chest require advanced imaging with ultrasound and MR imaging as well as expertise on the part of the interpreting pediatric radiologist. Congenital diaphragmatic hernia and congenital lung malformation are the most frequently seen, and in both conditions, the radiologist should provide both detailed anatomic description and measurement data for prognostication. This article provides a detailed approach to imaging the anatomy, in-depth explanation of available measurements and prognostic value, and keys to identifying candidates for fetal intervention. Less common congenital lung tumors and mediastinal and chest wall masses are also reviewed.

Muscle Flap Technique Safe for On-ECMO Congenital Diaphragmatic Hernia Repair

INTRODUCTION

Prosthetic patches (patch) and muscle flaps (flap) are techniques used for repair of congenital diaphragmatic hernia (CDH) with a large defect unamenable to primary closure. We hypothesized that the flap technique for CDH repair while on extra-corporeal membrane oxygenation (on-ECMO) would have decreased bleeding complications compared to patch due to the hemostatic advantage of native tissue.

METHODS

A single-center retrospective comparative study of patients who underwent on-ECMO CDH repair between 2008 and 2022 was performed.

RESULTS

Fifty-two patients met inclusion criteria: 18 patch (34.6%) and 34 flap (65.4%). There was no difference in CDH severity between groups. On univariate analysis, reoperation for surgical bleeding was lower following flap repair compared to patch (23.5% vs 55.6%, respectively; p = 0.045), 48-h postoperative blood product transfusion was lower after flap repair (132 mL/kg vs 273.5 mL/kg patch; p = 0.006), and two-year survival was increased in the flap repair group compared to patch (53.1% vs 17.7%, respectively; p = 0.036). On multivariate analysis adjusting for CDH side, day on ECMO repaired, and day of life CDH repaired, flap repair was significantly associated with lower five-day postoperative packed red blood cell transfusion amount, improved survival to hospital discharge, and improved two-year survival.

CONCLUSIONS

Our experience suggests that the muscle flap technique for on-ECMO CDH repair is associated with reduced bleeding complications compared to prosthetic patch repair, which may in part be responsible for the improved survival seen in the flap repair group. These results support the flap repair technique as a favored method for on-ECMO CDH repair.

LEVEL OF EVIDENCE

Level III.

Novel approach to prenatal predictors of outcomes for fetuses with severe Ebstein anomaly

OBJECTIVE

Ebstein anomaly (EA) is a cardiac malformation with highly variable presentation and severity with limited perinatal management options. We present incorporation of fetal lung measurements into a multidisciplinary evaluation for counseling and predicting postnatal outcomes in patients with severe EA.

METHODS

Five fetuses with severe fetal EA were reviewed. Third trimester sonographic observed/expected total lung area (O/E TLA) and lung to head ratio (O/E LHR), fetal MRI total fetal lung volume ratio (O/E-TFLV), echocardiographic cardio-thoracic ratio (CT ratio), sonographic estimated fetal weight (EFW) by Hadlock formula and presence of hydrops, were used to guide perinatal management.

RESULTS

Three of five had appropriate fetal growth, were delivered at term in a cardiac operative suite, and underwent immediate intervention with good neonatal outcomes. Two had severe fetal growth restriction (FGR), CT ratios > 0.8 and O/E LHR and TLA < 25%. One of which delivered prematurely with neonatal demise and one suffered in utero demise at 34 weeks.

CONCLUSIONS

FGR, hydrops, increased CT ratio and reduced O/E LHR and TFLV are potential prognosticators of poor outcomes in severe EA, and should be validated in larger cohorts that would allow for a statistical analysis of the predictive utility of these measurements.

The Timing of Congenital Diaphragmatic Hernia Repair on Extracorporeal Membrane Oxygenation Impacts Surgical Bleeding Risk

BACKGROUND

The optimal timing of surgical repair for infants with congenital diaphragmatic hernia (CDH) treated with extracorporeal membrane oxygenation (ECMO) support remains controversial. The risk of surgical bleeding is considered by many centers as a primary factor in determining the preferred timing of CDH repair for infants requiring ECMO support. This study compares surgical bleeding following CDH repair on ECMO in early versus delayed fashion.

METHODS

A retrospective review of 146 infants who underwent CDH repair while on ECMO support from 1995 to 2021. Early repair occurred during the first 48 h after ECMO cannulation (ER) and delayed repair after 48 h (DR). Surgical bleeding was defined by the requirement of reoperative intervention for hemostasis or decompression.

RESULTS

102 infants had ER and 44 infants DR. Surgical bleeding was more frequent in the DR group (36% vs 5%, p < 0.001) with an odds ratio of 11.7 (95% CI: 3.48-39.3, p < 0.001). Blood urea nitrogen level on the day of repair was significantly elevated among those who bled (median 63 mg/dL, IQR 20-85) vs. those who did not (median 9 mg/dL, IQR 7-13) (p < 0.0001). Duration of ECMO support was shorter in the ER group (median 13 vs 18 days, p = 0.005). Survival was not statistically different between the two groups (ER 60% vs. DR 57%, p = 0.737).

CONCLUSION

We demonstrate a significantly lower incidence of bleeding and shorter duration of ECMO with early CDH repair. Azotemia was a strong risk factor for surgical bleeding associated with delayed CDH repair on ECMO.

LEVEL OF EVIDENCE

Level III cohort study.

Extracorporeal life support in congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is the most common indication for ECLS in neonatal respiratory failure. The ultimate purpose of ECLS is to grant cardiopulmonary support, allowing time for operative intervention and optimization of cardiopulmonary function as the pathophysiologic processes of pulmonary hypertension, pulmonary hypoplasia, and ventricular dysfunction either improve or resolve. In CDH, ECLS plays a crucial role in the management of the most challenging patients, facilitating postnatal stabilization, allowing a ventilation strategy which minimizes barotrauma and volutrauma, and permitting treatment of and recovery from pulmonary hypertension and/or cardiac dysfunction. Understanding the nuances of CDH patients, which differ from other forms of neonatal respiratory failure, and the benefits of ECLS for these infants, is crucial for effective management. CDH patients present distinct challenges. Every aspect of ECLS, from mode of support and anticoagulation medication to pump selection, ventilation strategy, pulmonary hypertension management, and the weaning process, requires meticulous consideration. ECLS for CDH serves as a bridge to making informed decisions, granting clinicians stability and time to manage / recover from specific pathophysiologic consequences, and it offers the potential for survival among even the most challenging and complex patients. As overall care and management for infants with CDH receiving ECLS continue to improve, the focus has shifted toward managing survivor morbidity. Given the multisystem nature of the disease, this requires significant experience, expertise, and multidisciplinary teamwork to optimize long-term outcomes for these patients.

Third-trimester percentage predicted lung volume and percentage liver herniation as prognostic indicators in congenital diaphragmatic hernia

BACKGROUND

Over the last two decades, fetal imaging has greatly improved, and new prenatal imaging measurements have been developed to characterize congenital diaphragmatic hernia (CDH) severity.

OBJECTIVE

To determine the best prenatal imaging predictor of postnatal CDH outcomes, including use of extracorporeal membrane oxygenation (ECMO) and in-hospital mortality, with particular attention to the percentage of liver herniation (%LH) as a predictor. Additionally, we sought to guide best practices across hospital systems including improved models of prenatal risk assessment.

MATERIALS AND METHODS

We conducted a retrospective review of infants with left CDH who were prenatally diagnosed. We analyzed prenatal imaging measurements including observed-to-expected (O/E) lung-to-head ratio (LHR) on US, percentage predicted lung volume (PPLV) on MRI, and O/E total fetal lung volume (TFLV) and %LH on MRI. We compared prenatal imaging characteristics for infants with (1) in-hospital postnatal mortality and (2) use of ECMO. Then we performed multivariate logistic regression to determine independent predictors of postnatal outcomes.

RESULTS

We included 63 infants with a median gestation of 34 weeks at the time of prenatal MRI. Low O/E LHR (31.2 vs. 50, P < 0.0001), PPLV (14.7 vs. 22.6, P < 0.0001) and O/E TLFV (24.6 vs. 38.3, P < 0.0001) and high %LH (15.1 vs. 2.1, P = 0.0006) were associated with worse postnatal outcomes; however, only PPLV was predictive of survival and need for ECMO on multivariable analysis. PPLV survival to discharge model showed an area under the curve (AUC) of 0.93 (95% confidence interval [CI]: 0.86, 0.99), P < 0.0001; and an odds ratio of 68.7 (95% CI: 6.5-2,302), P = 0.003. PPLV need for ECMO model showed AUC = 0.87 (95% CI: 0.78, 0.96), P < 0.0001; and odds ratio = 20.1 (95% CI: 3.1-226.3), P = 0.011.

CONCLUSION

Low O/E LHR, PPLV and O/E TFLV and high %LH in the third trimester are associated with worse postnatal outcomes. PPLV most strongly predicted outcome using a logistic regression model. Percentage of liver herniation was not an independent predictor of outcomes.

Image-based prenatal predictors correlate with postnatal survival, extracorporeal life support use, and defect size in left congenital diaphragmatic hernia

OBJECTIVE

To evaluate the association between prenatal imaging predictors of patients with left-sided congenital diaphragmatic hernia (LCDH) and postnatal outcomes.

STUDY DESIGN

CDH study group data were reviewed for LCDH infants born 2015-2019. Prenatal ultrasound (US) and magnetic resonance imaging (MRI) data were collected and correlated with postnatal information including CDHSG defect size (A through D or non-repair (NR)).

RESULTS

In total, 929 LCDH patients were included. Both US and MRI imaging predictors correlated with postnatal survival (72.2%) and ECLS use (29.6%). Logistic regression models confirmed increased survival and decreased ECLS use with larger values for all predictors. Importantly, all prenatal values evaluated showed no significant difference between defect size D and NR patients.

CONCLUSIONS

This is the largest cohort of LCDH patients and demonstrates that prenatal imaging factors correlate with postnatal outcomes and confirms that patients in the non-repair group are prenatally similar to type D defects.

Congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a rare birth defect characterized by incomplete closure of the diaphragm and herniation of fetal abdominal organs into the chest that results in pulmonary hypoplasia, postnatal pulmonary hypertension owing to vascular remodelling and cardiac dysfunction. The high mortality and morbidity rates associated with CDH are directly related to the severity of cardiopulmonary pathophysiology. Although the aetiology remains unknown, CDH has a polygenic origin in approximately one-third of cases. CDH is typically diagnosed with antenatal ultrasonography, which also aids in risk stratification, alongside fetal MRI and echocardiography. At specialized centres, prenatal management includes fetal endoscopic tracheal occlusion, which is a surgical intervention aimed at promoting lung growth in utero. Postnatal management focuses on cardiopulmonary stabilization and, in severe cases, can involve extracorporeal life support. Clinical practice guidelines continue to evolve owing to the rapidly changing landscape of therapeutic options, which include pulmonary hypertension management, ventilation strategies and surgical approaches. Survivors often have long-term, multisystem morbidities, including pulmonary dysfunction, gastroesophageal reflux, musculoskeletal deformities and neurodevelopmental impairment. Emerging research focuses on small RNA species as biomarkers of severity and regenerative medicine approaches to improve fetal lung development.

Prenatal lung volumes in congenital diaphragmatic hernia and their effect on postnatal outcomes

Lung volume measurement on fetal MRI is a component of the imaging workup for various prenatal conditions, but its use as a prognosticator has been most heavily studied in congenital diaphragmatic hernia (CDH). Pediatric radiologists who perform and interpret fetal MRI must be familiar with the technical aspects of lung volume measurement to guarantee accurate measurement and reporting. Variability in timing and type of measurement at different fetal centers also requires pediatric radiologists to be up-to-date with the literature and aware of their center's internal data. This paper provides both a how-to guide for measuring fetal lung volumes on MRI and a comprehensive review of the CDH outcome literature to serve as a convenient reference for the pediatric radiologist.

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.

Novel Use of a Bronchial Blocker in a Challenging Case of Congenital Diaphragmatic Hernia—A Case Report

The diagnosis of congenital diaphragmatic hernia (CDH) is associated with significant morbidity and mortality. Survival of neonates with CDH has improved recently, although the clinical course is complicated by sequelae of hypoplastic pulmonary parenchyma and vasculature, pulmonary hypertension, ventilation/perfusion (V/Q) mismatch, reduced pulmonary function and poor somatic growth. In this case report, we describe an infant with an antenatal diagnosis of CDH with a poor prognosis who underwent initial surgery followed by a tracheostomy but had a worsening clinical course due to a large area of ventilated but poorly perfused lung based on a V/Q nuclear scintigraphy scan. The emphysematous left lung was causing mediastinal shift and compression of the right lung, further compromising gas exchange. The infant had clinical improvement following bronchial blockade of the under-perfused left lung. This paved the way for further management with resection of the under-perfused lung lobe and continued clinical improvement. We present the novel use of selective bronchial blockade in a challenging case of CDH to determine if surgical lung resection may benefit the infant. We also review the physiology of gas exchange during the use of a bronchial occluder and the relevant literature.

Primary contributors to gastrostomy tube placement in infants with Congenital Diaphragmatic Hernia

OBJECTIVE

To identify factors associated with gastrostomy tube (GT) placement in infants with congenital diaphragmatic hernia (CDH).

METHODS

Retrospective cohort study of 114 surviving infants with CDH at a single tertiary care neonatal intensive care unit from 2010-2019. Prenatal, perinatal and postnatal characteristics were compared between patients who were discharged home with and without a GT. Prenatal imaging was available for 50.9% of the cohort. Logistic regression was used to assess the association between GT placement and pertinent clinical factors. ROC curves were generated, and Youden's J statistic was used to determine optimal predictive cutoffs for continuous variables. Elastic net regularized regression was used to identify variables associated with GT placement in multivariable analysis.

RESULTS

GT was placed in 43.9% of surviving infants with CDH. Prenatal variables predictive of GT placement were percent predicted lung volume (PPLV) <21%, total lung volume (TLV) <30 ml, lung-head ratio (LHR) <1.2 or observed to expected LHR (O/E LHR) <55%. Infants who required a GT were diagnosed earlier prenatally (23.6 ± 3.4 vs. 26.4 ± 5.6 weeks). Patients whose stomach was above the diaphragm on prenatal ultrasound (up) had a higher odds of GT placement compared to those with stomachs below the diaphragm (down) position by a factor of 2.9 (95% CI: 1.25, 7.1); p = 0.0154. Postnatally, infants with GT had lower Apgar scores at 1 and 5 min, longer lengths of stay and higher proportion of flap closures. Infants with a type C or D defect and extracorporeal membrane oxygenation (ECMO) were associated with increased odds of needing a GT. Postnatal association included being NPO for >12 days, need for transpyloric (TP) feeds for >10 days, >14 days to transition to a 30 min bolus feed, presence of gastro-esophageal reflux (GER), chronic lung disease and pulmonary hypertension. In multivariable analysis, duration of NPO, time to TP feeds, transition to 30 min bolus feeds remained significantly associated with GT placement after adjusting for severity of pulmonary hypertension (PH), GER diagnosis and sildenafil treatment.

CONCLUSION

Identification of risk factors associated with need for long-term feeding access may improve timing of GT placement and prevent prolonged hospitalization related to feeding issues.

LEVEL OF EVIDENCE RATING

Level II (Retrospective Study).

Magnetic Resonance Prediction of Lung Maturity in Fetuses With Congenital Diaphragmatic Hernia

ABSTRACT

To determine if lung to liver MR T2 signal ratio is predictive of neonatal outcome in fetuses with congenital diaphragmatic hernia (CDH).After Interal Review Board approval, the PACS systems at the University of Washington and University of Utah were searched for cases having an in utero fetal MR examination diagnostic of CDH. Inclusion criteria were at least 1 prior ultrasound demonstrating a CDH and an MR obtained within 1 week of that prior ultrasound.A total of 69 patients from the University of Utah and 13 from the University of Washington satisfied the inclusion criteria for a total of 82. After adjusting for gestational age and contralateral lung volume, there was little apparent association between contralateral lung to liver MR T2 signal and 5-minute Apgar score and neonatal mortality When considering neonatal Apgar and mortality, increasing contralateral lung volume was significantly associated with lower risk (hazard ratio, 0.40 per doubling; 95% confidence interval, 0.24-0.69; P = 0.001) as expected.Our data demonstrate that the lung to liver MR signal ratio was not predictive of outcome. The measurement of contralateral lung area, and gestational age at the time of the examination (time of diagnosis) are still the best predictors of poor neonatal outcome.

Fetal body MRI and its application to fetal and neonatal treatment: an illustrative review

This Review depicts the evolving role of MRI in the diagnosis and prognostication of anomalies of the fetal body, here including head and neck, thorax, abdomen and spine. A review of the current literature on the latest developments in antenatal imaging for diagnosis and prognostication of congenital anomalies is coupled with illustrative cases in true radiological planes with viewable three-dimensional video models that show the potential of post-acquisition reconstruction protocols. We discuss the benefits and limitations of fetal MRI, from anomaly detection, to classification and prognostication, and defines the role of imaging in the decision to proceed to fetal intervention, across the breadth of included conditions. We also consider the current capabilities of ultrasound and explore how MRI and ultrasound can complement each other in the future of fetal imaging.

Fetal endoscopic tracheal occlusion for congenital diaphragmatic hernia: a narrative review of the history, current practice, and future directions

Fetal intervention for fetuses with congenital diaphragmatic hernia (CDH) has been investigated for over 30 years and is summarized in this manuscript. The review begins with a discussion of the history of fetal intervention for this severe congenital anomaly beginning with open fetal surgery with repair of the anatomical defect, shifting towards tracheal occlusion via open surgery techniques, and finally fetoscopic endoluminal balloon tracheal occlusion using a percutaneous approach. The current technique of fetal endoscopic tracheal occlusion (FETO) is described in detail with steps of the procedure and complementary figures. The main outcomes of single-institutional studies and multiple systematic reviews are examined and discussed. Despite these studies, the fetal community agrees that FETO remains investigational at this time as there is insufficient evidence to recommend it as the standard of care for CDH. A randomized controlled trial, The Tracheal Occlusion to Accelerate Lung Growth (TOTAL) trial, has been designed to attempt to answer this question in an elaborate, international, multi-institutional study and is described in the text. Finally, future directions of fetal intervention for antenatally diagnosed CDH are discussed, including options for non-isolated CDH, the Smart-TO balloon for nonoperative reversal of occlusion, and transplacental sildenafil for treatment of pulmonary hypertension prior to birth.

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.

Risk factors for acute kidney injury in neonates with congenital diaphragmatic hernia

OBJECTIVE

To examine incidence of acute kidney injury (AKI), antenatal and postnatal predictors, and impact of AKI on outcomes in infants with congenital diaphragmatic hernia (CDH).

STUDY DESIGN

Single center retrospective study of 90 CDH infants from 2009-2017. Baseline characteristics, CDH severity, possible AKI predictors, and clinical outcomes were compared between infants with and without AKI.

RESULT

In total, 38% of infants developed AKI, 44% stage 1, 29% stage 2, 27% stage 3. Lower antenatal lung volumes and liver herniation were associated with AKI. Extracorporeal life support (ECLS), diuretics, abdominal closure surgery, hypotension, and elevated plasma free hemoglobin were associated with AKI. Overall survival was 79%, 47% with AKI, and 35% with AKI on ECLS. AKI is associated with increased mechanical ventilation duration and length of stay.

CONCLUSION

AKI is common among CDH infants and associated with adverse outcomes. Standardized care bundles addressing AKI risk factors may reduce AKI incidence and severity.

Congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a potentially severe anomaly that should be referred to a fetal care center with expertise in multidisciplinary evaluation and management. The pediatric radiologist plays an important role in the evaluation of CDH, both in terms of anatomical description of the anomaly and in providing detailed prognostic information for use in caring for the fetus and pregnant mother as well as planning for delivery and postnatal care. This article reviews the types of hernias, including distinguishing features and imaging clues. The most common methods of predicting severity are covered, and current fetal and postnatal therapies are explained. The author of this paper provides a handy reference for pediatric radiologists presented with a case of CDH as part of their daily practice.

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.

Prenatal assessment of congenital diaphragmatic hernia at north american fetal therapy network centers: A continued plea for standardization

INTRODUCTION

Prenatal work-up for congenital diaphragmatic hernia (CDH) is important for risk stratification, standardization, counseling, and optimal therapeutic choice. To determine current practice patterns regarding prenatal CDH work-up, including prenatal ultrasound and magnetic resonance imaging (MRI) use, and to identify areas for standardization of such evaluation between fetal centers.

METHODS

A survey regarding prenatal CDH work-up was sent to each member center of the North American Fetal Therapy Network (NAFTNet) (n = 36).

RESULTS

All responded. Sonographic measurement of lung-to-head ratio (LHR) was determined by all, 89% (32/36) of which routinely calculate observed-to-expected LHR. The method for measuring LHR varied: 58% (21/36) used a "trace" method, 25% (9/36) used "longest axis," and 17% (6/36) used an "antero-posterior" method. Fetal MRI was routinely used in 78% (28/36) of centers, but there was significant variability in fetal lung volume measurement. Whereas all generated a total fetal lung volume, the planes, methodology and references values varied significantly. All evaluated liver position, 71% (20/28) evaluated stomach position and 54% (15/28) quantified the degree of liver herniation. More consistency in workup was seen between centers offering fetal intervention.

CONCLUSION

Prenatal CDH work-up and management differs considerably among North American fetal diagnostic centers, highlighting a need for its standardization.

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.

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.

Imagiological methods for prediction of fetal pulmonary hypoplasia: a systematic review

OBJECTIVE

To compare the different imagiological methods for prediction of fetal pulmonary hypoplasia (PH) in general diseases and associated with preterm rupture of membranes (PROM), and congenital diaphragmatic hernia (CDH).

METHODS

According to PRISMA guidelines, all the literature on PH from 1988 to 2018 was reviewed. Twenty-nine articles were selected and analyzed for two- and three- dimensional-ultrasounds (2D and 3D-US) as predictors for the lethal outcome.

RESULTS

Overall, the results identify a general gap correlating prenatal pulmonary measurements and survival at birth; discrepant predictive values for the same imagiological methods are explained by the group heterogeneity in terms of diseases and degree of severity, with the 2D measurements being more affected than 3D; 2D and 3D-US present equally predictive values for groups with 0% of survival. Regarding PROM, results demonstrate comparable accuracies for similar survival rates suggesting a useful predictive value of 2D-US in outcome estimation; they also identify ultrasonographic methods as a more accurate prognostic factor than gestational age at rupture, latency or amniotic fluid index. In CDH, consistent with previous studies, our review shows magnetic resonance imaging as a better survival predictor followed by the 3D and 2D methods, while 2D-LHR was the more precise prognosticator correlating prenatal PH, survival at birth, and the need for neonatal respiratory support.

CONCLUSION

Ultrasonographic methods can be valuable predictors for lethal PH and should be validated for a broad set of diseases (e.g. PROM). For that, restricted studies for disease groups and correlating fetal PH with the needed of neonatal support, and survival at birth is critically recommended.

Fetal brain morphometry on prenatal magnetic resonance imaging in congenital diaphragmatic hernia

BACKGROUND

Many infants with congenital diaphragmatic hernia (CDH) show brain abnormality on postnatal brain MRI related to severity of CDH, degree of lung hypoplasia, intrathoracic liver, right diaphragmatic hernia and large diaphragmatic defect. It is not known whether these factors affect brain growth in utero in CDH.

OBJECTIVE

To assess prenatal brain morphometry and abnormalities on fetal MR in congenital diaphragmatic hernia.

MATERIALS AND METHODS

We retrospectively reviewed 109 fetal MRIs in 63 fetuses with CDH from 2009 to 2014 (27 died before discharge, 36 survived to discharge). We compared brain injury and gestational-age-corrected z-scores of brain measurements between survivors and non-survivors. We assessed correlations between brain abnormalities and CDH severity.

RESULTS

Enlarged extraaxial space was the most common abnormality, frequently seen on fetal MRI at >28 weeks of gestation, similar in survivors versus non-survivors. Anteroposterior cerebellar vermis dimension at >28 weeks of gestation was smaller in non-survivors compared to survivors (P=.02) and positively correlated with observed/expected total fetal lung volume (P=.01). Transverse cerebellar diameter at >28 weeks of gestation was also positively correlated with observed/expected total fetal lung volume (P=.04). We did not identify maturational delay, abnormal parenchymal signal or intracranial hemorrhage on fetal MRI.

CONCLUSION

Enlarged extraaxial spaces in the third trimester was the most common abnormality on fetal MRI in congenital diaphragmatic hernia. Cerebellar dimensions on fetal MRI are associated with CDH severity. There was no major brain parenchymal injury on fetal MRI, even in the third trimester, in CDH survivors and non-survivors.

A new approach to risk stratification using fetal MRI to predict outcomes in congenital diaphragmatic hernia: the preliminary retrospective single institutional study

BACKGROUND

Congenital diaphragmatic hernia (CDH) is a condition with a wide range of severity. Prenatal diagnosis is essential to optimize postnatal management, especially for severe cases. The lung to head ratio (LHR) and liver herniation estimated by prenatal ultrasound has been used as prenatal predictors in CDH. However, reliability of these factors remains to be proven and prediction of outcome from prenatal imaging is still challenging. We propose our new stratification system using lung to liver signal intensity ratio (LLSIR) in fetal MRI, which has been shown to be related to pulmonary maturation.

METHODS

Retrospective chart review was conducted on 25 infants with CDH treated from 2009 through 2016 in our hospital. We stratified patients according to fetal T2-weighted MRI as Grade I, detectable ipsilateral lung at the apex; Grade II, undetectable ipsilateral lung at the apex and contralateral LLSR ≥2.0; Grade III, undetectable ipsilateral lung at the apex and contralateral LLSR <2.0. To evaluate this stratification system, we analyzed survival, severity [inhaled nitric oxide (iNO) usage with or without extracorporeal membrane oxygenation (ECMO)], and requirement of patch closure.

RESULTS

All 15 patients survived in Grade I, while 2 out of 6 died in Grade II, and 3 out of 4 died in Grade III (P=0.003). Four were severe in Grade I, and all in Grade II and III who survived (P=0.007). One needed patch in Grade I, and all in Grade II and III (OR: 414,238,332; 95% CI, 0-∞). Liver herniation was noted in five patients, and significantly associated with survival (P=0.04), however, neither with severity (P=1.00) nor with the requirement of patch closure (P=0.52).

CONCLUSIONS

The risk stratification algorithm using contralateral LLSIR in fetal MRI could be useful and more reliable than liver herniation to predict survival, severity, and need of patch closure. Further investigation is warranted.

Predictive value of oxygenation index for outcomes in left-sided congenital diaphragmatic hernia

BACKGROUND & OBJECTIVES

Congenital Diaphragmatic Hernia (CDH) is associated with significant morbidity and mortality. This study compares the efficacy of the highest oxygenation index in the first 48 h (HiOI) versus current prenatal indices to predict survival and morbidity.

METHODS

Medical records of 50 prenatally diagnosed, isolated, left-sided CDH patients treated from January 2011 to April 2016 were reviewed. Data abstracted included HiOI, lung to head ratio (LHR), observed to expected total fetal lung volume (O/E TFLV), percent liver herniation (%LH), 6 month survival, respiratory support at discharge, ventilator days and length of stay. Data were analyzed using parametric and nonparametric tests and regression analyses as appropriate.

RESULTS

HiOI was associated with significantly increased LOS (p<0.001), respiratory support at discharge (p<0.001), greater ventilator days (p=0.001) and higher odds of death (p=0.004) with risk of death increasing by 5% for every one-unit increase in OI. HiOI was statistically a better predictor of LOS than O/E TFLV (p=0.007) and %LH (p=0.02).

CONCLUSIONS

In isolated, left-sided CDH patients, HiOI is associated with higher mortality, greater length of stay, more ventilator days and increased respiratory support at discharge. HiOI is a better predictor of length of stay than O/E TFLV and %LH.

TYPE OF STUDY

Retrospective Study LEVEL OF EVIDENCE: II.

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.

Risk stratification for congenital diaphragmatic hernia by factors within 24 h after birth

OBJECTIVE

To establish a simple risk stratification system for patients with congenital diaphragmatic hernia (CDH) based on postnatal information within 24 h after birth.

STUDY DESIGN

A multi-institutional retrospective cohort study was conducted including 348 neonates who had isolated CDH born between 2006 and 2010. Based on the two most powerful variables for 90-day survival selected by multivariate analyses, a risk stratification system was established.

RESULTS

Multiple logistic regression analysis identified two adverse prognostic factors: an Apgar score at 1 min (Ap1) of 0-4 (odds ratio (OR) 3.3, P=0.004), and a best oxygenation index (OI) ⩾8.0 (OR 11.4, P<0.001). Based on a combinations of these two factors, patients were classified into three risk categories. The 90-day survival rates in categories 1-3 were 100, 88 and 52%, respectively (P<0.001).

CONCLUSION

Our simple risk stratification system based on Ap1 and best OI was capable of predicting mortality well.

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.

Lung size and liver herniation predict need for extracorporeal membrane oxygenation but not pulmonary hypertension in isolated congenital diaphragmatic hernia: systematic review and meta-analysis

OBJECTIVES

To identify antenatal predictors of persistent pulmonary hypertension (PPH) and the need for extracorporeal membrane oxygenation (ECMO) in fetuses with congenital diaphragmatic hernia (CDH).

METHODS

We performed a systematic literature review on antenatal diagnostic tests in fetuses with isolated CDH. The primary outcomes assessed were PPH within 28 days of age and the need for ECMO. Quality of studies was assessed with the QUADAS-2 tool. Meta-analysis was performed when at least three studies reported on the same test. Sensitivity analysis was performed according to prenatal management of CDH (tracheal occlusion vs expectant management).

RESULTS

Thirty-eight studies met the inclusion criteria. Fifteen reported on the incidence of PPH only, 19 on the need for ECMO only and four reported on both outcomes. The general quality of the studies was moderate; most studies were retrospective (61%) and single-center series (92%). One study included only fetuses undergoing tracheal occlusion, 22 included only fetuses managed expectantly in utero and 15 included both populations. We could not identify antenatal predictors of PPH. The need for ECMO was predicted by parameters indicative of lung size: lung-to-head ratio (LHR) (relative risk (RR) for LHR < 1, 1.65 (95% CI, 1.27-2.14)) and observed/expected LHR (standardized mean difference (SMD), -0.70 (95% CI, -0.98 to -0.42)) measured by ultrasound and observed/expected total lung volume (SMD, -1.00 (95% CI, -1.52 to -0.48)) measured by magnetic resonance imaging. Liver herniation was also associated with an increased risk of need for ECMO (RR, 3.04 (95% CI, 2.23-4.14)). These results were confirmed by a sensitivity analysis of studies that included only expectantly managed cases. Data on vascular assessment for the prediction of PPH could not be pooled as most of the parameters were evaluated in a single series or in different series by the same principal investigator.

CONCLUSIONS

In fetuses with CDH, lung size and liver herniation predict the need for ECMO, however a predictor for PPH is still lacking. Further studies aimed at diagnosing impaired vascular development in utero should therefore be undertaken. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

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.

Antenatal predictors of outcome in prenatally diagnosed congenital diaphragmatic hernia (CDH)

BACKGROUND

Pulmonary hypoplasia is the main cause of mortality in isolated congenital diaphragmatic hernia (CDH) and its prediction is paramount when counseling parents. We sought to identify antenatal parameters that predicted neonatal mortality in CDH.

METHOD

Search was conducted in MEDLINE, EMBASE, Cochrane Database of Systematic reviews, PubMed, Scopus, and Web of Science on the ability of lung-to-head ratio (LHR), observed-to-expected LHR (o/e LHR), total fetal lung volume (TFLV), o/e TFLV, percentage predicted lung volume (PPLV) and degree of liver herniation to predict neonatal morbidity and mortality in fetuses with CDH. Primary outcome was perinatal survival and secondary was the use of extracorporeal membrane oxygenation (ECMO).

RESULTS

Until April 2016, 1067 articles were found, of which 22 were included in our meta-analysis. This showed that the odds of survival with LHR <1.0 and liver herniation on ultrasound were 0.14 (CI 0.10-0.27) and 0.21 (CI 0.13-0.35) respectively. Mean LHR, o/e LHR, absolute TFLV, o/e TFLV, PPLV and liver herniation all predicted survival, however o/e LHR and o/e TFLV performed best in this prediction. When the longest diameter measurement method was used, the o/e TFLV (summary area under curve (AUC) 0.8) was slightly superior to o/e LHR (summary AUC 0.78). This difference disappeared when LHR was measured by the trace method. The most discriminatory threshold for O/E LHR and O/E TFLV was 25%. LHR <1 was predictive of extracorporeal life support (ECLS) use.

CONCLUSION

O/E LHR, o/e TFLV (thresholds of 25%) and liver herniation are good predictors of mortality in CDH.

LEVEL OF EVIDENCE

Level II Type of study: Systematic review and meta-analysis.

Does the ex utero intrapartum treatment to extracorporeal membrane oxygenation procedure change morbidity outcomes for high-risk congenital diaphragmatic hernia survivors?

PURPOSE

In high-risk congenital diaphragmatic hernia (CDH), significant barotrauma or death can occur before extracorporeal membrane oxygenation (ECMO) can be initiated. We previously examined ex utero intrapartum treatment (EXIT)-to-ECMO in our most severe CDH patients, but demonstrated no survival advantage. We now report morbidity outcomes in survivors of this high-risk cohort to determine whether EXIT-to-ECMO conferred any benefit.

METHODS

All CDH survivors with <15% predicted lung volume (PPLV) from September 1999 to December 2010 were included. We recorded prenatal imaging, defect size, and pulmonary, nutritional, cardiac, and neurodevelopmental outcomes.

RESULTS

Seventeen survivors (8 EXIT-to-ECMO, 9 non-EXIT) had an average PPLV of 11.7%. Eight of 9 non-EXIT received ECMO within 2days. There were no significant defect size differences between groups, mostly left-sided (13/17) and type D (12/17). Average follow-up was 6.7years (0-13years). There were no statistically significant differences in outcomes, including supplemental oxygen, diuretics, gastrostomy, weight-for-age Z scores, fundoplication, pulmonary hypertension, stroke or intracranial hemorrhage rate, CDH recurrence, and reoperation. No survivor in our cohort was neurologically devastated. All had mild motor and/or speech delay, which improved in most.

CONCLUSIONS

In this pilot series of severe CDH survivors, EXIT-to-ECMO confers neither significant survival nor long-term morbidity benefit.

LEVEL OF EVIDENCE

Level III treatment study.

Prenatally diagnosed severe CDH: mortality and morbidity remain high

PURPOSE

This study sought to evaluate prenatal markers' ability to predict severe congenital diaphragmatic hernia(CDH) and assess this subgroup's morbidity and mortality.

METHODS

A retrospective review was performed between 2006 and 2014. Prenatal criteria for severe CDH included: liver herniation, lung-to-head ratio (LHR) <1 on prenatal ultrasound and/or observed-to-expected LHR (o/eLHR) <25%, and/or observed-to-expected total lung volume (o/eTLV) <25% on fetal MRI. Postnatal characteristics included: mortality, ECMO utilization, patch closure, persistent suprasystemic pulmonary hypertension (PHtn), O2 requirement at discharge, and few ventilator-free days in the first 60. Statistics performed used unpaired t-test, p<0.05 significant.

RESULTS

Overall, 47.5%(29/61) of patients with prenatally diagnosed, isolated CDH met severe criteria. Mean LHR: 1.04±0.35, o/eLHR: 31±10% and o/eTLV: 20±7%. Distribution was 72% LCDH, 24% R-CDH. Overall survival: 38%. ECMO requirement: 92%. Patch rate: 91%. Mean ventilator-free days in 60: 7.1±14. Supplemental oxygen at discharge was required in 27%. In this prenatally diagnosed severe cohort, 58%(15/26) had persistent PHtn post-ECMO requiring inhaled nitric oxide±epoprostenol. Comparing patients with and without PHtn: mean ECMO duration 18±10 days versus 9±7 days (p=0.01) and survival 20% versus 72% (p=0.006).

CONCLUSION

A combination of prenatal markers accurately identified severe CDH patients. Outcomes of this group remain poor and persistent PHtn contributes significantly to mortality.

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.

Why do we need more data on MR volumetric measurements of the fetal lung?

Fetal lung hypoplasia is associated with a series of congenital anomalies, particularly the congenital diaphragmatic hernia. Evaluation of the severity of the lung hypoplasia is important for parental counseling, assessment of prognosis and planning of postnatal management. Although a large number of studies have been performed to measure fetal lung volumes in order to predict outcome, there are little data on fetuses younger than 24 weeks of gestation, the age when parental counseling is crucial if termination is considered. Few studies have evaluated prognosis of lung hypoplasia in fetuses with congenital chest anomalies other than congenital diaphragmatic hernia. We review the studies on measurements of the fetal lung volumes by MRI.

Prenatal and postnatal markers of severity in congenital diaphragmatic hernia have similar prognostic ability

OBJECTIVES

The purpose of this study was to compare prenatal versus postnatal markers of congenital diaphragmatic hernia (CDH) severity at a single fetal-care center.

METHODS

A retrospective study was performed of patients having a complete prenatal evaluation and surgical repair (n = 55). Observed-to-expected lung-to-head ratio (o/eLHR), observed-to-expected total lung volume (o/eTLV), liver position (LP), a predictive dependent variable from logistic regression of o/eLHR and liver position (o/eLHR + LP), and diaphragmatic defect size per the CDH Study Group A-D classification were plotted into receiver-operating characteristics (ROC) curves. Survival and need for extracorporeal membrane oxygenation (ECMO) were primary outcomes.

RESULTS

Survival was 69%, and ECMO utilization was 56%. Distribution was 80% left-sided defects. In the survival ROC curve, the area under the curve (AUC) for o/eLHR was 0.73, o/eTLV 0.74, LP 0.73, o/eLHR + LP 0.78, and defect size 0.84 (p = 0.23). The ROC curve for ECMO support showed o/eLHR had an AUC of 0.82, o/eTLV 0.89, LP 0.79, o/eLHR + LP 0.87, and defect size 0.90 (p = 0.19). The AUCs were similar when only left-sided CDH was analyzed.

CONCLUSIONS

These data suggest that prenatal evaluation was equivalent to the postnatal diaphragmatic defect classification for predicting survival and need for ECMO in CDH patients.

Imaging findings in fetal diaphragmatic abnormalities

Imaging plays a key role in the detection of a diaphragmatic pathology in utero. US is the screening method, but MRI is increasingly performed. Congenital diaphragmatic hernia is by far the most often diagnosed diaphragmatic pathology, but unilateral or bilateral eventration or paralysis can also be identified. Extralobar pulmonary sequestration can be located in the diaphragm and, exceptionally, diaphragmatic tumors or secondary infiltration of the diaphragm from tumors originating from an adjacent organ have been observed in utero. Congenital abnormalities of the diaphragm impair normal lung development. Prenatal imaging provides a detailed anatomical evaluation of the fetus and allows volumetric lung measurements. The comparison of these data with those from normal fetuses at the same gestational age provides information about the severity of pulmonary hypoplasia and improves predictions about the fetus's outcome. This information can help doctors and families to make decisions about management during pregnancy and after birth. We describe a wide spectrum of congenital pathologies of the diaphragm and analyze their embryological basis. Moreover, we describe their prenatal imaging findings with emphasis on MR studies, discuss their differential diagnosis and evaluate the limits of imaging methods in predicting postnatal outcome.

Prenatal consultation for foetal anomalies requiring surgery

BACKGROUND

During prenatal screening of pregnant women, foetal anomalies requiring surgery may be diagnosed. Healthcare providers should have a basic knowledge of these diseases, including their workup, comorbidities, prognosis, treatment options and any considerations that need to be made in planning for birth.

AIM

This article aims to provide this information by summarising the most recent literature for some of the most commonly diagnosed foetal anomalies requiring surgical correction.

METHODS

English language studies on prenatal diagnostic modalities, abdominal wall defects, congenital diaphragmatic hernias, surgical conditions leading to airway compromise, hydrops fetalis, intestinal obstruction and abdominal cysts were retrieved from the PubMed database.

FINDINGS

The most recent and relevant literature is summarised regarding the above listed paediatric conditions. The incidence and prevalence (when available), prognosis, workup, common comorbidities, foetal interventions and special birth considerations (when applicable), and postnatal surgical treatment options are reviewed.

CONCLUSIONS

Healthcare providers will occasionally encounter foetal anomalies which may require surgery while performing prenatal screening. They may need to provide early counselling to expectant parents to inform their expectations. When indicated, referrals should be made to a foetal care centre for prenatal consultation. For conditions which may cause danger or distress to the foetus in the immediate postnatal period, preparations should be made to ensure sufficient resources are available at the location of birth.

Controversies in the management of severe congenital diaphragmatic hernia

Despite years of progress in perinatal care, severe congenital diaphragmatic hernia (CDH) remains a clinical challenge. Controversies include almost every facet of clinical care: the definition of severe CDH by prenatal and postnatal criteria, fetal surgical intervention, ventilator management, pulmonary hypertension management, use of extracorporeal membrane oxygenation, surgical considerations, and long-term follow-up. Breakthroughs are likely only possible by sharing of experience, collaboration between institutions and innovative therapies within well-designed multicenter clinical trials.

Novel non-surgical prenatal approaches to treating congenital diaphragmatic hernia

This review focuses on the emerging field of non-surgical in-utero therapies in the management of fetal pulmonary hypoplasia and pulmonary hypertension associated with congenital diaphragmatic hernia (CDH). These experimental approaches include pharmacologic as well as stem-cell-based strategies. Current barriers of non-surgical therapies toward clinical translation are emphasized. As the severity of CDH will likely influence the efficacy of any in-utero therapy, the current status of prenatal imaging and the role of novel biomarkers, especially those related to fetal inflammation, are also reviewed.

The lung to thorax transverse area ratio has a linear correlation with the observed to expected lung area to head circumference ratio in fetuses with congenital diaphragmatic hernias

BACKGROUND/PURPOSE

The purpose of this study was to clarify the relationship between the lung to thorax transverse area ratio (L/T ratio) and the observed to expected lung area to head circumference ratio (O/E LHR), based on the results of a nationwide Japanese survey conducted in 2011, and to evaluate the compatibility of these prognostic predictors of fetal CDH.

METHODS

Two hundred and forty-two prenatally diagnosed isolated CDH patients born between 2006 and 2010 were included in the present analysis. A regression analysis was conducted to investigate the relationship between the L/T ratio and the O/E LHR based on 191 simultaneous measurements of these parameters in 120 patients.

RESULTS

The linear regression equation between the L/T ratio and the O/E LHR was: L/T ratio=0.0233+(0.00222×O/E LHR), (R=0.847, p<0.0001). According to this equation, 25% of the O/E LHR, the cut-off value used in the fetal intervention for CDH, was equivalent to an L/T ratio of 0.08, a commonly accepted cut-off value for identifying the most severe cases of fetal CDH.

CONCLUSIONS

As there is a positive correlation between the L/T ratio and the O/E LHR, these two parameters proved to be used interchangeably according to the linear regression equation.

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.