Assessment of lung area in fetuses with congenital diaphragmatic hernia

Observed-to-expected lung-area-to-head-circumference ratio on ultrasound examination vs total fetal lung volume on magnetic resonance imaging in prediction of survival in fetuses with left-sided diaphragmatic hernia

OBJECTIVE

To assess and compare the value of antenatally determined observed-to-expected (O/E) lung-area-to-head-circumference ratio (LHR) on ultrasound examination vs O/E total fetal lung volume (TFLV) on magnetic resonance imaging (MRI) examination to predict postnatal survival of fetuses with isolated, expectantly managed left-sided congenital diaphragmatic hernia (CDH).

METHODS

This was a multicenter retrospective study including all consecutive fetuses with isolated CDH that were managed expectantly in Mannheim, Germany, and in five other European centers, that underwent at least one ultrasound examination for measurement of O/E-LHR and one MRI scan for measurement of O/E-TFLV during pregnancy. All MRI data were centralized, and lung volumes were measured by two experienced operators blinded to the pre- and postnatal data. Multiple logistic regression analyses were performed to examine the effect on survival at hospital discharge of various perinatal variables, including the center of management. In left-sided CDH with intrathoracic herniation of the liver, receiver-operating-characteristics (ROC) curves were constructed separately for cases from Mannheim and the other five European centers and were used to compare O/E-TFLV and O/E-LHR in the prediction of postnatal survival.

RESULTS

From Mannheim, 309 patients were included with a median gestational age (GA) at ultrasound examination of 29.6 (range, 19.7-39.1) weeks and median GA at MRI examination of 31.1 (range, 18.0-39.9) weeks. From the other five European centers, 116 patients were included with a median GA at ultrasound examination of 26.7 (range, 20.6-37.6) weeks and median GA at MRI examination of 27.7 (range, 21.3-37.9) weeks. Regression analysis demonstrated that the survival rates at discharge were lower in left-sided CDH (odds ratio (OR), 0.349 (95% CI, 0.133-0.918), P = 0.033) and those with intrathoracic liver (OR, 0.297 (95% CI, 0.141-0.628), P = 0.001), and higher with increasing O/E-TFLV (OR, 1.123 (95% CI, 1.079-1.170), P < 0.001), advanced GA at birth (OR, 1.294 (95% CI, 1.055-1.588), P = 0.013) and when birth occurred in Mannheim (OR, 7.560 (95% CI, 3.368-16.967), P < 0.001). Given the difference in survival rate between Mannheim and the five other European centers, ROC curve comparisons between the two imaging modalities were presented separately. For cases of left-sided CDH with intrathoracic herniation of the liver, pairwise comparison showed no significant difference between the area under the ROC curves for the prediction of postnatal survival between O/E-TFLV and O/E-LHR in Mannheim (mean difference = 0.025, P = 0.610, standard error = 0.050), whereas there was a significant difference in the other European centers studied (mean difference = 0.056, P = 0.033, standard error = 0.056).

CONCLUSIONS

In fetuses with left-sided CDH and intrathoracic herniation of the liver, the predictive value for postnatal survival of O/E-TFLV on MRI examination and O/E-LHR on ultrasound examination was similar in one center (Mannheim), but O/E-TFLV had better predictive value compared to O/E-LHR in the five other European centers. Hence, in these five European centers, MRI should be included in the diagnostic process for left-sided CDH. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Clinical assessment of the fetal right Quantitative Lung Index

OBJECTIVES

We have previously described gestational-age-independent sonographic indices to assess fetal lung size in the right and left lungs: The Quantitative Lung Index for the right lung (QLI-R) and for the left lung (QLI-L), respectively. The purpose of this study was to evaluate the clinical cutoff point of the QLI-R to predict pulmonary hypoplasia and neonatal death.

MATERIALS AND METHODS

Retrospective assessment of the QLI-R in patients with left-sided congenital diaphragmatic hernia (CDH-L) and other fetal conditions at risk for fetal pulmonary hypoplasia. Cross-section and longitudinal assessment of the behavior of the QLI-R in untreated and treated patients. ROC curve analysis to determine the optimal cutoff point of the QLI-R in predicting neonatal death.

RESULTS

One hundred eighteen patients with CDH-L and other fetal conditions at risk for pulmonary hypoplasia had QLI-R measurements done. Seventeen patients were excluded for various reasons. Eleven patients with conditions other than CDH-L but at risk for pulmonary hypoplasia were used for intraclass coefficient measurements of the QLI-R. Ninety patients had CDH-L, of which 78 did not undergo antenatal intervention and in which the cutoff point for pulmonary hypoplasia and neonatal demise was assessed. Stent tracheal occlusion was performed in the remaining 12 patients with CDH-L, in which the behavior of the QLI after surgery was assessed. Analysis of the ICC showed an overall intra-rater reliability of 0.985 (Cronbach's Alpha-based). There was no correlation between gestational age and QLI-R (-0.73, Pearson correlation, p = .72). Twenty-six of the 78 patients (33%) with CDH-L managed expectantly had a neonatal demise. A QLI-R equal to or less than 0.45 was significantly predictive of neonatal demise (area under the curve 0.64, p = .046, sensitivity 77%). Nine of the 12 patients (75%) that underwent tracheal occlusion had neonatal survival. Of these, 10 had serial assessments of the QLI-R after surgery. An increase in the QLI-R of 0.11 was associated with a tendency for neonatal survival (p = .056).

CONCLUSION

Our study confirms that the QLI-R is a gestational-age-independent measurement of fetal lung size, with a high degree of reproducibility. In a population of expectantly managed CDH-L patients, a cutoff value of the QLI-R of 0.45 or lower is predictive of neonatal death from pulmonary hypoplasia. The QLI-R can be used to monitor fetal lung growth after tracheal occlusion, and an increase in the QLI-R is suggestive of neonatal survival. Further prospective studies are needed to confirm these findings and to explore the use of the QLI in other populations at risk for pulmonary hypoplasia and consequent neonatal demise.

Evolving the Era of 5D Ultrasound? A Systematic Literature Review on the Applications for Artificial Intelligence Ultrasound Imaging in Obstetrics and Gynecology

Artificial intelligence (AI) has gained prominence in medical imaging, particularly in obstetrics and gynecology (OB/GYN), where ultrasound (US) is the preferred method. It is considered cost effective and easily accessible but is time consuming and hindered by the need for specialized training. To overcome these limitations, AI models have been proposed for automated plane acquisition, anatomical measurements, and pathology detection. This study aims to overview recent literature on AI applications in OB/GYN US imaging, highlighting their benefits and limitations. For the methodology, a systematic literature search was performed in the PubMed and Cochrane Library databases. Matching abstracts were screened based on the PICOS (Participants, Intervention or Exposure, Comparison, Outcome, Study type) scheme. Articles with full text copies were distributed to the sections of OB/GYN and their research topics. As a result, this review includes 189 articles published from 1994 to 2023. Among these, 148 focus on obstetrics and 41 on gynecology. AI-assisted US applications span fetal biometry, echocardiography, or neurosonography, as well as the identification of adnexal and breast masses, and assessment of the endometrium and pelvic floor. To conclude, the applications for AI-assisted US in OB/GYN are abundant, especially in the subspecialty of obstetrics. However, while most studies focus on common application fields such as fetal biometry, this review outlines emerging and still experimental fields to promote further research.

Assessment of the fetal lungs in utero

Antenatal diagnosis of abnormal pulmonary development has improved significantly over recent years because of progress in imaging techniques. Two-dimensional ultrasound is the mainstay of investigation of pulmonary pathology during pregnancy, providing good prognostication in conditions such as congenital diaphragmatic hernia; however, it is less validated in other high-risk groups such as those with congenital pulmonary airway malformation or preterm premature rupture of membranes. Three-dimensional assessment of lung volume and size is now possible using ultrasound or magnetic resonance imaging; however, the use of these techniques is still limited because of unpredictable fetal motion, and such tools have also been inadequately validated in high-risk populations other than those with congenital diaphragmatic hernia. The advent of advanced, functional magnetic resonance imaging techniques such as diffusion and T2* imaging, and the development of postprocessing pipelines that facilitate motion correction, have enabled not only more accurate evaluation of pulmonary size, but also assessment of tissue microstructure and perfusion. In the future, fetal magnetic resonance imaging may have an increasing role in the prognostication of pulmonary abnormalities and in monitoring current and future antenatal therapies to enhance lung development. This review aims to examine the current imaging methods available for assessment of antenatal lung development and to outline possible future directions.

The Necessity of Magnetic Resonance Imaging in Congenital Diaphragmatic Hernia

This is a retrospective study investigating the relationship between ultrasound and magnetic resonance imaging (MRI) examinations in congenital diaphragmatic hernia (CDH). CDH is a rare cause of pulmonary hypoplasia that increases the mortality and morbidity of patients. Inclusion criteria were: patients diagnosed with CDH who underwent MRI examination after the second-trimester morphology ultrasound confirmed the presence of CDH. The patients came from three university hospitals in Bucharest, Romania. A total of 22 patients were included in the study after applying the exclusion criteria. By analyzing the total lung volume (TLV) using MRI, and the lung to head ratio (LHR) calculated using MRI and ultrasound, we observed that LHR can severely underestimate the severity of the pulmonary hypoplasia, even showing values close to normal in some cases. This also proves to be statistically relevant if we eliminate certain extreme values. We found significant correlations between the LHR percentage and herniated organs, such as the left and right liver lobes and gallbladder. MRI also provided additional insights, indicating the presence of pericarditis or pleurisy. We wish to underline the necessity of MRI follow-up in all cases of CDH, as the accurate measurement of the TLV is important for future treatment and therapeutic strategy.

Fetal endoscopic tracheal occlusion reverses the natural history of right-sided congenital diaphragmatic hernia: European multicenter experience

OBJECTIVE

To evaluate the neonatal outcome of fetuses with isolated right-sided congenital diaphragmatic hernia (iRCDH) based on prenatal severity indicators and antenatal management.

METHODS

This was a retrospective review of prospectively collected data on consecutive cases diagnosed with iRCDH before 30 weeks' gestation in four fetal therapy centers, between January 2008 and December 2018. Data on prenatal severity assessment, antenatal management and perinatal outcome were retrieved. Univariate and multivariate logistic regression analysis were used to identify predictors of survival at discharge and early neonatal morbidity.

RESULTS

Of 265 patients assessed during the study period, we excluded 40 (15%) who underwent termination of pregnancy, two cases of unexplained fetal death, two that were lost to follow-up, one for which antenatal assessment of lung hypoplasia was not available and six cases which were found to have major associated anomalies or syndromes after birth. Of the 214 fetuses with iRCDH included in the neonatal outcome analysis, 86 were managed expectantly during pregnancy and 128 underwent fetal endoscopic tracheal occlusion (FETO) with a balloon. In the expectant-management group, lung size measured by ultrasound or by magnetic resonance imaging was the only independent predictor of survival (observed-to-expected lung-to-head ratio (o/e-LHR) odds ratio (OR), 1.06 (95% CI, 1.02-1.11); P = 0.003). Until now, stratification for severe lung hypoplasia has been based on an o/e-LHR cut-off of 45%. In cases managed expectantly, the survival rate was 15% (4/27) in those with o/e-LHR ≤ 45% and 61% (36/59) for o/e-LHR > 45% (P = 0.001). However, the best o/e-LHR cut-off for the prediction of survival at discharge was 50%, with a sensitivity of 78% and specificity of 72%. In the expectantly managed group, survivors with severe pulmonary hypoplasia stayed longer in the neonatal intensive care unit than did those with mildly hypoplastic lungs. In fetuses with an o/e-LHR ≤ 45% treated with FETO, survival rate was higher than in those with similar lung size managed expectantly (49/120 (41%) vs 4/27 (15%); P = 0.014), despite higher prematurity rates (gestational age at birth: 34.4 ± 2.7 weeks vs 36.8 ± 3.0 weeks; P < 0.0001). In fetuses treated with FETO, gestational age at birth was the only predictor of survival (OR, 1.25 (95% CI, 1.04-1.50); P = 0.02).

CONCLUSIONS

Antenatal measurement of lung size can predict survival in iRCDH. In fetuses with severe lung hypoplasia, FETO was associated with a significant increase in survival without an associated increase in neonatal morbidity. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

The Chest Radiographic Thoracic Area Can Serve as a Prediction Marker for Morbidity and Mortality in Infants With Congenital Diaphragmatic Hernia

Objective: Valid postnatal prediction parameters for neonates with congenital diaphragmatic hernia (CDH) are lacking, but recently, the chest radiographic thoracic area (CRTA) was proposed to predict survival with high sensitivity. Here, we evaluated whether the CRTA correlated with morbidity and mortality in neonates with CDH and was able to predict these with higher sensitivity and specificity than prenatal observed-to-expected (O/E) lung-to-head ratio (LHR). Methods: In this retrospective cohort study, all neonates with CDH admitted to our institution between 2013 and 2019 were included. The CRTA was measured using the software Horos (V. 3.3.5) and compared with O/E LHR diagnosed by fetal ultrasonography in relation to outcome parameters including survival, extracorporeal membrane oxygenation (ECMO) support, and chronic lung disease (CLD). Results: In this study 255 neonates were included with a survival to discharge of 84%, ECMO support in 46%, and 56% developing a CLD. Multiple regression analysis demonstrated that the CRTA correlates significantly with survival (p = 0.001), ECMO support (p < 0.0001), and development of CLD (p = 0.0193). The CRTA displayed a higher prognostic validity for survival [area under the curve (AUC) = 0.822], ECMO support (AUC = 0.802), and developing a CLD (AUC = 0.855) compared with the O/E LHR. Conclusions: Our data suggest that the postnatal CRTA might be a better prognostic parameter for morbidity and mortality than the prenatal O/E LHR.

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.

Validation of a Prediction Rule for Mortality in Congenital Diaphragmatic Hernia

BACKGROUND

Congenital diaphragmatic hernia (CDH) is a rare congenital anomaly with a mortality of ∼27%. The Congenital Diaphragmatic Hernia Study Group (CDHSG) developed a simple postnatal clinical prediction rule to predict mortality in newborns with CDH. Our aim for this study is to externally validate the CDHSG rule in the European population and to improve its prediction of mortality by adding prenatal variables.

METHODS

We performed a European multicenter retrospective cohort study and included all newborns diagnosed with unilateral CDH who were born between 2008 and 2015. Newborns born from November 2011 onward were included for the external validation of the rule (n = 343). To improve the prediction rule, we included all patients born between 2008 and 2015 (n = 620) with prenatally diagnosed CDH and collected pre- and postnatal variables. We build a logistic regression model and performed bootstrap resampling and computed calibration plots.

RESULTS

With our validation data set, the CDHSG rule had an area under the curve of 79.0%, revealing a fair predictive performance. For the new prediction rule, prenatal herniation of the liver was added, and absent 5-minute Apgar score was taken out. The new prediction rule revealed good calibration, and with an area under the curve of 84.6%, it had good discriminative abilities.

CONCLUSIONS

In this study, we externally validated the CDHSG rule for the European population, which revealed fair predictive performance. The modified rule, with prenatal liver herniation as an additional variable, appears to further improve the model's ability to predict mortality in a population of patients with prenatally diagnosed CDH.

Congenital diaphragmatic hernia: current management strategies from antenatal diagnosis to long-term follow-up

Congenital diaphragmatic hernia (CDH) is a developmental birth defect consisting of a diaphragmatic defect and abnormal lung development. CDH complicates 2.3-2.8 per 10,000 live births. Despite efforts to standardize clinical practice, management of CDH remains challenging. Frequent re-evaluation of clinical practices in CDH reveals that management of CDH is evolving from one of postnatal stabilization to prenatal optimization. Translational research reveals promising avenues for in utero therapeutic intervention, including fetoscopic endoluminal tracheal occlusion. These remain highly experimental and demand improved antenatal diagnostics. Timely diagnosis of CDH and identification of severely affected fetuses allow time for delivery planning or in utero therapeutics. Optimal perinatal care and surgical treatment strategies are highly debated. Improved CDH mortality rates have placed increased emphasis on identifying and monitoring the long-term sequelae of disease throughout childhood and into adulthood. We review the current management strategies for CDH, highlighting where progress has been made, and where future developments have the potential to revolutionize care in this vulnerable patient population.

Fetal tracheal occlusion for congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) remains one of the most elusive birth defects to treat. Despite greater knowledge of disease and advances in technology, approximately one-third of CDH children born today still die. Consequently, clinicians and researchers have struggled to find the optimal treatment strategies for CDH. Without further innovations in postnatal treatment, many have focused an antenatal approach to improve pulmonary function. Fetoscopic Endoluminal Tracheal Occlusion (FETO) for CDH has evolved to the bedside after decades of research. While still under clinical investigation, FETO remains a promising adjunct to the treatment 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.

Fetal endoscopic tracheal occlusion reduces pulmonary hypertension in severe congenital diaphragmatic hernia

OBJECTIVE

Fetal endoscopic tracheal occlusion (FETO) is associated with increased perinatal survival and reduced need for extracorporeal membrane oxygenation (ECMO) in fetuses with severe congenital diaphragmatic hernia (CDH). This study evaluates the impact of FETO on the resolution of pulmonary hypertension (PH) in fetuses with isolated CDH.

METHODS

We reviewed retrospectively the medical records of all fetuses evaluated for CDH between January 2004 and July 2017 at a single institution. Fetuses with additional major structural or chromosomal abnormalities were excluded. CDH cases were classified retrospectively into mild, moderate and severe groups based on prenatal magnetic resonance imaging indices (observed-to-expected total fetal lung volume and percentage of intrathoracic liver herniation). Presence of PH was determined based on postnatal echocardiograms. Logistic regression analyses were performed to evaluate the relationship between FETO and resolution of PH by 1 year of age while controlling for side of the CDH, use of ECMO, gestational age at diagnosis, gestational age at delivery, fetal gender, sildenafil use at discharge and CDH severity. Resolution of PH by 1 year of age was compared between a cohort of fetuses with severe CDH that underwent FETO and a cohort that did not have the procedure (non-FETO). A subanalysis was performed restricting the analysis to isolated left CDH. Parametric and non-parametric tests were used for comparisons.

RESULTS

Of 257 CDH cases evaluated, 72% (n = 184) had no major structural or chromosomal anomalies of which 58% (n = 107) met the study inclusion criteria. The FETO cohort consisted of 19 CDH cases and the non-FETO cohort (n = 88) consisted of 31 (35%) mild, 32 (36%) moderate and 25 (28%) severe CDH cases. All infants with severe CDH, regardless of whether they underwent FETO, had evidence of neonatal PH. FETO (OR, 3.57; 95% CI, 1.05-12.10; P = 0.041) and ECMO (OR, 5.01; 95% CI, 2.10-11.96; P < 0.001) were independent predictors of resolution of PH by 1 year of age. A higher proportion of infants with severe CDH that underwent FETO had resolution of PH by 1 year after birth compared with infants with severe CDH in the non-FETO cohort (69% (11/16) vs 28% (7/25); P = 0.017). Similar results were observed when the analysis was restricted to cases with left-sided CDH (PH resolution in 69% (11/16) vs 28% (5/18); P = 0.032).

CONCLUSION

In infants with severe CDH, FETO and ECMO are independently associated with increased resolution of PH by 1 year of age. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

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.

Prenatal diagnosis and management of congenital diaphragmatic hernia

Congenital diaphragmatic hernia is characterized by failed closure of the diaphragm, thereby allowing abdominal viscera to herniate into the thoracic cavity and subsequently interfering with normal lung development. At birth, pulmonary hypoplasia leads to respiratory insufficiency and persistent pulmonary hypertension (PHT), that is lethal in up to 32% of patients. In isolated cases, the outcome may be predicted prenatally by medical imaging and advanced genetic testing. In those fetuses with a predicted poor outcome, fetoscopic endoluminal tracheal occlusion may be offered. This procedure is currently being evaluated in a global randomized clinical trial (www.TOTALtrial.eu). We are currently investigating alternative strategies including transplacental sildenafil administration to reduce the occurrence of persistent PHT.

A Multimodality Navigation System for Endoscopic Fetal Surgery: A Phantom Case Study for Congenital Diaphragmatic Hernia

This article presents a multi-modality tracking and navigation system achieved by merging optical tracking and ultrasound imaging into a novel navigation software to help in surgical pre-planning and real-time target setting and guidance. Fetal surgeries require extensive experience in coordination of hand-eye-ultrasound-surgical equipment, knowledge, and precise assessment of relative anatomy. While there are navigation systems available for similar constrained working spaces in arthroscopic and cardiovascular procedures, fetal minimally invasive surgery does not yet have a dedicated navigation platform capable of supporting robotic instruments that can be adapted to the set of unique procedures. This article discusses the testing of the novel multi-modality navigation system in a phantom environment developed for this purpose. The outcomes suggest that the subjects demonstrated an increase in average reaching accuracy by about 60% and an overall reduction in time taken by 33.6%. They also showed higher levels of confidence in reaching the targets, which was visualised from the pattern of trajectory of movements during the procedure. To evaluate the navigation system, a phantom surgical environment was found necessary. Therefore, the article also discusses the details of the development of a fetal phantom environment for congenital diaphragmatic hernia for surgical testing, evaluation, and training. A surgical procedure was conducted on the phantom using the proposed tracking navigation system and using only ultrasound.

Reproducibility of Lung-to-Head Ratio Ultrasound Measurements in Congenital Diaphragmatic Hernia

OBJECTIVES

This study investigated the reproducibility of standardization of lung-to-head ratio measurements in congenital diaphragmatic hernia (CDH) at our center among sonographers after we standardized the method.

METHODS

We reviewed ultrasound images of 12 fetuses with CDH at Mayo Clinic from 2010 to 2016. Nine operators (1 maternal-fetal medicine specialist with experience in measuring the lung-to-head ratio and 8 sonographers), who were blinded to previous findings, reviewed 33 selected images from 12 fetuses with left CDH. The method for lung-to-head ratio measurement was standardized before starting the measurements. The lung-to-head ratio was assessed by different methods to obtain the lung areas: anteroposterior, longest, and area tracing. We evaluated the correlation between operators using the intraclass correlation coefficient (ICC). We also compared agreement between the sonographers and a physician with experience in measuring the lung-to-head ratio using a Bland-Altman analysis.

RESULTS

The methods with the best interoperator reproducibility were the standardized anteroposterior lung-to-head ratio (ICC, 0.69) and the standardized lung-to-head ratio tracing (ICC, 0.65) compared to the longest lung-to-head ratio (ICC, 0.56). The standardized lung-to-head ratio tracing had the best agreement among sonographers and the physician (bias, 0.11; limits of agreement, -0.27 to +0.49) than the anteroposterior lung-to-head ratio (bias, 0.35; limits of agreement, -0.13 to + 0.83) and the longest lung-to-head ratio (bias, 0.27; limits of agreement, -0.35 to +0.89).

CONCLUSIONS

We demonstrated that the lung-to-head ratio tracing method has high interoperator reproducibility and the best agreement among the operators at our center. Further multicenter studies are necessary to confirm our results.

Fetoscopic endoluminal tracheal occlusion and reestablishment of fetal airways for congenital diaphragmatic hernia

Background

Congenital diaphragmatic hernia (CDH) is a congenital anomaly with high mortality and morbidity mainly due to pulmonary hypoplasia and hypertension. Temporary fetal tracheal occlusion to promote prenatal lung growth may improve survival. Entrapment of lung fluid stretches the airways, leading to lung growth.

Methods

Fetal endoluminal tracheal occlusion (FETO) is performed by percutaneous sono-endoscopic insertion of a balloon developed for interventional radiology. Reversal of the occlusion to induce lung maturation can be performed by fetoscopy, transabdominal puncture, tracheoscopy, or by postnatal removal if all else fails.

Results

FETO and balloon removal have been shown safe in experienced hands. This paper deals with the technical aspects of balloon insertion and removal. While FETO is invasive, it has minimal maternal risks yet can cause preterm birth potentially offsetting its beneficial effects.

Conclusion

For left-sided severe and moderate CDH, the procedure is considered investigational and is currently being evaluated in a global randomized clinical trial (https://www.totaltrial.eu/). The procedure can be clinically offered to fetuses with severe right-sided CDH.

Foetoscopic endotracheal occlusion (FETO) for severe isolated left-sided congenital diaphragmatic hernia: single center Polish experience

OBJECTIVE

To present early experience with foetoscopic endotracheal occlusion (FETO) for congenital diaphragmatic hernia (CDH) in a new center in Poland.

METHODS

This was a prospective study in singleton pregnancies with CDH treated by FETO between 2014 and 2016 in the Medical University of Warsaw, Poland. FETO was carried out at 25.6-30.1 (median 27.7) weeks' gestation in 28 consecutive cases of isolated left-sided CDH with observed over expected lung area to head circumference ratio (o/e LHR) of 20.7-22.6 (median 18.9).

RESULTS

Neonatal survival rate was 46.4% (13/28) at the time of discharge. The median o/e LHR the day before balloon removal was 33.4 (19.7-57.5) and median gestational age at delivery was 34.7 (29.0-38.1) weeks. Comparison of the survivors and perinatal deaths showed no significant differences in median gestational age at FETO or median o/e LHR before FETO, but higher median gestational age at delivery (35.9, range 32.7-38.1 weeks vs. 33.2, range 29.0-37.7 weeks; p = .007) and o/e LHR before balloon removal (33.7, range 28.3-57.5 vs. 30.9, range 19.7-37.5; p = .017).

CONCLUSIONS

FETO was implemented successfully in Poland and the survival rate (46.4%) is similar to that reported in other centers. Important determinants of survival were gestational age at delivery and pulmonary response to FETO. The rate of preterm prelabor rupture of membranes (PPROM) in our series is similar to the larger series treated with FETO in the pioneering centers of this technique.

The validity of the observed-to-expected lung-to-head ratio in congenital diaphragmatic hernia in an era of standardized neonatal treatment; a multicenter study

Objective

To assess the predictive value of observed‐to‐expected lung‐to‐head ratio (O/E LHR) for survival and chronic lung disease (CLD) in survivors of left‐sided congenital diaphragmatic hernia (CDH) in an era of standardized neonatal treatment, and to evaluate the predictive value of the O/E LHR trajectory for survival.

Methods

This retrospective cohort study was performed in two high‐volume CDH centers in the Netherlands in prenatally detected, isolated left‐sided CDH patients born between 2008 and 2014. O/E LHR and liver position were determined using 2D‐ultrasonography at three time points during gestation from 19 weeks onwards. Ultrasound measurements were performed on stored ultrasound data by one single experienced operator blinded to postnatal outcome.

Results

Of the 122 included cases, 77.9% survived of whom 38.9% developed CLD. A significant association was found between the first measured O/E LHR and survival and development of CLD in survivors. Prenatal liver position did not have additional predictive value. No significant association was found between the trajectory of the O/E LHR and survival.

Conclusion

In an era of standardized neonatal treatment for neonates with CDH, the first measured O/E LHR per patient significantly predicts survival and development of CLD in survivors in isolated left‐sided CDH infants. © 2017 The Authors. Prenatal Diagnosis 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.

Role of Ultrasound-Based Prenatal Prediction of Pulmonary Function in Congenital Diaphragmatic Hernia: Does It Have Prognostic Significance Postnatally?

BACKGROUND AND OBJECTIVES

The incidence of congenital diaphragmatic hernia (CDH) in India is 1 in 1000. About 60 % of these are isolated, and the survival prognosis in them depends upon the quantum of contralateral functional lung. Out of the various pulmonary and extrapulmonary sonological predictors, observed to expected lung-head ratio (O/E LHR) is an efficient gestation-independent predictor of pulmonary function. This study was carried out to see the correlation of this prenatal predictor with the postnatal outcome depending on the pulmonary function.

METHODOLOGY

This study was carried out at Apollo Center of Fetal Medicine, New Delhi, from January 2009 to December 2015. A total of 14 fetuses with isolated left-sided CDH were included. The contralateral lung area was measured in 2D transverse view of the thorax at the level of four-chamber view of the heart by tracing method. The obtained value (square mm) was then divided by the expected mean lung area at that gestation and multiplied with 100 to express O/E LHR as percentage. These were then classified as severe (O/E LHR <25 %), moderate (25-45 %) or mild (>45 %) varieties of CDH. The parents to be were counselled for termination or continuation of pregnancy based on severity of CDH and total lung area. The patients were followed up for obstetrical and neonatal outcome till the time of first postoperative visit (diaphragmatic repair).

RESULTS

The survival correlation in mild cases was 100 % (n = 5 out of 5) and 50 % in moderate cases (n = 2 out of 4), and both severe cases were terminated. There was a significant difference (p < 0.01) in the survival rate in the mild versus severe cases.

CONCLUSIONS

The prenatal predictor for postnatal pulmonary function correlates well with the neonatal outcome and hence is an important tool in prenatal counseling and triaging those who require termination of pregnancy versus expectant management. An obstetrician who is a first point of contact to the pregnant women can understand this and use it for counseling and differentiating the patients who need termination with regard to CDH.

Growth Patterns of Fetal Lung Volumes in Healthy Fetuses and Fetuses With Isolated Left-Sided Congenital Diaphragmatic Hernia

OBJECTIVES

To evaluate fetal lung growth using 3-dimensional sonography in healthy fetuses and those with congenital diaphragmatic hernia (CDH).

METHODS

Right and total lung volumes were serially evaluated by 3-dimensional sonography in 66 healthy fetuses and 52 fetuses with left-sided CDH between 20 and 37 weeks' menstrual age. Functions fitted to these parameters were compared for 2 groups: (1) healthy versus those with CDH; and (2) fetuses with CHD who survived versus those who died.

RESULTS

Fetal right and total lung volumes as well as fetal observed-to-expected right and total lung volume ratios were significantly lower in fetuses with CDH than healthy fetuses (P< .001) and in those fetuses with CDH who died (P< .001). The observed-to-expected right and total lung volume ratios did not vary with menstrual age in healthy fetuses or in those with CDH (independent of outcome).

CONCLUSIONS

Lung volume rates were lower in fetuses with left-sided CDH compared to healthy fetuses, as well as in fetuses with CDH who died compared to those who survived. The observed-to-expected right and total lung volume ratios were relatively constant throughout menstrual age in fetuses with left-sided CDH, suggesting that the origin of their lung growth abnormalities occurred before 20 weeks and did not progress. The observed-to-expected ratios may be useful in predicting the outcome in fetuses with CDH independent of menstrual age.

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.

Patterns of fetal lung growth in fetuses with isolated left-sided congenital diaphragmatic hernia

OBJECTIVE

To evaluate right lung growth pattern in fetuses with isolated left-sided congenital diaphragmatic hernia (iL-CDH) and to analyze the pattern according to postnatal outcome.

METHODS

Lung-to-head ratio (LHR) and observed-to-expected LHR (O/E LHR) were obtained in 58 cases. Correlation and regression analysis for the total number of measurements, general linear models for those cases with a least three serial measurements and linear mixed effect models were used to analyze the influence of gestational age on the right lung size. Cases expectantly managed and those with fetal endoscopic tracheal occlusion were analyzed separately.

RESULTS

LHR, but not O/E LHR, increased significantly with gestational age (GA) (r = 0.43, p = 0.003 and r = -0.13, p = 0.30, respectively). According to neonatal mortality, in those fetuses that died, LHR remained unchanged and O/E LHR decreased significantly with GA (r = 0.07, p = 0.65 and r = -0.37, p = 0.02, respectively). In those cases with at least three serial measurements, the same two patterns were found. Similarly, in cases with expectant management, surviving fetuses showed a significantly higher weekly increase in LHR (p = 0.01) and a trend to a lower weekly decrease in O/E LHR (p = 0.17) than in those that died.

CONCLUSIONS

Patterns of right lung growth in iL-CDH differ according to postnatal survival. Serial measurements, but not a single one, might increase the prediction of neonatal death.

Longitudinal assessment of lung area measurements by two-dimensional ultrasound in fetuses with isolated left-sided congenital diaphragmatic hernia

OBJECTIVE

To evaluate lung growth in healthy fetuses and those with congenital diaphragmatic hernia (CDH) using two-dimensional (2D) ultrasound.

METHODS

Fetal right lung measurements obtained by 2D ultrasound between 19 and 37 weeks' gestation were evaluated longitudinally in 66 healthy fetuses and 52 fetuses with isolated left-sided CDH. Right lung areas were determined by the 'tracing' and 'longest-diameters' methods and, subsequently, lung area-to-head circumference ratios (LHRs) were calculated. Functions fitted to these size parameters with respect to gestational age were evaluated for three sets of group-wise comparisons: (1) healthy vs CDH fetuses; (2) different degrees of severity of CDH; and (3) CDH fetuses that survived vs those that died by 6 months postpartum.

RESULTS

There was a significantly slower increase in right lung areas and LHRs with advancing gestational age in CDH fetuses than in healthy individuals (P < 0.05). Compared to those with milder forms of CDH, lung areas and LHRs of fetuses with more severe forms displayed a smaller increase (P < 0.05) and LHRs of fetuses with severe CDH did not increase during pregnancy (P > 0.05). Individuals who died postpartum did not show any increase in LHR (P > 0.05) throughout gestation.

CONCLUSIONS

The right lung area and LHR, calculated using either the longest-diameters or tracing method, display reduced growth rates during gestation in cases of isolated left-sided CDH as compared with healthy fetuses. The growth curve characteristics of fetal lung areas and LHRs may be useful for predicting neonatal mortality.

Prenatal management of the fetus with isolated congenital diaphragmatic hernia in the era of the TOTAL trial

Congenital diaphragmatic hernia (CDH) may be isolated or associated with other structural anomalies, the latter with poor prognosis. The defect allows viscera to herniate through the defect into the chest, competing for space with the developing lungs. At birth, pulmonary hypoplasia leads to respiratory insufficiency and persistent pulmonary hypertension that is lethal in up to 30% of patients. When isolated, survival chances can be predicted by antenatal measurement of lung size and liver herniation. Chromosomal microarrays and exome sequencing contribute to understanding genetic factors underlying isolated CDH. Prenatal intervention aims at stimulating lung development, clinically achieved by percutaneous fetal endoscopic tracheal occlusion (FETO) under local anesthesia. The Tracheal Occlusion To Accelerate Lung growth trial (www.totaltrial.eu) is an international randomized trial investigating the role of fetal therapy for severe and moderate pulmonary hypoplasia. Despite an apparent increase in survival following FETO, the search for lesser invasive and more potent prenatal interventions must continue.

Reference ranges for 2-dimensional sonographic lung measurements in healthy fetuses: a longitudinal study

OBJECTIVES

The purpose of this study was to establish reference ranges for 2-dimensional sonographic measurements of fetal lungs from longitudinal data.

METHODS

A total of 214 fetal lung measurements were longitudinally evaluated in 62 healthy fetuses between 20 and 36 weeks' menstrual age. Both right and left lung areas were measured in the heart 4-chamber view using lung area tracing and axis diameter methods. Multilevel modeling was used to evaluate the expected values and variability with respect to menstrual age and to generate reference ranges for the lung area, lung-to-head ratio, quantitative lung index, and observed-to-expected lung-to-head ratio for both lungs.

RESULTS

The expected values varied with menstrual age for all parameters. Variance was menstrual age dependent for all parameters except the longest diameter area measurements and their lung-to-head ratios.

CONCLUSIONS

Models are presented for expected 2-dimensional sonographic lung size parameters and their variance as a function of menstrual age. These data have been used to generate age-specific reference ranges for both measurements and indices.

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.

Early fetoscopic tracheal occlusion for extremely severe pulmonary hypoplasia in isolated congenital diaphragmatic hernia: preliminary results

OBJECTIVE

To evaluate the effect of early fetoscopic tracheal occlusion (FETO) (22-24 weeks' gestation) on pulmonary response and neonatal survival in cases of extremely severe isolated congenital diaphragmatic hernia (CDH).

METHODS

This was a multicenter study involving fetuses with extremely severe CDH (lung-to-head ratio < 0.70, liver herniation into the thoracic cavity and no other detectable anomalies). Between August 2010 and December 2011, eight fetuses underwent early FETO. Data were compared with nine fetuses that underwent standard FETO and 10 without fetoscopic procedure from January 2006 to July 2010. FETO was performed under maternal epidural anesthesia, supplemented with fetal intramuscular anesthesia. Fetal lung size and vascularity were evaluated by ultrasound before and every 2 weeks after FETO. Postnatal therapy was equivalent for both treated fetuses and controls. Primary outcome was infant survival to 180 days and secondary outcome was fetal pulmonary response.

RESULTS

Maternal and fetal demographic characteristics and obstetric complications were similar in the three groups (P > 0.05). Infant survival rate was significantly higher in the early FETO group (62.5%) compared with the standard group (11.1%) and with controls (0%) (P < 0.01). Early FETO resulted in a significant improvement in fetal lung size and pulmonary vascularity when compared with standard FETO (P < 0.01).

CONCLUSIONS

Early FETO may improve infant survival by further increases of lung size and pulmonary vascularity in cases with extremely severe pulmonary hypoplasia in isolated CDH. This study supports formal testing of the hypothesis with a randomized controlled trial.

Use of ultrasound and MRI for evaluation of lung volumes in fetuses with isolated left congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is an anomaly that results in lung hypoplasia and pulmonary hypertension. The lungs of the CDH fetus have an abnormal architecture, with fewer bronchial branches and decreased number of arteries and veins, factors which result in pulmonary compromise postnatally. The goal of this review is to evaluate prenatal prognostic factors in the fetus with isolated left CDH, with particular emphasis on fetal MRI. These imaging indicators may be used to provide health professionals and the parents with the most accurate information about fetal prognosis.

Fetal pulmonary response after fetoscopic tracheal occlusion for severe isolated congenital diaphragmatic hernia

OBJECTIVE

To estimate the response in lung growth and vascularity after fetal endoscopic tracheal occlusion for severe congenital diaphragmatic hernia in the prediction of neonatal survival.

METHODS

Between January 2006 and December 2010, fetal lung parameters (observed-to-expected lung-to-head ratio; observed-to-expected lung volume; and contralateral lung vascularization index) were evaluated before fetal tracheal occlusion and were evaluated longitudinally every 2 weeks in 72 fetuses with severe isolated congenital diaphragmatic hernia. Thirty-five fetuses underwent fetal endoscopic tracheal occlusion and 37 cases did not.

RESULTS

Survival rate was significantly higher in the fetal endoscopic tracheal occlusion group (54.3%) than in the no fetal endoscopic tracheal occlusion group (5.4%, P<.01). Fetal endoscopic tracheal occlusion resulted in a significant improvement in fetal lung size and pulmonary vascularity when compared with fetuses that did not go to the fetal intervention (increase of the observed-to-expected lung-to-head ratio, observed-to-expected total lung volume, and contralateral pulmonary vascularization index 56.2% compared with 0.3%, 37.9% compared with 0.1%, and 98.6% compared with 0.0%, respectively; P<.01). Receiver operating characteristic curves indicated that the observed-to-expected total fetal lung volume was the single best predictor of neonatal survival before fetal endoscopic tracheal occlusion (cutoff 0.23, area under the curve [AUC] 0.88, relative risk 5.3, 95% confidence interval [CI] 1.4-19.7). However, the contralateral lung vascularization index at 4 weeks after fetal endoscopic tracheal occlusion was more accurate in the prediction of neonatal outcome (cutoff 24.0%, AUC 0.98, relative risk 9.9, 95% CI 1.5-66.9) with the combination of observed-to-expected lung volumes and contralateral lung vascularization index at 4 weeks being the best predictor of outcome (AUC 0.98, relative risk 16.6, 95% CI 2.5-112.3).

CONCLUSION

Fetal endoscopic tracheal occlusion improves survival rate by increasing the lung size and pulmonary vascularity in fetuses with severe congenital diaphragmatic hernia. The pulmonary response after fetal endoscopic tracheal occlusion can be used to predict neonatal survival.

Congenital diaphragmatic hernia and protective ventilation strategies in pediatric surgery

Infants affected with congenital diaphragmatic hernias (CDH) suffer from some degree of respiratory insufficiency arising from a combination of pulmonary hypoplasia and pulmonary hypertension. Respiratory care strategies to optimize blood gasses lead to significant barotrauma, increased morbidity, and overuse of extracorporeal membrane oxygenation (ECMO). Newer permissive hypercapnia/spontaneous ventilation protocols geared to accept moderate hypercapnia at lower peak airway pressures have led to improved outcomes. High-frequency oscillatory ventilation can be used in infants who continue to have persistent respiratory distress despite conventional ventilation. ECMO can be used successfully as a resuscitative strategy to minimize further barotrauma in carefully selected patients.

Antenatal management of isolated congenital diaphragmatic hernia today and tomorrow: ongoing collaborative research and development. Journal of Pediatric Surgery Lecture

The diagnosis of congenital diaphragmatic hernia should be made prenatally in virtually all cases where routine maternal ultrasonography is available. At that time, the prognosis can be predicted based on whether it is isolated and assessment of lung size and/or the position of the liver. Prenatal intervention may be offered in those selected fetuses that have a predicted poor outcome. The aim of this procedure is to reverse the key determinant of survival-pulmonary hypoplasia. Percutaneous fetal endoscopic tracheal occlusion by a balloon is a minimally invasive procedure that has been shown safe and yields a 50% survival rate in severe cases. The outcome can be predicted by the gestational age at birth, the lung size before and after balloon placement, and whether the balloon has been removed prenatally. Currently, the added value of prenatal intervention is being investigated in the Tracheal Occlusion To Accelerate Lung Growth trial ((TOTAL); a European and North American collaboration). Future developments may include better prediction of outcome by more complex algorithms reflecting combinations of prenatal predictors, gene expression profiling to reflect lung development and response to tracheal occlusion, and alternative prenatal strategies for salvaging the worst cases. Fetuses with severe hypoplasia usually require postnatal operative repair using prosthetic patches, and tissue engineering offers the potential for ex utero culture.

Prediction and probability of neonatal outcome in isolated congenital diaphragmatic hernia using multiple ultrasound parameters

OBJECTIVES

To evaluate the accuracy and probabilities of different fetal ultrasound parameters to predict neonatal outcome in isolated congenital diaphragmatic hernia (CDH).

METHODS

Between January 2004 and December 2010, we evaluated prospectively 108 fetuses with isolated CDH (82 left-sided and 26 right-sided). The following parameters were evaluated: gestational age at diagnosis, side of the diaphragmatic defect, presence of polyhydramnios, presence of liver herniated into the fetal thorax (liver-up), lung-to-head ratio (LHR) and observed/expected LHR (o/e-LHR), observed/expected contralateral and total fetal lung volume (o/e-ContFLV and o/e-TotFLV) ratios, ultrasonographic fetal lung volume/fetal weight ratio (US-FLW), observed/expected contralateral and main pulmonary artery diameter (o/e-ContPA and o/e-MPA) ratios and the contralateral vascularization index (Cont-VI). The outcomes were neonatal death and severe postnatal pulmonary arterial hypertension (PAH).

RESULTS

Neonatal mortality was 64.8% (70/108). Severe PAH was diagnosed in 68 (63.0%) cases, of which 63 died neonatally (92.6%) (P < 0.001). Gestational age at diagnosis, side of the defect and polyhydramnios were not associated with poor outcome (P > 0.05). LHR, o/e-LHR, liver-up, o/e-ContFLV, o/e-TotFLV, US-FLW, o/e-ContPA, o/e-MPA and Cont-VI were associated with both neonatal death and severe postnatal PAH (P < 0.001). Receiver-operating characteristics curves indicated that measuring total lung volumes (o/e-TotFLV and US-FLW) was more accurate than was considering only the contralateral lung sizes (LHR, o/e-LHR and o/e-ContFLV; P < 0.05), and Cont-VI was the most accurate ultrasound parameter to predict neonatal death and severe PAH (P < 0.001).

CONCLUSIONS

Evaluating total lung volumes is more accurate than is measuring only the contralateral lung size. Evaluating pulmonary vascularization (Cont-VI) is the most accurate predictor of neonatal outcome. Estimating the probability of survival and severe PAH allows classification of cases according to prognosis.

Prenatal risk stratification for isolated congenital diaphragmatic hernia: results of a Japanese multicenter study

BACKGROUND/PURPOSE

The aim of this study was to establish a prenatal prognostic classification system for risk-stratified management in fetuses with isolated congenital diaphragmatic hernia (CDH).

METHODS

A multi-institutional retrospective cohort study of isolated CDH, diagnosed prenatally in fetuses delivered during the 2002 to 2007 period at 5 participating institutions in Japan, was conducted. The risk stratification system was formulated based on the odds ratios of prenatal parameters for mortality at 90 days. The clinical severity in CDH infants were compared among the stratified risk groups.

RESULTS

Patients were classified into the 3 risk groups: group A (n = 48) consisted of infants showing liver-down with contralateral lung-to-thorax transverse area ratio (L/T) ratio ≥0.08; group B of infants showing liver-down with L/T ratio <0.08 or liver-up with L/T ratio ≥0.08 (n = 35), and group C of infants showing liver-up with L/T ratio <0.08 (n = 20). The mortality at 90 days in groups A, B, and C were 0.0%, 20.0%, and 65.0%, respectively. The intact discharge rates were 95.8%, 60.0%, and 5.0%, respectively. This system also accurately reflected the clinical severity in CDH infants.

CONCLUSIONS

Our prenatal risk stratification system, which demonstrated a significant difference in postnatal status and final outcome, would allow for accurate estimation of the severity of disease in fetuses with isolated CDH, although it needs prospective validation in a different population.

Results of fetal endoscopic tracheal occlusion for congenital diaphragmatic hernia and the set up of the randomized controlled TOTAL trial

In isolated congenital diaphragmatic hernia, lung size and/or the position of the liver are predictive of neonatal outcome. Percutaneous Fetal Endoscopic Tracheal Occlusion (FETO) by a balloon can be undertaken to prompt lung growth in the worst cases. The feasibility and safety of FETO is no longer at stake, and it is associated with an apparent increase in neonatal survival. The gestational age at birth, the pre-existing lung size, the ability to remove the balloon prior to birth, and the lung response are predicting outcome. The most frequent complication is preterm premature rupture of the membranes, and as a consequence preterm delivery, which also complicates balloon removal. We have set up a randomized trial for the formal evaluation of FETO in Europe, including criteria for fetoscopy centers. Training of European as well as North American centers is taking place, so that the procedure could be safely and more widely offered.

Fetoscopic endotracheal occlusion for severe isolated diaphragmatic hernia: initial experience from a single clinic in Brazil

OBJECTIVE

To report on the initial experience in a single Brazilian university clinic of the use of fetoscopic endotracheal occlusion (FETO) to treat severe isolated congenital diaphragmatic hernia (CDH).

METHODS

The inclusion criteria for FETO for this prospective study were isolated CDH and intrathoracic herniation of the liver, as well as the lung area to head circumference ratio (LHR) <1.0. The main variables evaluated were LHR and observed to expected (o/e) LHR before and after FETO, gestational age (GA) at FETO, reversal of tracheal occlusion (TO), and birth and discharge of a living child from the hospital.

RESULTS

Among 8 isolated left-sided CDH cases with normal karyotypes, the median LHR and o/e LHR before FETO were 0.7 (range: 0.6-0.9) and 0.27 (range: 0.22-0.32), respectively. The median LHR and o/e LHR after FETO were 1.2 (range: 0.9-1.8) and 0.45 (0.31-0.67), respectively. The median GA at FETO, reversal of TO and birth were 26.8 (range: 26-29), 32.5 (range: 31.0-34.0) and 37 weeks (range: 35-37), respectively. Neonatal survival at the time of hospital discharge was 50% (4/8).

CONCLUSION

FETO is feasible at our institution and may help to improve postnatal survival of children with severe CDH in developing countries.

Reliability of the lung to thorax transverse area ratio as a predictive parameter in fetuses with congenital diaphragmatic hernia

PURPOSE

An accurate prenatal assessment of the patients' severity is essential for the optimal treatment of individuals with congenital diaphragmatic hernia (CDH). The purpose of this study was to clarify the reliability of the lung to thorax transverse area ratio (L/T) as a prenatal predictive parameter.

METHODS

A multicenter retrospective cohort study was conducted on 114 isolated CDH fetuses with a prenatal diagnosis during the period between 2002 and 2007 at five participating centers in Japan. The relationship between the gestational age and the L/T was analyzed. The most powerful measurement point and accurate cutoff value of the L/T was determined by an analysis of a receiver operating characteristic curve, which was verified by comparing the patients' severity.

RESULTS

There was a negative correlation between the gestational age and the L/T in the non-survivors, and no correlation in the survivors. There were significant differences in the parameters which represented the patients' severity including the respiratory and circulatory status, the surgical findings, and the final outcomes between the groups divided at 0.080 in the minimum value of the L/T during gestation.

CONCLUSION

The L/T was not strongly influenced by the gestational age, and it was found to be a reliable prenatal predictive parameter in fetuses with isolated CDH.

Comparable low-level mosaicism in affected and non affected tissue of a complex CDH patient

In this paper we present the detailed clinical and cytogenetic analysis of a prenatally detected complex Congenital Diaphragmatic Hernia (CDH) patient with a mosaic unbalanced translocation (5;12). High-resolution whole genome SNP array confirmed a low-level mosaicism (20%) in uncultured cells, underlining the value of array technology for identification studies. Subsequently, targeted Fluorescence In-Situ Hybridization in postmortem collected tissues demonstrated a similar low-level mosaicism, independently of the affected status of the tissue. Thus, a higher incidence of the genetic aberration in affected organs as lung and diaphragm cannot explain the severe phenotype of this complex CDH patient. Comparison with other described chromosome 5p and 12p anomalies indicated that half of the features presented in our patient (including the diaphragm defect) could be attributed to both chromosomal areas. In contrast, a few features such as the palpebral downslant, the broad nasal bridge, the micrognathia, microcephaly, abnormal dermatoglyphics and IUGR better fitted the 5p associated syndromes only. This study underlines the fact that low-level mosaicism can be associated with severe birth defects including CDH. The contribution of mosaicism to human diseases and specifically to congenital anomalies and spontaneous abortions becomes more and more accepted, although its phenotypic consequences are poorly described phenomena leading to counseling issues. Therefore, thorough follow-up of mosaic aberrations such as presented here is indicated in order to provide genetic counselors a more evidence based prediction of fetal prognosis in the future.

Learning curve for lung area to head circumference ratio measurement in fetuses with congenital diaphragmatic hernia

OBJECTIVE

To assess the learning curve for the fetal lung area to head circumference ratio (LHR) calculation in fetuses with congenital diaphragmatic hernia (CDH).

METHODS

Three trainees with the theoretical knowledge, but without prior experience in the LHR measurement, were selected. Each trainee and one experienced examiner measured the observed to expected (O/E)-LHR in the lung contralateral to the side of the hernia by two methods-manual tracing of lung borders and multiplication of the longest diameters-in a cohort of 95 consecutive CDH fetuses. The average difference between the three trainees and the expert in the O/E-LHR measurement was calculated. A difference below 10% was considered to indicate an accurate measurement. The average learning curve was delineated using cumulative sum analysis (CUSUM).

RESULTS

The CUSUM plots demonstrate that the learning curve was achieved by 77 and 72 tests performed for the area obtained by the manual-tracing and multiplication-of-the-longest-diameter methods, respectively.

CONCLUSION

The minimum number of scans required for an inexperienced trainee to become competent in examining the LHR is on average 70.

Value of prenatal magnetic resonance imaging in the prediction of postnatal outcome in fetuses with diaphragmatic hernia

OBJECTIVES

To investigate the potential value of antenatally determined total fetal lung volume (TFLV) by magnetic resonance imaging (MRI) in the prediction of the postnatal survival in congenital diaphragmatic hernia (CDH).

METHODS

We examined fetuses with isolated CDH, in which MRI was used at 22-38 weeks of gestation to measure TFLV and assess intrathoracic herniation of abdominal viscera, that were liveborn after 30 weeks of gestation and had postnatal follow-up until death or discharge from hospital. Regression analysis was used to investigate the effect on survival of gestational age at diagnosis, observed to expected (o/e) TFLV, intrathoracic herniation of the liver, side of CDH, gestational age at MRI, institution, year and gestational age at delivery. In 76 fetuses measurements of o/e TFLV and the lung area to head circumference ratio (LHR) were performed within 2 weeks of each other; in these cases o/e TFLV and o/e LHR were compared for their prediction of postnatal survival.

RESULTS

In the 148 cases that fulfilled the entry criteria, multiple regression analysis demonstrated that significant predictors of survival were the presence or absence of intrathoracic herniation of the liver and o/e TFLV. The area under the receiver-operating characteristics curves for prediction of postnatal survival from o/e TFLV was 0.786 (standard error, 0.059; P < 0.001) and that from o/e LHR was 0.743 (standard error, 0.069; P = 0.001).

CONCLUSIONS

In the assessment of fetuses with CDH, MRI-based o/e TFLV is useful in the prediction of postnatal survival.

Management of congenital diaphragmatic hernia

PURPOSE OF REVIEW

To evaluate the impact of recent research on the management of congenital diaphragmatic hernia in the light of new theories on embryological development, earlier antenatal diagnosis, fetal and postnatal interventions together with advances in perinatal intensive care.

RECENT FINDINGS

The year 2007 provided in excess of 200 publications that address various aspects of congenital diaphragmatic hernia. The genetic basis and the causes of pulmonary hypoplasia at the molecular level are slowly being unravelled. Fetal MRI of lung volume, lung-head ratio, liver position and size of diaphragmatic defect have all been evaluated as early predictors of outcome and with a view to prenatal counselling. The impact of fetal interventions such as fetal endoluminal tracheal occlusion, the mode of delivery, the surgical techniques and agents for treating pulmonary hypertension were evaluated. The influence of associated anomalies and therapeutic interventions on the outcome and quality of life of survivors continue to be appraised.

SUMMARY

Deferred surgery after stabilization with gentle ventilation and reversal of pulmonary hypertension remain the cornerstones of management. Optimal presurgery and postsurgery ventilatory settings remain unproven. Continued improvement in neonatal intensive care raises the bar against which any intervention such as fetal endoluminal tracheal occlusion and extracorporeal membrane oxygenation will be judged.

Comparison of fetal lung area to head circumference ratio with lung volume in the prediction of postnatal outcome in diaphragmatic hernia

OBJECTIVES

To compare prediction of postnatal survival in isolated diaphragmatic hernia by prenatal two-dimensional (2D) versus three-dimensional (3D) sonographic assessment of the contralateral lung.

METHODS

The lung area to head circumference ratio (LHR) of the contralateral lung was measured and expressed as a percentage of the normal mean for gestation (O/E) in 47 fetuses with isolated diaphragmatic hernia at 26 (range, 21-36) weeks of gestation. The lung area was measured by tracing the limits of the lungs (LHR trace) and by multiplying the longest diameter by its perpendicular (LHR diameters). The contralateral lung volume was measured by the Virtual Organ Computer-Aided anaLysis method and the O/E was calculated. Regression analysis was used to determine the significance of the LHRs and volume in the prediction of postnatal survival.

RESULTS

The survival rate was 59.6% (28 of 47). There were significant associations between O/E LHR trace and O/E LHR diameters, and between each O/E LHR and O/E volume, but multiple regression analysis demonstrated that significant prediction of survival was provided only by O/E LHR trace and intrathoracic herniation of the liver.

CONCLUSIONS

In diaphragmatic hernia prenatal prediction of postnatal outcome is better by 2D measurement of LHR trace than it is by 3D measurement of lung volume.