Quantification of liver herniation in fetuses with isolated congenital diaphragmatic hernia using two-dimensional ultrasonography

The interplay between prenatal liver growth and lung development in congenital diaphragmatic hernia

OBJECTIVE

Liver herniation is a known risk factor for increased severity in CDH and is associated with clinically significant pulmonary hypoplasia and pulmonary hypertension. Better studies are needed to understand the growth of the herniated liver compared to the liver that remains in the abdomen and how this liver growth then affects lung development. Serial hi-resolution fetal MRI enables characterization of liver growth throughout gestation and examination of macroscopic features that may regulate liver growth. Here, we hypothesized that the nature of liver herniation affects liver growth and, in turn, affects lung growth.

METHODS

Clinical data were retrospectively collected from consecutive cases of prenatally diagnosed isolated left-sided or right-sided CDH from June 2006 to August 2021. Only those cases with MRI lung volumetry for both mid-gestation and late-gestation time points were recruited for analysis. Cases with fetal chromosomal abnormalities and other major structural abnormalities were excluded. Fractional liver volume and liver growth was indexed to estimated fetal weight and compared to lung growth.

RESULTS

Data was collected from 28 fetuses with a left liver-down CDH (LLD), 37 left liver-up CDH (LLU) and 9 right liver-up CDH (RLU). Overall, RLU fetuses had greater overall and fractional (intra-thoracic vs. intra-abdominal) liver growth when compared to LLD and LLU fetuses. Additionally, intra-thoracic liver growth was consistently slower than intra-abdominal liver growth for either right- or left-sided CDH. When the liver was not herniated, a positive correlation was seen between liver growth and lung growth. However, when the liver was herniated above the diaphragm, this positive correlation was lost.

CONCLUSION

Right-sided CDH fetuses exhibit greater liver growth compared to left-sided CDH. Liver herniation disrupts the normal positive correlation between liver and lung growth that is seen when the liver is entirely within the abdomen.

Interrater agreement for sonographic stomach position classification in fetal diaphragmatic hernia across the North American Fetal Therapy Network

OBJECTIVE

To evaluate inter-rater agreement for sonographic classification of stomach position (as a surrogate for liver herniation) in fetal left congenital diaphragmatic hernia (LCDH) among: (i) fetal medicine specialists from the North American Fetal Therapy Network (NAFTNet) centers within and without the fetal endoscopic tracheal occlusion (FETO) consortium and in comparison to an expert external reviewer (ER1); and (iii) among two expert ERs (ER1 and ER2).

METHODS

Forty-eight physicians from 26 NAFTNet centers and 2 ERs were asked to assess 13 sonographic clips of isolated LCDH and classify stomach position as "intra-abdominal," "anterior left chest," "mid to posterior left chest," or "retro-cardiac" based on the classification published by Basta et al.⁸ Interrater agreement was assessed by determining proportion of stomach position ratings concordant amongst NAFTNet participants and ER1. Agreement for stomach position between ERs was calculated using kappa statistics.

RESULTS

Agreement for stomach position was 69% (39%-85%; n = 19) and 54% (23%-92%; n = 29) among FETO and non-FETO NAFTNet participants, respectively, when compared to ER1. Most disagreement in stomach position was related to a discrepancy of one position. ERs were in agreement for stomach position in 5 of 13 cases (38.5%) and inter-rater agreement was highest for "anterior" stomach position.

CONCLUSION

Interrater agreement for stomach position assessment in CDH was poor across NAFTNet and indeed amongst expert reviewers.

Reference range of fetal thorax using two-dimensional and three-dimensional ultrasound VOCAL technique and application in fetal thoracic malformations

Background

To establish the normal reference range of fetal thorax by two-dimensional (2D) and three-dimensional (3D) ultrasound VOCAL technique and evaluate the application in diagnosing fetal thoracic malformations.

Methods

A prospective cross-sectional study was undertaken involving 1077 women who have a normal singleton pregnancy at 13–40 weeks gestational age (GA). 2D ultrasound and 3D ultrasound VOCAL technique were utilized to assess fetal thoracic transverse diameter, thoracic anteroposterior diameter, thoracic circumference, thoracic area, lung volume, thoracic volume and lung-to-thoracic volume ratio. The nomograms of 2D and 3D fetal thoracic measurements were created to GA. 50 cases were randomly selected to calculate intra- and inter-observer reliability and agreement. In addition, the case groups including congenital skeletal dysplasia (SD) (15), congenital diaphragmatic hernia (CDH) (30), pulmonary sequestration (PS) (25) and congenital cystic adenomatoid malformation (CCAM) (36) were assessed by the nomograms and followed up subsequently.

Results

Both 2D and 3D fetal thoracic parameters increased with GA using a quadratic regression equation. The intra- and inter-observer reliability and agreement of each thoracic parameter were excellent. 2D fetal thoracic parameters could initially evaluate the fetal thoracic development and diagnose the skeletal thoracic deformity, and lung volume, thoracic volume and lung-to-thorax volume ratio were practical to diagnose and differentiate CDH, PS and CCAM.

Conclusion

We have established the normal fetal thoracic reference range at 13–40 weeks, which has a high value in diagnosing congenital thoracic malformations.

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.

Prenatal diagnosis, imaging, and prognosis in Congenital Diaphragmatic Hernia

Antenatal ultrasound screening identifies more than 60% of Congenital Diaphragmatic Hernia (CDH) cases and provides the opportunity for in utero referral to a tertiary care center for expert assessment and perinatal management. Prenatal assessment of fetuses with CDH has tremendously improved over the past ten years. The outcome may be predicted prenatally by medical imaging and advanced genetic testing. The combination of lung size and liver position determination by ultrasound measurements and MRI are widely accepted methods to stratify fetuses into groups that correlate not only with neonatal mortality but also with morbidity. Notwithstanding this, prediction of persistent pulmonary hypertension of the newborn still needs to be improved.

Standardization and reproducibility of sonographic stomach position grades in fetuses with congenital diaphragmatic hernia

OBJECTIVES

The purpose of this study was to evaluate the reproducibility of stomach position grading in congenital diaphragmatic hernia (CDH) as proposed by Cordier et al and Basta et al after standardization of the methods at our center.

METHODS

We collected sonographic images from 23 fetuses with left-sided CDH at our center from 2010 to 2018. Nine operators (one maternal fetal medicine expert and eight sonographers) reviewed the selected images and graded the stomach position according to the methods of Cordier et al and Basta et al. We assessed the interoperator agreement with Fleiss's kappa statistics.

RESULTS

Overall agreement amongst all operators was moderate for both methods proposed by Cordier et al (k = 0.60, SE 0.07, 95% CI 0.47-0.73, P < .0001) and Basta et al (k = 0.60, SE 0.06, 95% CI 0.47-0.73, P < .0001). Interoperator agreement was moderate for grade 3 with the method by Cordier et al (k = 0.45, SE 0.09, 95% CI 0.27-0.64, P < .0001) and fair for grade 4 with the method by Basta et al (k = 0.33, SE 0.08, 95% CI 0.18-0.49 P < .0001).

CONCLUSIONS

Our study demonstrates a fair to moderate interoperator agreement of the stomach position grading methods proposed in the literature after standardization of the methods at our center. Further multicenter studies are needed to confirm our results.

Reproducibility of Liver-to-Thorax Area Ratio Ultrasound Measurements in Congenital Diaphragmatic Hernia

OBJECTIVES

The aim of this study was to investigate the reproducibility of a standardized method to assess the ultrasound liver-to-thoracic area ratio in fetuses with congenital diaphragmatic hernia.

METHODS

We selected 24 images of 9 fetuses diagnosed with left-sided at our institution between January 2010 and December 2017. Eight operators (1 maternal-fetal medicine specialist and 7 sonographers) reviewed the selected images and assessed the ultrasound liver-to-thoracic area ratio according to a standardized protocol. We evaluated the correlation between operators using the intraclass correlation coefficient and compared agreement between the sonographers and a physician with experience in measuring the ultrasound liver-to-thoracic area ratio using a Bland-Altman analysis.

RESULTS

Good intraoperator reproducibility was observed for the standardized ultrasound liver-to-thoracic area ratio (intraclass correlation coefficient, 0.78). Good agreement among sonographers and the physician was also observed for the standardized measurements (bias, 0.01; precision, 0.03; limits of agreement, -0.05 to + 0.07).

CONCLUSIONS

We demonstrated that good intraoperator and interoperator reproducibility of ultrasound liver-to-thoracic area ratio assessment is feasible after standardizing the method in our center.

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.

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.

Three-dimensional assessment of umbilical vein deviation angle for prediction of liver herniation in left-sided congenital diaphragmatic hernia

OBJECTIVES

To introduce a new sonographic marker of intrathoracic liver herniation in fetuses with left-sided congenital diaphragmatic hernia (CDH).

METHODS

In a consecutive series of fetuses with isolated CDH, an ultrasound volume of the fetal abdomen was acquired. On this volume, offline calculation of the angle formed by the midline of the abdomen (joining the center of the vertebral body to the abdominal insertion of the umbilical cord) and a second line joining the center of the vertebral body to the intra-abdominal convexity of the umbilical vein was carried out to give the umbilical vein deviation angle (UVDA). The UVDA was measured in a group of normal fetuses selected as controls. At follow-up, the presence of liver herniation was investigated in all cases of CDH. UVDA values were compared between the CDH group and controls, and between CDH 'liver-up' vs 'liver-down' cases. A receiver-operating characteristics (ROC) curve was constructed to identify a cut-off value of the UVDA with the highest accuracy in predicting liver herniation in the CDH group.

RESULTS

Between 2009 and 2015, 22 cases of left-sided CDH were included in the study group, of which nine cases had liver herniation. Eighty-eight normal fetuses were recruited as controls. The UVDA was significantly higher in the cases vs controls (15.25 ± 7.91° vs 7.68 ± 1.55°; P < 0.0001). Moreover, the UVDA was significantly increased in CDH fetuses with liver-up vs liver-down (21.77 ± 8.79° vs 10.75 ± 2.10°; P < 0.0001). On ROC curve analysis the UVDA showed good prediction of liver herniation (area under the ROC curve, 0.94; P < 0.0001) with the best cut-off of 15.2°, yielding a sensitivity of 89% and a specificity of 100% (P < 0.0001).

CONCLUSIONS

In fetuses with CDH, umbilical vein bowing may be quantified by measuring the UVDA using three-dimensional ultrasound. This sonographic marker seems to be an accurate predictor of liver herniation in left-sided CDH. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

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.

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.

Spleen Behind the Heart Complicates Lung-to-Head Ratio Measurement in Left-Sided Congenital Diaphragmatic Hernia

In fetuses with left-sided congenital diaphragmatic hernia, intrathoracic herniation of the spleen is a common occurrence. The herniated spleen can reside posterior to the left atrium of the heart in the right hemithorax and is increasingly differentiated from the lung with the use of newer sonographic equipment. Estimation of the neonatal prognosis relies on accurate measurement of fetal lung size, particularly with commonly used measurements such as the lung-to-head ratio. Here we describe how herniation of the spleen behind the heart can complicate measurement of the lung-to-head ratio on sonography and lead to overestimation, with implications for perinatal prognostication and management.

Improving the Prediction of Neonatal Outcomes in Isolated Left-Sided Congenital Diaphragmatic Hernia by Direct and Indirect Sonographic Assessment of Liver Herniation

OBJECTIVES

Liver herniation can be assessed sonographically by either a direct (liver-to-thoracic area ratio) or an indirect (stomach position) method. Our objective was to evaluate the utility of those methods to assess liver herniation for the prediction of neonatal outcomes in patients with isolated left-sided congenital diaphragmatic hernia (CDH).

METHODS

We conducted a retrospective cohort study of all patients with CDH who had prenatal assessment and were delivered at Texas Children's Hospital between January 2004 and April 2014. The predictive value of sonographic parameters for mortality and the need for extracorporeal membrane oxygenation was evaluated by univariate, multivariate, and factor analysis and by receiver operating characteristics curves.

RESULTS

A total of 77 fetuses with isolated left-sided CDH were analyzed. The lung-to-head ratio, liver-to-thorax ratio, and stomach position (according to the classifications of Kitano et al [Ultrasound Obstet Gynecol 2011; 37:277-282] and Cordier et al [J Matern Fetal Neonatal Med 2015; 28:190-195]) were significantly associated with both neonatal outcomes (P < .03). Significant correlations were observed between all of these sonographic parameters. A combination of the liver-to-thorax ratio and stomach position (Kitano) or stomach position (Cordier) with the lung-to-head ratio increased the area under the receiver operating characteristic curve of the lung-to-head ratio for mortality prediction (0.86 [95% confidence interval, 0.74-0.98], 0.83 [0.72-0.95], and 0.83 [0.74-0.92], respectively).

CONCLUSIONS

Sonographic measurements of liver herniation (liver-to-thorax ratio and stomach position) are predictive of neonatal outcomes in isolated left-sided congenital diaphragmatic hernia. Our study shows that the combination of those sonographic measurements of liver herniation and lung size improves the accuracy of predicting mortality in those fetuses.

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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