Fetal lung-to-head ratio in the prediction of survival in severe left-sided diaphragmatic hernia treated by fetal endoscopic tracheal occlusion (FETO)

Predicting neonatal mortality prior to discharge from hospital in prenatally diagnosed left congenital diaphragmatic hernia

OBJECTIVES

To evaluate the association of standardized prenatal imaging parameters and immediate neonatal variables with mortality prior to discharge in infants with isolated left congenital diaphragmatic hernia (LCDH), and to compare the performance of ultrasound- and magnetic resonance imaging (MRI)-based severity grading for the prediction of neonatal mortality.

METHODS

This was a retrospective study of infants with prenatally diagnosed isolated LCDH referred to a single tertiary center between 2008 and 2020. Fetuses with right or bilateral congenital diaphragmatic hernia, additional major structural anomaly or known genetic condition, as well as cases that underwent fetal intervention or declined postnatal intervention, were excluded. Ultrasound and MRI images were reviewed retrospectively. Univariable and multivariable analyses were performed, incorporating prenatal and immediate neonatal factors to analyze the association with neonatal mortality prior to discharge, and a prediction calculator was generated. The performance of ultrasound and that of MRI for the prediction of neonatal mortality were compared.

RESULTS

Of 253 pregnancies with fetal CDH, 104 met the inclusion criteria, of whom 77 (74%) neonates survived to discharge. Seventy-five fetuses underwent both prenatal ultrasound and MRI. On multivariable analysis, observed/expected (o/e) lung-to-head ratio and o/e total fetal lung volume were associated independently with neonatal death (adjusted odds ratio, 0.89 (95% CI, 0.83-0.95) and 0.90 (95% CI, 0.84-0.97), respectively), whereas liver position was not. There was no significant difference in predictive performance between using ultrasound and MRI together (area under the receiver-operating-characteristics curve (AUC), 0.85 (95% CI, 0.76-0.93)) compared with using ultrasound alone (AUC, 0.81 (95% CI, 0.72-0.90); P = 0.19). The addition of neonatal parameters (gestational age at birth and small-for-gestational age) did not improve model performance (AUC, 0.87 (95% CI, 0.80-0.95)) compared with the combined ultrasound and MRI model (P = 0.22). There was poor agreement between severity assessment on ultrasound and MRI (Cohen's κ, 0.19). Most discrepancies were seen among cases deemed to be non-severe on ultrasound and severe on MRI, and outcomes were more consistent with MRI-based prognostication.

CONCLUSIONS

In fetuses with prenatally diagnosed isolated LCDH, mortality prediction using standardized ultrasound and MRI measurements performed reasonably well. In cases classified as non-severe on ultrasound, MRI is recommended, as it may provide more accurate prognostication and assist in the determination of candidacy for fetal intervention. © 2024 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Congenital diaphragmatic hernia

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

The randomized Tracheal Occlusion To Accelerate Lung growth (TOTAL)-trials on fetal surgery for congenital diaphragmatic hernia: reanalysis using pooled data

BACKGROUND

Two randomized controlled trials compared the neonatal and infant outcomes after fetoscopic endoluminal tracheal occlusion with expectant prenatal management in fetuses with severe and moderate isolated congenital diaphragmatic hernia, respectively. Fetoscopic endoluminal tracheal occlusion was carried out at 27⁺⁰ to 29⁺⁶ weeks' gestation (referred to as "early") for severe and at 30⁺⁰ to 31⁺⁶ weeks ("late") for moderate hypoplasia. The reported absolute increase in the survival to discharge was 13% (95% confidence interval, -1 to 28; P=.059) and 25% (95% confidence interval, 6-46; P=.0091) for moderate and severe hypoplasia.

OBJECTIVE

Data from the 2 trials were pooled to study the heterogeneity of the treatment effect by observed over expected lung-to-head ratio and explore the effect of gestational age at balloon insertion.

STUDY DESIGN

Individual participant data from the 2 trials were reanalyzed. Women were assessed between 2008 and 2020 at 14 experienced fetoscopic endoluminal tracheal occlusion centers and were randomized in a 1:1 ratio to either expectant management or fetoscopic endoluminal tracheal occlusion. All received standardized postnatal management. The combined data involved 287 patients (196 with moderate hypoplasia and 91 with severe hypoplasia). The primary endpoint was survival to discharge from the neonatal intensive care unit. The secondary endpoints were survival to 6 months of age, survival to 6 months without oxygen supplementation, and gestational age at live birth. Penalized regression was used with the following covariates: intervention (fetoscopic endoluminal tracheal occlusion vs expectant), early balloon insertion (yes vs no), observed over expected lung-to-head ratio, liver herniation (yes vs no), and trial (severe vs moderate). The interaction between intervention and the observed over expected lung-to-head ratio was evaluated to study treatment effect heterogeneity.

RESULTS

For survival to discharge, the adjusted odds ratio of fetoscopic endoluminal tracheal occlusion was 1.78 (95% confidence interval, 1.05-3.01; P=.031). The additional effect of early balloon insertion was highly uncertain (adjusted odds ratio, 1.53; 95% confidence interval, 0.60-3.91; P=.370). When combining these 2 effects, the adjusted odds ratio of fetoscopic endoluminal tracheal occlusion with early balloon insertion was 2.73 (95% confidence interval, 1.15-6.49). The results for survival to 6 months and survival to 6 months without oxygen dependence were comparable. The gestational age at delivery was on average 1.7 weeks earlier (95% confidence interval, 1.1-2.3) following fetoscopic endoluminal tracheal occlusion with late insertion and 3.2 weeks earlier (95% confidence interval, 2.3-4.1) following fetoscopic endoluminal tracheal occlusion with early insertion compared with expectant management. There was no evidence that the effect of fetoscopic endoluminal tracheal occlusion depended on the observed over expected lung-to-head ratio for any of the endpoints.

CONCLUSION

This analysis suggests that fetoscopic endoluminal tracheal occlusion increases survival for both moderate and severe lung hypoplasia. The difference between the results for the Tracheal Occlusion To Accelerate Lung growth trials, when considered apart, may be because of the difference in the time point of balloon insertion. However, the effect of the time point of balloon insertion could not be robustly assessed because of a small sample size and the confounding effect of disease severity. Fetoscopic endoluminal tracheal occlusion with early balloon insertion in particular strongly increases the risk for preterm delivery.

How should fetal surgery for congenital diaphragmatic hernia be implemented in the post-TOTAL trial era: a discussion. Prenat Diagn 2022;42:301-309. [PMID: 35032132 DOI: 10.1002/pd.6091]

Following prenatal diagnosis of congenital diaphragmatic hernia, severity can be predicted based on the presence of associated abnormalities, and in isolated cases, on lung size and position of the liver. Severe hypoplasia is defined by a contralateral lung size < 25% on ultrasound; moderate hypoplasia is when that lung measures between 25 and 45% of the normal. In fetuses with predicted poor postnatal outcome a procedure that reverses pulmonary hypoplasia may be considered. In uncontrolled studies, fetoscopic endoluminal tracheal occlusion (FETO) improved neonatal outcome. Recently, two randomized controlled trials compared the neonatal and infant outcomes in fetuses with isolated CDH (www.totaltrial.eu). In severe cases, FETO was carried out at 27⁺⁰ -29⁺⁶ weeks' gestation (referred to as "early") and in moderate at 30⁺⁰ -31⁺⁶ weeks ("late"). Survival to discharge from the neonatal intensive care unit increased by 25% (95%-CI:+6 - +46; P=.0091) and 13% (-1 - +28; P=.059), in fetuses with severe and moderate cases, respectively. Following FETO gestational age at delivery was on average 3.2 (2.3-4.1) weeks earlier following early and 1.7 (1.1 - 2.3) following late FETO. Here the strengths and weaknesses of the TOTAL trials and their translation to the clinic are debated. Discussants are the lead for the trial (JD) and a colleague (AF) not involved. The discussant notes that the observed survival, both in treated and expectantly managed fetuses, was overall less than what is reported by some high volume centers, particularly in North America. Additional criticisms are the potential effects of prematurity on the long term, the inclusion of low-volume centers, and the potential of FETO for severe iatrogenic complications. Therefore results may not be generalizable. The discussants concluded that although FETO may have its value it remains a procedure with a high risk for prematurity and it can be lethal when the balloon cannot be removed prior to delivery. This article is protected by copyright. All rights reserved.

Randomized Trial of Fetal Surgery for Moderate Left Diaphragmatic Hernia

BACKGROUND

Fetoscopic endoluminal tracheal occlusion (FETO) has been associated with increased postnatal survival among infants with severe pulmonary hypoplasia due to isolated congenital diaphragmatic hernia on the left side, but data are lacking to inform its effects in infants with moderate disease.

METHODS

In this open-label trial conducted at many centers with experience in FETO and other types of prenatal surgery, we randomly assigned, in a 1:1 ratio, women carrying singleton fetuses with a moderate isolated congenital diaphragmatic hernia on the left side to FETO at 30 to 32 weeks of gestation or expectant care. Both treatments were followed by standardized postnatal care. The primary outcomes were infant survival to discharge from a neonatal intensive care unit (NICU) and survival without oxygen supplementation at 6 months of age.

RESULTS

In an intention-to-treat analysis involving 196 women, 62 of 98 infants in the FETO group (63%) and 49 of 98 infants in the expectant care group (50%) survived to discharge (relative risk , 1.27; 95% confidence interval [CI], 0.99 to 1.63; two-sided P = 0.06). At 6 months of age, 53 of 98 infants (54%) in the FETO group and 43 of 98 infants (44%) in the expectant care group were alive without oxygen supplementation (relative risk, 1.23; 95% CI, 0.93 to 1.65). The incidence of preterm, prelabor rupture of membranes was higher among women in the FETO group than among those in the expectant care group (44% vs. 12%; relative risk, 3.79; 95% CI, 2.13 to 6.91), as was the incidence of preterm birth (64% vs. 22%, respectively; relative risk, 2.86; 95% CI, 1.94 to 4.34), but FETO was not associated with any other serious maternal complications. There were two spontaneous fetal deaths (one in each group) without obvious cause and one neonatal death that was associated with balloon removal.

CONCLUSIONS

This trial involving fetuses with moderate congenital diaphragmatic hernia on the left side did not show a significant benefit of FETO performed at 30 to 32 weeks of gestation over expectant care with respect to survival to discharge or the need for oxygen supplementation at 6 months. FETO increased the risks of preterm, prelabor rupture of membranes and preterm birth. (Funded by the European Commission and others; TOTAL ClinicalTrials.gov number, NCT00763737.).

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

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

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

OBJECTIVE

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

STUDY DESIGN

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

RESULT

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

CONCLUSION

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

Update on Congenital Diaphragmatic Hernia

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

Single-Center Outcome of Fetoscopic Tracheal Balloon Occlusion for Severe Congenital Diaphragmatic Hernia

OBJECTIVE

To assess feasibility and maternal and infant outcome after fetoscopic tracheal balloon occlusion in patients with severe congenital diaphragmatic hernia.

METHODS

We conducted a prospective cohort study of fetuses with congenital diaphragmatic hernia and observed/expected lung/head ratio less than 30%. Eligible women had planned fetoscopic tracheal balloon occlusion at 26 0/7-29 6/7 weeks of gestation and balloon removal 4-6 weeks later. Standardized prenatal and postnatal care was at a single institution. Fetoscopic tracheal balloon occlusion details, lung growth, obstetric complications, birth outcome, and infant outcome details until discharge were evaluated.

RESULTS

Of 57 women screened, 14 (25%) were enrolled between 2015 and 2019. The congenital diaphragmatic hernia was left in 12 (86%); the pre-fetoscopic tracheal balloon occlusion observed/expected lung/head ratio was 23.2% (range 15.8-29.0%). At a median gestational age of 28 5/7 weeks (range 27 3/7-29 6/7), fetoscopic tracheal balloon occlusion was successful in all cases, and balloons remained in situ. Removal was elective in 10 (71%) patients, by ultrasound-guided needle puncture in eight (57%), and occurred at a median of 33 4/7 weeks of gestation (range 32 1/7-34 4/7; median occlusion 34 days, range 17-44). The post-fetoscopic tracheal balloon occlusion observed/expected lung/head ratio increased to a median of 62.8% (44.0-108) and fell to a median of 46.6% (range 30-92) after balloon removal (all Mann Whitney U, P<.003). For prevention of preterm birth, all patients received vaginal progesterone; 11 (79%) required additional tocolytics, three (21%) had vaginal pessary placement for cervical shortening, and five (36%) had amnioreduction for polyhydramnios. Median gestational age at birth was 39 2/7 weeks (range 33 6/7-39 4/7), with term birth in eight (57%) patients. Twelve (86%) neonates required high-frequency ventilation, and seven (50%) required extracorporeal membrane oxygenation for a median of 7 days (range 3-19). All neonates needed patch repair. Neonatal survival was 93% (n=13, 95% CI 49-100%), and survival to hospital discharge was 86% (n=12, 95% CI 44-100%).

CONCLUSION

Fetoscopic tracheal balloon occlusion for severe congenital diaphragmatic hernia was feasible in our single-center setting, with few obstetric complications and favorable infant outcome.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT02710968.

A single-center observational study on congenital diaphragmatic hernia: Outcome, predictors of mortality and experience from a tertiary perinatal center in Singapore

BACKGROUND

Congenital diaphragmatic hernia (CDH) is a common birth defect associated with significant mortality and morbidity. There is limited outcome data on CDH in the Southeast Asian region. Rapid accessibility to our CDH Perinatal Center, as a consequence of the small geographic size of our country and efficient land transportation system, has largely eliminated deaths of live outborn babies prior arrival at our center. We selected a study period when extracorporeal membrane oxygenation (ECMO) support was not available at our institution. The data will therefore be relevant in developing management guidelines and antenatal counselling for perinatal centers in this region managing CDH with limited resources, without ECMO facilities.

METHODS

A retrospective study of antenatally or postnatally diagnosed CDH infants born between January 2002 and June 2005 was performed. We selected this study period as ECMO support was not available over this period. We studied the demographics, clinical characteristics, postnatal predictors of mortality and outcomes of CDH infants in a single tertiary institution.

RESULTS

A total of 24 patients with CDH were identified. Seventy-nine percent of liveborns with CDH survived to hospital discharge. Antenatal detection rate was 83.3%. Significant postnatal predictors of mortality were preoperative pneumothorax (p = 0.035), high CRIB score (p = 0.007), low one- and five-minute Apgar score (p = 0.011, p = 0.026 respectively) and high pCO2 on initial arterial blood gas (p = 0.007). At one-year follow-up, three patients had delayed gross motor milestones which resolved subsequently. Re-admissions were required for recurrent bronchiolitis (33%) and oesophageal reflux which resolved in all cases. Two (13.3%) infants had surgical complications and needed re-admission for probable adhesive intestinal obstruction; one required adhesiolysis and the other was managed conservatively with good outcome.

CONCLUSION

A single-center CDH outcome in Singapore, without ECMO use, was good. This is a cohort now with long-term survival outcome which will be valuable to the neonatology community.

Complementary Effect of Maternal Sildenafil and Fetal Tracheal Occlusion Improves Lung Development in the Rabbit Model of Congenital Diaphragmatic Hernia

OBJECTIVE

To evaluate the effect of combining antenatal sildenafil with fetal tracheal occlusion (TO) in fetal rabbits with surgically induced congenital diaphragmatic hernia (CDH).

BACKGROUND

Although antenatal sildenafil administration rescues vascular abnormalities in lungs of fetal rabbits with CDH, it only partially improves airway morphometry. We hypothesized that we could additionally stimulate lung growth by combining this medical treatment with fetal TO.

METHODS

CDH was created on gestational day (GD)23 (n=54). Does were randomized to receive either sildenafil 10 mg/kg/d or placebo by subcutaneous injection from GD24 to GD30. On GD28, fetuses were randomly assigned to TO or sham neck dissection. At term (GD30) fetuses were delivered, ventilated, and finally harvested for histological and molecular analyses. Unoperated littermates served as controls.

RESULTS

The lung-to-body-weight ratio was significantly reduced in sham-CDH fetuses either (1.2 ± 0.3% vs 2.3 ± 0.3% in controls, P=0.0003). Sildenafil had no effect on this parameter, while CDH fetuses undergoing TO had a lung-to-body-weight ratio comparable to that of controls (2.5 ± 0.8%, P<0.0001). Sildenafil alone induced an improvement in the mean terminal bronchiolar density (2.5 ± 0.8 br/mm vs 3.5 ± 0.9 br/mm, P=0.043) and lung mechanics (static elastance 61 ± 36 cmH2O /mL vs 113 ± 40 cmH2O/mL, P=0.008), but both effects were more pronounced in fetuses undergoing additional TO (2.1 ± 0.8 br/mm, P=0.001 and 31 ± 9 cmH2O/mL, P<0.0001 respectively). Both CDH-sham and CDH-TO fetuses treated with placebo had an increased medial wall thickness of peripheral pulmonary vessels (41.9 ± 2.9% and 41.8 ± 3.2%, vs 24.0 ± 2.9% in controls, P<0.0001). CDH fetuses treated with sildenafil, either with or without TO, had a medial thickness in the normal range (29.4% ± 2.6%). Finally, TO reduced gene expression of vascular endothelial growth factor and surfactant protein A and B, but this effect was counteracted by sildenafil.

CONCLUSION

In the rabbit model for CDH, the combination of maternal sildenafil and TO has a complementary effect on vascular and parenchymal lung development.

Variability in antenatal prognostication of fetal diaphragmatic hernia across the North American Fetal Therapy Network (NAFTNet)

OBJECTIVE

To evaluate variability in antenatal sonographic prognostication of congenital diaphragmatic hernia (CDH) within the North American Fetal Therapy Network (NAFTNet).

METHODS

NAFTNet centre were invited to complete a questionnaire and participate in videoconference calls, during which participants were observed while measuring lung area by ultrasound using the anteroposterior (AP) method, longest method, and trace method. Each center identified 1-2 experienced fetal medicine specialist(s) or medical imaging specialists locally to participate in the study. Practices were compared among NAFTNet centre within and without the fetal endoscopic tracheal occlusion (FETO) consortium.

RESULTS

Nineteen participants from 9 FETO center and 30 participants from 17 non-FETO center completed the survey and 31 participants were interviewed and observed while measuring sonographic lung area. All Centres measured observed-to-expected lung-to-head ratio (o/e LHR) or LHR for CDH prognostication. Image selection criteria for lung area measurement were consistent, including an axial section of the chest with clear lung borders and a 4-chamber cardiac view. Lung area measurement methods varied across NAFTNet, with most centre using longest (4/9 FETO vs. 13/29 non-FETO) or trace (3/9 FETO vs. 11/29 non-FETO) method. Centres differed in expected reference ranges for o/e LHR determination and whether the lowest, highest or average o/e LHR was utilized.

CONCLUSION

Variability in antenatal sonographic prognostication of CDH was identified across NAFTNet, indicating a need for consensus-based standardization.

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.

Prognostic value of the oxygenation index to predict survival and timing of surgery in infants with congenital diaphragmatic hernia

AIMS

To compare the mean oxygenation index on day1 (MOId1) with the best OI on day1 (BOId1) in predicting 30-day mortality in congenital diaphragmatic hernia (CDH). In addition, to determine whether serial OIs in the first 48 h after birth and preoperative OI (PreOp-OI), were associated with optimal timing of surgery, ventilation requirement and hospital stay in infants with CDH.

METHODS

The medical records of infants with antenatally diagnosed CDH during 2009-2015 were retrospectively reviewed. Receiver operator characteristic curves were constructed to identify MOId1 and BOId1 cutoff levels to predict 30-day mortality. In those who underwent surgery, the mean OI on each of the first two days (MOId1, MOId2) and PreOp-OI were correlated using Spearman (rs) with the age at surgery, the duration of ventilation and length of stay. Statistical significance was P < 0.05* and < 0.001**.

RESULTS

Survivors (n = 44) and nonsurvivors (n = 24) were comparable in gestational age, birth weight and defect laterality. Nonsurvivors had higher median BOId1 (15.4 vs 2.9; P < 0.01) and MOId1 (48 vs 7.5; p < 0.01) than survivors. Mortality was best predicted by two cutoffs [BOId1 > 6 (sensitivity 92%, specificity 89%); and MOId1 > 17 (sensitivity 96%, specificity 96%)]. Forty-four infants underwent surgery at a median postnatal age of five (range 2-19) days. MOId1 and MOId2 both correlated significantly with the age at surgery (rs = 0.4**, rs 0.5**) but not ventilation period and length of stay. PreOp-OI correlated significantly with age at surgery, duration of ventilation and length of stay (rs = 0.32*, rs = 0.47**, rs = 0.37*). A PreOp-OI <3 was predictive of optimal timing for surgery with improved duration of ventilation (8 vs 22, P = 0.001) and length of stay (26 vs 47, P = 0.004). However, 11/44 (25%) patients would not achieve a PreOp-OI < 3 by day 7+ of life and might still require surgery, one of them died.

CONCLUSION

Both MOId1 and BOId1 are highly predictive of mortality in CDH. Oxygenation indices in the first 48 h poorly predicted the timing of surgery. PreOp-OI <3 may be a cutoff for optimal timing for surgery in infants for CDH repair.

TYPE OF STUDY

Prognostic Study.

LEVEL OF EVIDENCE

Level III.

A multicentre study to predict neonatal survival according to lung-to-head ratio and liver herniation in fetuses with left congenital diaphragmatic hernia (CDH): Hidden mortality from the Latin American CDH Study Group Registry

OBJECTIVE

To evaluate natural history of fetuses congenital diaphragmatic hernia (CDH) prenatally diagnosed in countries where termination of pregnancy is not legally allowed and to predict neonatal survival according to lung area and liver herniation.

METHODS

Prospective study including antenatally diagnosed CDH cases managed expectantly during pregnancy in six tertiary Latin American centres. The contribution of the observed/expected lung-to-head ratio (O/E-LHR) and liver herniation in predicting neonatal survival was assessed.

RESULTS

From the total population of 380 CDH cases, 144 isolated fetuses were selected showing an overall survival rate of 31.9% (46/144). Survivors showed significantly higher O/E-LHR (56.5% vs 34.9%; P < .001), lower proportion of liver herniation (34.8% vs 80.6%, P < .001), and higher gestational age at birth (37.8 vs 36.2 weeks, P < 0.01) than nonsurvivors. Fetuses with an O/E-LHR less than 35% showed a 3.4% of survival; those with an O/E-LHR between 35% and 45% showed 28% of survival with liver up and 50% with liver down; those with an O/E-LHR greater than 45% showed 50% of survival rate with liver up and 76.9% with liver down.

CONCLUSIONS

Neonatal mortality in CDH is higher in Latin American countries. The category of lung hypoplasia should be classified according to the survival rates in our Latin American CDH registry.

Prenatal prediction of survival in congenital diaphragmatic hernia: An audit of postnatal outcomes

PURPOSE

Effective antenatal counseling in congenital diaphragmatic hernia (CDH) relies on proper measurement of prognostic indices. This quality initiative audited the accuracy of prenatal imaging with postnatal outcomes at two tertiary pediatric referral centers.

METHODS

Prenatal lung-head ratio (LHR) and total fetal lung volume (TFLV) for CDH patients treated between 2006 and 2017 were retrieved. Study inclusion required at least one LHR or TFLV measurement between 24 and 32 weeks gestational age. Postnatal outcomes [mortality, extracorporeal life support (ECLS) need, patch repair, persistent pulmonary hypertension, oxygen requirement at 28 days] were abstracted from the Canadian Pediatric Surgery Network (CAPSNet) database and local chart review. Univariate and descriptive analyses were conducted.

RESULTS

Eighty-two of 121 eligible CDH patients (68%) were included. Overall mortality, ECLS rates, and patch repair were 33%, 12.5%, and 45%, respectively. Lower LHR values correlated with increased rates of each outcome and persisted despite multiple measurements. Values obtained were higher than those in published schemata. LHR values >45% were most associated with survival, avoidance of ECLS, and primary repair. TFLV values only correlated with mortality and patch repair.

CONCLUSIONS

This audit confirms that LHR and TFLV values predict CDH outcomes. However, absolute values obtained require careful interpretation and internal review.

LEVEL OF EVIDENCE

IV.

Maternal complications following open and fetoscopic fetal surgery: A systematic review and meta-analysis

OBJECTIVE

To establish maternal complication rates for fetoscopic or open fetal surgery.

METHODS

We conducted a systematic literature review for studies of fetoscopic or open fetal surgery performed since 1990, recording maternal complications during fetal surgery, the remainder of pregnancy, delivery, and after the index pregnancy.

RESULTS

One hundred sixty-six studies were included, reporting outcomes for open fetal (n = 1193 patients) and fetoscopic surgery (n = 9403 patients). No maternal deaths were reported. The risk of any maternal complication in the index pregnancy was 20.9% (95%CI, 15.22-27.13) for open fetal and 6.2% (95%CI, 4.93-7.49) for fetoscopic surgery. For severe maternal complications (grades III to V Clavien-Dindo classification of surgical complications), the risk was 4.5% (95% CI 3.24-5.98) for open fetal and 1.7% (95% CI, 1.19-2.20) for fetoscopic surgery. In subsequent pregnancies, open fetal surgery increased the risk of preterm birth but not uterine dehiscence or rupture. Nearly one quarter of reviewed studies (n = 175, 23.3%) was excluded for failing to report the presence or absence of maternal complications.

CONCLUSIONS

Maternal complications occur in 6.2% fetoscopic and 20.9% open fetal surgeries, with serious maternal complications in 1.7% fetoscopic and 4.5% open procedures. Reporting of maternal complications is variable. To properly quantify maternal risks, outcomes should be reported consistently across all fetal surgery studies.

Reproducibility of fetal lung-to-head ratio in left diaphragmatic hernia across the North American Fetal Therapy Network (NAFTNet)

OBJECTIVE

To determine the antenatal sonographic lung area measurement method in left congenital diaphragmatic hernia (CDH) with the highest interrater agreement among North American Fetal Therapy Network (NAFTNet) centers within and outside the fetoscopic tracheal occlusion (FETO) consortium and in comparison with a European "expert" reviewer (ER).

METHODS

Nineteen members from nine FETO consortium centers and 29 reviewers from 17 non-FETO centers reviewed ultrasound clips of the chest from 13 fetuses with isolated left CDH and were asked to select a static plane for lung area measurement using anteroposterior (AP), longest, and trace methods. Interrater agreement in lung area measurements was determined using intraclass correlation coefficient (ICC). Bland-Altman analysis was used to evaluate mean difference (bias) between NAFTNet reviewers and ER.

RESULTS

Among FETO centers, agreement was highest using trace (ICC 0.94; 95% CI, 0.83-0.98), followed by longest (ICC 0.89; 95% CI, 0.75-0.97) and lowest for A-P (ICC 0.83; 95% CI, 0.67-0.94). Similar trends were noted in non-FETO centers. When compared with ER, bias was lowest for trace: 14 ± 38 mm² and 19 ± 36 mm² for FETO and non-FETO centers, respectively.

CONCLUSION

The trace method demonstrated the highest interrater agreement and lowest bias for lung area estimation in left CDH across NAFTNet.

Use of prostaglandin E1 to treat pulmonary hypertension in congenital diaphragmatic hernia

BACKGROUND/PURPOSE

Prostaglandin E1 (PGE) has been used to maintain ductus arteriosus patency and unload the suprasystemic right ventricle (RV) in neonates with congenital diaphragmatic hernia (CDH) and severe pulmonary hypertension (PH). Here we evaluate the PH response in neonates with CDH and severe PH treated with PGE.

METHODS

We performed a retrospective chart review of CDH infants treated at our center between 2011 and 2016. In a subset, PGE was initiated for echocardiographic evidence of severe PH, metabolic acidosis, or hypoxemia. To assess PH response, we evaluated laboratory data, including B-type natriuretic peptide (BNP) and echocardiograms before and after PGE treatment. Categorical and continuous data were analyzed with Fisher's exact tests and Mann-Whitney t-tests, respectively.

RESULTS

Fifty-seven infants were treated with PGE a mean 17 ± 2 days. BNP levels declined after 1.4 ± 0.2 days of treatment and again after 5.2 ± 0.6 days. After 6 ± 0.8 days of treatment, echocardiographic estimates of severe PH by tricuspid regurgitation jet velocity, ductus arteriosus direction, and ventricular septum position also improved significantly. Treatment was not associated with postductal hypoxemia or systemic hypoperfusion.

CONCLUSIONS

In patients with CDH and severe PH, PGE is well tolerated and associated with improved BNP and echocardiographic indices of PH, suggesting successful unloading of the RV.

TYPE OF STUDY

Treatment study.

LEVEL OF EVIDENCE

Level III.

Longitudinal changes in lung size and intrapulmonary-artery Doppler during the second half of pregnancy in fetuses with congenital diaphragmatic hernia

OBJECTIVES

The objectives of the study are to evaluate longitudinal changes in lung size and intrapulmonary-artery (IPa) Doppler in fetuses with congenital diaphragmatic hernia (CDH) and assess their contribution in predicting neonatal survival.

METHODS

The observed/expected lung-to-head ratio (O/E-LHR) and IPa-pulsatility index (PI) and peak early diastolic reversed flow (PEDRF) were evaluated in a cohort of left-sided CDH fetuses managed expectantly during pregnancy. Longitudinal changes were analyzed by multilevel analysis, and their value to predict survival using the multiple logistic regression and decision-tree analysis was assessed.

RESULTS

A total of 232 scans were performed on 69 CDH fetuses. The O/E-LHR values remained unchanged during fetal monitoring, whereas IPa-PI and PEDRF showed a progressive increase throughout follow-up, becoming abnormal on average at 30 weeks of gestation. Absent/reversed end-diastolic velocity (EDV) in the IPa was observed in 20.3%. O/E-LHR and IPa Doppler indices were significantly associated with probability of survival (O/E-LHR ≥ 26%, odds ratio [OR] 19.0; IPa-PI <+2.0 z score, OR 3.0; and positive EDV, OR 7.4). All cases with IPa-reversed EDV died after birth.

CONCLUSION

While lung size remains stable during pregnancy, CDH fetuses show progressive deterioration in intrapulmonary blood flow. IPa Doppler evaluation may aid in predicting survival of CDH fetuses managed expectantly during pregnancy.

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.

The impact of fetal endoscopic tracheal occlusion in isolated left-sided congenital diaphragmatic hernia on left-sided cardiac dimensions

OBJECTIVES

Fetal endoscopic tracheal occlusion (FETO) is offered to fetuses with congenital diaphragmatic hernia (CDH) and severe lung hypoplasia to promote lung growth and may secondarily affect left heart growth. The effects of FETO on left heart hypoplasia (LHH) are not described post-CDH repair.

METHODS

A retrospective analysis was performed for fetuses with left-sided CDH who underwent FETO and severity-matched controls from 2007 to 2016 at our institution. Echocardiographic, ultrasound, and MRI data were reviewed. Left heart dimensions were assessed prenatally and postnatally. Primary clinical outcome evaluated was death.

RESULTS

Twelve FETO patients and 18 controls were identified. Fetal LHH was noted in both groups and worsened after FETO. Postnatal mitral valve dimensions were larger in the FETO group pre-CDH repair (P = .03). Post-CDH repair, mitral valve and left ventricular dimensions were not significantly different between groups (P = .79 and P = .63 respectively) while FETO aortic valve dimensions were smaller (P = .04). Extracorporeal membrane oxygenation use was lower in the FETO group. No associations were found between left heart dimensions and outcomes.

CONCLUSION

Although increased lung growth was seen after FETO, fetal LHH persisted with relative normalization seen post-repair. Persistent LHH post-FETO could be secondary to a small contribution of pulmonary venous return to the fetal left heart and increased intrathoracic pressures post-FETO.

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.

Characterizing cardiac dysfunction in fetuses with left congenital diaphragmatic hernia

OBJECTIVE

To evaluate cardiac function by conventional echocardiography and tissue Doppler imaging in fetuses with left congenital diaphragmatic hernia (CDH).

METHODS

Conventional echocardiography (myocardial performance index, ventricular filling velocities, and E/A ratios) and tissue Doppler imaging (annular myocardial peak velocities, E/E' and E'/A' ratios) in mitral, septal, and tricuspid annulus were evaluated in a cohort of 31 left-sided CDH fetuses and compared with 75 controls matched for gestational age 2:1.

RESULTS

In comparison to controls, CDH fetuses had prolonged isovolumetric time periods (isovolumetric contraction time 35 ms vs 28 ms, P < .001), with higher myocardial performance index (0.49 vs 0.42, P < .001) and tricuspid E/A ratios (0.77 vs 0.72, P = .033). Longitudinal function assessed by tissue Doppler showed signs of impaired relaxation (mitral lateral A' 8.0 vs 10.1 cm/s, P < .001 and an increased mitral lateral E'/A' ratio 0.93 vs 0.78, P < .001) in the CDH fetuses as compared with controls, with preserved systolic function.

CONCLUSION

Left CDH fetuses show echocardiographic signs of diastolic dysfunction, probably secondary to fetal heart compression, maintaining a preserved systolic function.

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.

[Fetoscopic tracheal occlusion for severe congenital diaphragmatic hernia: retrospective study]

BACKGROUND AND OBJECTIVES

The temporary fetal tracheal occlusion performed by fetoscopy accelerates lung development and reduces neonatal mortality. The aim of this paper is to present an anesthetic experience in pregnant women, whose fetuses have diaphragmatic hernia, undergoing fetoscopic tracheal occlusion (FETO).

METHOD

Retrospective, descriptive study, approved by the Institutional Ethics Committee. Data were obtained from medical and anesthetic records.

RESULTS

FETO was performed in 28 pregnant women. Demographic characteristics: age 29.8±6.5; weight 68.64±12.26; ASA I and II. Obstetric: IG 26.1±1.10 weeks (in FETO); 32.86±1.58 (reversal of occlusion); 34.96±2.78 (delivery). Delivery: cesarean section, vaginal delivery. Fetal data: Weight (g) in the occlusion and delivery times, respectively (1045.82±222.2 and 2294±553); RPC in FETO and reversal of occlusion: 0.7±0.15 and 1.32±0.34, respectively. Preoperative maternal anesthesia included ranitidine and metoclopramide, nifedipine (VO) and indomethacin (rectal). Preanesthetic medication with midazolam IV. Anesthetic techniques: combination of 0.5% hyperbaric bupivacaine (5-10mg) and sufentanil; continuous epidural predominantly with 0.5% bupivacaine associated with sufentanil, fentanyl, or morphine; general. In 8 cases, there was need to complement via catheter, with 5 submitted to PC and 3 to BC. Thirteen patients required intraoperative sedation; ephedrine was used in 15 patients. Fetal Anesthesia: fentanyl 10 to 20mg·kg^-1 and pancuronium 0,1-0,2mg·kg^-1 (IM). Neonatal survival rate was 60.7%.

CONCLUSION

FETO is a minimally invasive technique for severe congenital diaphragmatic hernia repair. Combined blockade associated with sedation and fetal anesthesia proved safe and effective for tracheal occlusion.

Congenital diaphragmatic hernia-influence of fetoscopic tracheal occlusion on outcomes and predictors of survival

The morbidity of infants with congenital diaphragmatic hernia (CDH) who had undergone foetal endoscopic tracheal occlusion (FETO) to those who had not was compared and predictors of survival regardless of antenatal intervention were identified. FETO was undertaken on the basis of the lung to head ratio or the position of the liver. A retrospective review of the records of 78 CDH infants was undertaken to determine the lung-head ratio (LHR) at referral and prior to birth, maximum oxygen saturation in the labour suite and neonatal outcomes. The 43 FETO infants were born earlier (mean 34 versus 38 weeks) (p < 0.001). They had a lower mean LHR at referral (0.65 versus 1.24) (p < 0.001) but not prior to birth and did not have a higher mortality than the 35 non-FETO infants. The FETO infants required significantly longer durations of ventilation (median: 15 versus 6 days) and supplementary oxygen (28 versus 8 days) and hospital stay (29 versus 16 days). Overall, the best predictor of survival was the OI in the first 24 h.

CONCLUSION

The FETO group had increased morbidity, but not mortality. The lowest oxygenation index in the first 24 h was the best predictor of survival regardless of antenatal intervention.

WHAT IS KNOWN

• Randomised controlled trials have demonstrated that foetal endotracheal occlusion (FETO) in high risk infants with congenital diaphragmatic hernia is associated with a higher survival rate. • Mortality is greater in foetuses who underwent FETO and delivered prior to 35 weeks of gestation. What is New: • Infants who had undergone FETO compared to those who had not had significantly longer durations of mechanical ventilation, supplementary oxygen and hospital stay. • Regardless of antenatal intervention, the lowest oxygenation index in the first 24 h was the best predictor of survival.

Prematurity and fetal lung response after tracheal occlusion in fetuses with severe congenital diaphragmatic hernia

OBJECTIVE

To evaluate the independent association of fetal pulmonary response and prematurity to postnatal outcomes after fetal tracheal occlusion for congenital diaphragmatic hernia.

METHODS

Fetal pulmonary response, prematurity (<37 weeks at delivery) and extreme prematurity (<32 weeks at delivery) were evaluated and compared between survivors and non-survivors at 6 months of life. Multivariable analysis was conducted with generalized linear mixed models for variables significantly associated with survival in univariate analysis.

RESULTS

Eighty-four infants were included, of whom 40 survived (47.6%) and 44 died (52.4%). Univariate analysis demonstrated that survival was associated with greater lung response (p=0.006), and the absence of extreme preterm delivery (p=0.044). In multivariable analysis, greater pulmonary response after FETO was an independent predictor of survival (aOR 1.87, 95% CI 1.08-3.33, p=0.023), whereas the presence of extreme prematurity was not statistically associated with mortality after controlling for fetal pulmonary response (aOR 0.52, 95% CI 0.12-2.30, p=0.367).

CONCLUSION

Fetal pulmonary response after FETO is the most important factor associated with survival, independently from the gestational age at delivery.

Fetal surgery: an overview

In utero fetal surgery interventions are currently considered in selected cases of congenital diaphragmatic hernia, cystic pulmonary abnormalities, amniotic band sequence, selected congenital heart abnormalities, myelomeningocele, sacrococcygeal teratoma, obstructive uropathy, and complications of twin pregnancy. Randomized controlled trials have demonstrated an advantage for open fetal surgery of myelomeningocele and for fetoscopic selective laser coagulation of placental vessels in twin-to-twin transfusion syndrome. The evidence for other fetal surgery interventions, such as tracheal occlusion in congenital diaphragmatic hernia, excision of lung lesions, fetal balloon cardiac valvuloplasty, and vesicoamniotic shunting for obstructive uropathy, is more limited. Conditions amenable to intrauterine surgical treatment are rare; the mother may consider termination of pregnancy as an option for many of them; treatment can be lifesaving but in itself carries risks to both the infant (preterm premature rupture of the membranes, preterm delivery) and the mother. This makes conducting prospective or randomized trials difficult and explains the relative lack of good-quality evidence in this field. Moreover, there is scanty information on long-term outcomes. It is recommended that fetal surgery procedures be performed in centers with extensive facilities and expertise. The aims of this review were to describe the main fetal surgery procedures and their evidence-based results and to provide generalist obstetricians with an overview of current indications for fetal surgery.

Difficulties in the hemodynamic assessment of the newborn with prenatally treated congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a malformation with a diverse clinical picture. Its severity can be assessed prenatally using the lung area to head circumference ratio (LHR). LHR lower than 1 as associated with high mortality is an indication for prenatal treatment involving occlusion of fetal trachea. Before such treatment other congenital malformations must be excluded. Assessment of circulatory system in these patients is difficult. Heart is compressed by viscera in the thorax that decreases blood return to the left atrium, and structures of the left heart may be smaller than in healthy fetuses. The echocardiographic picture may be similar to some congenital defects of the left heart. Differentiation between structural and functional cardiac abnormalities is difficult but essential for diagnostic and therapeutic decisions in the most severe type of CDH. The authors present problems with interpretation of hemodynamic disturbances in a neonate with prenatally diagnosed and treated severe CDH.

Prediction of Neonatal Respiratory Function and Pulmonary Hypertension in Fetuses with Isolated Congenital Diaphragmatic Hernia in the Fetal Endoscopic Tracleal Occlusion Era: A Single-Center Study

Objective: To correlate prenatal indicators of pulmonary hypoplasia with neonatal lung function and pulmonary hypertension (PHT) in isolated congenital diaphragmatic hernia (iCDH). Materials and Methods: Prospective single-center study on 40 fetuses with iCDH either expectantly managed (n = 13) or undergoing tracheal occlusion (n = 27). Prenatal predictors included observed/expected lung-head ratio (O/E LHR), observed/expected total fetal lung volume, fetal pulmonary reactivity to maternal O2 administration (Δpulsatility index, ΔPI) and liver-to-thorax ratio (LiTR) as measured in the second and third trimesters. Postnatal outcome measures included survival until discharge, best oxygenation index (OI) and alveolar-arterial oxygen gradient [D(A-a)O2] in the first 24 h of life and the occurrence of PHT in the first 28 days of life. Results: Median gestational age (GA) at evaluations was 27.2 and 34.3 weeks. GA at delivery was 36.0 weeks, and overall survival was 55%. In the second trimester, measurement of lung size, LiTR and pulmonary reactivity were significantly related to survival and the best OI and D(A-a)O2.The occurrence of PHT was better predicted by ΔPI and LiTR. Conclusions: O/E LHR, LiTR and vascular reactivity correlate with ventilatory parameters in the first 24 h of life. Occurrence of PHT at ≥28 days was best predicted by LiTR and ΔPI, but not by lung size.

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.

Fetoscopic endoluminal tracheal occlusion (FETO) for congenital diaphragmatic hernia in Australia and New Zealand: are we willing, able, both or neither?

AIM

An estimated 140 pregnancies are diagnosed with congenital diaphragmatic hernia (CDH) in Australia and New Zealand each year, with these fetuses having a less than even chance of 1-year survival. Fetoscopic endoluminal tracheal occlusion (FETO) is a relatively new technique that offers a prenatal interventional strategy for selective cases of CDH. This is not routinely offered in Australia or New Zealand. The aim of this systematic review is to critically appraise controlled clinical trials investigating the role of FETO in moderate and severe isolated CDH and explore whether this treatment is justified within our region.

METHODS

A systematic literature search of multiple electronic databases was undertaken, with restrictions to human subjects and controlled clinical trials.

RESULTS

Nine relevant studies were identified. No current evidence was found in favour of FETO for moderate severity CDH. For severe CDH, the most recent evidence demonstrates significantly improved survival following FETO performed using contemporary percutaneous minimally invasive techniques. Optimum timing for balloon insertion, removal and occlusion duration remains conjectural. Substantial variation in survival rates observed among control groups highlights the impact of post-natal care in prenatally diagnosed CDH.

CONCLUSION

Until recently, evidence to support a role for FETO in prenatal CDH management was weak. Recently reported and ongoing controlled trials give cause for optimism, with improved FETO safety and increased survival reported for severe CDH cases. Should Australasia embrace FETO for selected CDH cases, a co-ordinated, evidence-informed service should be established under the guidance of experienced international partnerships.

Outcome of CDH infants following fetoscopic tracheal occlusion - influence of premature delivery

PURPOSE

To evaluate the mortality and morbidity of infants with congenital diaphragmatic hernia who had undergone fetal endoscopic tracheal occlusion (FETO) and whether this was influenced by premature birth.

METHODS

The gestational age at delivery, lung-head ratio (LHR) pre and post FETO, neonatal outcomes, and respiratory, gastro-intestinal, neurological, surgical, and musculoskeletal problems at follow up of consecutive infants who had undergone FETO were determined. Elective reversal of FETO was planned at 34 weeks of gestation.

RESULTS

The survival rate of the 61 FETO infants was 48%, with 84% delivered prematurely. Thirty-one delivered <35 weeks of gestation. Their survival rate was 18%. Twenty-three of 24 infants who had emergency balloon removal were born <35 weeks of gestation. Survival was related to gestational age at delivery (OR 0.55, 95% CI 0.420, 0.77, p<0.001) and the duration of FETO (OR 0.73, 95% CI 0.59, 0.91, p<0.005). Infants born prior to 35 weeks of gestation compared to those born at ≥ 35 weeks required a longer duration of ventilation (median 45 days versus 12 days, p<0.001), and a greater proportion had surgery for gastro-oesophageal reflux (50% versus 9%, p=0.011).

CONCLUSION

These results emphasize the need to reduce premature delivery following FETO.

The ex utero intrapartum treatment (EXIT) procedure: application of a new therapeutic paradigm

The ex utero intrapartum treatment (EXIT) procedure is a term given to a technique that can transform a potentially fatal neonatal emergency to a controlled intervention with an improved outcome. It has revolutionised the care of prenatally diagnosed congenital malformations in which severe upper airway obstruction is anticipated. An extended period of utero-placental circulation can be utilised to avoid profound cardiopulmonary compromise. Its therapeutic applications have been broadened to include fetuses with congenital diaphragmatic hernia after tracheal plugging, high-risk intrathoracic masses, severe cardiac malformations and conjoined twins. It requires the co-ordination of a highly skilled and experienced multidisciplinary team. The recent enthusiasm for the EXIT procedure needs to be balanced against maternal morbidity. Specific indications and guidelines are likely to be refined as a consequence of ongoing advances in fetal intervention and antenatal imaging.

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.

Usefulness of lung-to-head ratio and intrapulmonary arterial Doppler in predicting neonatal morbidity in fetuses with congenital diaphragmatic hernia treated with fetoscopic tracheal occlusion

OBJECTIVE

To explore the potential value of intrapulmonary artery Doppler velocimetry in predicting neonatal morbidity in fetuses with left-sided congenital diaphragmatic hernia (CDH) treated with fetoscopic tracheal occlusion (FETO).

METHODS

Observed/expected lung-to-head ratio (O/E-LHR), and intrapulmonary Doppler pulsatility index and peak early-diastolic reversed flow were evaluated within 24 h before FETO in a consecutive cohort of 51 fetuses with left-sided CDH at between 24 and 33 weeks' gestation. Lung Doppler parameters were converted into Z-scores and defined as abnormal if the pulsatility index had a Z-score of > 1.0 or the peak early-diastolic reversed flow had a Z-score of > 3.5. The association of O/E-LHR and Doppler velocimetry with neonatal outcome was assessed using multiple linear or logistic regression analysis adjusted for gestational age at birth.

RESULTS

Among the 26 fetuses that survived, 18 (69.2%) had normal and eight (30.8%) had abnormal Doppler values. O/E-LHR was not associated with neonatal morbidity in surviving fetuses. Compared with the group with normal Doppler parameters, cases with abnormal intrapulmonary Doppler were associated with a significant increase in the duration of mechanical ventilation (average increase of 21.2 (95% CI, 9.99-32.5) days; P < 0.01), conventional ventilation (15.2 (95% CI, 7.43-23.0) days; P < 0.01), high-frequency ventilation (6.34 (95% CI, 0.69-11.99) days; P < 0.05), nitric oxide therapy (5.73 (95% CI, 0.60-10.9) days; P < 0.05), oxygen support (36.5 (95% CI, 16.3-56.7) days; P < 0.01), parenteral nutrition (19.1 (95% CI, 7.53-30.7) days; P < 0.01) and stay in neonatal intensive care unit (42.7 (95% CI, 22.9-62.6) days; P < 0.001), and with significantly higher rates of high-frequency ventilation (87.5 vs. 44.4%;P < 0.05), oxygen requirement at 28 days of age (75.0 vs. 11.1%; P < 0.01), gastroesophageal reflux (62.5 vs. 22.2%; P < 0.05) and tube feeding at discharge (37.5 vs. 5.56%; P < 0.05).

CONCLUSION

As previously reported, O/E-LHR did not predict neonatal morbidity. In contrast, intrapulmonary artery Doppler evaluation was predictive of neonatal morbidity in CDH fetuses treated with FETO.

Neuromuscular blockade and lung function during resuscitation of infants with congenital diaphragmatic hernia

BACKGROUND

There is no consensus or evidence as to whether a neuromuscular blocking agent should be used during the initial resuscitation of infants with congenital diaphragmatic hernia (CDH) in the labour ward.

OBJECTIVE

To determine if administration of a neuromuscular blocking agent affected the lung function of infants with CDH during their initial resuscitation in the labour ward.

METHODS

Fifteen infants with CDH were studied (median gestational age 38 weeks, range 34-41; birth weight 2,790 g, range 1,780-3,976). Six infants had undergone feto-endotracheal occlusion (FETO). Flow, airway pressure, tidal volume and dynamic lung compliance changes were recorded using a respiratory function monitor (NM3, Respironics). Twenty inflations immediately before, immediately after and 5 min after administration of a neuromuscular blocking agent (pancuronium bromide) were analysed.

RESULTS

The median dynamic lung compliance of the 15 infants was 0.22 ml/cm H2O/kg (range 0.1-0.4) before and 0.16 ml/cm H2O/kg (range 0.1-0.3) immediately after pancuronium bromide administration (p < 0.001) and remained at a similar low level 5 min after pancuronium bromide administration. The FETO compared to the non-FETO infants had a lower median dynamic compliance both before (p < 0.0001) and 5 min after pancuronium administration (p < 0.001) and required significantly longer durations of ventilation (p = 0.004), supplementary oxygen (p = 0.003) and hospitalisation (p = 0.007).

CONCLUSIONS

Infants with CDH, particularly those who have undergone FETO, have a low lung compliance at birth, and this is further reduced by administration of a neuromuscular blocking agent.

Advances in maternal fetal medicine practice

Maternal fetal medicine (MFM) is a subspecialty of obstetrics that focuses on identified risk pregnancies. The role includes obstetric ultrasound for fetal assessment and diagnosis of anomalies, invasive prenatal diagnosis and management of pregnancies complicated by maternal medical disorders, multiple fetuses and the antenatal management of extreme prematurity. Skill specialisation within MFM includes fetal interventions such as fetal shunting procedures, intrauterine transfusion, fetoscopic laser photocoagulation of anastomotic vessels for twin to twin transfusion syndrome and ex utero intrapartum treatment. MFM specialists are actively involved in clinical and basic science research to improve maternal and neonatal outcomes. Most Australian MFM specialists are associated with metropolitan teaching hospitals. MFM sub-specialisation has reduced the impact of disability associated with aneuploidy, structural anomalies, multiple pregnancy and extreme prematurity. Management aims are to give families timely counselling, appropriate intervention, and optimisation of the time and location of delivery. The aim of this paper is to update the reader regarding current advances in MFM practices.

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.

Increase in fetal pulmonary artery diameters during late gestation is a predictor of outcome in congenital diaphragmatic hernia with liver herniation

AIM

Liver herniation (LH) in congenital diaphragmatic hernia (CDH) may not be a reliable prognostic indicator. We measured pulmonary artery (PA) diameters in CDH + LH as an alternative.

METHODS

Of 41 consecutive cases of prenatally diagnosed left-sided CDH treated from 2002 to 2010, 19 had CDH + LH and 22 had CDH - LH. Ultrasonography and magnetic resonance imaging were used to assess LH and echocardiography to measure PA diameters during the third trimester (fetal; 32-34 weeks), at birth, and on day 2 of life.

RESULTS

In CDH + LH survivors (9/19; 47%), fetal right PA (RPA) diameters were significantly larger than in nonsurvivors (2.58 ± 0.56 vs 1.82 ± 0.35 mm; P < .01), but left PA (LPA) diameters were not (1.73 ± 0.38 vs 1.59 ± 0.22). In survivors, fetal RPA was greater than 2 mm in all but one case, and both PA diameters increased significantly by birth (RPA, 2.58 ± 0.56 vs 3.52 ± 0.54; LPA, 1.73 ± 0.38 vs 2.60 ± 0.40; both P < .01). Final diameters at birth in survivors were at least 2.5 and 2.0 mm, respectively. In nonsurvivors, both PAs were significantly smaller (RPA, 3.52 ± 0.54 vs 2.04 ± 0.31; LPA, 2.60 ± 0.40 vs 1.68 ± 0.18; P < .01), with no observed increase by birth. Survival in CDH - LH was 82% (18/22).

CONCLUSION

PA diameter appears to be correlated with prognosis in infants with CDH + LH.

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.