The lung-to-head ratio and fetoscopic temporary tracheal occlusion: prediction of survival in severe left congenital diaphragmatic hernia

Survival and Predictors of Mortality of Congenital Diaphragmatic Hernia in Newborns at a Tertiary Care Hospital in Saudi Arabia

Background Congenital diaphragmatic hernia (CDH) is a condition where abdominal contents protrude into the chest due to defects in the diaphragm muscle. It is considered an emergency that needs urgent intervention to prevent further complications or death. Our study aimed to estimate survival and evaluate predictors of mortality in newborns with CDH using available prediction tools in the literature. Methods This retrospective cohort study included neonates with CDH in King Abdulaziz Medical City (KAMC), Jeddah, from 2000 to 2021. Prevalence, demographics, and clinical characteristics were compared between surviving and deceased infants. C-statistics were used to measure the area under the curve for the prenatal and postnatal predictor tools, and a p-value of <0.05 was considered significant. Results Between 2000 and 2021, 45 neonates with CDH were included (six per 10,000 inborn live births). The mortality rate was 51.1%. The differences in demographics were not significant among surviving and deceased patients. One prenatal predictor tool, the lung-to-head ratio, was found to be significant; in addition, three postnatal predictor tools of mortality, SNAP-II, CDHSG-probability survival, and Brindle Score, had the highest concordance (C) statistics of 0.8, 0.79, and 0.8, respectively. Conclusion Although the incidence of CDH was found to be higher in our study compared to global statistics, our mortality rates correspond with international figures. The most significant differences between predictors and prediction models of mortality were lung-to-head ratio prenatally, SNAP-II, CDHSG-probability survival, and Brindle Score postnatally. Further multicentered studies are recommended with a larger sample size.

Fetal endoscopic tracheal occlusion for congenital diaphragmatic hernia: systematic review and meta-analysis

OBJECTIVE

It is debated whether fetal endoscopic tracheal occlusion (FETO) is beneficial to fetuses with congenital diaphragmatic hernia (CDH) and whether FETO has different effects in moderate and severe CDH. We conducted a systematic review and meta-analysis including the latest evidence to assess the overall effects of FETO on clinical outcomes of CDH.

METHODS

We searched PubMed, EMBASE, The Cochrane Library, China National Knowledge Infrastructure, China Science and Technology Journal Database and Wanfang Database to retrieve eligible studies published before 8 September 2022. No language or study design restrictions were applied. Studies were included if CDH fetuses underwent FETO surgery and were compared with a cohort that underwent expectant management, with at least one outcome reported. The primary outcomes were mortality at 1, 6 and 12 months after birth, rates of pulmonary hypertension, use of extracorporeal membrane oxygenation (ECMO) and prematurity. Meta-analysis was conducted to obtain pooled odds ratios (ORs) and mean differences. The quality of included studies and pooled evidence was also assessed.

RESULTS

A total of 1187 CDH fetuses from 20 studies were included in the quantitative synthesis. FETO significantly reduced 1-month (OR, 0.56 (95% CI, 0.34-0.93); P = 0.02, number needed to treat (NNT) = 7.67) and 6-month (OR, 0.34 (95% CI, 0.18-0.65); P = 0.0009, NNT = 5.26) CDH mortality (moderate/low quality of evidence). Subgroup analysis suggested that the effects of FETO on the rates of pulmonary hypertension and ECMO usage were significant in severe CDH (low/moderate quality of evidence) but not in moderate CDH (low/very low quality of evidence). FETO was also associated with an increased risk of preterm prelabor rupture of membranes before 37 weeks' gestation (OR, 4.94 (95% CI, 2.25-10.88); P < 0.0001, number needed to harm (NNH) = 3.13) and preterm birth before 37 weeks (OR, 5.24 (95% CI, 3.33-8.23); P < 0.00001, NNH = 2.79) (high/moderate quality of evidence). However, FETO was not associated with severe complications, such as preterm birth before 32 weeks, placental abruption or chorioamnionitis (very low/low quality of evidence).

CONCLUSIONS

FETO is associated with a reduction in mortality, rate of pulmonary hypertension and ECMO usage in severe CDH, while it reduces only the risk of mortality in moderate CDH. Although FETO increases the risk of late prematurity, it does not result in extreme prematurity. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Expected small left heart size in the presence of congenital diaphragmatic hernia: Fetal values and Z-scores for infants confirmed to have no heart disease postnatally

OBJECTIVES

In fetuses with left-sided congenital diaphragmatic hernia (CDH), left heart structures may appear small, but usually normalize after birth in the absence of structural cardiac anomalies. To decrease the possibility of an erroneous diagnosis of structural heart disease, we identify normal values for left heart structures in the presence of left CDH and secondarily investigate the relationship of left heart size and survival to neonatal hospital discharge.

METHODS

Left heart structures [mitral valve (MV) and aortic valve (AoV) annulus diameter, left ventricle (LV) length and width] were measured by fetal echocardiogram in fetuses with left CDH and no congenital heart disease. We generated linear regression models to establish the relationship of gestational age for each left heart structure using data from fetuses who survived after birth. We calculated z-scores (normalized to gestational age), and assessed the relationship of survival to the size of each structure.

RESULTS

One hundred forty-two fetuses underwent fetal echocardiogram (median 25 weeks' gestation, IQR 23, 27 weeks). Left heart structures were deemed small when using published normative data from unaffected fetuses (z-scores: MV -1.09 ± 1.35, AoV -2.12 ± 1.16, LV length -1.36 ± 1.24, LV width -4.79 ± 0.79). CDH-specific models derived from log-transformed values yielded left-shifted distributions, reflecting the small structures (mean z-score lower by: MV 0.99 ± 0.30, AoV 2.04 ± 0.38, LV length 1.30 ± 0.36, and LV width 4.69 ± 0.28; p < 0.0001 for all comparisons). Non-survivors had worse z-scores than survivors for all measurements, but this did not reach statistical significance.

CONCLUSIONS

Log-transformed linear models generated new normative data for fetal left heart structures in left CDH, which may be used to allay antenatal concerns regarding structural left heart anomalies. There were no significant differences in z-scores between survivors and non-survivors, suggesting that in the absence of true structural disease, cardiac evaluation is not predictive in isolation and that causes of mortality are likely multifactorial in this population.

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.

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.

Radiologic assessment of fetal tracheal balloon occlusion

Fetal endoscopic tracheal occlusion (FETO) is a novel technique to treat cases of isolated severe congenital diaphragmatic hernia (CDH). Although there are benefits of MRI over ultrasound in assessing lung volumes, it is unknown whether there are benefits of MRI for localizing the tracheal balloon. This is a retrospective study reviewing the imaging characteristics of FETO in patients who underwent both MRI and ultrasound exams done to localize tracheal balloons.

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.

Rate of increase of lung-to-head ratio over the course of gestation is predictive of survival in left-sided congenital diaphragmatic hernia

PURPOSE

Congenital diaphragmatic hernia (CDH) is associated with high postnatal mortality because of pulmonary hypoplasia. The prognostic utility of serial lung-to-head circumference measurements as a marker of lung growth has not been described. Our objective was to examine the relationship between the rate of interval increase of LHR and postnatal survival in left-sided CDH.

METHODS

We retrospectively reviewed charts of all left-sided CDH patients from January 2004 to July 2014. All ultrasound studies performed at our institution (n=473) were reviewed. Categorical and continuous data were analyzed by chi-square and Mann-Whitney t-test, respectively, and slope analysis was performed by linear regression analysis (p<0.05).

RESULTS

A total of 226 patients were studied, with 154 long-term survivors and 72 non-survivors. Established markers of CDH severity, including intrathoracic liver position and requirement for patch repair, were significantly increased in non-survivors (p<0.0001). The rate of LHR increase as measured by linear regression and slope analysis was significantly increased in long-term survivors (p=0.0175).

CONCLUSIONS

Our findings indicate that the interval increase in LHR levels over the course of gestation correlate with survival in left-sided CDH patients. Regular ultrasonographic re-evaluation of LHR throughout gestation following diagnosis of CDH may provide prognostic insight and help guide patient management.

Fetal Stomach Position Predicts Neonatal Outcomes in Isolated Left-Sided Congenital Diaphragmatic Hernia

INTRODUCTION

We sought to determine the relationship between the degree of stomach herniation by antenatal sonography and neonatal outcomes in fetuses with isolated left-sided congenital diaphragmatic hernia (CDH).

MATERIALS AND METHODS

We retrospectively reviewed neonatal medical records and antenatal sonography of fetuses with isolated left CDH cared for at a single institution (2000-2012). Fetal stomach position was classified on sonography as follows: intra-abdominal, anterior left chest, mid-to-posterior left chest, or retrocardiac (right chest).

RESULTS

Ninety fetuses were included with 70% surviving to neonatal discharge. Stomach position was intra-abdominal in 14% (n = 13), anterior left chest in 19% (n = 17), mid-to-posterior left chest in 41% (n = 37), and retrocardiac in 26% (n = 23). Increasingly abnormal stomach position was linearly associated with an increased odds of death (OR 4.8, 95% CI 2.1-10.9), extracorporeal membrane oxygenation (ECMO; OR 5.6, 95% CI 1.9-16.7), nonprimary diaphragmatic repair (OR 2.7, 95% CI 1.4-5.5), prolonged mechanical ventilation (OR 5.9, 95% CI 2.3-15.6), and prolonged respiratory support (OR 4.0, 95% CI 1.6-9.9). All fetuses with intra-abdominal stomach position survived without substantial respiratory morbidity or need for ECMO.

DISCUSSION

Fetal stomach position is strongly associated with neonatal outcomes in isolated left CDH. This objective tool may allow for accurate prognostication in a variety of clinical settings.

Fetal ultrasound markers of severity predict resolution of pulmonary hypertension in congenital diaphragmatic hernia

OBJECTIVE

Congenital diaphragmatic hernia (CDH) results in morbidity and death from lung hypoplasia and persistent pulmonary hypertension (PH). We sought to define the relationship between fetal ultrasound markers of severity in CDH and the time to resolution of neonatal PH.

STUDY DESIGN

We conducted a retrospective study of fetuses with an antenatal ultrasound scan and left-sided CDH cared for at the University of California San Francisco (2002-2012). Fetal liver position was classified on ultrasound scan as abdominal (entire liver within the abdomen) or thoracic (any portion of the liver within the thorax). Fetal stomach position was classified from least to most aberrant: abdominal, anterior left chest, mid-posterior left chest, or retrocardiac (right chest). Lung-to-head ratio (LHR) was determined from available scans at 20-29 weeks of gestational age (GA). Routine neonatal echocardiograms were performed weekly for up to 6 weeks or until PH resolved or until discharge. PH was assessed by echocardiogram with the use of a hierarchy of ductus arteriosus level shunt, interventricular septal position, and tricuspid regurgitant jet velocity. Days to PH-free survival was defined as the age at which pulmonary artery pressure was estimated to be <2/3 systemic blood pressure. Cox proportional hazards models adjusted for GA at birth, era of birth, fetal surgery, and GA at ultrasound scan (LHR model only), with censoring at 100 days.

RESULTS

Of 118 patients, the following fetal markers were available: LHR (n = 53), liver position (n = 112), and stomach position (n = 80). Fewer infants experienced resolved PH if they had LHR <1 (P = .006), thoracic liver position (P = .001), or more aberrant stomach position (P < .001). There was also a decreased rate of resolution of PH in infants with LHR <1 (hazard ratio, 0.30; P = .007), thoracic liver position (hazard ratio, 0.38; P < .001), and more aberrant stomach position (hazard ratios, 0.28 [P = .002]; 0.1 [P < .001]; and 0.07 [P < .001]).

CONCLUSION

Fetal ultrasound markers of CDH severity are predictive not only of death but also of significant morbidity. LHR <1, thoracic liver, and aberrant stomach position are associated with delayed time to resolution of PH in infants with CDH and may be used to identify fetuses at high risk of persistent PH.

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.

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.

Intravesical pressure: A new prognostic indicator in congenital diaphragmatic hernia

AIMS

To evaluate the usefulness of intravesical pressure as a prognostic indicator in congenital diaphragmatic hernia.

MATERIAL AND METHODS

In 25 cases, bladder pressure was measured intraoperatively during repair.

RESULTS

Cases were divided into three groups according to the intravesical pressure. Group 1: pressure <10 cm (n.9), Group 2: 10-15 cm (n.11) and Group 3: >15 cm (n.5). Number of ventilated days was tabulated against these groups. Median number of ventilated days for Group 1, with the lowest pressure, was 3 days, while that for Group 2 was 5 and for Group 3, with the highest pressure, was 10 days. This was significant, with a P-value of 0.016.

CONCLUSION

Measurement of intravesical pressure is a reliable prognostic indicator in newborns with congenital diaphragmatic hernia. It also helps in predicting postoperative ventilatory requirement.

Impact of prenatal evaluation and protocol-based perinatal management on congenital diaphragmatic hernia outcomes

BACKGROUND/PURPOSE

Although intuitive, the benefit of prenatal evaluation and multidisciplinary perinatal management for fetuses with congenital diaphragmatic hernia (CDH) is unproven. We compared the outcome of prenatally diagnosed patients with CDH whose perinatal management was by a predefined protocol with those who were diagnosed postnatally and managed by the same team. We hypothesized that patients with CDH undergoing prenatal evaluation with perinatal planning would demonstrate improved outcome.

METHODS

Retrospective chart review of all patients with Bochdalek-type CDH at a single institution between 2004 and 2009 was performed. Patients were stratified by history of perinatal management, and data were analyzed by Fisher's Exact test and Student's t test.

RESULTS

Of 116 patients, 71 fetuses presented in the prenatal period and delivered at our facility (PRE), whereas 45 infants were either outborn or postnatally diagnosed (POST). There were more high-risk patients in the PRE group compared with the POST group as indicated by higher rates of liver herniation (63% vs 36%, P = .03), need for patch repair (57% vs 27%, P = .004), and extracorporeal membrane oxygenation use (35% vs 18%, P = .05). Despite differences in risk, there was no difference in 6-month survival between groups (73% vs 73%).

CONCLUSIONS

Patients with CDH diagnosed prenatally are a higher risk group. Prenatal evaluation and multidisciplinary perinatal management allows for improved outcome in these patients.

Three-dimensional ultrasound fetal lung volumes and infant respiratory outcome: a prospective observational study

OBJECTIVE

To determine if fetal lung volumes (FLVs), determined by three-dimensional rotational ultrasound and virtual organ computer-aided analysis software (vocal), correlated with neonatal respiratory outcomes in surviving infants who had a high risk [fetuses with congenital diaphragmatic hernia (CDH)], lower risk [fetuses with anterior wall defects (AWDs)] and no risk (controls) of abnormal antenatal lung growth.

DESIGN

Prospective observational study.

SETTING

Tertiary fetal medicine and neonatal intensive care units.

POPULATION

Sixty fetuses (25 with CDH, 25 with AWDs and ten controls).

METHODS

FLVs were measured and expressed as the percentage of the observed compared with the expected for gestational age.

MAIN OUTCOME MEASURES

Neonatal respiratory outcome was determined by the duration of supplemental oxygen, mechanical ventilation and dependencies, and assessment of lung volume using a gas dilution technique to measure functional residual capacity (FRC).

RESULTS

The infants with CDH had lower FLV results than both the infants with AWDs (P=0.05) and the controls (P<0.05). The infants with CDH had longer durations of mechanical ventilation (P<0.001) and supplementary oxygen (P<0.001) dependence, compared with infants with AWDs. The infants with CDH had a lower median FRC than both the infants with AWDs (P<0.001) and the controls (P<0.001). FLV results correlated significantly with the durations of dependency on ventilation (r= -0.744, P<0.01) and oxygen (r= -0.788, P<0.001), and with FRC results (r=0.429, P=0.001).

CONCLUSIONS

These results suggest that FLVs obtained using three-dimensional rotational ultrasound might be useful in predicting neonatal respiratory outcome in surviving infants who had varying risks of abnormal lung growth. Larger and more comprehensive studies are needed to clarify the role that lung volume measurements have in assessing lung function and growth.

Prenatal detection of pulmonary hypoplasia in fetuses with congenital diaphragmatic hernia: a systematic review and meta-analysis of diagnostic studies

BACKGROUND

Fetuses with congenital diaphragmatic hernia (CDH) are at risk of death from pulmonary hypoplasia at birth.

OBJECTIVE

To determine the value of prenatal imaging parameters for predicting lethal pulmonary hypoplasia in fetuses with CDH.

SEARCH STRATEGY

Relevant papers were identified by searching MEDLINE (1966-2008), EMBASE (1988-2008) and the Cochrane Library (2008 issue 3).

SELECTION CRITERIA

Selected studies examined diagnostic tests for the prenatal prediction of lethal pulmonary hypoplasia in fetuses with CDH. The primary outcome measure was perinatal survival.

RESULTS

Twenty-one studies fulfilled the entry criteria, of which six examined entirely unique heterogeneous parameters and the remaining 15 examined lung-head ratios (LHR) and/or the presence of liver in the fetal thorax. The strongest association was that of LHR > or = 0.6 compared to <0.6 (OR: 17.02; 95% CI: 2.10-137.89), although more clinically relevant was that of LHR >1.0 (OR: 5.07; 95% CI: 2.94-8.74). The finding of liver in the fetal chest was a poor prognostic feature (survival OR: 0.32; 95% CI: 0.21-0.49).

CONCLUSION

In CDH, LHR and the presence of liver in the fetal thorax may be a useful predictive indicator of perinatal survival. Future usage of developing techniques needs careful evaluation prior to usage to guide therapy.

Value of liver herniation in prediction of outcome in fetal congenital diaphragmatic hernia: a systematic review and meta-analysis

OBJECTIVES

Intrathoracic liver herniation (ILH) is being used to estimate prognosis and hence guide antenatal interventions in fetal congenital diaphragmatic hernia (CDH). However, the literature regarding its utility in this role is conflicting. This review systematically examines the currently available evidence of ILH use in fetal CDH.

METHODS

MEDLINE and EMBASE databases were searched for the terms ((congenital diaphragmatic hernia) OR CDH) AND liver. Inclusion criteria were human case series of fetuses diagnosed with CDH using either ultrasound or magnetic resonance imaging. Included studies were required to have reported the antenatal liver position and the outcome (survival or not). Case reports, reviews and eventration series were excluded. Studies reporting similar cases from the same center over an overlapping time period were considered duplicates; only the larger of the studies were therefore included. Absolute totals were extracted and sums calculated. Fisher's exact test (FET) was used to compare survival rates in different groups.

RESULTS

The original search retrieved 338 studies. Applying inclusion/exclusion criteria and removing duplicates left 21 case series in 20 studies. Retrieved studies differed in the definitions of liver herniation, survival and treatment modality. In total, there were 407 fetuses in the liver-up (herniated) and 303 in the liver-down (not herniated) groups. Survival rates were 45.4% and 73.9%, respectively. The difference was statistically significant (FET = 56.4, P < 0.005). Sensitivity analysis for cases that had only conventional postnatal treatment was still significant (FET = 52.8, P < 0.005).

CONCLUSIONS

Liver herniation is associated with poorer prognosis in fetal CDH. Grading liver herniation or using it as part of a panel of markers may enhance the value of liver herniation as a prognostic test in fetal CDH.

Contribution of intrapulmonary artery Doppler to improve prediction of survival in fetuses with congenital diaphragmatic hernia treated with fetal endoscopic tracheal occlusion

OBJECTIVE

To evaluate the contribution of intrapulmonary artery Doppler in predicting the survival of fetuses with congenital diaphragmatic hernia (CDH) treated with fetoscopic tracheal occlusion (FETO).

METHODS

A cohort of 41 fetuses (between 24 and 28 weeks of gestation) with CDH was treated with FETO. The observed/expected lung-to-head ratio (O/E-LHR), pulmonary artery pulsatility index (PI), peak early diastolic reversed flow (PEDRF) and peak systolic velocity (PSV) were evaluated before FETO, and their isolated and combined value to predict survival using multiple logistic regression and decision-tree analysis was assessed.

RESULTS

O/E-LHR and intrapulmonary artery PI and PEDRF were significantly associated with the probability of survival (O/E-LHR > or = 26%, OR 14.2; PI < 1 Z-score, OR 8.4; and PEDRF < 3.5 Z-scores, OR 5.7). Decision-tree analysis showed that O/E-LHR was the best initial predictor of prognosis (O/E-LHR > or = 26%, 90% survival; O/E-LHR < 26%, 45% survival). For fetuses with an O/E-LHR of < 26%, Doppler parameters allowed discrimination of cases with moderate (66-71% survival) and very poor (0% survival) prognosis.

CONCLUSION

Intrapulmonary artery Doppler evaluation helps to refine the prediction of survival after FETO in fetuses with severe CDH.

Management of prenatally diagnosed congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a congenital anomaly that presents with a broad spectrum of severity dependent upon components of pulmonary hypoplasia and pulmonary hypertension. While advances in neonatal care have improved the overall survival of CDH in experienced centers, mortality and morbidity remain high in a subset of CDH infants with severe CDH. The most important prenatal predictor of outcome in left-sided CDH is liver position. More precise and reproducible prenatal predictive parameters need to be developed to allow standardization of results between centers and appropriate design of clinical trials in CDH. Thus far, all randomized trials comparing prenatal intervention to standard postnatal therapy have shown no benefit to prenatal intervention. Although recent non-randomized reports of success with balloon tracheal occlusion (and release) are promising, prenatal therapy should not be widely adopted until a well-designed prospective randomized trial demonstrating efficacy is performed. The increased survival and subsequent morbidity of CDH survivors has resulted in the need to provide resources for the long-term follow-up and support of the CDH population.

The use of ultrasound in fetal surgery

Obstetric ultrasound (US) is an integral part of fetal surgery for open and minimally invasive techniques. With advances in US imaging, the ability to refine diagnosis, predict prognosis, and contribute to fetal treatment continues to grow. Current research in fetal diagnosis and treatment includes identifying the most reliable sonographic features for determining prognosis before and after surgery.

[Fetal lung imaging]

Exponential improvements in imaging techniques over the last ten years, through patients' and physicians' wishes for less invasive fetal work-up, now allow us to better explore and understand fetal lung physiology during pregnancy. Diagnostic and prognostic consequences at stake are huge, especially for fetuses at risk of pulmonary hypoplasia. We will decline in three parts (normal lung, malformative lung and pulmonary hypoplasia), through a review of the literature and at the light of our experience, the potentialities and limitations of all imaging modalities (Ultrasound, Doppler, 3D, MRI). Then, we will dwell on future leads and the need for large-scale collaborative studies.

The lung-to-thorax transverse area ratio at term and near term correlates with survival in isolated congenital diaphragmatic hernia

OBJECTIVE

The purpose of this study was to determine how well liver position, the lung area-to-head circumference (L/H) ratio, and the lung-to-thorax transverse area (L/T) ratio predicted the need for extra-corporeal membrane oxygenation (ECMO) and survival in fetuses with isolated congenital diaphragmatic hernia (CDH).

METHODS

Antenatal records of 25 fetuses with isolated left-sided CDH who were born by cesarean delivery under fetal stabilization at this institution were reviewed. The latest determinations of the L/H and L/T ratios before birth (between 34 and 38 weeks' gestation) were compared on the basis of the cutoff points for mortality: less than 1.0 versus 1.0 or greater for the L/H ratio and 0.08 or less versus greater than 0.08 for the L/T ratio. Outcome measures assessed were survival (discharge to home) and the need for ECMO.

RESULTS

Overall survival was 64% (16/25). Postnatal survival in fetuses with an L/T ratio of 0.08 or less was statistically lower than in those with an L/T ratio of greater than 0.08 (33% versus 81%; P = .0308). The percentage requiring ECMO in the group with an L/T ratio of 0.08 or less was also higher than that of the group with an L/T ratio of greater than 0.08, but the difference was not statistically significant (67% versus 25%; P = .0872). Neither the L/H ratio nor herniation of the fetal liver into the chest affected survival or the need for ECMO.

CONCLUSIONS

In fetuses with isolated CDH at term or near term, the L/T ratio may be a better predictor of outcome than the L/H ratio or liver herniation.

How useful is the lung-to-head ratio in predicting outcome in the fetus with congenital diaphragmatic hernia? A systematic review and meta-analysis

OBJECTIVE

Fetal surgery to improve lung growth comprises tracheal occlusion in selected 'high-risk' fetuses with congenital diaphragmatic hernia (CDH). Sonographically measured fetal lung-to-head ratio (LHR) is utilized to recruit candidates for fetal surgery. This study provides a meta-analysis of the evidence regarding the prognostic use of lung-to-head ratio measurements in fetal CDH.

METHODS

MEDLINE, SCOPUS and ISI PROCEEDINGS databases were searched for MeSH terms: lung, head, hernia and ratio. References in retrieved studies were also searched. Studies were categorized as follows: Phase I studies measured normal fetal LHR; Phase II studies compared fetal LHR in CDH survivors and non-survivors (if LHR informed therapy decisions or LHR was not measured during the window for intervention (< 32 weeks' gestation), studies were excluded); Phase III studies used LHR to guide selection for fetal surgery (non-randomized trials were excluded); Phase IV studies measured CDH survival before and after LHR application in clinical practice.

RESULTS

The one Phase I study showed that LHR varied substantially with gestation and technique. No complete studies met the selection criteria for Phase II: meta-analysis of subgroups revealed similar LHR in CDH survivors and non-survivors. A single Phase III study revealed no benefit for LHR-directed fetal surgery. No Phase IV studies were identified.

CONCLUSION

The prognostic use of LHR in fetal CDH entered clinical practice prior to publication of robust normal data and is not supported by current evidence. Application of a structured approach to any 'new' prognostic test could improve its validity and clinical application.

Liver position and lung-to-head ratio for prediction of extracorporeal membrane oxygenation and survival in isolated left congenital diaphragmatic hernia

OBJECTIVE

The purpose of this study was to determine the ability of liver position and lung-to-head ratio to predict outcome in isolated left congenital diaphragmatic hernia.

STUDY DESIGN

We reviewed prenatal studies and postnatal outcomes of congenital diaphragmatic hernia between January 1996 and January 2006.

RESULTS

Eighty-nine patients received prenatal and postnatal care at 1 institution. In fetuses with liver up, extracorporeal membrane oxygenation was required in 39 of 49 fetuses (80%), compared with 10 of 40 fetuses (25%) for those with liver down (P < .0001). Overall survival rate was 45%, compared with 93% for those with liver down (P < .00005). Low lung-to-head ratio (<1.0) predicted increased incidence of extracorporeal membrane oxygenation (75%; P = .036) and lower survival (35%; P = .0003). However, when measured at <24 weeks of gestation, lung-to-head ratio was not predictive of outcome (extracorporeal membrane oxygenation, P = .108; survival, P = .150); liver position remained highly predictive (extracorporeal membrane oxygenation, P = .006; survival, P = .001).

CONCLUSION

Liver position is the best prenatal predictor of outcome in isolated left congenital diaphragmatic hernia. Lung-to-head ratio alone should not be used to counsel families regarding mid gestational management choices.

Antenatal and postnatal lung and vascular anatomic and functional studies in congenital diaphragmatic hernia: implications for clinical management

Congenital diaphragmatic hernia is characterized by fetal and neonatal lung hypoplasia as well as vascular hypoplasia. Antenatal imaging studies have been performed that attempt to quantify the degree of hypoplasia and its impact on infant prognosis. Prenatal and perinatal growth of the lung and vasculature are interdependent and their continued coordinated growth is critical for survival after birth in this patient population. Lung protection strategies appear to improve survival in newborns with diaphragmatic hernia, but a subset of infants remain who demonstrate sufficiently severe lung hypoplasia that we are unable to provide support long-term after birth. Fetal intervention is a strategy designed to enhance fetal lung growth towards improving survival in this most severely affected group, though other therapies to enhance postnatal lung and vascular growth should be concurrently investigated. However, any of these interventions will require careful selection of those infants at risk for poor outcome and thorough follow up, since long-term morbidity is significant in children with diaphragmatic hernia.

Reliability of the lung-to-head ratio as a predictor of outcome in fetuses with isolated left congenital diaphragmatic hernia at gestation outside 24-26 weeks

OBJECTIVE

The purpose of this study was to investigate the relationship between lung-to-head ratio (LHR) and gestational age (GA) in fetuses with isolated left congenital diaphragmatic hernia and to determine the applicability and reliability of LHR to predict postnatal outcome beyond 24-26 weeks of gestation.

STUDY DESIGN

The institutional review board approved this retrospective review of the University of California, San Francisco, Fetal Treatment Center database for cases with left congenital diaphragmatic hernia who were referred between March 1995 and June 2004. LHR was determined at the initial evaluation. One hundred seven live-born fetuses at 20-34 weeks of gestation (excluding cases that were lost to follow-up, with factors that potentially could influence the LHR measurement or postnatal outcome, or that were terminated electively).

RESULTS

The median GA at LHR measurement was 25.6 weeks; the median LHR was 1.01; the median GA at birth was 37.7 weeks; and the overall survival rate was 59% (64/107). The median LHR of nonsurvivors was significantly lower than that of survivors, but neither GA at LHR measurement nor at delivery was significantly different between the groups. Multiple logistic regression analysis confirmed LHR to be an independent predictor of postnatal survival, and receiver-operator characteristic curve analysis demonstrated that an LHR of > or = 0.97 has the highest performance in predicting postnatal survival. When fetuses were grouped by GA at initial LHR measurement to determine reliability of LHR, specifically with respect to GA, in the 26-34 and 24-26 weeks of gestation groups, median LHR of survivors was significantly higher than that of nonsurvivors, and receiver-operator characteristic curve analysis confirmed LHR to be a reliable predictor of postnatal survival. However, for fetuses at 20-24 weeks of gestation, there was a trend toward a higher LHR in survivors, although this did not reach statistical significance.

CONCLUSION

A significant positive linear relationship exists between LHR and GA at the time of measurement, such that LHR reliably predicts postnatal survival in fetuses with left congenital diaphragmatic hernia at 24-34 weeks of gestation and less reliable at 20-24 weeks. However, given the limitations of a retrospective, cross-sectional study, further prospective longitudinal studies that will investigate the change of LHR with GA and its association with fetal outcome are necessary.

Prenatal intervention for isolated congenital diaphragmatic hernia

PURPOSE OF REVIEW

We aim to review the recent literature regarding early prenatal prediction of outcome in babies diagnosed with isolated congenital diaphragmatic hernia, as well as results of fetal therapy for this condition.

RECENT FINDINGS

Current survival rates in population-based studies are around 55-70%. Highly specialized centers report 80% and more, but discount the hidden mortality, mainly in the antenatal period. Fetuses presenting with liver herniation and a lung-to-head ratio of less than 1.0 measured in midgestation have a poor prognosis. Other volumetric techniques are being evaluated for use in midtrimester. Recently, a randomized trial failed to show benefit from prenatal therapy, but lacked power to document the potential advantage of prenatal therapy in severe cases. We proposed percutaneous fetal endoluminal tracheal occlusion with a balloon at 26-28 weeks through a 3.3 mm incision. In severe cases, fetal endoluminal tracheal occlusion increased lung size as well as survival, with an early (7 day) survival, late neonatal (28 day) survival and survival at discharge of 75, 58 and 50%, respectively, comparing favorably with 9% in contemporary controls. Airways can be restored prior to birth improving neonatal survival (83.3% compared with 33.3%). The procedure carries a risk for preterm prelabour rupture of the fetal membranes, although that may decrease with experience.

SUMMARY

Fetuses with severe congenital diaphragmatic hernia can be identified in the second trimester. Fetal endoluminal tracheal occlusion can be considered as a minimally invasive fetal therapy, improving outcome in such highly selected cases.

Fetal pulmonary artery diameter measurements as a predictor of morbidity in antenatally diagnosed congenital diaphragmatic hernia: a prospective study

OBJECTIVE

The objective of the study was to examine the size and growth of fetal pulmonary artery diameters in congenital diaphragmatic hernia and assess their correlation with postnatal survival and morbidity outcomes.

STUDY DESIGN

Prospective antenatal echocardiographic examination of fetal branch pulmonary arteries were correlated with postnatal survival and respiratory morbidity in cases of congenital diaphragmatic hernia. Receiver operator curves were developed to assess their utilization as predictors of respiratory morbidity and survival.

RESULTS

Twenty-one cases were diagnosed antenatally over 3 years. Fifteen subjects survived postnatally. The ipsilateral fetal branch pulmonary artery diameter was smaller throughout gestation in left-sided congenital diaphragmatic hernia (P = .008). The small left pulmonary diameter did not correlate with survival but correlated strongly with morbidity outcomes. Progressive ipsilateral fetal pulmonary artery hypoplasia was demonstrated throughout gestation in subjects who died or had severe morbidity.

CONCLUSION

Fetal pulmonary artery diameter measurements correlate with respiratory morbidity in postnatal congenital diaphragmatic hernia and may assist with prediction of outcome. Survival has improved, possibly because of improved postnatal management of congenital diaphragmatic hernia, limiting this measurement in assessing survival.

Prenatal prognosis of congenital diaphragmatic hernia using magnetic resonance imaging measurement of fetal lung volume

OBJECTIVES

To investigate the correlation between fetal lung volume (FLV), measured with magnetic resonance imaging (MRI), and postnatal mortality in newborns with prenatally diagnosed isolated congenital diaphragmatic hernia (CDH).

METHODS

In a 4-year prospective multicenter study, 77 fetuses with isolated CDH diagnosed between 20 and 33 weeks' gestation underwent fast spin-echo T2-weighted lung MRI. These MRI-FLV measurements were compared with a previously published normative curve obtained in 215 fetuses without thoracoabdominal malformations and with normal ultrasound biometric findings. FLV measurements were correlated with postnatal survival. The mean gestational age at MRI was 31.3 weeks.

RESULTS

The measured/expected FLV ratio was significantly lower in the newborns with CDH who died compared with those who survived (23.6 +/- 12.2 vs. 36.1 +/- 13.0, P < 0.001). When the ratio was below 25%, there was a significant decrease in postnatal survival (19% vs. 40.3%, P = 0.008). Survival was significantly lower for neonates when one lung could not be seen by fetal MRI compared with those fetuses with two visible lungs on MRI (17.9% vs. 62.1%, P < 0.001).

CONCLUSION

In isolated CDH, FLV measurement by MRI is a good predictor of postnatal mortality due to pulmonary hypoplasia.

Outcomes of congenital diaphragmatic hernia: a population-based study in Western Australia

OBJECTIVES

There have been many recent reports of improved survival rates for congenital diaphragmatic hernia (CDH), largely derived from institution-based data. These are often flawed by case selection bias. The objectives of this study were to document the true incidence, management, and outcomes of CDH in a geographically defined population over a 12-year period and to determine the changing trends in these over time. We also sought to ascertain the prenatal and postnatal factors associated with morbidity and death among these infants.

METHODS

A retrospective study of all cases of CDH in Western Australia from 1991 to 2002 was conducted. Cases were identified from 5 independent databases within the Western Australian health network, including the Western Australian Birth Defects Registry. All fetuses and neonates diagnosed with CDH in Western Australia during this period were identified, including miscarriages, stillbirths, and terminations of pregnancies in which a diagnosis of fetal CDH had been made, as well as those diagnosed postnatally. Cases not known to involve CDH until diagnosis at autopsy were also included. Infants with diaphragmatic eventration were excluded from the study. Detailed information was obtained from review of maternal and infant medical records.

RESULTS

One hundred sixteen cases of CDH were identified. Of these, 71 (61%) infants were born alive and 37 survived beyond 1 year of age (52% of live-born infants, 32% of all cases of CDH). Pregnancies involving 38 (33%) fetuses were terminated electively, 4 (3%) fetuses were aborted spontaneously, and 3 (3%) fetuses were stillborn. Another major congenital anomaly was present in 54 (47%) cases. Twenty-one (18%) cases had other anomalies that were likely to be fatal. Of all cases with an additional major anomaly, 42 (78%) died. Twenty-seven (71%) of 38 fetuses for whom the pregnancy was terminated had another major anomaly. Twenty-three (32%) live-born infants had another major anomaly (4 of which were considered fatal conditions); however, this did not affect their survival rates. Fifty-three percent of cases were diagnosed prenatally, and 49% of these pregnancies were then terminated. Of live-born infants with prenatally diagnosed CDH, 10 (33%) survived beyond 1 year of age. The gestational age at diagnosis did not affect the survival rate for live-born infants. Postnatal diagnosis occurred in 55 (47%) cases. Of these, 41 (74%) case subjects were born alive and diagnosed on clinical grounds after birth. In the remaining 14 cases, the diagnosis was made in postmortem examinations of fetuses from pregnancies that were terminated for other reasons (8 cases) or after spontaneous abortion or stillbirth (5 cases). Significant differences were found between prenatally and postnatally diagnosed live-born infants. Among live-born infants, prenatal diagnosis was associated with a significantly reduced survival rate (33%, compared with 66% for postnatally diagnosed infants). Prenatally diagnosed live-born infants were of lower birth weight and were born at an earlier gestational age. There was no statistically significant difference between the 2 groups in the onset of labor (spontaneous or induced) or in the rate of elective cesarean sections. Prenatally diagnosed live-born infants were more likely to be delivered in a tertiary perinatal center and were intubated more commonly at delivery. No difference was found in the Apgar scores at either 1 or 5 minutes between the groups. Of 71 live-born infants, 37 (52%) survived to 1 year of age. The majority of deaths occurred within the first 7 days of life (44%). Preoperative air leaks occurred for 16 (22%) infants, of whom 14 (88%) died. Factors found to predict death of live-born infants included prenatal diagnosis, right-sided hernia, major air leak, earlier gestational age at birth, lower birth weight, and lower Apgar scores at 1 and 5 minutes. Over the course of the decade, there were significant increases in the proportion of cases in which the diagnosis of CDH was made with prenatal ultrasonography and in the number of live-born infants born at the tertiary perinatal center. The mortality rate for all cases, the mortality rate for live-born infants, and the proportion of pregnancies involving prenatally diagnosed cases that were terminated electively were all greater in the later epoch but not significantly so.

CONCLUSIONS

This was a comprehensive, population-based study of CDH, with full case ascertainment, large sample size, and complete outcome data for all cases. The majority of published studies of CDH examined specific patient populations, such as neonates referred to tertiary pediatric surgical centers. Invariably, those studies failed to detect the demise of cases with CDH before arrival at the referral center, whether through termination of pregnancy, in utero fetal demise, or postnatal death occurring before transfer. Exclusion of these cases from calculations of mortality rates results in significant case selection bias. In our study, 35% of live-born infants died before referral or transport. The population of infants reaching the tertiary surgical center represented only 40% of the total cases of CDH. Wide variations in reported survival rates occur throughout the literature. These differences reflect the influence of this case selection bias, as well as variable referral policies and management practices. For our study population, survival rates differed vastly depending on the subgroup analyzed. Ninety-two percent of postoperative infants survived beyond 1 year of age, as did 80% of infants who reached the surgical referral center. However, only 52% of live-born infants, 32% of all cases, and 16% of all prenatally diagnosed cases survived. Therefore, the overall mortality rate for this condition remains high, despite increased prenatal detection, transfer to tertiary institutions for delivery, and advances in neonatal care, and is influenced significantly by the rate of prenatal termination. In our study, 33% of all cases of CDH and 49% of prenatally diagnosed fetuses underwent elective termination of pregnancy. This large number of fetal terminations confounds the accurate assessment of the true outcomes of this condition.

Recent advances in congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a common birth defect which continues to challenge paediatric surgeons and intensivists. Affecting approximately 1:2500 births, a baby with CDH is born every 24-36 hours in the UK.

Antenatal diagnosis of congenital diaphragmatic hernia

Congenital diaphragmatic hernia occurs in approximately 1 of 2200 live births and is associated with a high degree of morbidity and mortality. Poor outcome in these cases is primarily related to the presence of additional anomalies or abnormal karyotype and the development of pulmonary and cardiovascular complications. Prenatal diagnosis occurs in approximately 50% of cases. Multiple ultrasound markers have been identified as being predictive of outcome. Three-dimensional ultrasound, fetal echocardiography, and magnetic resonance imaging have been identified as additional imaging modalities that can assist in making the antenatal diagnosis and accurately assessing perinatal outcome.

Accuracy of magnetic resonance imaging for measuring fetal sheep lungs and other organs

OBJECTIVE

Lung volume measurement by fetal magnetic resonance imaging (fetMRI) has been used to predict survival of fetuses with isolated congenital diaphragmatic hernia (CDH). So far, the accuracy and precision of fetMRI for volumetry of either the normal or hypoplastic developing lung has not been formally studied.

METHODS

A total of nine sheep carrying 14 fetuses underwent fetMRI under general anesthesia at a mean of 118 days' gestational age (term = 145 days). A total of 61 organs were measured in nine normal fetal sheep and five that underwent surgical creation of diaphragmatic hernia (DH), so as to induce pulmonary hypoplasia. Lungs were measured on T2-WI (weighted images) in three different planes, while liver and kidneys were measured in the axial (T1-WI) and sagittal (T2-WI) planes, respectively. Necropsy was done within 24 h after fetMRI to determine the volume postmortem by the water displacement method. Values were linearly correlated and a Bland and Altman analysis was done for volume measurement comparison, calculating means +/- SD, bias (mean of the difference of volume measurements), precision (SD of the difference) and absolute and proportionate limits of agreement for both methods. The accuracy of fetMRI volume measurement was determined for different organ groups by calculating the median relative error and precision index, both being measures of error in proportion to the magnitude of the volume measured, as a clinically relevant proxy of potential errors.

RESULTS

The fetMRI volume measurements were on average larger than postmortem volumes, except for the kidneys. Kidney volume determination had a relative error of 29%, while measurements of larger organs had larger relative errors (42% for liver). Normal lungs were less accurately measured in the coronal or sagittal than in the axial plane (relative error 53%, 73% and 38%, respectively; P < 0.05 for sagittal vs. axial). Axially-measured lung volumes were more accurate for lungs of normal sheep compared to DH lungs (relative error 38% vs. 73%, respectively; P < 0.05).

CONCLUSION

FetMRI measured systematically higher volumes for organs such as fetal liver or lung. This may be related to fluid loss or lack of perfusion at the time of necropsy. Measurement of lung volume by fetMRI was most accurate in the axial plane. Measurements of lung and liver volumes by fetMRI in normal sheep were both in agreement with volumes measured at necropsy. Loss of accuracy for DH-lungs in comparison with the accuracy when measuring other similarly small organs, such as kidneys, suggests that fetMRI measurements can be less accurate for hypoplastic lungs related to CDH. With improving hardware, it might become easier to render the fetal lung and determine its volume reliably.

Reliability of the lung-to-head ratio in predicting outcome and neonatal ventilation parameters in fetuses with congenital diaphragmatic hernia

OBJECTIVES

The ratio of the lung area (on the contralateral side of the hernia) to the head circumference, the lung-to-head ratio (LHR), has been proposed as a reliable tool in the assessment of the prognosis of congenital diaphragmatic hernia (CDH). An LHR < 0.6 has been associated with poor outcome whereas one > 1.4 has been associated with survival. We aimed to analyze the role of LHR in predicting fetal outcome and ventilation parameters in cases of isolated CDH in our center.

METHODS

During the 40-month study period, 22 fetuses with an isolated CDH were delivered alive under optimized conditions at our perinatal center. LHR was measured at the time of diagnosis (median, 27 weeks' gestation). In addition to survival, postnatal ventilation parameters including pCO2, pO2, inspiratory O2 partial pressure, inspiratory pressure and oxygenation index were determined, as was the occurrence of pulmonary hypertension.

RESULTS

The overall survival rate was 59%. The LHR was not able to predict fetal outcome reliably. There was no correlation between the liver herniation, LHR and fetal outcome. The prenatally determined lung size reflected in the LHR did not show any significant association with individual ventilation parameters. Eleven of 17 infants examined had signs of pulmonary hypertension and the LHR did not predict this condition.

CONCLUSION

Our study cannot support the optimistic results reported by other groups on the use of LHR as a reliable predictor of outcome in fetuses with CDH. The LHR, as a reflection of lung size, correlates neither with survival patterns nor with various postnatal ventilation parameters.

Survival of severe congenital diaphragmatic hernia has morbid consequences

BACKGROUND/PURPOSE

Fetal tracheal occlusion (TO) was developed in an attempt to enhance prenatal lung growth and improve survival in fetuses with severe congenital diaphragmatic hernia (CDH). We conducted a randomized, controlled clinical trial in 24 fetuses with severe left CDH (liver herniated into the thorax and low lung-to-head ratio) to compare survival after endoscopic fetal TO vs standard perinatal care (control) and prospectively followed up the 16 survivors (9 control, 7 TO) to compare neurodevelopmental, respiratory, surgical, growth, and nutritional outcomes.

METHODS

At 1 and 2 years old, subjects underwent evaluation consisting of medical and neurological history and physical, developmental testing, nutritional assessment, oxygen saturation and pulmonary function testing, chest radiograph, and echocardiogram. Growth and developmental measures were corrected for prematurity. Data were analyzed by Mann-Whitney rank sum test, Fisher's Exact test, and logistic and linear regression.

RESULTS

Infants with TO were significantly more premature at birth (control vs TO, 37.4 +/- 1.0 vs 31.1 +/- 1.7 weeks; P < .01). Growth failure ( z score for weight <2 SDs below mean) was severe in both groups at 1 year of age (control vs TO, 56% vs 86%; P = .31). There was considerable catch-up growth by age 2 years (growth failure: control vs TO, 22% vs 33%; P = .19). There were no differences in other growth parameters. There were also no differences in neurodevelopmental outcome at 1 and 2 years. Supplemental oxygen at hospital discharge was a significant predictor of worse neurodevelopmental outcome at 1 and 2 years old (P = .05 and P = .02, respectively). Hearing loss requiring amplification has been diagnosed in 44% of the group (control vs TO, 44% vs 43%; P = 1.0).

CONCLUSIONS

In this group of infants with severe CDH, there were no differences in outcome at 2 years old despite significant prematurity in the TO group. Oxygen supplementation at hospital discharge identified the most vulnerable group with respect to neurodevelopmental outcome, but all infants had significant growth failure, and hearing impairment is a substantial problem in this population. Severe CDH carries significant risk of chronic morbidity.

A randomized trial of fetal endoscopic tracheal occlusion for severe fetal congenital diaphragmatic hernia

BACKGROUND

Experimental and clinical data suggest that fetal endoscopic tracheal occlusion to induce lung growth may improve the outcome of severe congenital diaphragmatic hernia. We performed a randomized, controlled trial comparing fetal tracheal occlusion with standard postnatal care.

METHODS

Women carrying fetuses that were between 22 and 27 weeks of gestation and that had severe, left-sided congenital diaphragmatic hernia (liver herniation and a lung-to-head ratio below 1.4), with no other detectable anomalies, were randomly assigned to fetal endoscopic tracheal occlusion or standard care. The primary outcome was survival at the age of 90 days; the secondary outcomes were measures of maternal and neonatal morbidity.

RESULTS

Of 28 women who met the entry criteria, 24 agreed to randomization. Enrollment was stopped after 24 patients had been enrolled because of the unexpectedly high survival rate with standard care and the conclusion of the data safety monitoring board that further recruitment would not result in significant differences between the groups. Eight of 11 fetuses (73 percent) in the tracheal-occlusion group and 10 of 13 (77 percent) in the group that received standard care survived to 90 days of age (P=1.00). The severity of the congenital diaphragmatic hernia at randomization, as measured by the lung-to-head ratio, was inversely related to survival in both groups. Premature rupture of the membranes and preterm delivery were more common in the group receiving the intervention than in the group receiving standard care (mean [+/-SD] gestational age at delivery, 30.8+/-2.0 weeks vs. 37.0+/-1.5 weeks; P<0.001). The rates of neonatal morbidity did not differ between the groups.

CONCLUSIONS

Tracheal occlusion did not improve survival or morbidity rates in this cohort of fetuses with congenital diaphragmatic hernia.