Predictors and statistical models in congenital diaphragmatic hernia

Prenatal predictors of mortality in fetuses with congenital diaphragmatic hernia: a systematic review and meta-analysis

PURPOSE

This study aimed to evaluate prenatal predictors of mortality in fetuses with congenital diaphragmatic hernia (CDH).

METHODS

A systematic literature search was performed to identify relevant observational studies that evaluated the ability of lung-to-head ratio (LHR), observed-to-expected LHR (o/e-LHR), observed-to-expected total fetal lung volume (o/e-TFLV), lung-to-thorax transverse area ratio (L/T ratio), intrathoracic herniation of the liver and the stomach, and side of diaphragmatic hernia, using a threshold for the prediction of mortality in fetuses with CDH. Study quality was assessed using the QUADAS-2 tool. Hierarchical summary receiver operating characteristic curves were constructed.

RESULTS

A total of 50 articles were included in this meta-analysis. The QUADAS-2 tool identified a high risk of bias in more than one domain scored in all parameters. Among those parameters, the diagnostic odds ratio of mortality with o/e-LHR < 25%, o/e-TFLV < 25%, and L/T ratio < 0.08 were 11.98 [95% confidence interval (CI) 4.65-30.89], 11.14 (95% CI 5.19-23.89), and 10.28 (95% CI 3.38-31.31), respectively. The predictive values for mortality were similar between the presence of liver herniation and retrocardiac fetal stomach position.

CONCLUSIONS

This systematic review suggests that o/e-LHR, o/e-TFLV, and L/T ratio are equally good predictors of neonatal mortality in fetuses with isolated CDH.

Optimal gestational age at delivery in isolated left-sided congenital diaphragmatic hernia

OBJECTIVE

To evaluate the morbidity and mortality of neonates with left-sided isolated congenital diaphragmatic hernia (CDH) according to gestational age at delivery.

METHODS

This was a retrospective study of fetuses diagnosed prenatally with isolated left-sided CDH that were delivered in the University Hospitals of Antoine Béclère-Bicêtre and Leuven between 1 January 2010 and 31 December 2018. The Kaplan-Meier method was used to calculate cumulative survival at 28 days after birth according to gestational age at delivery. The association between gestational age at delivery, as a continuous variable, and survival at 28 days was modeled using a fractional polynomial. Adjustment for position of the liver, management center and mode of delivery was performed. The association was also evaluated according to the severity of CDH, as defined by the observed-to-expected lung-to-head ratio (o/e-LHR), which was classified as severe (o/e-LHR < 25%), moderate (o/e-LHR between 25% and 45%) or mild (o/e-LHR > 45%).

RESULTS

We included 213 fetuses with isolated left-sided CDH, with a median gestational age at delivery of 38 + 2 weeks (interquartile range, 37 + 0 to 39 + 1 weeks). The survival rates at 28 days and at 6 months were 66.7% (142/213) and 64.3% (137/213), respectively. Kaplan-Meier analysis showed a higher survival rate at 28 days for babies delivered between 37 + 0 and 38 + 6 weeks than for those delivered at or after 39 + 0 weeks (log-rank test, P < 0.001). In the subgroup of moderate CDH, the 28-day survival rate was significantly higher in newborns delivered between 37 + 0 and 38 + 6 weeks than in those delivered at or after 39 + 0 weeks (81.5% vs 61.5%; P = 0.03), and this was also the case for survival rate at 6 months. In the subgroup with moderate CDH, 28-day survival significantly increased with advancing gestational age at birth up to about 38-39 weeks (P = 0.005), and significantly decreased from 39 weeks onwards.

CONCLUSION

Delivery between 37 + 0 and 38 + 6 weeks' gestation is associated with a higher survival rate at 28 days in neonates with isolated left-sided CDH and moderate lung hypoplasia, independently of intrathoracic liver, management center and mode of delivery. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Assessment of Carina Position Antenatally and Postnatally in Infants with Congenital Diaphragmatic Hernia

OBJECTIVE

To determine whether endotracheal tube (ETT) insertion depth should be modified in infants with congenital diaphragmatic hernia (CDH) to reduce the risk of main-stem intubation.

STUDY DESIGN

The distance from the thoracic inlet to the carina was measured antenatally by fetal magnetic resonance imaging (MRI) between 20-28 weeks' (early) and 30-34 weeks' (late) gestation in 30 infants with CDH and compared with 12 early and 36 late MRIs in control infants without CDH. Postnatal tube position was assessed by chest radiograph in the same 30 infants with CDH and compared with 20 control infants with postnatal birth depression.

RESULTS

The carina position was displaced upward in fetuses and newborns with CDH. Distance from the thoracic inlet to the carina compared with controls was 1.04 ± 0.1 cm vs 1.42 ± 0.07 cm on early MRI (P < .05), 1.43 ± 0.14 cm vs 1.9 ± 0.04 cm on late MRI (P < .01), and 2.36 ± 0.07 cm vs 3.28 ± 0.05 cm on postnatal radiographs (P < .01). Adjusting the ETT depth by 1 cm resulted in a median distance of 1.27 cm from the tip of the ETT to the carina.

CONCLUSION

Cephalad displacement of the carina in infants with CDH may predispose them to right main-stem intubation and subsequent development of pneumothorax. We speculate that modifying the ETT insertion depth to 5.5 cm + weight in newborns born at term may prevent pneumothoraces and improve outcomes for infants with CDH.

Risk factors for postoperative mortality in congenital diaphragmatic hernia: a single-centre observational study

BACKGROUND

The management of congenital diaphragmatic hernia (CDH) is a major challenge. The mortality is dependent on associated malformations, the severity of pulmonary hypoplasia, pulmonary hypertension and iatrogenic lung injury associated with aggressive mechanical ventilation. The aims of the study were to investigate the mortality over time in a single paediatric surgical centre, to compare the results with recent reports and to define the risk factors for mortality.

METHODS

The medical records of infants with CDH from two time periods: 1995-2005 and 2006-2016 were reviewed. Cox regression was used for statistical analysis.

RESULTS

The study included 113 infants. The mortality rate was significantly decreased in the later time period, compared to the earlier, 4.4 and 17.9%, respectively. At the early time period five patients (7.5%) were treated with ECMO and in the later time period ECMO was used in three patients (6.5%). The mortality in ECMO-treated patients was 50% in both time periods. Prenatal diagnosis, intrathoracic liver, low Apgar score and low birth weight were defined as independent risk factors for mortality.

CONCLUSION

Despite no significant differences in the incidence of independent risk factors and the use of ECMO between the two time periods, mortality decreased over time. The mortality was lower than previously reported. The results indicate that there are many important factors involved in a successful outcome after CDH repair. Large multicentre studies are necessary to define those critical factors and to determine optimal treatment strategies.

Risk-stratification of severity for infants with CDH: Prenatal versus postnatal predictors of outcome

PURPOSE

The purpose of this study was to compare the predication accuracy of a newly described postnatally-based clinical prediction model to fetal imaging-based predictors of mortality for infants with CDH.

METHODS

We performed a retrospective review of all CDH patients treated at a comprehensive fetal care center from January 2004 to January 2014. Prenatal data reviewed included lung-to-head ratio (LHR), observed/expected-total fetal lung volume (O/E-TFLV), and percent liver herniation (%LH). Based on the postnatal prediction model, neonates were categorized as low, intermediate, and high risk of death. The primary outcome was 6-month mortality.

RESULTS

Of 176 CDH patients, 58 had a major cardiac anomaly, and 28 had a genetic anomaly. Patients with O/E-TFLV <35% and %LH >20% were at increased risk for mortality (44% and 36%, respectively). There was a significant difference in mortality between low, intermediate, and high-risk groups (4% vs. 22% vs. 51%; p<0.001). On multivariate regression, the O/E-TFLV and postnatal-based mortality risk score were the two independent predictors of 6-month mortality.

CONCLUSION

The CDH Study Group postnatal predictive model provides good discrimination among three risk groups in our patient cohort. The prenatal MRI-based O/E-TFLV is the strongest prenatal predictor of 6-month mortality in infants with CDH and will help guide prenatal counseling and discussions regarding fetal intervention and perinatal management.

A simplified formula using early blood gas analysis can predict survival outcomes and the requirements for extracorporeal membrane oxygenation in congenital diaphragmatic hernia

The aims of this study were to investigate whether early arterial blood gas analysis (ABGA) could define the severity of disease in infants with congenital diaphragmatic hernia (CDH). We conducted a retrospective study over a 21-yr period of infants diagnosed with CDH. Outcomes were defined as death before discharge, and extracorporeal membrane oxygenation requirements (ECMO) or death. A total 114 infants were included in this study. We investigated whether simplified prediction formula [PO2-PCO2] values at 0, 4, 8, and 12 hr after birth were associated with mortality, and ECMO or death. The area under curve (AUC) of receiver operating characteristic curve was used to determine the optimum ABGA values for predicting outcomes. The value of [PO2-PCO2] at birth was the best predictor of mortality (AUC 0.803, P < 0.001) and at 4 hr after birth was the most reliable predictor of ECMO or death (AUC 0.777, P < 0.001). The value of [PO2-PCO2] from ABGA early period after birth can reliably predict outcomes in infants with CDH.

Outcome analysis of neonates with congenital diaphragmatic hernia treated with venovenous vs venoarterial extracorporeal membrane oxygenation

PURPOSE

Venoarterial extracorporeal membrane oxygenation (ECMO) (VA) is used more commonly in neonates with congenital diaphragmatic hernia (CDH) than venovenous ECMO (VV). We hypothesized that VV may result in comparable outcomes in infants with CDH requiring ECMO.

METHODS

We retrospectively analyzed the Extracorporeal Life Support Organization (ELSO) database (1991-2006). Multivariate logistic regression analyses were used to compare VV- and VA-associated mortality.

RESULTS

Four thousand one hundred fifteen neonates required ECMO, with an overall mortality rate of 49.6%. Venoarterial ECMO was used in 82% and VV in 18% of neonates. Pre-ECMO inotrope use and complications were equivalent between VA and VV. The mortality rate for VA and VV was 50% and 46%, respectively. After adjusting for birth weight, gestational age, prenatal diagnosis, ethnicity, Apgar scores, pH less than 7.20, Paco(2) greater than 50, requiring high-frequency ventilation, and year of ECMO, there was no difference in mortality between VV vs VA. Renal complications and on-ECMO inotrope use were more common with VV, whereas neurologic complications were more common with VA. The conversion rate from VV to VA was 18%; conversion was associated with a 56% mortality rate.

CONCLUSION

The short-term outcomes of VV and VA are comparable. Patients with CDH who fail VV may be predisposed to a worse outcome. Nevertheless, VV offers equal benefit to patients with CDH requiring ECMO while preserving the native carotid.

Identifying neonates at a very high risk for mortality among children with congenital diaphragmatic hernia managed with extracorporeal membrane oxygenation

PURPOSE

The purpose of this study was to identify mortality risk factors in children with congenital diaphragmatic hernia (CDH) treated with extracorporeal membrane oxygenation (ECMO) and generate a prediction score for those at a very high risk for mortality.

METHODS

Data on first ECMO runs of all neonates with CDH, between January 1997 and June 2007, were obtained from the Extracorporeal Life Support Organization registry (N = 2678). The data were split into "training data (TD)" (n = 2006) and "validation data" (n = 672). The primary outcome analyzed was in-hospital mortality. Modified Poisson regression was used for analyses.

RESULTS

Overall in-hospital mortality among 2678 neonates (males, 57%; median age at ECMO, 1 day) was 52%. The univariate and multivariable analyses were performed using TD. An empirically weighted mortality prediction score was generated with possible scores ranging from 0 to 35 points. Of 69 who scored 14 or higher in the TD, 62 died (positive predictive value [PPV], 90%), of 37 with 15 or higher, 35 died (PPV, 95%), of 23 with 16 or higher, 22 died (PPV, 96%). A cut-off point of 15 was chosen and was tested using the separate validation dataset. In validation data, the cut-off point 15 had a PPV of 96% (23 died of 24).

CONCLUSION

Scoring 15 or higher on the prediction score identifies neonates with CDH at a very high risk for mortality among those managed with ECMO and could be used in surgical decision making and counseling.