Factors associated with survival in infants with congenital diaphragmatic hernia requiring extracorporeal membrane oxygenation: a report from the Congenital Diaphragmatic Hernia Study Group

Abdominal wall muscle weakness outcomes after split abdominal flap repair of large congenital diaphragmatic hernias in newborn

PURPOSE

Split abdominal wall muscle flap (SAWMF) is a technique to repair large defects in congenital diaphragmatic hernia (CDH). A possible objection to this intervention could be any associated abdominal muscle weakness. Our aim is to analyze the evolution of this abdominal muscle wall weakness.

METHODS

Retrospective review of CDH repair by SAWMF (internal oblique muscle and transverse) from 2004 to 2023 focusing on the evolution of muscle wall weakness.

RESULTS

Eighteen neonates of 148 CDH patients (12,1%) were repaired using SAWMF. Mean gestational age and birth weight were 35.7 ± 3.5 weeks and 2587 ± 816 g. Mean lung-to-head ratio was 1.49 ± 0.28 and 78% liver-up. Seven patients (38%) were prenatally treated by tracheal occlusion. Ninety-four percent of the flaps were used for primary repair and one to repair a recurrence. One patient (5.6%) experienced recurrence. Abdominal muscle wall weakness was present in the form of a bulge. Resolution of weakness at 1, 2 and 3 years was 67%, 89% and 94%, respectively. No patient required treatment for weakness or died.

CONCLUSIONS

Abdominal muscular weakness after a split abdominal wall muscle flap repair is not a limitation for its realization since it is asymptomatic and presents a prompt spontaneous resolution.

LEVEL OF EVIDENCE

IV.

"Heart of the Matter": Cardiac Dysfunction in Congenital Diaphragmatic Hernia

Despite advances in caring for neonates with congenital diaphragmatic hernia (CDH), mortality and morbidity continues to be high. Additionally, the pathophysiology of cardiac dysfunction in this condition is poorly understood. Postnatal cardiac dysfunction in neonates with CDH may be multifactorial with origins in fetal life. Mechanical obstruction, competition from herniated abdominal organs into thoracic cavity combined with redirection of ductus venosus flow away from patent foramen ovale leading to smaller left-sided structures may be a contributing factor. This shunting decreases left atrial and left ventricular blood volume, which may result in altered micro- and macrovascular aberrations affecting cardiac development in the prenatal period. Direct mass effect from herniated intra-abdominal contents restricting cardiac growth and/or reduced left ventricular preload may contribute independently to left ventricular dysfunction in the absence of right ventricular dysfunction and or pulmonary hypertension. With variable clinical phenotypes of cardiac dysfunction, pulmonary hypertension, and respiratory failure in patients with CDH, there is increased need for individualized diagnosis and tailored therapy. Routine use of therapy such as inhaled nitric oxide and sildenafil that induces significant pulmonary vasodilation may be detrimental in left ventricle dysfunction, whereas in a patient with pure right ventricle dysfunction, they may be beneficial. Targeted functional echocardiography serves as a real-time tool for defining the pathophysiology and aids optimization of vasoactive therapy in affected neonates. KEY POINTS: · Cardiac dysfunction in neonates with CDH is multifactorial.. · Postnatal cardiac dysfunction in patients with CDH has its origins in fetal life.. · Right ventricular dysfunction contributes to systemic hypotension.. · Left ventricular dysfunction contributes to systemic hypotension.. · Supportive therapy should be tailored to clinical phenotype..

The role of extracorporeal life support and timing of repair in infants with congenital diaphragmatic hernia

Extracorporeal life support (ECLS) serves as a rescue therapy for patients with congenital diaphragmatic hernia (CDH) and severe cardiopulmonary failure, and only half of these patients survive to discharge. This costly intervention has a significant complication risk and is reserved for patients with the most severe disease physiology refractory to maximal cardiopulmonary support. Some contraindications to ECLS do exist such as coagulopathy, lethal chromosomal or congenital anomaly, very preterm birth, or very low birth weight, but many of these limits are being evaluated through further research. Consensus guidelines from the past decade vary in recommendations for ECLS use in patients with CDH but this therapy appears to have a survival benefit in the most severe subset of patients. Improved outcomes have been observed for patients treated at high-volume centers. This review details the evolving literature surrounding management paradigms for timing of CDH repair for patients receiving preoperative ECLS. Most recent data support early repair following cannulation to avoid non-repair which is uniformly fatal in this population. Longer ECLS runs are associated with decreased survival, and patient physiology should guide ECLS weaning and eventual decannulation rather than limiting patients to arbitrary run lengths. Standardization of care across centers is a major focus to limit unnecessary costs and improve short-term and long-term outcomes for these complex patients.

The CDH Study Group: Past, Present, and Future

The Congenital Diaphragmatic Hernia Study Group (CDHSG) is an international consortium of medical centers actively collecting and voluntarily contributing data pertaining to live born congenital diaphragmatic hernia (CDH) patients born and/or managed at their institutions. These data are aggregated to construct a comprehensive registry that participating centers can access to address specific clinical inquiries and track patient outcomes. Since its establishment in 1995, 147 centers have taken part in this initiative, including 53 centers from 17 countries outside the United States, with 95 current active centers across the globe. The registry has amassed data on over 14,000 children, resulting in the creation of over 75 manuscripts based on registry data to date. International, multicenter consortia enable health care professionals managing uncommon, complex, and diverse diseases to formulate evidence-based hypotheses and draw meaningful and generalizable conclusions for clinical inquiries. This review will explore the formation and structure of the CDHSG and its registry, outlining their functions, center participation, and the evolution of data collection. Additionally, we will provide an overview of the evidence generated by the CDHSG, with a particular emphasis on contributions post-2014, and look ahead to the future directions the study group will take in addressing CDH.

Direct thrombin inhibitors fail to reverse the negative effects of heparin on lung growth and function after murine left pneumonectomy

Neonates with congenital diaphragmatic hernia (CDH) frequently require cardiopulmonary bypass and systemic anticoagulation. We previously demonstrated that even subtherapeutic heparin impairs lung growth and function in a murine model of compensatory lung growth (CLG). The direct thrombin inhibitors (DTIs) bivalirudin and argatroban preserved growth in this model. Although DTIs are increasingly used for systemic anticoagulation clinically, patients with CDH may still receive heparin. In this experiment, lung endothelial cell proliferation was assessed following treatment with heparin-alone or mixed with increasing concentrations of bivalirudin or argatroban. The effects of subtherapeutic heparin with or without DTIs in the CLG model were also investigated. C57BL/6J mice underwent left pneumonectomy and subcutaneous implantation of osmotic pumps. Pumps were preloaded with normal saline, bivalirudin, or argatroban; treated animals received daily intraperitoneal low-dose heparin. In vitro, heparin-alone decreased endothelial cell proliferation and increased apoptosis. The effect of heparin on proliferation, but not apoptosis, was reversed by the addition of bivalirudin and argatroban. In vivo, low-dose heparin decreased lung volume compared with saline-treated controls. All three groups that received heparin demonstrated decreased lung function on pulmonary function testing and impaired exercise performance on treadmill tolerance testing. These findings correlated with decreases in alveolarization, vascularization, angiogenic signaling, and gene expression in the heparin-exposed groups. Together, these data suggest that bivalirudin and argatroban fail to reverse the inhibitory effects of subtherapeutic heparin on lung growth and function. Clinical studies on the impact of low-dose heparin with DTIs on CDH outcomes are warranted.NEW & NOTEWORTHY Infants with pulmonary hypoplasia frequently require cardiopulmonary bypass and systemic anticoagulation. We investigate the effects of simultaneous exposure to heparin and direct thrombin inhibitors (DTIs) on lung growth and pulmonary function in a murine model of compensatory lung growth (CGL). Our data suggest that DTIs fail to reverse the inhibitory effects of subtherapeutic heparin on lung growth and function. Clinical studies on the impact of heparin with DTIs on clinical outcomes are thus warranted.

A pneumonectomy model to study flow-induced pulmonary hypertension and compensatory lung growth

In newborns, developmental disorders such as congenital diaphragmatic hernia (CDH) and specific types of congenital heart disease (CHD) can lead to defective alveolarization, pulmonary hypoplasia, and pulmonary arterial hypertension (PAH). Therapeutic options for these patients are limited, emphasizing the need for new animal models representative of disease conditions. In most adult mammals, compensatory lung growth (CLG) occurs after pneumonectomy; however, the underlying relationship between CLG and flow-induced pulmonary hypertension (PH) is not fully understood. We propose a murine model that involves the simultaneous removal of the left lung and right caval lobe (extended pneumonectomy), which results in reduced CLG and exacerbated reproducible PH. Extended pneumonectomy in mice is a promising animal model to study the cellular response and molecular mechanisms contributing to flow-induced PH, with the potential to identify new treatments for patients with CDH or PAH-CHD.

Successful extracorporeal membrane oxygenation for postoperative cardiopulmonary failure in newborns with congenital diaphragmatic hernia: case reports and literature reviews

Introduction

Congenital diaphragmatic hernia (CDH) is a structural defect caused by inadequate fusion of the pleuroperitoneal membrane that forms the diaphragm, allowing peritoneal viscera to protrude into the pleural cavity. Up to 30% of newborns with CDH require extracorporeal membrane oxygenation (ECMO) support. As with all interventions, the risks and benefits of ECMO must be carefully considered in these patients. Cardiopulmonary function has been shown to worsen rather than improve after surgical CDH repair. Even after a detailed perioperative assessment, sudden cardiopulmonary failure after surgery is dangerous and requires timely and effective treatments.

Method

Three cases of cardiopulmonary failure after surgical CDH treatment in newborns have been reported. ECMO support was needed for these three patients and was successfully discontinued. We report our treatment experience.

Conclusion

ECMO is feasible for the treatment of postoperative cardiopulmonary failure in newborns with CDH.

Association Between Early Prostacyclin Therapy and Extracorporeal Life Support Use in Patients With Congenital Diaphragmatic Hernia

Importance

Prostacyclin (PGI2) is a therapeutic option to treat congenital diaphragmatic hernia (CDH)-associated pulmonary hypertension in neonates. Its use may decrease the need for extracorporeal life support (ECLS).

Objective

To evaluate the association of early PGI2 therapy with ECLS use and outcomes among patients with CDH.

Design, Setting, and Participants

This was a cohort study from the CDH Study Group (CDHSG) registry of patients born from January 2007 to December 2019. Patients were from 88 different tertiary pediatric referral centers worldwide that contributed data to the CDHSG. Patients were included in the study if they were admitted within the first week of life. Propensity score matching was performed using estimated gestational age, birth weight, transfer status, 1-minute and 5-minute Apgar scores, highest and lowest partial pressure of arterial carbon dioxide in the first 24 hours of life, and degree of pulmonary hypertension as covariates to generate a matched cohort of exposed and unexposed patients. Data were analyzed from January 2021 to December 2022.

Exposures

Early PGI2 therapy was defined as initiation of PGI2 within the first week of life. Patients who received ECLS were included in the early PGI2 group if PGI2 was started prior to ECLS.

Main Outcomes and Measures

The primary outcome of the study was the proportion of patients receiving ECLS in the exposed and unexposed groups.

Results

Of 6227 patients who met inclusion criteria (mean [SD] gestational age, 37.4 [2.36] weeks; 2618 [42%] female), 206 (3.3%) received early PGI2 therapy. ECLS was used in 46 of 206 patients who received PGI2 (22.2%) and 1682 of 6021 who did not (27.9%). After propensity score matching, there were 147 patients in the treatment and control groups. Thirty-four patients who received PGI2 (23.3%) and 63 who did not (42.9%) received ECLS. Those who received PGI2 were less likely to receive ECLS (adjusted odds ratio, 0.39; 95% CI, 0.22-0.68) and had shorter mean (SD) duration of ECLS (8.6 [3.73] days vs 12.6 [6.61] days; P < .001), although there was no significant difference in in-hospital mortality.

Conclusions and Relevance

In this study, there was decreased use of ECLS and decreased ECLS duration among patients with CDH who started PGI2 therapy during the first week of life. These results identify a potential advantage of early prostacyclin therapy in this population.

Direct thrombin inhibitors as alternatives to heparin to preserve lung growth and function in a murine model of compensatory lung growth

Infants with congenital diaphragmatic hernia (CDH) may require cardiopulmonary bypass and systemic anticoagulation. Expeditious lung growth while on bypass is essential for survival. Previously, we demonstrated that heparin impairs lung growth and function in a murine model of compensatory lung growth (CLG). We investigated the effects of the direct thrombin inhibitors (DTIs) bivalirudin and argatroban. In vitro assays of lung endothelial cell proliferation and apoptosis were performed. C57BL/6 J mice underwent left pneumonectomy and subcutaneous implantation of osmotic pumps. Pumps were pre-loaded with normal saline (control), bivalirudin, argatroban, or heparin and outcomes were assessed on postoperative day 8. Heparin administration inhibited endothelial cell proliferation in vitro and significantly decreased lung volume in vivo, while bivalirudin and argatroban preserved lung growth. These findings correlated with changes in alveolarization on morphometric analysis. Treadmill exercise tolerance testing demonstrated impaired exercise performance in heparinized mice; bivalirudin/argatroban did not affect exercise tolerance. On lung protein analysis, heparin decreased angiogenic signaling which was not impacted by bivalirudin or argatroban. Together, this data supports the use of DTIs as alternatives to heparin for systemic anticoagulation in CDH patients on bypass. Based on this work, clinical studies on the impact of heparin and DTIs on CDH outcomes are warranted.

Blood transfusion is associated with increased mortality for neonates with congenital diaphragmatic hernia on extracorporeal membrane oxygenation support

BACKGROUND AND OBJECTIVES

Blood transfusion is frequently needed to maintain adequate haemostasis and improve oxygenation for patients treated with extracorporeal membrane oxygenation (ECMO). It is more so for neonates with immature coagulation systems who require surgical intervention such as congenital diaphragmatic hernia (CDH) repair. There is growing evidence suggesting an association between blood transfusions and increased mortality. The aim of this study is to evaluate the association of blood transfusions during the peri-operative period of CDH repair, among other clinical parameters, with mortality in neonates undergoing on-ECMO CDH repair.

MATERIALS AND METHODS

We performed a single centre retrospective chart review of all neonates with CDH undergoing on-ECMO surgical repair from January 2010 to December 2020. Logistic regression was used to investigate associations with survival status.

RESULTS

Sixty-two patients met the inclusion criteria. Platelet transfusions (odds ratio [OR] 1.42, 95% confidence interval [CI]: 1.06-1.90) in the post-operative period and ECMO duration (OR 1.17, 95% CI: 1.05-1.30) were associated with increased mortality. Major bleeding complications had the strongest association with mortality (OR 10.98, 95% CI: 3.27-36.91). Gestational age, birth weight, Apgar scores, sex, blood type, right versus left CDH, venovenous versus venoarterial ECMO and duration of ECMO before CDH repair and circuit change after adjusting for ECMO duration were not significantly associated with survival.

CONCLUSION

Platelet transfusion in the post-operative period and major bleeding are associated with increased mortality in CDH neonates with surgical repair. The data suggest a need to develop robust plans for monitoring and preventing coagulation aberrancies during neonatal ECMO support.

Extracorporeal Membrane Oxygenation (ECMO) and its complications in newborns with congenital diaphragmatic hernia

BACKGROUND

Extracorporeal Membrane Oxygenation (ECMO) is offered to patients with congenital diaphragmatic hernia (CDH) who are in severe respiratory and cardiac failure. We aim to describe the types of complications among these patients and their impact on survival.

METHODS

A single-center, retrospective review of CDH patients cannulated onto ECMO between January 2005 and November 2020 was conducted. ECMO complications, as categorized by the Extracorporeal Life Support Organization (ELSO), were correlated with survival status. Descriptive statistics were used to compare observed complications between survivors and non-survivors.

RESULTS

In our cohort of CDH neonates, 21% (54/258) were supported with ECMO, of whom, 61% (33/54) survived. Survivors and non-survivors were similar in baseline characteristics except for birthweight z-score (p = 0.043). Seventy percent of CDH neonates experienced complications during their ECMO run, with the most common categories being metabolic (48.1%) and mechanical (38.9%), followed by hemorrhage (22.2%), neurological (18.5%), renal (11.1%), pulmonary (7.4%), and cardiovascular (7.4%). The median number of complications per patient was higher in the non-survivor group  (2 (IQR: 1-4) vs 1 (IQR: 0-2), p = 0.043). In addition, mechanical (57.1% vs 27.3%, p = 0.045) and renal (28.6% vs 0%, p = 0.002) complications were more common among non-survivors compared to survivors.

CONCLUSION

Complications occur frequently among ECMO-treated newborns with CDH, some of which have serious long-term consequences. Survivors had higher birth weight z-scores, shorter ECMO runs, and fewer complications per patient. Mechanical and renal complications were independently associated with mortality, emphasizing the utility of more focused strategies to target fluid balance and renal protection and to prevent circuit and cannula complications.

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.

Perinatal Prognostic Factors for Congenital Diaphragmatic Hernia: A Korean Single-Center Study

Purpose: This study aimed to identify prognostic factors based on treatment outcomes for congenital diaphragmatic hernia (CDH) at a single-center and to identify factors that may improve these outcomes.Methods: Thirty-five neonates diagnosed with CDH between January 2011 and December 2021 were retrospectively analyzed. Pre- and postnatal factors were correlated and analyzed with postnatal clinical outcomes to determine the prognostic factors. Highest oxygenation index (OI) within 24 hours of birth was also calculated. Treatment strategy and outcome analysis of published literatures were also performed.Results: Overall survival rate of this cohort was 60%. Four patients were unable to undergo anesthesia and/or surgery. Three patients who commenced extracorporeal membrane oxygenation (ECMO) post-surgery were non-survivors. Compared to the survivor group, the non-survivor group had a significantly higher occurrence of pneumothorax on the first day, need for high-frequency ventilator and inhaled nitric oxide use, and high OI within the first 24 hours. The non-survivor group showed an early trend towards the surgery timing and a greater number of patch closures. Area under the receiver operating characteristic curve was 0.878 with a sensitivity of 76.2% and specificity of 92.9% at an OI cutoff value of 7.75.Conclusion: OI within 24 hours is a valuable predictor of survival. It is expected that the application of ECMO based on OI monitoring may help improve the opportunity for surgical repair, as well as the prognosis of CDH patients.

Survival Benefit Associated With the Use of Extracorporeal Life Support for Neonates With Congenital Diaphragmatic Hernia

OBJECTIVE

To measure the survival among comparable neonates with CDH supported with and without ECLS.

SUMMARY OF BACKGROUND DATA

Despite widespread use in the management of newborns with CDH, ECLS has not been consistently associated with improved survival.

METHODS

A retrospective cohort study was performed using ECLS-eligible CDH Study Group registry patients born between 2007 and 2019. The primary outcome was in-hospital mortality. Neonates who did and did not receive ECLS were matched based on variables affecting risk for the primary outcome. Iterative propensity score-matched, survival (Cox regression and Kaplan-Meier), and center effects analyses were performed to examine the association of ECLS use and mortality.

RESULTS

Of 5855 ECLS-eligible CDH patients, 1701 (29.1%) received ECLS. "High-risk" patients were best defined as those with a lowest achievable first-day arterial partial pressure of CO2 of ≥60 mm Hg. After propensity score matching, mortality was higher with ECLS (47.8% vs 21.8%, odds ratio 3.3, 95% confidence interval 2.7-4.0, hazard ratio 2.3, P < 0.0001). For the subgroup of high-risk patients, there was lower mortality observed with ECLS (64.2% vs 84.4%, odds ratio 0.33, 95% confidence interval 0.17-0.65, hazard ratio 0.33, P = 0.001). This survival advantage was persistent using multiple matching approaches. However, this ECLS survival advantage was found to occur primarily at high CDH volume centers that offer frequent ECLS for the high-risk subgroup.

CONCLUSIONS

Use of ECLS is associated with excess mortality for low- and intermediate-risk neonates with CDH. It is associated with a significant survival advantage among high-risk infants, and this advantage is strongly influenced by center CDH volume and ECLS experience.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Targeting the lung endothelial niche to promote angiogenesis and regeneration: A review of applications

Lung endothelial cells comprise the pulmonary vascular bed and account for the majority of cells in the lungs. Beyond their role in gas exchange, lung ECs form a specialized microenvironment, or niche, with important roles in health and disease. In early development, progenitor ECs direct alveolar development through angiogenesis. Following birth, lung ECs are thought to maintain their regenerative capacity despite the aging process. As such, harnessing the power of the EC niche, specifically to promote angiogenesis and alveolar regeneration has potential clinical applications. Here, we focus on translational research with applications related to developmental lung diseases including pulmonary hypoplasia and bronchopulmonary dysplasia. An overview of studies examining the role of ECs in lung regeneration following acute lung injury is also provided. These diseases are all characterized by significant morbidity and mortality with limited existing therapeutics, affecting both young children and adults.

Predicting treatment of pulmonary hypertension at discharge in infants with congenital diaphragmatic hernia

OBJECTIVE

To predict pulmonary hypertension (PH) therapy at discharge in a large multicenter cohort of infants with congenital diaphragmatic hernia (CDH).

STUDY DESIGN

Six-year linked records from Children's Hospitals Neonatal Database and Pediatric Health Information System were used; patients whose diaphragmatic hernia was repaired before admission or referral, who were previously home before admission or referral, and non-survivors were excluded. The primary outcome was the use of PH medications at discharge and the secondary outcome was an inter-center variation of therapies during inpatient utilization. Clinical factors were used to develop a multivariable equation randomly applied to 80% cohort; validated in the remaining 20% infants.

RESULTS

A total of 831 infants with CDH from 23 centers were analyzed. Overall, 11.6% of survivors were discharged on PH medication. Center, duration of mechanical ventilation, and duration of inhaled nitric oxide were associated with the use of PH medication at discharge. This model performed well in the validation cohort area under the receiver operating characteristic curve of 0.9, goodness-of-fit χ², p = 0.17.

CONCLUSIONS

Clinical variables can predict the need for long-term PH medication after NICU hospitalization in surviving infants with CDH. This information may be useful to educate families and guide the development of clinical guidelines.

A nationwide database analysis of demographics and outcomes related to Extracorporeal Membrane Oxygenation (ECMO) in congenital diaphragmatic hernia

PURPOSE

The aim of the study was to understand the use of Extracorporeal Membrane Oxygenation (ECMO) in congenital diaphragmatic hernia (CDH) and its outcomes.

METHODS

The 2016 Kid's Inpatient Database (KID) obtained from the national Healthcare Cost and Utilization Project (HCUP) was used to obtain CDH birth, demographic, and outcome data associated with ECMO use. Categorical variables were analyzed and odds ratios (OR) with 95% confidence intervals (CI) are reported for variables found to have significance (p < 0.05). Appropriate regressions were used for comparing categorical and continuous data using SPSS 25 for Macintosh.

RESULTS

The database contained 1189 cases of CDH, of which 133 (11.2%) received ECMO. The overall mortality of neonates with CDH was 18.9% (225/1189). Newborns with CDH on ECMO had a survival of 46% (61/133) compared to 85.5% without ECMO (903/1056) (OR 6.966, p < 0.001, 95% CI 4.756-10.204). ECMO increased length of stay from 24.6 to 69.8 days (OR 2.834, p < 0.001, 95% CI 2.768-2.903) and average cost from $375,002.20 to $1641,586.83 (OR 4.378, p < 0.001, 95% CI 3.341-5.735).

CONCLUSIONS

Increased length of stay, costs, and outcomes with ECMO use in CDH should prompt an examination of criteria necessitating ECMO.

Fetal liver and lung volume index of neonatal survival with congenital diaphragmatic hernia

BACKGROUND

Magnetic resonance imaging (MRI) assesses pulmonary hypoplasia in fetal congenital diaphragmatic hernia (CDH). Neonatal mortality may occur with CDH.

OBJECTIVE

To quantify MRI parameters associated with neonatal survival in fetuses with isolated CDH.

MATERIALS AND METHODS

Fetal MRI for assessing CDH included region of interest (ROI) measurements for total lung volume (TLV), herniated liver volume, herniated other organ volume and predicted lung volume. Ratios of observed lung volume and liver up volume to predicted lung volume (observed to predicted TLV, percentage of the thorax occupied by liver) were calculated and compared to neonatal outcomes. Analyses included Wilcoxon rank sum test, multivariate logistic regression and receiver operating characteristic (ROC) curves.

RESULTS

Of 61 studies, the median observed to predicted TLV was 0.25 in survivors and 0.16 in non-survivors (P=0.001) with CDH. The median percentage of the thorax occupied by liver was 0.02 in survivors and 0.22 in non-survivors (P<0.001). The association of observed to predicted TLV and percentage of the thorax occupied by liver with survival for gestational age (GA) >28 weeks was greater compared to GA ≤28 weeks. The ROC analysis demonstrated an area under the curve of 0.96 (95% confidence interval 0.91-1.00) for the combined observed to predicted TLV, percentage of the thorax occupied by liver and GA.

CONCLUSION

The percentage of the thorax occupied by liver and observed to predicted TLV was predictive of neonatal survival in fetuses with CDH.

Honeymoon Period in Newborn Rats With CDH Is Associated With Changes in the VEGF Signaling Pathway

Background: Patients with congenital diaphragmatic hernia (CDH) have a short postnatal period of ventilatory stability called the honeymoon period, after which changes in pulmonary vascular reactivity result in pulmonary hypertension. However, the mechanisms involved are still unknown. The aim of this study was to evaluate mechanical ventilation's effect in the honeymoon period on VEGF, VEGFR-1/2 and eNOS expression on experimental CDH in rats. Materials and Methods: Neonates whose mothers were not exposed to nitrofen formed the control groups (C) and neonates with left-sided defects formed the CDH groups (CDH). Both were subdivided into non-ventilated and ventilated for 30, 60, and 90 min (n = 7 each). The left lungs (n = 4) were evaluated by immunohistochemistry of the pulmonary vasculature (media wall thickness), VEGF, VEGFR-1/2 and eNOS. Western blotting (n = 3) was performed to quantify the expression of VEGF, VEGFR-1/2 and eNOS. Results: CDH had lower biometric parameters than C. Regarding the pulmonary vasculature, C showed a reduction in media wall thickness with ventilation, while CDH presented reduction with 30 min and an increase with the progression of the ventilatory time (honeymoon period). CDH and C groups showed different patterns of VEGF, VEGFR-1/2 and eNOS expressions. The receptors and eNOS findings were significant by immunohistochemistry but not by western blotting, while VEGF was significant by western blotting but not by immunohistochemistry. Conclusion: VEGF, its receptors and eNOS were altered in CDH after mechanical ventilation. These results suggest that the VEGF-NO pathway plays an important role in the honeymoon period of experimental CDH.

Investigation of the mechanisms of VEGF-mediated compensatory lung growth: the role of the VEGF heparin-binding domain

Morbidity and mortality for neonates with congenital diaphragmatic hernia-associated pulmonary hypoplasia remains high. These patients may be deficient in vascular endothelial growth factor (VEGF). Our lab previously established that exogenous VEGF164 accelerates compensatory lung growth (CLG) after left pneumonectomy in a murine model. We aimed to further investigate VEGF-mediated CLG by examining the role of the heparin-binding domain (HBD). Eight-week-old, male, C57BL/6J mice underwent left pneumonectomy, followed by post-operative and daily intraperitoneal injections of equimolar VEGF164 or VEGF120, which lacks the HBD. Isovolumetric saline was used as a control. VEGF164 significantly increased lung volume, total lung capacity, and alveolarization, while VEGF120 did not. Treadmill exercise tolerance testing (TETT) demonstrated improved functional outcomes post-pneumonectomy with VEGF164 treatment. In lung protein analysis, VEGF treatment modulated downstream angiogenic signaling. Activation of epithelial growth factor receptor and pulmonary cell proliferation was also upregulated. Human microvascular lung endothelial cells (HMVEC-L) treated with VEGF demonstrated decreased potency of VEGFR2 activation with VEGF121 treatment compared to VEGF165 treatment. Taken together, these data indicate that the VEGF HBD contributes to angiogenic and proliferative signaling, is required for accelerated compensatory lung growth, and improves functional outcomes in a murine CLG model.

Risk factors for mortality in infants with congenital diaphragmatic hernia: a single center experience

Background

Despite current progress in research of congenital diaphragmatic hernia, its management remains challenging, requiring an interdisciplinary team for optimal treatment.

Objective

Aim of the present study was to evaluate potential risk factors for mortality of infants with congenital diaphragmatic hernia.

Methods

A single-center chart review of all patients treated with congenital diaphragmatic hernia over a period of 16 years, at the Medical University of Vienna, was performed. A comparison of medical parameters between survivors and non-survivors, as well as to published literature was conducted.

Results

During the observational period 66 patients were diagnosed with congenital diaphragmatic hernia. Overall survival was 84.6%. Left-sided hernia occurred in 51 patients (78.5%) with a mortality of 7.8%. In comparison, right-sided hernia occurred less frequently (n = 12) but showed a higher mortality (33.3%, p = 0.000). Critically instable patients were provided with venoarterial extracorporeal membrane oxygenation (ECMO, 32.3%, n = 21). Survival rate among these patients was 66.7%. Right-sided hernia, treatment with inhaled nitric oxide (iNO) over 15 days and the use of ECMO over 10 days were significant risk factors for mortality.

Conclusion

The survival rate in this cohort is comparable to the current literature. Parameters such as the side of the diaphragmatic defect, duration of ECMO and inhaled nitric oxide were assessed as mortality risk factors. This analysis of patients with congenital diaphragmatic hernia enhances understanding of risk factors for mortality, helping to improve management and enabling further evaluation in prospective clinical trials.

Discordant prenatal ultrasound and fetal MRI in CDH: wherein lies the truth?

PURPOSE

Prenatal risk assessment of congenital diaphragmatic hernia (CDH) relies on prenatal ultrasound (U/S) and fetal magnetic resonance imaging (MRI). When the modalities differ in prognosis, it is unclear which is more reliable.

METHODS

Retrospective chart review identified cases of prenatally diagnosed CDH from 4/2010-6/2018 meeting inclusion criteria. Demographic, radiologic, and postnatal outcomes data were collected. Ultrasound- versus MRI-based prognosis (mild, moderate, and severe) was compared with clinical outcomes. Kappa measures compared congruency in disease severity scaling between imaging modalities, while logistic regression and receiver operating characteristics curves compared the ability of each modality to predict outcomes.

RESULTS

Forty-two patients met criteria. Both U/S- and MRI-based prognosis categories differentiated for survival. MRI categories differentiated for ECMO use, surgical repair, and defect type. O/e TFLV better discriminated for survivors and defect type than o/e LHR. Seventeen (40.5%) had discordant prenatal prognostic categories. In 13/17 (76.5%), o/e TFLV predicted higher severity when compared to o/e LHR, but sample size was insufficient to compare accuracy in cases of discordance.

CONCLUSIONS

Clinical outcomes suggest fetal MRI may more accurately predict severe pulmonary hypoplasia compared to prenatal ultrasound. Our analysis suggests fetal MRI is a valuable adjunct in the prenatal evaluation of CDH.

LEVEL OF EVIDENCE

Level III.

TYPE OF STUDY

Retrospective Review.

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.

Predictors of long ECMO runs for congenital diaphragmatic hernia

BACKGROUND

Although longer ECMO run times for patients with congenital diaphragmatic hernia (CDH) have been associated with worse outcomes, a large study has not been conducted to examine the risk factors for long ECMO runs.

METHODS

The Extracorporeal Life Support Organization (ELSO) Registry from 2000 to 2015 was used to identify predictors of long ECMO runs in CDH patients. A long run was any duration of ≥14 days. Multivariable logistic regression models were used to examine the association between demographics, pre-ECMO blood gas/ventilator settings, comorbid conditions, and therapies on long ECMO runs.

RESULTS

There were 4730 CDH-infants examined. The largest association with long ECMO runs was on-ECMO repair (OR: 3.72, 95% CI: 3.013-4.602, p < 0.001) and the use of THAM (OR: 1.463, 95% CI: 1.062-2.016, p = 0.02). Each drop in pH quartile was associated with an increased risk of long ECMO run: pH ≥ 7.3 (reference), pH 7.2-7.9 (OR 1.24, 95% CI: 0.98-1.57, p = 0.07), pH 7.08-7.19 (OR 1.46, 95% CI: 1.17-1.84, p = 0.001), pH ≤ 7.07 (OR 1.64, 95% CI: 1.29-2.07, p < 0.001).

CONCLUSIONS

We found a correlation between both pre-ECMO demographics/timing of repair and the subsequent risk of long ECMO runs, providing insight for both providers and parents about the risk factors for longer runs.

TYPE OF STUDY

Treatment Study.

LEVEL OF EVIDENCE

Level III.

The development of multiorgan dysfunction in CDH-ECMO neonates is associated with the level of pre-ECMO support

PURPOSE

Congenital diaphragmatic hernia (CDH) is the most common indication for neonatal extracorporeal membrane oxygenation (ECMO), but mortality remains at 50%. Multiorgan failure can occur in 25% and has been linked to worse outcomes. We sought to examine the factors that would increase the risk of multiorgan dysfunction (MOD).

METHODS

The Extracorporeal Life Support Organization (ELSO) database was used to identify infants with CDH (2000-2015). The primary outcome was MOD, which was defined as the presence of organ failure in ≥2 organ systems. We used a multivariable logistic regression to examine the effect of demographics, pre-ECMO respiratory status, comorbidities, and therapies on MOD.

RESULTS

There were a total of 4374 CDH infants who were treated with ECMO. Overall mortality was 52.4%. The risk models demonstrated that pre-ECMO cardiac arrest (OR 1.458, CI: 1.146-1.861, p = 0.002) and hand-bagging (OR 1.461, CI: 1.094-1.963, p = 0.032) had the strongest association with MOD. In addition, other pre-ECMO indicators of disease severity (pH, HFOV, MAP, 5-min APGAR) and pre-ECMO therapies (bicarb, neuromuscular [NM] blockers) were also associated with MOD.

CONCLUSIONS

The level of pre-ECMO support has a significant association with the development of MOD, and initiation of ECMO prior to arrest seems to be critical to avoid complications.

TYPE OF STUDY

Treatment study.

LEVEL OF EVIDENCE

Level III.

The role of ECMO in the management of congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is the most common indication for extra-corporeal membrane oxygenation (ECMO) for neonatal respiratory failure. CDH management is evolving with advanced prenatal diagnostic imaging modalities. The risk profiles of infants receiving ECMO for CDH are shifting towards higher risk. Many clinicians are developing and following clinical practice guidelines to standardize and optimize the care of CDH neonates. Despite these efforts, there are significant differences in the practice patterns among ECMO centers as to how and when they choose to initiate ECMO for CDH, when they believe repair is safe, as well as many other nuances that are based on center experience or style. The purpose of this report is to summarize our current understanding of the new and recent developments regarding management of infants with CDH managed with ECMO.

Early CDH repair on ECMO: Improved survival but no decrease in ECMO duration (A CDH Study Group Investigation)

PURPOSE

"Early on-ECMO" repair of CDH entails repair within 48-72 h of cannulation in an effort to optimize pulmonary physiology, shorten ECMO duration, and, ultimately, improve survival. This study evaluated the effect of early on-ECMO repair as compared to leaving patients unrepaired during ECMO.

METHODS

The CDH Study Group database was queried for CDH patients requiring ECMO who either underwent repair within the first 72 h after cannulation or remained unrepaired on ECMO. Primary outcomes were survival to decannulation and ECMO duration.

RESULTS

A total of 248 patients underwent early repair and 922 remained unrepaired on ECMO. The early repair group had increased risk factors for poor outcomes, including higher odds of cardiac defects and thoracic liver location, and lower odds of hernia sac presence. Nonetheless, ECMO survival for the early repair group was 87.1% compared to 78.4% in the unrepaired group (p = 0.002). However, the early repair group had a longer median ECMO duration than the unrepaired group (240.6 vs 196.8 h, p = 0.001).

CONCLUSION

While early ECMO repair does not shorten ECMO duration, it results in increased survival to decannulation as compared to those unrepaired on ECMO. This suggests that there may be a physiologic benefit leading to increased ECMO survival in a subset of patients undergoing on-ECMO repair over those designated to undergo post-ECMO repair.

LEVEL OF EVIDENCE

Level III.

Development and Validation of Extracorporeal Membrane Oxygenation Mortality-Risk Models for Congenital Diaphragmatic Hernia

The purpose of our study was to develop and validate extracorporeal membrane oxygenation (ECMO)–specific mortality risk models for congenital diaphragmatic hernia (CDH). We utilized the data from the Extracorporeal Life Support Organization Registry (2000–2015). Prediction models were developed using multivariable logistic regression. We identified 4,374 neonates with CDH with an overall mortality of 52%. Predictive discrimination (C statistic) for pre-ECMO mortality model was C = 0.65 (95% confidence interval, 0.62–0.68). Within the highest risk group, based on the pre-ECMO risk score, mortality was 87% and 75% in the training and validation data sets, respectively. The pre-ECMO risk score included pre-ECMO ventilator settings, pH, prior diaphragmatic hernia repair, critical congenital heart disease, perinatal infection, and demographics. For the on-ECMO model, mortality prediction improved substantially: C = 0.73 (95% confidence interval, 0.71–0.76) with the addition of on-ECMO–associated complications. Within the highest risk group, defined by the on-ECMO risk score, mortality was 90% and 86% in the training and validation data sets, respectively. Mortality among neonates with CDH needing ECMO can be reliably predicted with validated clinical variables identified in this study. ECMO-specific mortality prediction tools can allow risk stratification to be used in research and quality improvement efforts, as well as with caution for individual case management.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Congenital heart disease associated with congenital diaphragmatic hernia: A systematic review on incidence, prenatal diagnosis, management, and outcome

PURPOSE

The purpose of this study was to evaluate the impact of congenital heart disease (CHD) on infants with congenital diaphragmatic hernia (CDH).

METHODS

Using a defined search strategy (PubMed, Cochrane, Embase, Web of Science MeSH headings), we searched studies reporting the incidence, management, and outcome of CDH infants born with associated CHD.

RESULTS

Of 6410 abstracts, 117 met criteria. Overall, out of 28,974 babies with CDH, 4427 (15%) had CHD, of which 42% were critical. CDH repair was performed in a lower proportion of infants with CHD (72%) than in those without (85%; p < 0.0001). Compared to CDH babies without CHD, those born with a cardiac lesion were more likely to have a patch repair (45% vs. 30%; p < 0.01) and less likely to undergo minimally invasive surgery (5% vs. 17%; p < 0.0001). CDH babies with CHD had a lower survival rate than those without CHD (52 vs. 73%; p < 0.001). Survival was even lower (32%) in babies with critical CHD.

CONCLUSION

CHD has a strong impact on the management and outcome of infants with CDH. The combination of CDH and CHD results in lower survival than those without CHD or an isolated cardiac defect. Further studies are needed to address some specific aspects of the management of this fragile CDH cohort.

TYPE OF STUDY

Systematic review and meta-analysis.

LEVEL OF EVIDENCE

Level III.

Clinical profile and outcome of neonates with congenital diaphragmatic hernia: A 16-year experience from a developing country

Recent advances in the perinatal interventions for neonates with congenital diaphragmatic hernia have remarkably improved the outcome in developed countries, but high mortality for such cases continues to be a challenge in resource-poor settings. This study examines clinical profiles and short-term outcome of neonates with congenital diaphragmatic hernia, using a retrospective analysis of medical records of neonates operated for congenital diaphragmatic hernia at a tertiary care center in North India from January 2001 to December 2016. Forty-two neonates were operated during the study period with male:female ratio = 1.6:1. Postoperative survival rate was 69% (29/42). Average birth weight in the survivors was 2528±267 g as compared with 2132±309 g in the non-survivors. The average gestational age in the two groups was 37.2±0.8 weeks and 34.8±1.8 weeks respectively. Twenty-one patients presented in the initial 48 h of life, out of them 52% (11/21) survived. Congenital heart diseases were associated with seven and malrotation of the gut in five neonates. The most significant factors resulting in the unfavorable outcome were preterm gestation, low birth weight, hypothermia and shock at presentation, the onset of symptoms <48 h of life, liver-up, need of postoperative inotropes and mechanical ventilation. In addition to establishing advanced therapeutic modalities, good antenatal screening, better awareness in peripheral health workers about the malformation leading to timely referral, well-equipped inter-hospital and intra-hospital transport facilities and development of level III neonatal intensive care units can improve survival in neonates with congenital diaphragmatic hernia in developing countries.

Extracorporeal Membrane Oxygenation in Congenital Diaphragmatic Hernia

Congenital diaphragmatic hernia (CDH) is characterized by failure of diaphragmatic development with lung hypoplasia and persistent pulmonary hypertension of the newborn (PPHN). If conventional treatment with gentle ventilation and optimized vasoactive medication fails, extracorporeal membrane oxygenation (ECMO) may be considered. The benefits of ECMO in CDH are still controversial, since there are only few randomized trials demonstrating the advantages of this therapeutic option. At present, there is no precise prenatal and/or early postnatal prognostication parameter to predict reversibility of PPHN in CDH patients. Indications for initiating ECMO include either respiratory or circulatory parameters, which are also undergoing continuous refinement. Centers with higher case numbers and the availability of ECMO published promising survival rates, but data on long-term results, including morbidity and quality of life, are rare. Survival might be influenced by the timing of ECMO initiation and the timing of surgical repair. In this regard a trend toward early initiation of ECMO and early surgery on ECMO exists. The results concerning the cannulation modes are similar and a consensus on time limit for ECMO runs does not exist. The use of ECMO in CDH will continue to be evaluated, and prospective randomized trials and registry network are necessary to help answering the addressed questions of patient selection and management.

Congenital diaphragmatic hernia repair in patients on extracorporeal membrane oxygenation: How early can we repair?

BACKGROUND

The benefits to early repair (<72 h postcannulation) of infants with congenital diaphragmatic hernia (CDH) on extracorporeal membrane oxygenation (ECMO) are increasingly recognized. Yet it is not known if even earlier repair (<24 h) results in comparable or improved patient outcomes. The goal of this study was to compare "super-early" (<24 h) to early repair (24-72 h) of CDH patients on ECMO.

METHODS

A retrospective review of infants with CDH placed on ECMO (2004-2017; n = 72) was performed. Data collected on the patients repaired while on ECMO within 72 h of cannulation (n = 33) included pre- and postnatal disease severity stratification variables and postnatal outcomes. Comparison groups were those patients repaired within 24 h of cannulation (n = 14) and those repaired between 24 and 72 h postcannulation (n = 19).

RESULTS

Patients undergoing "super-early" (<24 h) repair had an average survival of 71.4% compared to the average survival of 59.7% in the early repair group. Pre- and postnatal variables predicting disease severity were not significantly different between the groups. Mean hospital stays, ventilator days, and cannulation days were statistically similar between the groups.

CONCLUSIONS

Repair of patients with CDH patients on ECMO at less than 24 h postcannulation achieves outcomes that are comparable to those of repair between 24 and 72 h. While the present data suggest that there is not a "too early" time point for CDH repair on ECMO, larger multicenter studies are needed to validate our findings and determine the overall benefits.

TYPE OF STUDY

Retrospective comparative study.

LEVEL OF EVIDENCE

Level III.

Controversies in extracorporeal membrane oxygenation (ECMO) utilization and congenital diaphragmatic hernia (CDH) repair using a Delphi approach: from the American Pediatric Surgical Association Critical Care Committee (APSA-CCC)

PURPOSE

Review current practices and expert opinions on contraindications to extracorporeal membrane oxygenation (ECMO) in congenital diaphragmatic hernia (CDH) and contraindications to repair of CDH following initiation of ECMO.

METHODS

Modified Delphi method was employed to achieve consensus among members of the American Pediatric Surgical Association Critical Care Committee (APSA-CCC).

RESULTS

Overall response rate was 81% including current and former members of the APSA-CCC. An average of 5-15 CDH repairs were reported annually per institution; 26-50% of patients required ECMO. 100% of respondents would not offer ECMO to a patient with a complex or unrepairable cardiac defects or lethal chromosomal abnormality; 94.1% would not in the setting of severe intracranial hemorrhage (ICH). 76.5% and 72.2% of respondents would not offer CDH repair to patients on ECMO with grade III-IV ICH or new diagnosis of lethal genetic or metabolic abnormalities, respectively. There was significant variability in whether or not to repair CDH if unable to wean from ECMO at 4-5 weeks.

CONCLUSIONS

Significant variability in practice pattern and opinions exist regarding contraindications to ECMO and when to offer repair of CDH for patients on ECMO. Ongoing work to evaluate outcomes is needed to standardize management and minimize potentially futile interventions.

LEVEL OF EVIDENCE

V (expert opinion).

Factors Associated With Mortality in Children Who Successfully Wean From Extracorporeal Membrane Oxygenation

OBJECTIVES

Extracorporeal membrane oxygenation is an established therapy for cardiac and respiratory failure unresponsive to usual care. Extracorporeal membrane oxygenation mortality remains high, with ongoing risk of death even after successful decannulation. We describe occurrence and factors associated with mortality in children weaned from extracorporeal membrane oxygenation.

DESIGN

Retrospective cohort study.

SETTING

Two hundred five extracorporeal membrane oxygenation centers reporting to the Extracorporeal Life Support Organization.

SUBJECTS

Eleven thousand ninety-six patients, less than 18 years, supported with extracorporeal membrane oxygenation during 2007-2013, who achieved organ recovery before decannulation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Primary outcome was hospital mortality less than or equal to 30 days post extracorporeal membrane oxygenation decannulation. Among 11,096 patients, indication for extracorporeal membrane oxygenation cannulation was respiratory (6,206; 56%), cardiac (3,663; 33%), or cardiac arrest (extracorporeal cardiopulmonary resuscitation, 1,227; 11%); the majority were supported with venoarterial extracorporeal membrane oxygenation at some stage in their course (8,576 patients; 77%). Mortality was 13%. Factors associated with mortality included younger age (all < 1 yr categories compared with older, p < 0.05), lower weight among neonates (≤ 3 vs > 3 kg; p < 0.001), mode of extracorporeal membrane oxygenation support (venoarterial extracorporeal membrane oxygenation compared with venovenous extracorporeal membrane oxygenation, p < 0.001), longer admission to extracorporeal membrane oxygenation cannulation time (≥ 28 vs < 28 hr; p < 0.001), cardiac and extracorporeal cardiopulmonary resuscitation compared with respiratory extracorporeal membrane oxygenation (both p < 0.001), extracorporeal membrane oxygenation duration greater than or equal to 135 hours (p < 0.001), preextracorporeal membrane oxygenation hypoxemia (PO2 ≤ 43 vs > 43 mm Hg; p < 0.001), preextracorporeal membrane oxygenation acidemia (p < 0.001), and extracorporeal membrane oxygenation complications, particularly cerebral or renal (both p < 0.001).

CONCLUSIONS

Despite extracorporeal membrane oxygenation decannulation for organ recovery, 13% of patients die in hospital. Mortality is associated with patient factors, preextracorporeal membrane oxygenation illness severity, and extracorporeal membrane oxygenation management. Evidence-based strategies to optimize readiness for extracorporeal membrane oxygenation decannulation and postextracorporeal membrane oxygenation decannulation care are needed.

Lower Distending Pressure Improves Respiratory Mechanics in Congenital Diaphragmatic Hernia Complicated by Persistent Pulmonary Hypertension

OBJECTIVE

To investigate the effects of distending pressures on respiratory mechanics and pulmonary circulation in newborn infants with congenital diaphragmatic hernia (CDH) and persistent pulmonary hypertension (PPHN).

STUDY DESIGN

In total, 17 consecutive infants of ≥37 weeks of gestational age with CDH and PPHN were included in this prospective, randomized, crossover pilot study. Infants were assigned randomly to receive 2 or 5 cmH₂O of positive end-expiratory pressure (PEEP) for 1 hour in a crossover design. The difference between peak inspiratory pressure and PEEP was kept constant. Respiratory mechanics, lung function, and hemodynamic variables assessed by Doppler echocardiography were measured after each study period.

RESULTS

At 2 cmH₂O of PEEP, tidal volume and minute ventilation were greater (P < .05), and respiratory system compliance was 30% greater (P < .05) than at 5 cmH₂O. PaCO₂ and ventilation index were lower at 2 cmH₂O than at 5 cmH₂O (P < .05). Although preductal peripheral oxygen saturation was similar at both PEEP levels, postductal peripheral oxygen saturation was lower (median [range]: 81% [65-95] vs 91% [71-100]) and fraction of inspired oxygen was greater (35% [21-70] vs 25% [21-60]) at 5 cmH₂O. End-diastolic left ventricle diameter, left atrium/aortic root ratio, and pulmonary blood flow velocities in the left pulmonary artery were lower at 5 cmH₂O.

CONCLUSIONS

After surgical repair, lower distending pressures result in better respiratory mechanics in infants with mild-to-moderate CDH. We speculate that hypoplastic lungs in CDH are prone to overdistension, with poor tolerance to elevation of distending pressure.

Prenatal intervention for the management of congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is the result of incomplete formation of the diaphragm that occurs during embryogenesis. The defect in the diaphragm permits the herniation of abdominal organs into the thoracic cavity contributing to the impairment of normal growth and development of the fetal lung. In addition to the hypoplastic lung, anomalies of the pulmonary arterioles worsen the pulmonary hypertension that can have detrimental effects in severe cases. Most cases of CDH can be effectively managed postnatally. Advances in neonatal and surgical care have resulted in improved outcomes over the years. When available, extracorporeal membrane oxygenation can provide temporary cardiorespiratory support for those not effectively supported by mechanical ventilation. In spite of these advances, very severe cases of CDH still carry a very high mortality and morbidity rate. Advances in imaging and evaluation now allow for early and accurate prenatal diagnosis of CDH, thereby identifying those at greatest risk who may benefit from prenatal intervention. This review article discusses some of the surgical and non-surgical prenatal interventions in the management of isolated severe congenital diaphragmatic hernia.

Comparison of early versus delayed strategies for repair of congenital diaphragmatic hernia on extracorporeal membrane oxygenation

PURPOSE

For the last seven years, our institution has repaired infants with CDH that require ECMO early after cannulation. Prior to that, we attempted to decannulate before repair, but repaired on ECMO if we were unable to wean after two weeks. This study compares those strategies.

METHODS

From 2002 to 2016, 65 infants with CDH required ECMO. 67.7% were repaired on ECMO, and 27.7% were repaired after decannulation. Data were compared between patients repaired ≤5days after cannulation ("early protocol", n=30) and >5days after cannulation or after de-cannulation ("late protocol", n=35). We used Cox regression to assess differences in outcomes between groups.

RESULTS

Survival for the early and late protocol groups was 43.3% and 68.8%, respectively (p=0.0485). For patients that were successfully decannulated before repair, survival was 94.4%. Moreover, the early repair protocol was associated with prolongation of ECMO (16.8±7.4 vs. 12.6±6.8days, p=0.0216). After multivariate regression, the early repair protocol was an independent predictor of both mortality (HR=3.48, 95% CI=1.28-9.45, p=0.015) and days on ECMO (IRR=1.39, 95% CI=1.07-1.79, p=0.012). All bleeding occurred in patients repaired on ECMO (29.5%, 13/44).

CONCLUSIONS

Our data suggest that protocolized CDH repair early after ECMO cannulation may be associated with increased mortality and prolongation of ECMO. However, early repair is not necessarily harmful for those patients who would otherwise be unable to wean from ECMO before repair. Further work is needed to better move towards individualized patient care.

TYPE OF STUDY

Treatment Study.

LEVEL OF EVIDENCE

Level III.

Role of ECMO in congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is typified morphologically by failure of diaphragmatic development with accompanying lung hypoplasia and persistent pulmonary hypertension of the newborn (PPHN). Patients who have labile physiology and low preductal saturations despite optimal ventilatory and inotropic support may be considered for extracorporeal membrane oxygenation (ECMO). Systematic reviews into the benefits of ECMO in CDH concluded that any benefit is unclear. Few randomised trials exist to demonstrate clear benefit and guide management. However, ECMO may have its uses in those that have reversibility of their respiratory disease. A few centres and networks have demonstrated an increase in survival rate by post hoc analysis (based on a difference in referral patterns with the availability of ECMO) in their series. One issue may be that of careful patient selection with regard to reversibility of pathophysiology. At present, there is no single test or prognostication that predicts reversibility of PPHN and criteria for referral for ECMO is undergoing continued refinement. Overall survival is similar between cannulation modes. There is no consensus on the time limit for ECMO runs. The optimal timing of surgery for patients on ECMO is difficult to definitively establish, but it seems that repair at an early stage (with careful perioperative management) is becoming less of a taboo, and may improve outcome and help with either coming off ECMO or decisions on withdrawal later. The provision of ECMO will continue to be evaluated, and prospective randomised trial are needed to help answer question of patient selection and management.

Extracorporeal membrane oxygenation in infants with congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a severe congenital anomaly which impairs normal pulmonary development leading to acute and chronic respiratory failure, pulmonary hypoplasia, pulmonary hypertension, and mortality. CDH is the most common non-cardiac indication for neonatal ECMO. Prenatal and postnatal predictors of CDH severity aid in patient selection. Centers vary in preferred mode of ECMO and timing of CDH repair. Survivors of severe CDH with ECMO are at risk for long-term sequelae including neurodevelopmental delays.

Short-Term Neurodevelopmental Outcome in Congenital Diaphragmatic Hernia: The Impact of Extracorporeal Membrane Oxygenation and Timing of Repair

OBJECTIVES

The purpose of this study was to assess the need and timing of extracorporeal membrane oxygenation in relation to congenital diaphragmatic hernia repair as modifiers of short-term neurodevelopmental outcomes.

DESIGN

Retrospective study.

SETTING

A specialized tertiary care center.

PATIENTS

Between June 2004 and February 2016, a total of 212 congenital diaphragmatic hernia survivors enrolled in our follow-up program. Neurodevelopmental outcome was assessed at a median age of 22 months (range, 5-37) using the Bayley Scales of Infant Development, third edition. Fifty patients (24%) required extracorporeal membrane oxygenation support. Four patients (8%) were repaired prior to cannulation, 25 (50%) were repaired on extracorporeal membrane oxygenation, and 21 (42%) were repaired after decannulation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Children with congenital diaphragmatic hernia, who required extracorporeal membrane oxygenation scored on average 4.6 points lower on cognitive composite (p = 0.031) and 9.2 points lower on the motor composite (p < 0.001). Language scores were similar between groups. Mean scores for children with congenital diaphragmatic hernia repaired on extracorporeal membrane oxygenation were significantly lower for cognition (p = 0.021) and motor (p = 0.0005) outcome. Language scores were also lower, but did not reach significance. A total of 40% of children repaired on extracorporeal membrane oxygenation scored below average in all composites, whereas only 9% of the non-extracorporeal membrane oxygenation, 4% of the repaired post-extracorporeal membrane oxygenation, and 25% of the repaired pre-extracorporeal membrane oxygenation patients scored below average across all domains. Only 20% of congenital diaphragmatic hernia survivors repaired on extracorporeal membrane oxygenation support scored within the average range for all composite domains. Duration of extracorporeal membrane oxygenation support was not associated with a higher likelihood of adverse cognitive (p = 0.641), language (p = 0.147), or motor (p = 0.720) outcome.

CONCLUSIONS

Need for extracorporeal membrane oxygenation in congenital diaphragmatic hernia survivors is associated with worse neurocognitive and neuromotor outcome. Need for congenital diaphragmatic hernia repair while on extracorporeal membrane oxygenation is associated with deficits in multiple domains. Overall time on extracorporeal membrane oxygenation did not impact neurodevelopmental outcome.

Shifting Risks and Conflicting Outcomes-ECMO for Neonates with Congenital Diaphragmatic Hernia in the Modern Era

OBJECTIVES

To update previously described trends for neonates with congenital diaphragmatic hernia (CDH) receiving ECMO with changes in recommendations for care, and to determine how recent advancements in respiratory care have affected this patient population.

STUDY DESIGN

This study is a retrospective review of more than 2500 neonates with CDH who received ECMO listed in the Extracorporeal Life Support Organization (ELSO) registry. Cochran-Armitage and multivariate regression analyses were used to analyze changes in the patient population over time and in mortality-related risk factors.

RESULTS

Almost one-half (48.1%) of the term neonates survived to discharge, representing a 13.8% decline in survival over the past 25 years (P < .0001). Over the past 10 years, the prevalence of respiratory acidosis more than doubled (P < .0001) and the prevalence of major complications increased (P < .001). During the same period, the number of ECMO courses longer than 1 week increased (P < .001), whereas the prevalence of multiple complications (>4) decreased (P < .0001). Surgeries performed on ECMO were associated with worse outcomes than those performed off ECMO. ECMO duration no longer represents a mortality-related risk factor.

CONCLUSIONS

Survival rates for neonates with CDH receiving ECMO have continued to drop in the modern era. Although the safety of ECMO has improved over the last decade, the number of patients experiencing significant respiratory acidosis has more than doubled-increasing the risk of intracranial hemorrhage and overall mortality. The evidence for permissive hypercapnia remains mixed; nonetheless, we believe that the risks outweigh the rewards in this patient population.

Extracorporeal Membrane Oxygenation for Neonates with Congenital Renal and Urological Anomalies and Pulmonary Hypoplasia: A Case Report and Review of the Extracorporeal Life Support Organization Registry

Objective  Congenital anomalies of the kidney and urinary tract constitute up to 30% of anomalies identified in the neonatal period. In utero oligohydramnios is often associated with pulmonary hypoplasia and respiratory failure in the neonate who may not be responsive to mechanical ventilation. Placement of these neonates on extracorporeal membrane oxygenation (ECMO) remains controversial and is considered in most centers to be a relative contraindication. The objective of this study is to use the Extracorporeal Life Support Organization (ELSO) database to describe the outcomes and complications of patients with congenital renal and urogenital anomalies with pulmonary hypoplasia who underwent ECMO in the neonatal period. Data Sources  Data from the ELSO registry were retrospectively reviewed for all patients with congenital renal and urogenital anomalies with pulmonary hypoplasia treated with ECMO support between 1990 and November 2014 using ICD-9 diagnosis codes. Data Synthesis  We identified 45 patients. The average age of the patient at the time of ECMO was 1.7 days (range: 0-14 days) and weight was 3.1 kg (interquartile range [IQR]: 2.5-3.3). Patients spent an average of 162 hours on ECMO (IQR: 81-207). The majority of patients were managed with venoarterial ECMO (60%), and the overall survival of this cohort was 42%. Survivors had higher weights (3.4 vs. 2.8 kg; p  < 0.019) and were more likely to be male (90 vs. 44%; p  < 0.002). Patients with obstructive urogenital lesions had an overall survival of 71 versus 16.6% in patients with a primary intrinsic renal diagnosis ( p  = 0.004). Renal replacement therapy was required in 51% of the patients during their ECMO support. Conclusion  Neonates with renal or urogenital disease and pulmonary hypoplasia have an overall survival rate of 42%. Patients with a diagnosis of urogenital obstruction have much more favorable outcomes when compared with those with intrinsic renal disease such as polycystic kidney disease.

Bilateral congenital diaphragmatic hernia: prognostic evaluation of a large international cohort

BACKGROUND

Congenital diaphragmatic hernia (CDH) is a lethal birth defect, which occurs in 1:2000-3000 live births. Bilateral CDH is a rare form (1%), with a high mortality. This study presents the outcomes of the largest cohort of bilateral CDH patients.

METHODS

The records of patients with bilateral CDH from the Congenital Diaphragmatic Hernia Registry born between 1995 and 2015 were retrospectively analyzed to identify parameters associated with mortality.

RESULTS

Eighty patients with a bilateral CDH were identified. Overall mortality was 74% (n=59). Apgar scores at 1 and 5min were statistically lower in the non-survivors compared to the survivors (median 3.0 and 5.0, versus 6.5 and 8.0, respectively, p<0.001). All survivors were repaired (n=21), compared to 22% of the non-survivors (n=17). The type of repair was equally divided in the survivors (52% primary versus 48% patch), while non-survivors were mainly patch repaired (82% versus 12%). Nineteen were treated with extracorporeal membrane oxygenation (ECMO) (24%), only three of them survived. When calculating the risk on mortality for the patients who lived until repair, ECMO had an adjusted odds ratio for mortality of 10.8 (95% CI: 2.0-57.7) and patch repair 5.2 (95% CI: 0.8-34.9).

CONCLUSIONS

The treatment of bilateral CDH patients remains challenging with a high mortality rate. Lower Apgar-scores, ECMO (probably as a surrogate for the severity of disease), and patch repair were negatively associated with outcome.

LEVEL OF EVIDENCE

Level IV study.

ECMO in CDH: Is there a role?

Despite wide use and decades of experience, survival of congenital diaphragmatic hernia (CDH) patients treated with extra-corporeal membrane oxygenation (ECMO), as reported by the extra-corporeal life support organization (ELSO), remains unchanged at 50%. High-survival rates both with and without utilizing ECMO have been reported, fueling questions about the utility of ECMO support in this difficult population. This review looks at data from the Congenital Diaphragmatic Hernia Study Group and individual center reports, to evaluate the role of ECMO in CDH, focusing on defining the patients most likely to benefit, and discussing how those benefits can best be achieved. These data show that ECMO improves survival in those CDH patients who are most severely affected, but potential complications of ECMO delivery outweigh benefit in patients with less severely affected. Improved results can be expected by minimizing ECMO complications, and by improving rates of CDH repair in patients that require ECMO.

Congenital diaphragmatic hernia: The role of multi-institutional collaboration and patient registries in supporting best practice

Among congenital malformations, congenital diaphragmatic hernia (CDH) is distinguished by its relatively low occurrence rate, need for resource intensive, integrated multidisciplinary care, and widespread variation in practice and outcome. Although randomized controlled trials (RCTs) are considered the gold standard for generating evidence, they are poorly suited to the study of a condition like CDH due to challenges in illness severity adjustment, unpredictability in clinical course and the impact limitations of studying a single intervention at a time. An alternative to RCTs for comparative effectiveness research for CDH is the patient registry, which aggregates multi-institutional condition-specific patient level data into a large CDH-specific database for the dual purposes of collaborative research and quality improvement across participating sites. This article discusses patient registries from the perspective of structure, data collection and management, and privacy protection that guide the use of registry data to support collaborative, multidisciplinary research. Two CDH-specific registries are described as illustrative examples of the "value proposition" of registries in improving the evidence basis for best practices for CDH.