Improved results in patients who have congenital diaphragmatic hernia using preoperative stabilization, extracorporeal membrane oxygenation, and delayed surgery

Re-ECMO for congenital diaphragmatic hernia: Is it worth the effort?

AIM

To evaluate the results in CDH patients subjected to a second course of ECMO at a single institution.

MATERIAL AND METHODS

Retrospective review of medical charts of patients treated for CDH and ECMO in our center since 1990 to December 2018 was performed. For patients subjected to a second course of ECMO and who survived to hospital discharge charts from follow up visits were also reviewed.

RESULTS AND DISCUSSION

From Jan 1990 until December 2018, 311 patients with CDH were treated in the department. 267 of these (86%) were discharged alive from the hospital and 81% (237/293) of the Swedish patients were alive by December 2018. 101 patients (32%) were subjected to ECMO treatment of whom 71 survived (70%). 22 patients underwent a second ECMO run and 13 of these survived to hospital discharge. Seven of the Swedish patients [19] were long-term survivors (37%). The vast majority was on V-A ECMO.

CONCLUSIONS

It is possible to recannulate the right common carotid artery and internal jugular vein for a second course of venoarterial ECMO in CDH patients, who deteriorate severely after decannulation. Previous research has shown that long-term survivors subjected to ECMO twice reported similar frequencies of pulmonary, gastrointestinal, neurological and musculoskeletal sequelae as the long-term survivors, who needed ECMO support only once, and similar health-related quality of life. Regarding their psychosocial function, they scored within normal range in the behavioral, emotional and social scales domains. A second ECMO run may contribute to a higher survival and that the long-term morbidity among survivors is not more pronounced than among survivors after a single course of ECMO. It is therefore suggested that a second course of ECMO should be offered on the same indications as the first course.

LEVEL OF EVIDENCE

III Case series.

Educational level and socioeconomic status in patients born with congenital diaphragmatic hernia: A population-based study

BACKGROUND

Neurodevelopmental dysfunction is one of the most disabling outcomes for congenital diaphragmatic hernia (CDH) survivors and may have a long lasting impact in adult life.

AIM

To evaluate to which extent being born with CDH has an impact on the educational level and socioeconomic status as a proxy for neurocognitive development.

MATERIAL AND METHODS

Nationwide, population-based prospective study of newborn children in Sweden from 1982 to 2015. School grades, highest educational level and income were assessed through Swedish public registries. Children above 15 years of age with CDH were compared with randomly selected controls.

RESULTS

A significantly higher number of cases (17% vs 10%) did achieve neither a school nor a university degree. Among those who achieved a degree there was no difference in the highest level of education. The qualification points in elementary school did not differ, but in high school female cases had significantly lower qualification points than female controls. There were no differences in individual disposable income between cases and controls. However, males had higher income compared to females. Prematurity and a long hospital stay had a negative impact on educational level.

CONCLUSIONS

A higher proportion of children born with CDH compared to controls do not achieve a school degree. Among those who achieved a degree, the school achievements and educational level were similar to controls. Prematurity and a long hospital stay are risk factors for not achieving an educational degree.

TYPE OF STUDY

Prognosis study (high-quality prospective cohort study with 99% of patients followed to the study end point).

LEVEL OF EVIDENCE

Level I. I for a prognosis study - This is a high-quality, prospective cohort study with 99% of patients followed to the study end point.

Tidal volumes at birth as predictor for adverse outcome in congenital diaphragmatic hernia

OBJECTIVE

To assess the predictive value of tidal volume (Vt) of spontaneous breaths at birth in infants with congenital diaphragmatic hernia (CDH).

DESIGN

Prospective study.

SETTING

Tertiary neonatal intensive care unit.

PATIENTS

Thirty infants with antenatally diagnosed CDH born at Hospital Sant Joan de Déu in Barcelona from September 2013 to September 2015.

INTERVENTIONS

Spontaneous breaths and inflations given in the first 10 min after intubation at birth were recorded using respiratory function monitor. Only expired Vt of uninterrupted spontaneous breaths was included for analysis. Receiver operating characteristics (ROC) analysis was performed and the area under the curve (AUC) was estimated to assess the predictive accuracy of Vt.

MAIN OUTCOME MEASURES

Mortality before hospital discharge and chronic lung disease (CLD) at day 28 of life.

RESULTS

There were 1.233 uninterrupted spontaneous breaths measured, and the overall mean Vt was 2.8±2.1 mL/kg. A lower Vt was found in infants who died (n=14) compared with survivors (n=16) (1.7±1.6 vs 3.7±2.1 mL/kg; p=0.008). Vt was lower in infants who died during admission or had CLD (n=20) compared with survivors without CLD (n=10) (2.0±1.7 vs 4.3±2.2 mL/kg; p=0.004). ROC analysis showed that Vt ≤2.2 mL/kg predicted mortality with 79% sensitivity and 81% specificity (AUC=0.77, p=0.013). Vt ≤3.4 mL/kg was a good predictor of death or CLD (AUC=0.80, p=0.008) with 85% sensitivity and 70% specificity.

CONCLUSION

Vt of spontaneous breaths measured immediately after birth is associated with mortality and CLD. Vt seems to be a reliable predictor but is not an independent predictor after adjustment for observed/expected lung to head ratio and liver position.

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.

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.

Health-related quality of life in children and adolescents with congenital diaphragmatic hernia: a cross-sectional study

BACKGROUND

Patients with congenital diaphragmatic hernia (CDH) have a high residual morbidity rate. We compared self-reported health-related quality of life (HRQoL) between patients with CDH and healthy children.

METHODS

Forty-five patients with CDH who were born from January 1, 1990, through February 15, 2015, were matched to healthy, age-matched control participants at a 1:2 ratio. The health records of the study participants were reviewed to determine comorbid conditions, and HRQoL was assessed by both the participants and their parents with the Pediatric Quality of Life Inventory (PedsQL). The HRQoL scores of the patients with CDH and the control participants were compared by using analysis of variance to adjust for age group and sex. Among patients with CDH, analysis of variance was used to compare HRQoL scores across groups defined according to their characteristics at initial hospitalization, postdischarge events, and comorbid conditions.

RESULTS

Compared with control participants, patients with CDH had lower mean PedsQL scores, as reported by the parent and child, for the physical and psychosocial domains (P < 0.001). Risk factors associated with lower parent-reported HRQoL included bronchopulmonary dysplasia, longer initial hospitalization, severe cognitive impairment, and orthopedic symptoms; among patients with CDH, low HRQoL was associated with chronic respiratory issues.

CONCLUSION

Patients with CDH had lower HRQoL compared with healthy participants. Parent-reported HRQoL tended to be higher than child-reported HRQoL. Results were also inconsistent for the risk factors associated with HRQoL obtained by using child- and parent-reported scores. Therefore, when interpreting HRQoL in CDH survivors, a proxy report should not be considered a substitute for a child's self-report.

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.

Parenting stress among parents of children with congenital diaphragmatic hernia

PURPOSE

The aim of this study was to examine parental stress among parents of children with congenital diaphragmatic hernia (CDH).

METHODS

Between 2005 and 2009, a total of 51 children with CDH were treated at Astrid Lindgren Children's Hospital. The survival rate at discharge was 86% and long-term survival rate 80%. One parent each of the long-term survivors (41 children) was included in the present study, and 34 parents (83%) agreed to participate. Participants received the Swedish Parenthood Stress Questionnaire (SPSQ). The questionnaire was supplemented by data from case records.

RESULTS

Parents of children with CDH, who had been supported by ECMO or had a long hospital stay, showed significantly higher overall parental stress. Mothers scored an overall higher parental stress compared with fathers. A prenatal diagnosis of CDH or lower parental educational level resulted in significantly higher parental stress in some of the factors.

CONCLUSIONS

Parental stress in parents of children with CDH seems to increase with the severity of the child's malformation. Mothers tend to score higher parental stress than fathers.

Ventilation modalities in infants with congenital diaphragmatic hernia

Neonates with congenital diaphragmatic hernia are among the more complex patients to support with mechanical ventilation. They have particular features that add to the difficulties already present in the neonatal patient. A ventilation strategy tailored to the patient's underlying physiology rather than mode of ventilation is a crucial issue for clinicians treating these delicate patients.

Outcomes of congenital diaphragmatic hernia repair on extracorporeal life support

PURPOSE

Extracorporeal life support (ECLS) is applied to refractory pulmonary hypertension in congenital diaphragmatic hernia (CDH). We evaluate the single-center outcomes of infants with CDH to determine the utility of late repair on ECLS versus repair post-decannulation.

METHODS

Records of infants with CDH (2004-2014) were retrospectively reviewed.

RESULTS

CDH was diagnosed in 177 infants. Sixty six (37%) underwent ECLS, of which, 11 died prior to repair, 33 were repaired post-decannulation, and 22 were repaired on ECLS. Repair was delayed in patients on ECLS (19 versus 10 days, p < 0.001). Patients repaired on ECLS had longer ECLS runs (22 versus 12 days, p < 0.001) and higher rates of bleeding and mortality than those repaired post-decannulation. Survival was 54% in infants undergoing ECLS, 65% in those who underwent repair, 36% in those repaired during ECLS, and 85% in those who were decannulated prior to repair. Eighteen percent (N = 4) of deaths after repair on ECLS were attributable to surgical bleeding. The remainder was due to pulmonary hypertension or sepsis.

CONCLUSION

Infants who underwent CDH repair post-decannulation had excellent outcomes and no mortalities attributable to repair. Neonates who underwent repair on ECLS late on bypass had the lowest survival rate with only 18% of mortality in this cohort attributable to surgical bleeding.

Appropriate timing of surgery for neonates with congenital diaphragmatic hernia: early or delayed repair?

PURPOSE

This study was aimed to evaluate the influence of timing of surgery on patient outcomes, and to clarify appropriate timing of surgery in neonates with congenital diaphragmatic hernia (CDH).

METHODS

A total of 477 neonates with isolated CDH were included. Patients were classified into two groups by timing of surgery: early repair (ER) (≤48 h) and delayed repair (DR) (>48 h). The primary outcome was 90-day survival, with treatment duration (ventilation, oxygen, and hospitalization) being a secondary outcome. To adjust for disease severity, patients were stratified into three severities by Apgar score 1 min ("mild" 8-10, "moderate" 4-7, and "severe" 0-3), and outcomes were compared between ER and DR within each severity.

RESULTS

Although 90-day survival was significantly different among the three severities ("mild" 97%, "moderate" 89%, and "severe" 76%, p = 0.002), there were no differences in 90-day survival between DR and ER within each severity. In "mild", there were no differences in treatment duration between ER and DR. In "moderate", treatment duration was shorter in ER than DR (ventilation 11 vs. 16 days, oxygen 15 vs. 20 days, and hospitalization 34 vs. 48 days). In "severe", treatment duration was shorter in ER than DR, while the best OI was higher in DR than ER.

CONCLUSIONS

Timing of CDH repair seems to have no influence on 90-day survival regardless of disease severity. Patients with moderate severity may benefit from the early repair by reducing treatment duration.

Bilateral Morgagni Hernia: A Unique Presentation of a Rare Pathology

Morgagni hernia is an unusual congenital herniation of abdominal content through the triangular parasternal gaps of the anterior diaphragm. They are commonly asymptomatic and right-sided. We present a case of a bilateral Morgagni hernia resulting in delayed growth in a 10-month-old boy. The presentation was unique due to its bilateral nature and its symptomatic compression of the mediastinum. Diagnosis was made by 3D reconstructed CT angiogram. The patient underwent medical optimization until he was safely able to tolerate laparoscopic surgical repair of his hernia. Upon laparoscopy, the CT findings were confirmed and the hernia was repaired.

Self-assessed physical health among children with congenital diaphragmatic hernia

PURPOSE

The aim of this long-term follow-up study was to investigate the current self assessed physical health in a CDH birth cohort at a single center.

METHODS

Between 1990 and 2009, 195 children born with CDH were treated at Astrid Lindgren Children's Hospital. The primary survival rate was 85 %, and in 2010, 78 % were still alive. Data from medical records were supplemented by a questionnaire consisting of questions about perceived physical function. Patients were divided into groups according to time for intubation and need for extracorporeal membrane oxygenation.

RESULTS

Children born with CDH reported themselves to be having greater problems with asthma, developmental delay, seizure disorder, poor vision, and scoliosis in comparison with normal Swedish children. They also described a sense of having less strength and becoming breathless more often than healthy friends. Symptoms of gastroesophageal reflux and abdominal pain were also reported.

CONCLUSIONS

The majority of the children perceived their physical health as being overall good, but there was an increase of reported symptoms correlating with the severity of the malformation.

Survival of outborns with congenital diaphragmatic hernia: the role of protective ventilation, early presentation and transport distance: a retrospective cohort study

Background

Congenital diaphragmatic hernia (CDH) is a congenital malformation associated with life-threatening pulmonary dysfunction and high neonatal mortality. Outcomes are improved with protective ventilation, less severe pulmonary pathology, and the proximity of the treating center to the site of delivery. The major CDH treatment center in Croatia lacks a maternity ward, thus all CDH patients are transferred from local Zagreb hospitals or remote areas (outborns). In 2000 this center adopted protective ventilation for CDH management. In the present study we assess the roles of protective ventilation, transport distance, and severity of pulmonary pathology on survival of neonates with CDH.

Methods

The study was divided into Epoch I, (1990–1999, traditional ventilation to achieve normocapnia), and Epoch II, (2000–2014, protective ventilation with permissive hypercapnia). Patients were categorized by transfer distance (local hospital or remote locations) and by acuity of respiratory distress after delivery (early presentation-occurring at birth, or late presentation, ≥6 h after delivery). Survival between epochs, types of transfers, and acuity of presentation were assessed. An additional analysis was assessed for the potential association between survival and end-capillary blood CO₂ (P_cCO₂), an indirect measure of pulmonary pathology.

Results

There were 83 neonates, 26 in Epoch I, and 57 in Epoch II. In Epoch I 11 patients (42 %) survived, and in Epoch II 38 (67 %) (P = 0.039). Survival with early presentation (N = 63) was 48 % and with late presentation 95 % (P <0.001). Among early presentation, survival was higher in Epoch II vs. Epoch I (57 % vs. 26 %, P = 0.031). From multiple logistic regression analysis restricted to neonates with early presentation and adjusting for severity of disease, survival was improved in Epoch II (OR 4.8, 95%CI 1.3–18.0, P = 0.019). Survival was unrelated to distance of transfer but improved with lower partial pressure of P_cCO₂ on admission (OR 1.16, 95%CI 1.01–1.33 per 5 mmHg decrease, P = 0.031).

Conclusions

The introduction of protective ventilation was associated with improved survival in neonates with early presentation. Survival did not differ between local and remote transfers, but primarily depended on severity of pulmonary pathology as inferred from admission capillary PcCO₂.

Management Practice and Mortality for Infants with Congenital Diaphragmatic Hernia

OBJECTIVE

Congenital diaphragmatic hernia (CDH) is fatal in 20 to 40% of cases, largely due to pulmonary dysmaturity, lung hypoplasia, and persistent pulmonary hypertension. Evidence for survival benefit of inhaled nitric oxide (iNO), extracorporeal membrane oxygenation (ECMO), and other medical interventions targeting pulmonary hypertension is lacking. We assessed medical interventions and mortality over time in a large multicenter cohort of infants with CDH.

STUDY DESIGN

We identified all infants ≥ 34 weeks' gestation with CDH discharged from 29 neonatal intensive care units between 1999 and 2012 with an average of ≥ 2 CDH admissions per year. We examined mortality and the proportion of infants exposed to medical interventions, comparing four periods of time: 1999-2001, 2002-2004, 2005-2007, and 2008-2012.

RESULTS

We identified 760 infants with CDH. From 1999-2001 to 2008-2012, use of iNO increased from 20% of infants to 50%, sildenafil use increased from 0 to 14%, and milrinone use increased from 0 to 22% (p < 0.001). Overall mortality (28%) did not significantly change over time compared with the earliest time period.

CONCLUSION

Despite changing use of iNO, sildenafil, and milrinone, CDH mortality has not significantly decreased in this population of infants.

Optimal timing of congenital diaphragmatic hernia repair in infants on extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) is a vital pre-operative adjunct for the stabilization of patients with severe congenital diaphragmatic hernia (CDH) that develop cardiorespiratory failure. The optimal timing of diaphragmatic repair in patients with CDH that require ECMO remains controversial. This article offers a review of the data available addressing the risks and outcomes of patients who require ECMO support with regard to timing of repair.

Acute Neonatal Respiratory Failure

Acute respiratory failure requiring assisted ventilation is one of the most common reasons for admission to the neonatal intensive care unit. Respiratory failure is the inability to maintain either normal delivery of oxygen to the tissues or normal removal of carbon dioxide from the tissues. It occurs when there is an imbalance between the respiratory workload and ventilatory strength and endurance. Definitions are somewhat arbitrary but suggested laboratory criteria for respiratory failure include two or more of the following: PaCO₂ > 60 mmHg, PaO₂ < 50 mmHg or O₂ saturation <80 % with an FiO₂ of 1.0 and pH < 7.25 (Wen et al. 2004).

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.

Stability prior to surgery in Congenital Diaphragmatic Hernia: is it necessary?

BACKGROUND

Delaying surgery for infants with CDH until they achieve clinical stability is common practice. Stability, however, is inconsistently defined, and many infants fail to reach pre-established criteria. We sought to determine if infants undergoing surgery without meeting pre-established criteria could achieve meaningful survival.

METHODS

All infants in the CAPSNet database were analyzed (2005-2010). Patients undergoing operative repair were divided into two groups based on whether they met strict (FiO2<0.40, conventional ventilation, preductal saturation >92%, no inotropes or vasodilators), or lenient (FiO2 <0.60, conventional ventilation, preductal saturation >88%, no vasodilators) criteria. Univariate analyses were performed comparing characteristics of those who survived after surgery (N=273) with those who did not (N=21).

RESULTS

294 patients (85%) survived to surgery. Predictors of post-operative survival included prenatal liver position (p=0.003), preoperative oxygen requirements (p=0.008), preoperative inotropes (p<0.0001), and non-conventional ventilation (p=0.004). Infants meeting strict criteria had increased survival (99%; p<0.0001). Infants meeting lenient criteria constituted 70% of survivors. Nearly one-third of survivors met neither strict nor lenient criteria.

CONCLUSIONS

Infants with CDH can achieve good survival even when criteria for pre-operative stability are not met. We suggest that all infants should be repaired even if lenient criteria for ventilatory, inotrope, or vasodilator requirements are not achieved.

Management of prenatally diagnosed congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a congenital anomaly that presents with a broad spectrum of severity that is dependent upon components of pulmonary hypoplasia and pulmonary hypertension. While advances in neonatal care have improved the overall survival of CDH in experienced centers, mortality and morbidity remain high in a subset of CDH infants with severe CDH. Prenatal predictors have been refined for the past two decades and are the subject of another review in this issue. So far, all randomized trials comparing prenatal intervention to standard postnatal therapy have shown no benefit to prenatal intervention. Although recent non-randomized reports of success with fetoscopic endoluminal tracheal occlusion (FETO) and release are promising, prenatal therapy should not be widely adopted until a well-designed prospective randomized trial demonstrating efficacy is performed. The increased survival and subsequent morbidity of CDH survivors has resulted in the need to provide resources for the long-term follow up and support of the CDH population.

An evidence-based review of the current treatment of congenital diaphragmatic hernia

Congenital diaphragmatic hernia is a rare but severe condition affecting 1 in 2000 to 3000 newborns with a survival rate of 67%. Although regular antenatal screening allows prenatal diagnosis in many cases, traditionally treatment has been based on postnatal surgical repair. Recent literature has pointed out the survival benefits of initial stabilization and the use of gentle ventilation strategies prior to definitive treatment, shifting the trend from immediate to delayed surgical repair. Advances in fetal intervention have allowed the introduction of fetal endoscopic tracheal occlusion as a method to hasten lung development before birth in order to minimize postnatal morbidity. Despite appropriate treatment, the long-term outcomes of these patients are plagued with numerous complications, associated with the primary pathology and also aggressive therapeutic measures. International centers of excellence have recently come together in an effort to standardize the care of such patients in hopes of maximizing their outcomes.

Does a highest pre-ductal O(2) saturation <85% predict non-survival for congenital diaphragmatic hernia?

OBJECTIVE

To analyze operative repair, extracorporeal membrane oxygenation (ECMO) and survival rates based on highest pre-ductal oxygen saturation (Pre-O(2)SAT) in a large infant cohort reported to Congenital Diaphragmatic Hernia Study Group Registry between 2000 and 2010.

STUDY DESIGN

Analyzed data included gestational age, birth weight, defect side and size, repair, ECMO use, survival and highest reported PaO(2) and Pre-O(2)SAT in first 24 h of life. We excluded 614 infants due to severe anomaly. Pre-O(2)SAT data were available for 1672 infants.

RESULT

Among infants with highest Pre-O(2)SAT value <85%, survival (24/105=23%) and repair (55/105=52%) rates were significantly decreased compared with infants with higher values. Survival increased to 44% for infants with highest Pre-O(2)SAT<85% who underwent operative repair. Of these, 83% (20/24) required ECMO support compared with 15% (144/961) of survivors with Pre-O(2)SAT>99% (P<0.001). The lowest reported Pre-O(2)SAT with survival was 32% and for survival without ECMO was 52%.

CONCLUSION

A reported highest Pre-O(2)SAT<85% in the first 24 h of life was not uniformly fatal; but survival of infants with Pre-O(2)SAT<85% was associated with high ECMO use and prolonged hospitalization.

Congenital diaphragmatic hernia: to repair on or off extracorporeal membrane oxygenation?

BACKGROUND

Congenital diaphragmatic hernia (CDH) can be repaired on or off extracorporeal membrane oxygenation (ECMO). In many centers, operating off ECMO is advocated to prevent bleeding complications. We aimed to compare surgery-related bleeding complications between repair on or off ECMO.

METHODS

All patients with CDH repair and ECMO treatment between January 1, 1995, and May 31, 2008, were retrospectively reviewed. Tranexamic acid was routinely given to all patients repaired on ECMO for 24 hours perioperatively after 2003. Extra-fluid expansion, transfusion, or relaparotomy caused by postoperative bleeding were scored as surgery-related bleeding complications and were related to the Extracorporeal Life Support Organization (ELSO) registry. We used χ(2) test and t test for statistics.

RESULTS

Demographic data and surgery-related bleeding complications in the on-ECMO group were not significantly different compared with the off-ECMO group (P = .331) in our institute. In contrast, more surgery-related bleeding complications were reported by ELSO in their on-ECMO group (P < .0001).

CONCLUSION

In contrast to the data from the ELSO registry, we did not observe significantly more surgery-related bleeding complications after CDH repair on ECMO. Using a specific perioperative hemostatic treatment enabled us to perform CDH repair on ECMO with a low frequency of bleeding complications, thereby taking advantage of having the physiologic benefits of ECMO available perioperatively.

Congenital diaphragmatic hernia

Congenital Diaphragmatic Hernia (CDH) is defined by the presence of an orifice in the diaphragm, more often left and posterolateral that permits the herniation of abdominal contents into the thorax. The lungs are hypoplastic and have abnormal vessels that cause respiratory insufficiency and persistent pulmonary hypertension with high mortality. About one third of cases have cardiovascular malformations and lesser proportions have skeletal, neural, genitourinary, gastrointestinal or other defects. CDH can be a component of Pallister-Killian, Fryns, Ghersoni-Baruch, WAGR, Denys-Drash, Brachman-De Lange, Donnai-Barrow or Wolf-Hirschhorn syndromes. Some chromosomal anomalies involve CDH as well. The incidence is < 5 in 10,000 live-births. The etiology is unknown although clinical, genetic and experimental evidence points to disturbances in the retinoid-signaling pathway during organogenesis. Antenatal diagnosis is often made and this allows prenatal management (open correction of the hernia in the past and reversible fetoscopic tracheal obstruction nowadays) that may be indicated in cases with severe lung hypoplasia and grim prognosis. Treatment after birth requires all the refinements of critical care including extracorporeal membrane oxygenation prior to surgical correction. The best hospital series report 80% survival but it remains around 50% in population-based studies. Chronic respiratory tract disease, neurodevelopmental problems, neurosensorial hearing loss and gastroesophageal reflux are common problems in survivors. Much more research on several aspects of this severe condition is warranted.

Congenital diaphragmatic hernia: still a moving target

The primary therapeutic target for congenital diaphragmatic hernia (CDH) patients has shifted from emergency surgical repair towards a non-operative emergency of the newborn treated by interdisciplinary teams. The increased understanding of the epidemiological and pathophysiological aspects of CDH have led to an improved knowledge and application of prenatal diagnosis, postnatal ventilation strategies, treatment of associated pulmonary hypertension and the role of extracorporeal membrane oxygenation therapy. In the surgical field, the perspectives have changed with delayed CDH repair, the introduction of minimally invasive surgery and use of prosthetic material for closure of large defects. With decreased mortality, long term multi-organ morbidity has increased in some survivors. In the near future, randomized controlled trials on different aspects of therapy will determine evidence-based optimal care.

CONTEMPORARY NEONATAL INTENSIVE CARE MANAGEMENT IN CONGENITAL DIAPHRAGMATIC HERNIA: DOES THIS OBVIATE THE NEED FOR FETAL THERAPY?

The management of congenital diaphragmatic hernia (CDH) in the newborn infant has changed radically since the first successful outcomes were reported 60 years ago. Then it seemed a surgical problem with a surgical solution – do an operation, remove the intestines and solid viscera from the thoracic cavity, repair the defect and allow the lung to expand. CDH in that era was regarded as the quintessential neonatal surgical emergency. The expectation was that urgent surgery would result in improvement in lung function and oxygenation. That approach persisted up to the 1980s when it was realized that the problem was far more complex and involved both an abnormal pulmonary vascular bed as well as pulmonary hypoplasia. The use of systemically delivered pulmonary vasodilator therapy, principally tolazoline, became a focus of interest in the 1980s with small case reports and case series suggesting improved survival. In the 1990s, based on studies that showed worsening thoracic compliance and gas exchange following surgical repair, deferred surgery and pre-operative stabilization became the standard of care. At the same time extracorporeal membrane oxygenation (ECMO) was increasingly used either as part of pre-operative stabilization or as a rescue therapy after repair. Other centres chose to use high frequency oscillatory ventilation (HFOV). Despite all these innovations the survival in live born infants with CDH did not improve to more than 50% in large series published from high volume centres. However, in the past 10 years there has been an appreciable improvement in survival to the extent that many centres are now reporting survival rates of greater than 80%. Probably the biggest impact on this improvement has been the recognition of the role that ventilation induced lung injury plays in mortality and the need for ECMO rescue. This has ushered in an era of a lung protective or “gentle ventilation” strategy which has been widely adopted as a standard approach. While there have been these radical changes in postnatal management attempts have been made to improve outcome with prenatal interventions, starting with prenatal repair, which was abandoned because of preterm labour. More recently there has been increasing experience in the use of balloon occlusion of the trachea as a prenatal intervention strategy with patients being selected based on prenatal predictors of poor outcome. This approach can only be justified if those predictors can be validated and the outcomes (death or serious long term morbidity) can be shown to be better than those currently achievable, namely 80% survival in high volume CDH centres rather than the 50–60% survival frequently quoted in historical papers.

Can we improve outcome of congenital diaphragmatic hernia?

This review gives an overview of the disease spectrum of congenital diaphragmatic hernia (CDH). Etiological factors, prenatal predictors of survival, new treatment strategies and long-term morbidity are described. Early recognition of problems and improvement of treatment strategies in CDH patients may increase survival and prevent secondary morbidity. Multidisciplinary healthcare is necessary to improve healthcare for CDH patients. Absence of international therapy guidelines, lack of evidence of many therapeutic modalities and the relative low number of CDH patients calls for cooperation between centers with an expertise in the treatment of CDH patients. The international CDH Euro-Consortium is an example of such a collaborative network, which enhances exchange of knowledge, future research and development of treatment protocols.

Absolute vs relative improvements in congenital diaphragmatic hernia survival: what happened to "hidden mortality"

PURPOSE

The aim of this study is to determine if there has been a true, absolute, or apparent relative increase in congenital diaphragmatic hernia (CDH) survival for the last 2 decades.

METHOD

All neonatal Bochdalek CDH patients admitted to an Ontario pediatric surgical hospital during the period when significant improvements in CDH survival was reported (from January 1, 1992, to December 31, 1999) were analyzed. Patient characteristics were assessed for CDH population homogeneity and differences between institutional and vital statistics-based population survival outcomes. SAS 9.1 (SAS Institute, Cary, NC) was used for analysis.

RESULT

Of 198 cohorts, demographic parameters including birth weight, gestational age, Apgar scores, sex, and associated congenital anomalies did not change significantly. Preoperative survival was 149 (75.2%) of 198, whereas postoperative survival was 133 (89.3%) of 149, and overall institutional survival was 133 (67.2%) of 198. Comparison of institution and population-based mortality (n = 65 vs 96) during the period yielded 32% of CDH deaths unaccounted for by institutions. Yearly analysis of hidden mortality consistently showed a significantly lower mortality in institution-based reporting than population.

CONCLUSION

A hidden mortality exists for institutionally reported CDH survival rates. Careful interpretation of research findings and more comprehensive population-based tools are needed for reliable counseling and evaluation of current and future treatments.

Congenital diaphragmatic hernia: an overview of the etiology and current management

AIM

To review provide an overview of the etiology and current strategies in the management of congenital diaphragmatic hernia (CDH).

METHODS

We did a comprehensive review of research trends, evidence based studies and epidemiologic studies.

RESULTS

CDH is a life-threatening pathology in infants, and a major cause of death due to the pulmonary hypoplasia and pulmonary hypertension. There is much research related to elucidating the etiology of CDH and developing management strategies to improve the outcomes in these infants.

CONCLUSION

An early diagnosis with increased understanding of this disease is a crucial factor for a timely approach to managing the critically ill infant, and to offer the potential for improved outcomes and substantial reductions in morbidity.

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.

Imaging of congenital diaphragmatic hernias

Congenital diaphragmatic hernias are complex and life-threatening lesions that are not just anatomic defects of the diaphragm, but represent a complex set of physiologic derangements of the lung, the pulmonary vasculature, and related structures. Imaging plays an increasingly important role in the care of these infants. Prenatal sonography and MRI have allowed early and accurate identification of the defect and associated anomalies. These tools have also been the key to defining the degree of pulmonary hypoplasia and to predicting neonatal survival and need for aggressive respiratory rescue strategies. In the postnatal period, conventional radiography supplemented by cross-sectional imaging in selected cases can be very useful in sorting out the differential diagnosis of intrathoracic masses, in the detection of associated anomalies, and in the management of complications. Understanding the pathogenesis of diaphragmatic defects, the underlying physiologic disturbances, and the strengths and limitations of current imaging protocols is essential to the effective and accurate management of these complex patients.

Platelet-derived growth factor inhibition--a new treatment of pulmonary hypertension in congenital diaphragmatic hernia?

Increased pulmonary vascular resistance causing pulmonary artery hypertension is a major problem in the treatment of congenital diaphragmatic hernia with a strong association to mortality. We here report a patient with intractable pulmonary hypertension at 4 weeks of age unresponsive to conventional treatment. After administration of the platelet-derived growth factor (PDGF) receptor antagonist imatinib, pulmonary artery pressure gradually decreased to acceptable levels and the patient's clinical condition gradually improved.

Congenital diaphragmatic hernia: improved surgical results should influence abortion decision making

AIMS

To compare surgical results for congenital diaphragmatic hernia (CDH) in two Scandinavian university hospitals and to evaluate the effects of abortions on the clinical profile of CDH in Iceland.

METHODS

A retrospective study including all CDH-cases in Iceland 1983-2002 and children referred to Lund University Hospital 1993-2002. Aborted fetuses with CDH from a nation-wide Icelandic abort-registry were also included.

RESULTS

In Iceland, 19 out of 23 children with CDH were diagnosed < 24 hours from delivery, one with associated anomalies. Eight fetuses were diagnosed prenatally and seven of them aborted, three having isolated CDH at autopsy. In Iceland, 15 of 18 children operated on survived surgery (83% operative survival). In Lund 28 children were treated with surgery, 23 of them diagnosed early after birth or prenatally. Four children did not survive surgery (86% operative survival) and 9 (31%) had associated anomalies. All the discharged children treated in Iceland and Lund are alive, 3-22 years postoperatively.

CONCLUSION

CDH is a serious anomaly where morbidity and mortality is directly related to other associated anomalies and pulmonary hypoplasia. However, majority of CDH patients do not have other associated anomalies. In spite of improved surgical results (operative mortality < 20%), a large proportion of pregnancies complicated with CDH are terminated. We conclude that the improved survival rate after corrective surgery must be emphasized when giving information to parents regarding abortion of fetuses with a prenatally diagnosed CDH.

Congenital diaphragmatic hernia: a systematic review and summary of best-evidence practice strategies

OBJECTIVES

Recent reports suggest that specific care strategies improve survival of infants with congenital diaphragmatic hernia (CDH). This review presents details of care from centers reporting high rates of survival among CDH infants.

STUDY DESIGN

We conducted a MEDLINE search (1995 to 2006) and searched all citations in the Cochrane Central Register of Controlled Trials. Studies were included if they contained reports of >20 infants with symptomatic CDH, and >75% survival of isolated CDH.

RESULT

Thirteen reports from 11 centers met inclusion criteria. Overall survival, including infants with multiple anomalies, was 603/763 (79%; range: 69 to 93%). Survival for isolated CDH was 560/661 (85%; range: 78 to 96%). The frequency of extracorporeal membrane oxygenation (ECMO) use for isolated CDH varied widely among reporting centers 251/622 (40%; range: 11 to 61%), as did survival for infants with isolated CDH placed on ECMO: 149/206 (73%; range: 33 to 86%). There was no suggestion of benefit from use of antenatal glucocorticoids given after 34 weeks gestation or use of postnatal surfactant. Low mortality was frequently attributed to minimizing lung injury and adhering to center-specific criteria for ECMO.

CONCLUSION

Use of strategies aimed at minimizing lung injury, tolerance of postductal acidosis and hypoxemia, and adhering to center-specific criteria for ECMO were strategies most consistently reported by successful centers. The literature lacks randomized clinical trials of these or other care strategies in this complex patient population; prospective studies of safety and long-term outcome are needed.

The MRI findings of the right-sided fetal lung can be used to predict postnatal mortality and the requirement for extracorporeal membrane oxygenation in isolated left-sided congenital diaphragmatic hernia

We evaluated whether a correlation existed between fetal pulmonary magnetic resonance imaging (MRI) findings and postnatal mortality, as well as the requirements for extracorporeal membrane oxygenation (ECMO) in infants with prenatally diagnosed, isolated left-sided congenital diaphragmatic hernia (CDH). Twenty-one pregnant women carrying fetuses with CDH underwent 30 MRI scans, and the right-sided fetal lung volume (FLV) was measured. In the control, a regression analysis was performed to associate FLV with gestational age. This yielded a formula that enabled the calculation of the expected right fetal lung volume (ERFLV). In cases with CDH, the right-sided observed FLV/ERFLV (= %RFLV) was compared with both the postnatal mortality and whether ECMO was required. Additionally, we investigated the relationship between the lung shape on MRI (whether there was a complete pulmonary baseline present) and postnatal mortality. The %RFLV was significantly lower in nonsurvivors compared with survivors. Among survivors, the %RFLV was significantly lower in infants who required ECMO compared with those who did not. The pulmonary baseline was completely present in 3 (38%) and 13 (100%) of the nonsurvivors and survivors, respectively. In isolated left-sided CDH, the %RFLV is a good predictor not only of postnatal mortality but also of the requirement for ECMO.

Mechanical ventilation strategies in the management of congenital diaphragmatic hernia

Most infants with congenital diaphragmatic hernia (CDH) require respiratory support. The goal of this report is to present an overview of mechanical ventilation strategies in the management of infants with CDH. The anatomic and physiologic limitations in the lungs of infants with diaphragmatic hernia make decisions on the best strategy and use of mechanical ventilation challenging. We will briefly review lung development in infants with CDH, identifying factors that provide a basis for lung protection strategies. Background on the use of specific mechanical ventilation modes and the rationale for each are provided. Finally, we review mechanical ventilation practices described in published case series of successful CDH management, with a brief review of additional treatments, including inhaled nitric oxide and extracorporeal membrane oxygenation. Although details of a single specific best strategy for mechanical ventilation for CDH infants cannot be identified from current literature, a lung protection ventilation approach, regardless of the device used, appears to reduce mortality risk.

Antenatal detection and impact on outcome of congenital diaphragmatic hernia: A 12-year experience in Auvergne (France)

OBJECTIVE

To evaluate the detection rate of prenatal diagnosis and its impact on outcome in congenital diaphragmatic hernia (CDH).

STUDY DESIGN

We retrospectively studied 51 cases of CDH registered in the Auvergne area from January 1992 to December 2003 (Birth Defect Registry of Auvergne, Institut Européen des Génomutations). Our main outcome measurements were the detection rate of prenatal diagnosis, the incidence and types of associated anomalies and outcome (termination of pregnancy, in utero fetal demise, neonatal death, survival at the time of registration).

RESULTS

Twenty-nine cases of isolated CDH were identified of which 13 were detected prenatally (45%) at a mean gestational age of 26.1 weeks and 22 cases of CDH with associated anomalies with prenatal diagnosis of CDH or any associated anomaly in 16 (73%; p=0.03) at a mean gestational age of 23.9 weeks. In the prenatally detected group (29 cases), there was 1 (3%) in utero fetal death (IUFD), 17 (59%) terminations of pregnancy (TOP) and 11 (38%) live births with early neonatal death in 7 (24%) cases despite delivery in a tertiary care centre in 10/11 cases (four survivors=14%). Most of the undetected cases were isolated CDH (16/22=73%) of which 1 (5%) was a stillborn and 21 (95%) live births with 17 survivors (77%) although 15/21 (71%) were not born at the tertiary care centre (p=0.001). The overall survival rate was 41% with a large variability depending on associated anomalies and prenatal diagnosis (p<0.0001) (prenatally detected cases: 3/13 (23%) isolated CDH and 1/16 (6%) CDH with associated anomalies; undetected cases: 13/16 (81%) isolated CDH and 4/6 (67%) CDH with associated anomalies).

CONCLUSION

Prenatal diagnosis of CDH leads to the delivery of affected babies in tertiary care centres but it remains a challenge in particular for isolated CDH cases and it is associated with a lower survival rate. Associated anomalies contribute to prenatal detection, are related to a higher TOP rate but do not facilitate the detection of diaphragmatic defect per se.

Liver position in fetal congenital diaphragmatic hernia retains a prognostic value in the era of lung-protective strategy

BACKGROUND/PURPOSE

The aims of this study were to analyze the outcomes of fetuses with congenital diaphragmatic hernia (CDH) treated by a lung-protective strategy using high-frequency oscillatory ventilation (HFOV) in a single center with a perinatology service and extracorporeal membrane oxygenation (ECMO) capability and to define the natural history of CDH in the era of lung-protective ventilation.

METHODS

A retrospective chart review of 30 neonates with CDH seen between April 2002 and October 2004 was conducted. All fetuses with a prenatal diagnosis were evaluated by fetal magnetic resonance imaging to define the liver position, and those with a significant volume of the liver in the chest were regarded as liver-up. Patients were managed by a lung-protective strategy using pressure-limited (maximum mean airway pressure [MAP], 18 cm H(2)O) HFOV. The patients were initially placed on HFOV with a fraction of inspired oxygen (Fio(2)) of 1.0 and a MAP of 12 cm H(2)O. Hypercapnea and preductal saturation as low as 85% were accepted. Inhaled nitric oxide and ECMO were introduced when the baby could not be oxygenated with a MAP of 18 cm H(2)O.

RESULTS

Twenty-six neonates (22 inborns with prenatal diagnosis and 4 outborns) were treated with this protocol. Four cases were not treated or died in utero because of severe associated anomalies. Thirteen of the 14 liver-down cases survived without ECMO and were discharged home (93% survival). On the contrary, 4 of 12 liver-up cases survived (33% survival). ECMO was required for initial stabilization in 5 cases with 1 survivor.

CONCLUSIONS

Liver-down CDH babies have a good chance for survival without ECMO by a planned delivery and the lung-protective strategy using HFOV. Liver herniation demonstrated by prenatal magnetic resonance imaging retains a poor prognostic value even with this approach.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Rescue of the Hypoplastic Lung by Prenatal Cyclical Strain

We determined the effects of sustained and cyclical prenatal mechanical strain on the hypoplastic lung of the ovine model of congenital diaphragmatic hernia. Over a period of 4 weeks in late gestation, repeated cyclical tracheal occlusion for 23 hours with 1-hour release stimulated minimal growth, but promoted maturation with the development of a saccular lung. In contrast, a cycle consisting of 47 hours with 1-hour release induced optimal lung growth and morphologic maturation of the hypoplastic lung parenchyma. Sustained occlusion resulted in exaggerated lung growth, exceeding that of unaffected controls, and abnormal alveolar development. The extent of induction of lung growth by mechanical strain was inversely proportional to the number of alveolar type II cells remaining in the lung epithelium. These studies show that, although mechanical strain is capable of inducing lung growth and differentiation, cyclical strain is a prerequisite for normal development and that mechanically induced growth occurs at the expense of the alveolar type II cell. We conclude that cyclical strain may allow optimal alveolar development while maintaining a population of alveolar type II cells and may thus facilitate an improvement in postnatal lung function in infants with congenital diaphragmatic hernia.

SNAP-II predicts mortality among infants with congenital diaphragmatic hernia

OBJECTIVE

Outcomes analysis in congenital diaphragmatic hernia (CDH) requires a validated risk-adjustment tool. The purpose of this study was to use the Canadian Neonatal Network (CNN) database to validate the Score for Neonatal Acute Physiology, Version II (SNAP-II) for prediction of mortality among CDH infants admitted to a neonatal intensive care unit (NICU), and to compare this to the predictive equation recently developed by the Congenital Diaphragmatic Hernia Study Group (CDHSG).

STUDY DESIGN

Infants with CDH in the CNN database were identified. Bivariate and multivariable logistic regression models were used to identify risk factors predictive of mortality. Model predictive performance and calibration were assessed using the area under the receiver operator characteristic curve and the technique of Hosmer-Lemeshow, respectively, and compared with the CDHSG predictive equation.

RESULTS

There were 88 patients with CDH among 19,507 admissions to CNN hospitals. The mortality rate among CDH patients surviving to NICU admission was 17%, and 12.5% received extracorporeal membrane oxygenation therapy. Gestational age and admission SNAP-II score predicted mortality. Model predictive performance and calibration were optimized with these variables combined. The CDHSG equation was equally predictive of mortality, but was only marginally calibrated.

CONCLUSIONS

SNAP-II is highly predictive of mortality among patients with CDH, and can be used to risk-adjust these patients.

Insulinlike growth factor I gene expression is increased in the fetal lung after tracheal ligation

BACKGROUND/PURPOSE

The mortality and morbidity in congenital diaphragmatic hernia are mainly caused by pulmonary hypoplasia. To improve clinical results, further methods inducing lung growth may have to be used. The aim of this report was to evaluate the expression of insulinlike growth factor I (IGF-I), estrogen receptor alpha, estrogen receptor beta, growth hormone receptor, and thioredoxin in a rat model of hypoplastic, hyperplastic, and normal fetal lungs to improve understanding of lung growth.

METHODS

Hypoplastic diaphragmatic hernia lungs were created by giving nitrofen by gavage to pregnant rats on day 9.5. Hyperplastic lungs were achieved by intrauterine tracheal ligation of rat fetuses on day 19. All lungs were harvested on gestational day 21. Total nucleic acids were extracted by proteinase K digestion and extraction in phenol/chloroform. The total nucleic acids mixture was hybridized with radioactively labeled RNA probes, and the radioactivity of the hybrids was compared with the respective standard curve of known amounts of in vitro synthesized mRNA. Immunohistochemistry staining was performed for IGF-I.

RESULTS

The IGF-I mRNA was significantly (P < .01) higher in hyperplastic lungs compared with control and hypoplastic lungs. The latter 2 did not differ. No difference was found between the other mRNA levels in the study groups.

CONCLUSIONS

IGF-I is involved in the accelerated lung growth seen after intrauterine tracheal ligation.

The use of extracorporeal membrane oxygenation in infants with congenital diaphragmatic hernia

The use of extracorporeal membrane oxygenation (ECMO) has revolutionized the care of the critical infant born with a congenital diaphragmatic hernia (CDH). In some respects, this is surprising given our current lack of understanding regarding optimal preoperative ventilation strategy, identification of patients most likely to benefit from ECMO, and the correct timing of hernia repair for the infant treated with ECMO. Historically, repair of CDH was considered one of the few true pediatric surgical emergencies. Mortality, however, was high. In the 1970s, ECMO was first utilized as a rescue therapy following repair of CDH when conventional methods failed. In the 1980s, advancements in neonatal intensive care and an understanding of the pathophysiology of pulmonary hypertension associated with CDH led to a strategy involving preoperative stabilization and delayed surgical intervention. Historical reviews demonstrate an improvement of survival in infants treated with ECMO from 56% to 71%. This paper will outline the advances in the care of the CDH patient and the approach used for treatment with ECMO.