The role of extracorporeal membrane oxygenation in congenital diaphragmatic hernia

Transport on extracorporeal membrane oxygenation for congenital diaphragmatic hernia: A unique center experience

BACKGROUND

Support on Extracorporeal oxygenation membrane (ECMO) represents the last therapeutic option in the management of respiratory failure and pulmonary hypertension refractory to treatment in patients with congenital diaphragmatic hernia (CDH).

AIM

The objective of this work was to present our experience of all the cases of CDH that we have transported on ECMO.

MATERIAL AND METHODS

Medical records of patients, national and international, with CDH transported by our service on ECMO from 1997 to 2018 were reviewed.

RESULTS

During 22 years, we performed 40 ECMO transports of newborns with CDH, 39 primary and one secondary. In 10% (4/40) we transferred patients from their primary hospital after the implantation of cannulae and commencement of ECMO to another center abroad owing to the lack of beds in our unit. Twenty (50%) of the transports were from a foreign country. Median transport distance was 560 (428-1381) km and the median transport time was 4.5 (4.2-6.3) h. The mode of transport was ground ambulance in 20%, helicopter in 10%, fixed wing aircraft in 62.5% and ground ambulance in Freight aircraft in 7.5%. In 40% of the transports, 20 complications occurred. In one of every four transports with complications, more than one event occurred. Most frequent complication was loss of tidal volumes (35%) and in 30% of the complications another patient related event was recorded. Equipment failure occurred in 20%, and climate problems and transport vehicle problems in 15%. No deaths occurred during transport. Venoarterial ECMO was used in 39 of the 40 cases. Survival to discharge was 87% for the entire period and long-term survival was 77%.

CONCLUSIONS

Long and short distance interhospital transports of CDH patients on ECMO can be performed safely. Despite occurrence of adverse events, the risk of mortality is very low. The personnel involved must be highly competent in intensive care, physiology and physics of ECMO, cannulation, intensive care transport and air transport medicine. They must also be trained to recognize risk factors in these patients.

LEVEL OF EVIDENCE

III Retrospective cohort study.

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.

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.

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.

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.

The Surgical Correction of Congenital Deformities: The Treatment of Diaphragmatic Hernia, Esophageal Atresia and Small Bowel Atresia

BACKGROUND

More than half of all congenital deformities can be detected in utero. The initial surgical correction is of paramount importance for the achievement of good long-term results with low surgical morbidity and mortality.

METHODS

Selective literature review and expert opinion.

RESULTS

Congenital deformities are rare, and no controlled trials have been performed to determine their optimal treatment. In this article, we present the prenatal assessment, treatment, and long-term results of selected types of congenital deformity. Congenital diaphragmatic hernia (CDH) affects one in 3500 live-born infants, while esophageal atresia affects one in 3000 and small-bowel atresia one in 5000 to 10,000. If a congenital deformity is detected and its prognosis can be reliably inferred from a prenatal assessment, the child should be delivered at a specialized center (level 1 perinatal center). The associated survival rates are 60-80% after treatment for CDH and well over 90% after treatment for esophageal or small-bowel atresia. Despite improvements in surgical correction over the years, complications and comorbidities still affect 20-40% of the treated children. These are not limited to surgical complications in the narrow sense, such as recurrence, postoperative adhesions and obstruction, stenoses, strictures, and recurrent fistulae, but also include pulmonary problems (chronic lung disease, obstructive and restrictive pulmonary dysfunction), gastrointestinal problems (dysphagia, gastro-esophageal reflux, impaired intestinal motility), and failure to thrive. Moreover, the affected children can develop emotional and behavioral disturbances. Minimally invasive surgery in experienced hands yields results as good as those of conventional surgery, as long as proper selection criteria are observed.

CONCLUSION

Congenital deformities should be treated in recognized centers with highly experienced interdisciplinary teams. As no randomized trials of surgery for congenital deformities are available, longitudinal studies and registries will be very important in the future.

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.

Understanding and treating pulmonary hypertension in congenital diaphragmatic hernia

Lung hypoplasia and pulmonary hypertension are classical features of congenital diaphragmatic hernia (CDH) and represent the main determinants of survival. The mechanisms leading to pulmonary hypertension in this malformation are still poorly understood, but may combine altered vasoreactivity, pulmonary artery remodeling, and a hypoplastic pulmonary vascular bed. Efforts have been directed at correcting the "reversible" component of pulmonary hypertension of CDH. However, pulmonary hypertension in CDH is often refractory to pulmonary vasodilators. A new emerging pattern of late (months after birth) and chronic (months to years after birth) pulmonary hypertension are described in CDH survivors. The true incidence and implications for outcome and management need to be confirmed by follow-up studies from referral centers with high patient output. In order to develop more efficient strategies to treat pulmonary hypertension and improve survival in most severe cases, the ultimate therapeutic goal would be to promote lung and vascular growth.

First 24-h SNAP-II score and highest PaCO2 predict the need for ECMO in congenital diaphragmatic hernia

BACKGROUND/PURPOSE

Early clinical predictors for the use of ECMO in patients with congenital diaphragmatic hernia (CDH) are lacking. We sought to evaluate the first 24-h SNAP-II score and highest PaCO2 as predictors of ECMO support and in-hospital mortality in neonates with CDH.

METHODS

Retrospective review of 47 consecutive neonates with CDH admitted to our institution from January 2007 to December 2010 was performed. Covariates of ECMO use including SNAP-II score and highest PaCO2 within the first 24 h of NICU admission were evaluated.

RESULTS

Of the 47 infants in this study, 24 patients were supported with ECMO. The ECMO group had a higher incidence of pulmonary hypertension, higher PaCO2, and higher 24-h SNAP-II scores. Only the SNAP-II score and not highest PaCO2 predicted mortality following multivariate adjustment.

CONCLUSIONS

The first 24-h SNAP-II score and highest PaCO2 may provide some prognostic value in identifying neonates who undergo ECMO support; however neither measure was independently associated with the use of therapy. Only the SNAP-II score was associated with in-hospital mortality following multivariate adjustment. Additional study is needed to validate these results in a larger data set.

Repair of congenital diaphragmatic hernias on Extracorporeal Membrane Oxygenation (ECMO): does early repair improve patient survival?

INTRODUCTION

The optimal timing of repair for congenital diaphragmatic hernia (CDH) patients that require ECMO is controversial. Early repair on ECMO theoretically allows for restoration of normal thoracic anatomy but entails significant bleeding risks. The purpose of this study was to examine the institutional outcomes of early CDH repair on ECMO.

METHODS

The records of infants with CDH placed on ECMO from 2001 to 2011 were reviewed. Since 2009, a protocol was instituted for early repair while on ECMO. For this study, three cohorts were analyzed: early repair (<72 h), late repair (>72 h), and post-decannulation. These groups were compared for outcomes regarding morbidity and survival.

RESULTS

Forty-six CDH patients received ECMO support with an overall survival of 53%. Twenty-nine patients (11 early/18 late) were repaired on ECMO, while 17 patients had repair post-decannulation. Survival was 73%, 50%, and 64% for those repaired early, late, or post-decannulation, respectively. Despite significantly worse prenatal factors, patients repaired early on ECMO had a similar survival. When comparing patients repaired on ECMO, the early group patients were decannulated 6 days earlier (p-value=0.009) and had significantly lower circuit complications (p=0.03).

CONCLUSION

In conclusion, early repair on ECMO was associated with decreased ECMO duration, decreased circuit complications, and a trend towards improved survival.

Patient selection for neonatal extracorporeal membrane oxygenation: beyond severity of illness

OBJECTIVE

To explore how neonates with respiratory failure are selected for extracorporeal membrane oxygenation (ECMO) once severity of illness criteria are met, and to determine how conflicts between ECMO providers and parents over the initiation of ECMO are addressed.

STUDY DESIGN

A cross-sectional study was conducted using a data collection survey, which was sent to the directors of neonatal respiratory ECMO centers.

RESULT

The lowest birth weight and gestational age at which respondents would consider placing a neonate on ECMO were frequently below recommended thresholds. There was wide variability in respondents' willingness to place neonates on ECMO in the presence of conditions such as intraventricular hemorrhage and hypoxic ischemic encephalopathy. The number of respondents who would never seek to override parental refusal of ECMO was equal to the number who would always do so.

CONCLUSION

Significant variability exists in the selection criteria for neonatal ECMO and in how conflicts with parents over the provision of ECMO are resolved.

Patent ductus arteriosus flow patterns in the treatment of congenital diaphragmatic hernia

BACKGROUND

Congenital diaphragmatic hernia (CDH) mortality still remains high, due to lung hypoplasia and persistent pulmonary hypertension of the neonate (PPHN). Effective management of PPHN and time of operation are quite important to the improvement of CDH treatment. In order to determine the optimal time for operation, we monitored PPHN with cardiac ultrasound.

METHODS

PPHN was assessed with three parameters: patent ductus arteriosus flow patterns (PDAFP), %left ventricular diameter at diastole, and left ventricular fraction of shortening (LVFS). Four patients with an antenatal diagnosis were treated under this protocol. Diaphragm repair was performed when PDAFP became left to right shunt dominant and the pre- and postoperative course was analyzed with regular chart reviews.

RESULTS

The alveolar-arterial oxygen difference levels of four patients were 590, 335, 613 and 530 mmHg, and operations were carried out when the patients were 2, 2, 3 and 2 days old, respectively. In three of the four patients (all except case 3) the PDAFP changed from right to left shunt dominant or bidirectional (BD), to left to right shunt dominant within 48 h. The %left ventricular diameter at diastole was relatively stable around the time of operation. The LVFS of all patients decreased after the operation. Only the LVFS of case 3 decreased temporarily to less than 30% (which indicates poor left ventricular function) but recovered. No patients needed extracorporeal membrane oxygenation support. All patients survived the procedure and were extubated. Case 3, who took 10 days to become left to right shunt dominant after the operation, needed home oxygenation therapy for 10 months.

CONCLUSIONS

PDAFP was a reliable marker of PPHN on a high-frequency oscillatory ventilator to determine the optimal time for the operation for CDH. The optimal time for operation is supposed to be the time when PDAFP become left to right shunt dominant.

Congenital diaphragmatic hernia requiring extracorporeal membrane oxygenation: does timing of repair matter?

PURPOSE

Severe congenital diaphragmatic hernia (CDH) requiring extracorporeal membrane oxygenation (ECMO) is associated with high mortality. Timing of CDH repair relative to ECMO therapy remains controversial. Our hypothesis was that survival would significantly differ between those who underwent repair during ECMO and those who underwent repair after ECMO therapy.

METHODS

We examined deidentified data from the CDH study group (CDHSG) registry from 1995 to 2005 on patients who underwent repair and ECMO therapy (n = 636). We used Cox regression analysis to assess differences in survival between those who underwent repair during and after ECMO.

RESULTS

Five covariates were significantly associated with mortality as follows: timing of repair relative to ECMO (P = .03), defect side (P = .01), ECMO run length (P < .01), need for patch repair (P = .03), birth weight (P < .01), and Apgar score at 5 minutes (P = .03). Birth year, inborn vs transfer status, diaphragmatic agenesis, age at repair, and presence of cardiac or chromosomal abnormalities were not associated with survival. Repair after ECMO therapy was associated with increased survival relative to repair on ECMO (hazard ratio, 1.407; P = .03).

CONCLUSION

These data suggest that CDH repair after ECMO therapy is associated with improved survival compared to repair on ECMO, despite controlling for factors associated with the severity of CDH.

Redefining outcomes in right congenital diaphragmatic hernia

PURPOSE

Available data comparing the management and outcome of right-sided (R-CDH) vs left-sided congenital diaphragmatic hernia (L-CDH) are inconsistent. Large-volume CDH studies are limited by small numbers of R-CDH or are confounded by compilations from multiple institutions with multiple treatment strategies. Consequently, they are underpowered to draw conclusions. To define the behavior and outcomes of R-CDH better, we report the largest single-institution series of R-CDH and ask if factors traditionally linked to poor prognosis in L-CDH were applicable to R-CDH.

METHODS

We reviewed a single institution's experience with 267 consecutive evaluable neonates with unilateral CDH repaired from 1990 to 2006, with specific focus on R-CDH. chi(2) tests were performed for disease-related categorical variables. Two-tailed unpaired t tests were used for continuous variables. Factors associated with morbidity and survival were determined by univariate regression. Statistical significance was set at P < .05.

RESULTS

Forty right-sided (15%) and 227 (85%) left-sided cases of CDH were identified. Prenatal diagnosis was made in 20 right-sided vs 170 left-sided defects (50% vs 75%, P < .01). Survival was 22 of 40 in R-CDH compared with 175 of 227 in L-CDH (55% vs 77%, P < .01). Extracorporeal membrane oxygenation was required in 16 right-sided and 33 left-sided cases (40% vs 15%, P < .001). A diaphragmatic patch was used in 22 of 29 right-sided compared with 82 of 199 left-sided repairs (76% vs 41%, P < .01); rates of abdominal wall prosthesis were also higher in right-sided hernias (38% vs 19%, P < .05). No differences were detected in right-sided vs left-sided recurrences (14% vs 8%, P = .38), mean time from birth to operation (5.3 vs 4.8 days, P = .80), or presence of cardiac anomalies (15% vs 12%, P = .63). Morbidity persisting beyond 6 months of age was present in 16 of 22 R-CDH survivors compared with 76 of 175 L-CDH survivors (73% vs 43%, P > .05). Among R-CDHs, prenatal diagnosis was the only factor to predict survival by univariate regression (P < .01). Use of a prosthesis in the diaphragm (P < .05) for R-CDH repair correlated with morbidity.

CONCLUSION

Although previous reports suggest that associated anomalies, need for extracorporeal membrane oxygenation, and time to repair can influence L-CDH survival, these data do not support extrapolation to R-CDH survival. Right-sided CDH carries a disproportionately high morbidity and mortality. Prenatal diagnosis was the only factor predictive of R-CDH survival. Morbidity may correlate with use of prosthetic material for R-CDH repair. Right-sided CDH is a unique disease that may require a modified antenatal consultation.

Predictors of outcome in patients with congenital diaphragmatic hernia requiring extracorporeal membrane oxygenation

BACKGROUND

The role of extracorporeal membrane oxygenation (ECMO) in patients with congenital diaphragmatic hernia is still evolving. The use of ECMO is invasive with potential complications during instrumentation for cannulation and heparinization. There are no reliable predictors of outcome in patients requiring ECMO. We aimed to identify (a) the factors that could predict outcome and (b) the incidence and relation of complications during ECMO to outcome.

METHODS

"Pre" ECMO (age, sex, birth weight, blood gasses, and ventilator settings) and "on" ECMO variables (mode of ECMO, use of nitric oxide, surfactant, liquid ventilation, inotropes, timing of repair, and complications on ECMO) were analyzed to identify predictors of outcome.

RESULTS

Fifty-two patients were included. The overall survival was 58%. Mean duration of ECMO (181 +/- 120 vs 317 +/- 156 hours, P = .001), use of nitric oxide (6 vs 10, P = .049), and renal complications (4 vs 14; P < .001) differed between survivors and nonsurvivors. The survival of patients requiring ECMO support for more than 2 weeks is significantly lower than that of patients requiring ECMO support for less than 2 weeks (18% vs 68%, P = .005). Multiple logistic regression revealed ECMO duration of 2 weeks or more and renal complications to be associated with mortality.

CONCLUSION

No pre-ECMO variable could be identified as predictor of mortality. Prolonged duration of ECMO and renal complications on ECMO were independently associated with mortality.

The split abdominal wall muscle flap repair for large congenital diaphragmatic hernias on extracorporeal membrane oxygenation

BACKGROUND

Numerous techniques exist for repairing large congenital diaphragmatic hernias (CDHs) including prosthetic patches, tissue-engineered grafts, and various muscle flaps. A split abdominal wall muscle flap is a simple, durable way to repair a large diaphragmatic hernia. This technique has not gained widespread use, and some have suggested that it would be inappropriate in the setting of extracorporeal membrane oxygenation (ECMO) because of bleeding risk. We present our series of diaphragmatic hernias with a focus on those repaired with the split abdominal wall technique while on ECMO.

METHODS

A retrospective, single-institution chart review was performed on all patients who underwent surgical repair for CDH over 6 years beginning in August 2000.

RESULTS

Seventy-five patients underwent repair. Sixteen were performed with patients on ECMO. Of these, 4 were closed primarily, 7 used a prosthetic patch, and 5 used a split abdominal wall muscle flap. Two patients in the prosthetic group developed a recurrent hernia, and 2 required reoperation for bleeding while on ECMO. No reoperations for bleeding were required in the abdominal muscle flap group.

CONCLUSIONS

The split abdominal wall muscle flap can be safely performed on anticoagulated patients. We believe it is a practical option for repairing large CDHs.

Ex utero intrapartum treatment with extracorporeal membrane oxygenation for severe congenital diaphragmatic hernia

PURPOSE

The purpose of this study was to determine whether ex utero intrapartum treatment with extracorporeal membrane oxygenation (EXIT to ECMO) is a reasonable approach for managing patients antenatally diagnosed with severe congenital diaphragmatic hernia (CDH).

METHODS

A 6-year retrospective review was performed on fetuses with severe CDH (liver herniation and a lung/head ratio <1.4, percentage of predicted lung volume <15, and/or congenital heart disease). Fourteen of the patients underwent EXIT with a trial of ventilation. Fetuses with poor preductal oxygen saturations despite mechanical ventilation received ECMO before their delivery. Maternal-fetal outcomes were analyzed.

RESULTS

There were no maternal-reported complications. Three babies passed the ventilation trial and survived, but 2 of them required ECMO within 48 hours. The remaining 11 fetuses received ECMO before their delivery. Overall survival after EXIT-to-ECMO was 64%. At 1-year follow-up, all survivors had weaned off supplemental oxygen, but 57% required diuretics and/or bronchodilators.

CONCLUSION

This is the largest reported experience using EXIT to ECMO in the management of severe CDH. The EXIT-to-ECMO procedure is associated with favorable survival rates and acceptable pulmonary morbidity in fetuses expected to have a poor prognosis under conventional management.

Neurodevelopmental outcomes and surgery in neonates

A neonate requiring major surgery in 2006 has a greater prospect of survival than ever before. Increasingly, however, there is awareness that critical illness may affect later neurodevelopment. Pre-existing conditions in addition to the physiologic stresses associated with cardiac and general surgery are implicated but remain unavoidable in the case of significant structural abnormalities such as transposition of the great arteries or congenital diaphragmatic hernia. For those affected by neurodevelopmental impairment, there is a significant cost to the child, family and society. Current research focuses on the preventable causes of brain injury, before, during and after the intervention, and the rate of impairment in apparently uncomplicated procedures. In contrast to the quantity of neurodevelopmental outcome data following cardiac surgery, there remain few outcome studies dealing with non-cardiac surgery despite such intervention being two to three times more common. There appear to be compelling clinical and economic arguments for the instigation of formalised population-based developmental assessments for all infants undergoing major surgery.

Fog2 is required for normal diaphragm and lung development in mice and humans

Congenital diaphragmatic hernia and other congenital diaphragmatic defects are associated with significant mortality and morbidity in neonates; however, the molecular basis of these developmental anomalies is unknown. In an analysis of E18.5 embryos derived from mice treated with N-ethyl-N-nitrosourea, we identified a mutation that causes pulmonary hypoplasia and abnormal diaphragmatic development. Fog2 (Zfpm2) maps within the recombinant interval carrying the N-ethyl-N-nitrosourea-induced mutation, and DNA sequencing of Fog2 identified a mutation in a splice donor site that generates an abnormal transcript encoding a truncated protein. Human autopsy cases with diaphragmatic defect and pulmonary hypoplasia were evaluated for mutations in FOG2. Sequence analysis revealed a de novo mutation resulting in a premature stop codon in a child who died on the first day of life secondary to severe bilateral pulmonary hypoplasia and an abnormally muscularized diaphragm. Using a phenotype-driven approach, we have established that Fog2 is required for normal diaphragm and lung development, a role that has not been previously appreciated. FOG2 is the first gene implicated in the pathogenesis of nonsyndromic human congenital diaphragmatic defects, and its necessity for pulmonary development validates the hypothesis that neonates with congenital diaphragmatic hernia may also have primary pulmonary developmental abnormalities.