Lethal nonpulmonary anomalies associated with congenital diaphragmatic hernia: implications for early intrauterine surgery

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

TYPE OF STUDY

Systematic review and meta-analysis.

LEVEL OF EVIDENCE

Level III.

Current advances in prenatal imaging of congenital diaphragmatic [corrected] hernia

Congenital diaphragmatic hernia, despite advances in therapy, remains a complex condition with significant morbidity and mortality. The etiology of the disorder is still incompletely understood, though the pulmonary hypoplasia and pulmonary hypertension that develop secondarily must be overcome to improve survival. Prenatal US and fetal MRI have helped in the development of a greater understanding of this disease. Also with these modalities, measurement techniques have been developed in an attempt to provide prognosticators for the development of pulmonary hypoplasia and pulmonary hypertension. There is a broad range of approaches for performing these measurements, and variability among imaging centers is noted. Despite inconsistent approaches, these techniques have become the foundation for counseling and prenatal and postnatal therapy. It is hoped that with further research with prenatal US and fetal MRI and the development of innovative medical and surgical therapies that the morbidity and mortality of children with congenital diaphragmatic hernias can be significantly reduced.

Gastric antrum hypertrophy causing outlet obstruction in an infant with congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is associated with multiple congenital anomalies affecting several organ systems, including the gastrointestinal system. Pyloric stenosis and bands are known and previously reported etiologies of gastric outlet obstruction in infants with CDH. We report the first case of gastric antrum hypertrophy causing gastric outlet obstruction in an infant with CDH.

Fryns syndrome a presentation of two siblings with congenital diaphragmatic hernia

INTRODUCTION

Congenital diaphragmatic hernia (CDH) is a congenital malformation that has a reported incidence ranging from 2.4 to 4.1 in 10,000 births. Despite advances in neonatal care, a mortality rate of 33% is still reported with isolated CDH, predominantly due to hypoxic respiratory failure secondary to pulmonary hypoplasia. Fryns syndrome is the most common autosomal recessive syndrome associated with CDH, reported in up to 10% of patients with CDH, comprising CDH, pulmonary hypoplasia, craniofacial abnormalities, distal limb hypoplasia and internal malformations.

CASE PRESENTATION

We present two siblings with lethal CDH born within a 30 month period. The clinical course in these two infants is described and the possible mode of inheritance for CDH in this family is reviewed.

CONCLUSION

In spite of lacking many advanced chromosomal evaluations in our institute we recommended for further investigation into isolated and particularly familial cases may lead to the identification of genetic abnormalities detectable with FISH assay, locus-specific DNA probes, or other new techniques. There remains an ongoing need for careful clinical review and blood banking of cases of CDH to allow better insight into the genetic causes of severe fetal anomalies such as CDH.

The hidden mortality of congenital diaphragmatic hernia: a 20-year review

AIMS

The true mortality associated with congenital diaphragmatic hernia (CDH) is hidden because survival analyses do not include fetuses with CDH. A retrospective review of all postmortems (PMs) with a diagnosis of CDH over a 20-year period was carried out to highlight this hidden mortality and also measure the nature and number of associated anomalies.

METHODS

Postmortem case record details were reviewed for the period January 1986 to December 2005. Data were collected on live birth, stillbirth, therapeutic abortion, and spontaneous abortion.

RESULTS

There was a decline in the annual number of PMs during the period of the study. The median for the four 5-year intervals being 609 (570-657), 528 (488-565), 515 (413-537), and 373 (357-388). A total of 130 PMs were identified, which included a diagnosis of CDH; 97 (75%) were left sided, 22 (17%) were right sided, and 11 (8%) were bilateral. There were 69 live births, 46 therapeutic abortions, 10 stillbirths, and 5 intrauterine deaths; 22% were right sided/bilateral in the live and therapeutic abortion groups, whereas 53% were right sided/bilateral in the latter 2 groups. Of 130, 82 (63%) had major associated anomalies, and 50% of these had at least 1 further major anomaly. The commonest categories of anomalies were cardiac (30), gastrointestinal/abdominal wall defect (28), and neural tube defects (25).

CONCLUSIONS

The true incidence of CDH is considerably higher than that seen in neonatal surgical practice. The decline in number of PMs in our region will exacerbate the underestimation of the true incidence. There is a higher incidence of right-sided/bilateral hernias and more than one major anomaly in those who die in utero.

Congenital diaphragmatic hernia

The incidence of congenital diaphragmatic hernia (CDH) may be as high as 1 in 2000. Over the past two decades, antenatal diagnosis rates have increased, the pathophysiology of CDH has become better understood, and advances in clinical care, including foetal surgery, have occurred. However, there remains a paucity of randomised controlled trials to provide evidence-based management guidelines. Reports of improved survival rates appear to be confined to a select subset of CDH infants, surviving to surgical repair, while the overall mortality, at over 60%, appears to be unchanged, largely due to the often forgotten 'hidden mortality' of CDH. The significant long-term morbidity in surviving infants has become apparent, and the need for long-term multidisciplinary follow up established. A total of 10% of cases may present later in life, and misdiagnosis on initial chest X-ray may lead to significant morbidity.

Recurrent congenital diaphragmatic hernia in Ehlers-Danlos syndrome

Ehlers-Danlos syndrome (EDS) includes a group of connective tissue disorders with abnormal collagen metabolism and a diverse clinical spectrum. We report two siblings with EDS who both presented with congenital diaphragmatic hernia (CDH). The elder sister suffered from recurrent diaphragmatic hernia twice and EDS was overlooked initially. Echocardiography as well as contrast-enhanced magnetic resonance angiography (MRA) showed dilatation of the pulmonary artery, and marked elongation and tortuosity of the aorta and its branches. A diagnosis of EDS was eventually established when these findings were coupled with the clinical features of hyperelastic skin. Her younger brother also had similar features. This report emphasizes that EDS may present as CDH in a small child which could easily be overlooked. Without appropriate surgery, diaphragmatic hernia might occur. Echocardiographic screening is recommended in patients with CDH. Contrast-enhanced MRA can be helpful in delineation of abnormally tortuous aortic great vessels that are an important clue to the early diagnosis of EDS.

[Fetal magnetic resonance imaging. Diagnostics in congenital diaphragmatic hernia]

Ultrasonography is the primary imaging modality for the evaluation of fetal or maternal anomalies. This method is safe, relatively inexpensive, easily accessible, and allows real-time imaging. Continuous technical improvements in ultrasonography in the last 10-15 years have led to improved diagnostic accuracy for fetal malformations. In cases of complex anomalies magnetic resonance imaging (MRI) can provide additional information. MRI has evolved as a valuable diagnostic method for evaluating fetal pathology. Particularly with regard to similarity of liver and lung parenchyma in ultrasonography, diagnosis of congenital diaphragmatic hernia (CDH) can be difficult. Beside morphological aspects, e.g., herniation of abdominal contents into the chest, small amounts of compressed lung can be visualized on MRI. The feasibility of using volumetric measurement on MRI may be helpful to predict high-risk fetuses and facilitate decisions to assure adequate prenatal and postnatal management to improve postnatal outcome.

Prenatal diagnosis of congenital diaphragmatic hernia in a fetus with 46,XY/46,X,-Y,+der(Y)t(Y;1)(q12;q12) mosaicism: a case report

Congenital diaphragmatic hernia (CDH) is often associated with major anomalies and chromosomal abnormalities. Chromosomal abnormalities are usually detected in 9.5% to 34% of fetuses with CDH prenatally diagnosed and the defect has also been reported in association with multiple syndromes such as Pallister-Killian syndrome, Fryns syndrome, Di George syndrome and Apert syndrome. Among the chromosomal abnormalities associated with CDH, trisomy 21, 18, and 13 are most common. Association with complex chromosomal aberrations such as mosaicism has also been reported. However, CDH presented in a fetus with Y-autosome translocation is extremely rare. Herein, we reported a case of fetus with 46,XY/46,X,-Y, +der(Y)t(Y;1)(q12;q12) mosaicism who presented with CDH diagnosed by ultrasonography at 19 weeks' gestation.

Antenatal diagnosis of congenital diaphragmatic hernia

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

Congenital diaphragmatic hernia: associated anomalies and antenatal diagnosis. Outcome-related variables at two Detroit hospitals

This retrospective study reviews the medical records of 77 fetuses and babies with congenital diaphragmatic hernia (CDH) referred to two hospitals in Detroit from 1986 through 2000. The aims were to examine the effects on outcome of multiple variables, especially the type of CDH, associated anomalies, and ultrasound prognostic parameters. Ultrasound measurements of head (HC), chest (CC), and abdominal circumferences (AC) were obtained from videotapes. ANOVA and chi-square analysis were used to determine statistical significance between groups and proportions. Eighty-nine percent (65/73) of pregnancies resulted in live births, and 54% (35/65) of patients survived past 30 days. Liveborn patients with low APGAR scores were less likely to survive. Forty-three percent (30/70) had major associated anomalies, with cardiac anomalies constituting about 52% (33/64) of the major associated anomalies. Seventy percent of patients with isolated CDH survived versus 36% of patients with both CDH and cardiac anomalies. Sixty-seven percent (8/12) of fetuses antenatally diagnosed before 25 weeks of gestation survived past 30 days of birth. The survival rate of right-sided CDH with liver herniation was 80% (8/10), compared with 29% (4/14) for left-sided CDH with liver herniation (p=0.088). There was a significant linear relationship (r=0.603, p =0.029) between CC/AC and CC/HC among patients with CDH; survivors had higher CC/AC and CC/HC values than nonsurvivors. These results support the utility of CC/AC and CC/HC measurements and the presence of liver herniation as important prognostic factors that can be used in antenatal counseling and in planning clinical trials.

Bilateral cataracts, retinal detachment and vitreous hemorrhage in a newborn with congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is associated with a wide range of other malformations. We describe a patient with CDH who also had significant eye findings noted at birth.

Fetal therapy: state of the art

OBJECTIVE

To review our experience with the use of sonography in evaluating potential candidates for in utero fetal therapy performed at The Center for Fetal Diagnosis and Treatment at The Children's Hospital of Philadelphia.

METHODS

This review article was designed to discuss open hysterotomy for the 4 fetal surgical procedures that have been performed at our institution. The procedures included surgical repair of myelomeningocele, resection of sacrococcygeal teratoma in fetuses with nonimmune hydrops, resection of an enlarging congenital cystic adenomatoid malformation that is not amenable to thoracoamniotic shunting, and tracheal clip occlusion for severe left congenital diaphragmatic hernia.

RESULTS

For each surgical procedure, the use of sonography in the prenatal diagnosis of the congenital anomaly was detailed, as were indications for surgery and surgical procedures, postoperative monitoring and finally delivery, postnatal treatment, and long-term follow-up. Three of the procedures have been reasonably successful with rather dramatic results in some cases such that these techniques are still being performed. The 1 exception was open hysterotomy for the tracheal clip procedure for congenital diaphragmatic hernia, which has been abandoned.

CONCLUSIONS

Fetal therapy is a rapidly evolving specialty, which is being practiced at several centers in this country. Sonography is an integral part of this specialty practice and has been used extensively in the diagnosis of some congenital anomalies that have debilitating or lethal consequences for the fetus. Technologic improvements in both sonography and magnetic resonance imaging have assisted tremendously in the many advances herein reported in the diagnosis and treatment of the above-described 4 congenital anomalies.

Congenital diaphragmatic hernia in Scandinavia from 1995 to 1998: Predictors of mortality

BACKGROUND/PURPOSE

There is a lack of large contemporary studies on the management of congenital diaphragmatic hernia (CDH), and the prediction of mortality remains difficult. The aim of this study was to investigate the influence of perinatal factors on mortality rate in a contemporary multicenter study.

METHODS

The authors conducted a retrospective multicenter cohort study. Twelve of 13 Scandinavian pediatric surgical centers participated in the study. During a 4-year period (1995 through 1998) 195 children with CDH were included. The main endpoints were hospital mortality rate and total mortality rate (before 2001). Bivariate and multivariate survival analyses were performed using Kaplan-Meier plots, Log-rank test, and Cox regression.

RESULTS

Overall hospital mortality rate was 30%. Among 168 neonates with symptoms within 24 hours (early presenters) 35% died before discharge. All 61 deaths occurred in 157 neonates with symptoms within the first 2 hours of life. Among early presenters, 27% had prenatal ultrasound diagnosis, 26% were delivered by cesarean section, and 21% had associated major malformations. Bivariate analysis of early presenters showed increased risk of death in neonates with prenatal diagnosis, associated anomalies, right-sided diaphragmatic hernia (RCDH), low 1-minute and 5-minute Apgar scores, low birth weight, short gestational age, and cesarean delivery. Neonates with prenatal diagnosis were characterized by significantly lower Apgar scores, lower birth weight, and increased frequency of associated anomalies than those diagnosed after birth. Multivariate analysis found that prenatal diagnosis (P =.004), 1-minute Apgar (P =.001), and RCDH (P =.042) were independent predictors of total mortality rate.

CONCLUSIONS

In a series of 195 CDH patients, all 61 deaths occurred in the 157 neonates presenting with symptoms within the first 2 hours of life. Prenatal diagnosis, 1-minute Apgar score, and RCDH were significant independent predictors of total mortality.

Challenging embryological theories on congenital diaphragmatic hernia: future therapeutic implications for paediatric surgery

Lung hypoplasia is central to the poor prognosis of babies with congenital diaphragmatic hernia (CDH). Prolapse of abdominal organs through a diaphragmatic defect has traditionally been thought to impair lung growth by compression. The precise developmental biology of CDH remains unresolved. Refractory to fetal correction, lung hypoplasia in CDH may instead originate during embryogenesis and before visceral herniation. Resolving these conflicting hypotheses may lead to reappraisal of current clinical strategies. Genetic studies in murine models and the fruitfly, Drosophila melanogaster are elucidating the control of normal respiratory organogenesis. Branchless and breathless are Drosophila mutants lacking fibroblast growth factor (FGF) and its cognate receptor (FGFR), respectively. Sugarless and sulphateless mutants lack enzymes essential for heparan sulphate (HS) biosynthesis. Phenotypically, all these mutants share abrogated airway branching. Mammalian organ culture and transgenic models confirm the essential interaction of FGFs and HS during airway ramification. Embryonic airway development (branching morphogenesis) occurs in a defined spatiotemporal sequence. Unlike the surgically-created lamb model, the nitrofen rat model permits investigation of embryonic lung growth in CDH. Microdissecting embryonic lung primordia from the nitrofen CDH model and normal controls, we demonstrated that disruption of stereotyped airway branching correlates with and precedes subsequent CDH formation. To examine disturbed branching morphogenesis longitudinally, we characterised a system that preserves lung hypoplasia in organ culture. We tested FGFs and heparin (an HS analogue) as potential therapies on normal and hypoplastic lungs. Observing striking differences in morphological response to FGFs between normal and hypoplastic lung primordia, we postulated abnormalities of FGF/HS signalling in the embryonic CDH lung. Evaluating this hypothesis further, we examined effects of an HS-independent growth factor (epidermal growth factor, EGF) on hypoplastic lung development. Visible differences in morphological response indicate an intrinsic abnormality of hypoplastic lung primordia that may involve shared targets of FGFs and EGE. These studies indicate that lung hypoplasia precedes diaphragmatic hernia and may involve disturbances of mitogenic signalling pathways fundamental to embryonic lung development. What does this imply for human CDH? Fetal surgery may be 'too little, too late' to correct an established lung embryopathy. In utero growth factor therapy may permit antenatal lung rescue. Prevention of the birth defect by preconceptual prophylaxis may represent the ultimate solution.

Influence of congenital heart disease on survival in children with congenital diaphragmatic hernia

OBJECTIVE

We sought to assess outcome in patients with CDH and HD to determine if LHR is also predictive of outcome in this subset of patients.

STUDY DESIGN

We carried out a retrospective review (April 1996-October 2000) of patients with isolated CDH (n = 143, 82.2%) and patients with HD (n = 31, 17.8%) to determine the incidence of additional anomalies, survival to term, CDH repair, cardiac repair, and survival to discharge. Survival based on LHR was analyzed in a subset of fetuses.

RESULTS

The risk of death from birth to last follow-up was 2.9 times higher for patients with CDH plus HD than for patients with CDH alone (P <.0001). Of 11 patients with CDH plus HD who had CDH repair (5 of whom also had HD repair), 5 survived. All 10 patients with an LHR <1.2 died; 3 of 6 with an LHR >1.2 survived (Fisher exact test, P =.04).

CONCLUSION

Heart disease remains a significant risk factor for death in infants with CDH. The LHR helps predict survival in this high-risk group of patients.

Noncardiac thoracic anomalies

FHT is a rare diagnosis that may be an isolated finding or associated with multiple fetal anomalies, congenital infection or isoimmunization. The natural history of the lesion is variable. The effusion may regress spontaneously; remain stable in size; or progress to involve both sides of the chest and produce fetal hydrops, pulmonary hypoplasia, and fetal or neonatal demise. Hydrops is associated with significant fetal mortality. Antenatal decompression of the hydrothorax with pleuroamniotic shunting or thoracocentesis may result in a significant decrease in perinatal morbidity and mortality. Persistent hydrothorax can usually be treated with noninvasive measures in the newborn period.

Duplication of chromosome region 4q28.3-qter in monozygotic twins with discordant phenotypes

We describe monozygotic twins with partially discordant phenotypes who were found to have a duplication of chromosome region 4q28.3-qter. The duplicated region of chromosome 4 resulted from an unbalanced segregation of a balanced maternal (4;22)(q28.3;p13) translocation. Duplication of the long arm of chromosome 4 has been described in >60 patients; however, it usually results from the unbalanced segregation of a parental balanced translocation and has an associated monosomy. Twenty cases of dup 4q without an associated monosomy have been reported, and this is the only case of dup 4q28. 3-qter. All cases of dup 4q are reviewed, and phenotypic aspects are analyzed. Issues of monozygotic twinning and other birth defects also are addressed.

Congenital diaphragmatic hernia: a meta-analysis of mortality factors

PURPOSE

The aim of this study was to review all available studies reported in the English-language literature from 1975 through 1998, and by meta-analysis assess the importance of prenatal diagnosis, associated malformations, side of hernia, timing of surgery, and study population on mortality rates in patients with congenital diaphragmatic hernia (CDH).

METHODS

One-hundred-two studies were identified, and 51 studies (2,980 patients) fulfilled the prespecified inclusion criteria. Studies were grouped according to study population into: (I) fetuses diagnosed prenatally; (II) neonates admitted to a treatment center; and (III) population-based studies.

RESULTS

Pooled total mortality rate was significantly higher in category I than in category III (75.6% v 58.2%, P < .001). Pooled hidden postnatal mortality rate (deaths before admittance to a treatment center) in population-based studies was 34.9%. Prenatally diagnosed patients in both category II and III had significantly higher mortality rates than those diagnosed postnatally. Mortality rates were significantly higher among CDH infants with associated major malformations compared with isolated CDH in all 3 categories. An increased mortality rate in right-sided CDH was found in category II and III.

CONCLUSIONS

Prenatal diagnosis of CDH, presence of associated major malformations, and the study population have a major influence on mortality rate. The very high mortality rate in studies of fetuses with a prenatal diagnosis of CDH should be taken into account in prenatal counselling.

Skeletal malformations associated with congenital diaphragmatic hernia: experimental and human studies

BACKGROUND/PURPOSE

Skeletal malformations are seen occasionally in infants with congenital diaphragmatic hernia (CDH). This study examines whether nitrofen, able to produce CDH in fetal rats, also induces skeletal anomalies and, if so, whether these are similar to those seen in CDH patients.

METHODS

Pregnant rats received either nitrofen (100 mg, n = 7) or no treatment (n = 2) on gestational day 9.5. Skeletal anatomy was studied in fetuses recovered on day 21 after alcian blue-alizarin red staining. The charts and postmortem records of 117 stillborns or newborns who died of CDH were investigated retrospectively for skeletal defects. The proportions of anomalies found in the different groups were compared.

RESULTS

The 15 control rat fetuses were normal, whereas 57 of 90 nitrofen-exposed animals (63%) had CDH accompanied by other malformations. Skeletal defects limited to vertebral segmentation or identity anomalies (split vertebra or absent, hypoplastic, or fused ribs) were seen at low thoracic and high lumbar levels in 68% of animals with CDH and in 57% of those without. Delayed ossification of limbs was seen in treated animals. There were skeletal malformations in 31.6% of the 117 human patients with CDH. Costovertebral defects (malformed, extra or defective vertebral bodies or ribs and spina bifida) were comparably frequent in infants with syndromes and in those without them (31.2% v 17.8%, not significant), whereas limb defects were significantly more frequent in those with syndromes (56.2% v 13.9%, P<.05).

CONCLUSION

The nature and location of costovertebral malformations found in both CDH patients and nitrofen-exposed rats suggest that the diaphragmatic defect and the associated organ malformations might be caused by the same early embryonal disturbance involving axial and para-axial mesoderm.

[Congenital diaphragmatic hernia. II. Is pulmonary hypoplasia an indefinable obstacle?]

Despite major insights into the pathogenesis and pathophysiology of congenital diaphragmatic hernia, and despite the availability of an antenatal diagnosis and continuous progress in neonatal intensive care, little improvement has been obtained in the prognosis of this malformation. Thus obstetricians, neonatologists and pediatric surgeons are still facing a several dilemma: dilemma before birth to predict the prognosis, i.e., to evaluate the severity of the associated pulmonary hypoplasia in order to decide whether or not to interrupt pregnancy; dilemma after birth in case of severe respiratory failure to decide how far to go in life support. Based on a review of the literature and their own experience, the authors attempt to recapitulate the perinatal management and outcome of this severe malformation.

Survival of patients with congenital diaphragmatic hernia during the ECMO era: an 11-year experience

BACKGROUND/PURPOSE

Congenital diaphragmatic hernia (CDH) is associated with significant mortality and morbidity. To evaluate the impact of extracorporeal membrane oxygenation (ECMO) on survival, a review of our experience with CDH patients was initiated.

METHODS

The authors performed a retrospective nonrandomized analysis of 98 consecutive CDH patients who were ECMO candidates, and were symptomatic within the first day of life, and underwent repair between May 1985 and May 1996. The patients were divided into three groups: Group 1 (n = 38) refers to patients who were clinically stable and underwent repair before 48 hours of age and did not need ECMO rescue; Group 2 (n = 29) consists of patients who underwent repair but required ECMO rescue; and Group 3 (n = 31) refers to patients who met ECMO criteria preoperatively and required ECMO for stabilization and later underwent repair on ECMO. The Kaplan-Meier survival graph was used for survival analysis.

RESULTS

During the 11-year span, the overall survival rate of all CDH patients was 72% (71 of 98). The survival rate of patients who did not require ECMO support was 92% (35 of 38), whereas patients who required ECMO after repair had a 72% (21 of 29) survival rate. These were compared with a 48% (15 of 31) survival rate for those undergoing repair on ECMO. The differences in survival among the three groups were statistically significant using the log-rank test (P = .0018).

CONCLUSIONS

Survival was significantly better for infants who underwent successful repair without ECMO than those who required ECMO rescue pre- or postrepair. The overall improved survival of CDH patients to 72% compared with historical controls of 38% to 58% may be attributed to ECMO, but the requirement of ECMO before repair, as well as the presence of congenital anomalies (P < .01), prematurity (P < .01), the need for a Gore-Tex patch at repair (P < .05), prenatal diagnosis at less than 25 weeks' gestation (P < .01), and the occurrence of an intracranial hemorrhage (P < .01), decreases the chances of survival.

Partial liquid ventilation and nitric oxide in congenital diaphragmatic hernia

PURPOSE

In congenital diaphragmatic hernia (CDH) there is immature lung development with a resulting clinical picture of pulmonary hypoplasia, surfactant deficiency, and pulmonary hypertension. Pulmonary hypoplasia and surfactant deficiency both have been successfully treated using partial liquid ventilation (PLV). Pulmonary hypertension associated with CDH has proven difficult to treat, but inhaled nitric oxide, which is a potent highly selective pulmonary vasodilator, may have potential. The aim of this study was to assess PLV in CDH and to document the effect of nitric oxide when administered through perfluorocarbon.

METHODS

This study using the lamb CDH model consisted of two groups; a conventional mechanically ventilated (CMV) group and a PLV group. At 1 and 3 hours, nitric oxide (80 ppm) was given for 15 minutes. Data collected included blood gases, pulmonary function tests, pulmonary and systemic blood pressure.

RESULTS

After 30 minutes of ventilation, blood gases in the PLV group were all significantly improved (P < .001): pH, CMV 6.92 +/- 0.15 versus PLV 7.24 +/- 0.11; P(CO2), CMV 139 +/- 26 mmHg versus PLV 52 +/- 11 mmHg; P(O2), CMV 26 +/- 15 mmHg versus PLV 184 +/- 60 mmHg. In addition, there was a significant increase in dynamic compliance and a reduction in pulmonary hypertension. Nitric oxide was only efficacious in the PLV group, causing a further increase in oxygenation and a decrease in pulmonary hypertension. These effects were reversed when the nitric oxide was stopped.

CONCLUSION

This study shows that PLV both improves gas exchange and pulmonary mechanics in CDH and allows the effective delivery of nitric oxide to reduce the pulmonary hypertension associated with CDH.

Tracheal ligation: the dark side of in utero congenital diaphragmatic hernia treatment

Currently there are two in utero procedures that have been proposed for the treatment of Congenital diaphragmatic hernia (CDH); reduction of the herniated viscera with repair of the diaphragmatic defect (CDH repair) and stimulation of lung growth by ligation of the fetal trachea (CDH + TL). Recent studies have shown that CDH + TL may result in a significant surfactant deficiency. The aim of this study was to compare the postnatal lung function of these two interventions using the fetal lamb model of CDH. CDH was created in 14 lambs at 78 days' gestation. At 110 days, seven lambs had their trachea ligated through a transverse neck incision and seven had repair of their diaphragmatic defect via a left subcostal incision. At term the lambs were instrumented with the umbilical circulation intact, then delivered and ventilated to a standard protocol for 4 hours. Pulmonary hemodynamics and blood gas levels were measured and compared every 30 minutes. Four lambs in the CDH repair group and five lambs in the CDH + TL group survived to be studied. After the initial data were analyzed, a further group of CDH + TL lambs (n = 4) were studied. In this group a replacement dose of surfactant (Infasurf, Ony Inc, Buffalo, NY) was administered. These initial results cast doubt on tracheal ligation as an in utero therapy for CDH, and indicate that the lung produced by this intervention is not physiologically normal as previously thought. However, the function of these lungs can be normalized if the surfactant deficiency is corrected. If this improvement can be maintained and there is recovery of the endogenous surfactant system, then in utero tracheal ligation may become a viable treatment for fetal CDH.

The use of interphase FISH for prenatal diagnosis of Pallister-Killian syndrome

Pallister-Killian syndrome (tetrasomy 12p) is a relatively rare aneuploidy syndrome characterized by the presence of mosaicism for an isochromosome 12p [i(12p)]. We report two new cases diagnosed following chorionic villus sampling and an abnormal ultrasound, respectively. Fluorescent in situ hybridization (FISH) was used to enumerate the number of interphase cells containing the isochromosome. The results of these studies illustrate the importance of the use of interphase FISH to detect the presence of the i(12p) in uncultured, non-dividing cells. A review of the literature identified 23 additional cases of Pallister-Killian syndrome diagnosed prenatally. Approximately 50 per cent of these cases were associated with the presence of a congenital diaphragmatic hernia. We suggest that a perinatal-lethal form of Pallister-Killian syndrome is underdiagnosed and recommend that all cases of prenatally detected diaphragmatic hernia be tested for Pallister-Killian syndrome using interphase FISH on uncultured amniocytes.

Prenatal ultrasonography frequently fails to diagnose congenital diaphragmatic hernia

Despite increased use of prenatal ultrasonography and well-defined guidelines to aid in the detection of congenital diaphragmatic hernia (CDH), approximately half of neonates born with CDH undergo a prenatal scan that does not diagnose the defect. The purpose of this study was to (1) examine the use of prenatal ultrasonography in neonates with CDH, (2) determine possible reasons that contributed to the failure to detect the abnormality, and (3) evaluate the clinical impact of a diagnostic versus a nondiagnostic study. From 1985 to 1995, 136 consecutive neonates with CDH symptomatic within 24 hours of birth were treated at the University of Michigan Medical Center. Medical records and a University of Michigan CDH database were reviewed for prenatal ultrasound status, side of herniation, site of birth, survival, and extracorporeal life support (ECLS) use. Sonograms that did not diagnose CDH were collected and reviewed by a radiologist for possible-reasons why the diagnosis was missed. Over the 10-year period, use of ultrasonography increased from 33% to 100%, but the false-negative rate remained approximatedly 55%. In reviewing 40 nondiagnostic studies in 25 patients, 25% had technical difficulties, 57% failed to follow established guidelines (localization of the stomach and visulization of the heart with all four chambers), and 33% missed findings (intrathoracic stomach and mediastinal shift) consistent with CDH. There was no significant difference in survival or use of ECLS between neonates with a diagnostic versus nondiagnostic study (53% v 77% survival, P = 0.09; 64% v 42% ECLS, P = .29) Careful attention to following established guidelines and an increased appreciation for the abnormalities would be expected to increase the sensitivity of ultrasonography in detecting CDH. Increased prenatal diagnosis will allow for thorough evaluation for associated malformations, detection of chromosomal abnormalities, and early referra with intrauterine transport to a tertiary care center before delivery.

Structural chromosome anomalies in congenital diaphragmatic hernia

In order to determine the outcome and associated chromosomal and structural anomalies in fetuses diagnosed in utero as having a congenital diaphragmatic hernia, we reviewed 48 consecutive cases referred to our regional Fetal Diagnostic Unit between 1988 and 1995. All babies were delivered in units with appropriate neonatal resuscitation facilities. Thirteen babies [34 per cent of those tested, confidence interval (CI) 19-49 per cent] had karyotypic abnormalities. Three had trisomies but the other nine had more complex karyotypic abnormalities including translocations, deletions, and marker chromosomes. Twenty-one fetuses (44 per cent, CI 30-58 per cent) had additional ultrasound abnormalities which affected the heart in ten cases (21 per cent). Overall, 13 babies survived (27 per cent, CI 14-40 per cent). In babies with normal chromosomes and no additional structural abnormalities the survival rate was 50 per cent (CI 25-75 per cent). Poor outcome was not predicted by early gestation at diagnosis, the hernial contents, or the presence of polyhydramnios. We conclude that parents should be counselled about prognosis with information derived from series of prenatally diagnosed diaphragmatic hernias. The investigations offered should include a detailed ultrasound examination, particularly of the heart, and karyotyping by fetal blood sampling.

Congenital diaphragmatic hernia with ipsilateral eventration: a report of two cases

We report herein the cases of two patients in whom the unusual association of a diaphragmatic hernia with eventration of the diaphragm on the same side were confirmed. Although various recognized patterns of malformations have been described in children with diaphragmatic defects or eventration, to the best of our knowledge, this association has never been reported before. Following our case reports, the literature on this unusual topic is reviewed and a discussion on the possible pathogenesis is presented.

No evidence of WT1 gene mutations in children with congenital diaphragmatic hernia

Children with congenital diaphragmatic hernia are born with a defect of the diaphragm that usually leads to a herniation of abdominal organs up into the thoracic cavity on the same side. The condition is often fatal, usually because of concomitant lung hypoplasia. The cause of this condition is unknown. The majority of cases are sporadic, but familial aggregation has been observed, indicating a genetic background. The tumor suppressor gene WT1 is involved in normal early urogenital development, and it is expressed in the mesothelium in the early human fetus. Recently, knockout mice homozygous for WT1 gene mutations were constructed. The embryos died between days 13 and 15 of gestation. Besides serious urogenital and thoracic malformations, the mice had defects in the diaphragm that caused herniation of lung tissue into the abdomen. These findings prompted the authors to screen for WT1 gene mutations in 27 children who had congenital diaphragmatic hernia. Using exon-per-exon polymerase chain reaction (PCR) amplifications and denaturing gradient gel electrophoresis, no WT1 mutations were detected. Southern blot analysis did not show any large rearrangements in the WT1 gene. These results exclude WT1 gene mutations as a major etiological factor for the isolated diaphragmatic defect. However, it is possible that other genes in the WT1 pathway are involved in this defect.

VACTERL association, epidemiologic definition and delineation

This study departed from a preconceived definition of VACTERL, including more than one of these six anomalies in the same infant: V (vertebral anomalies), A (anal atresia), C (congenital heart disease), TE (tracheoesophageal fistula or esophageal atresia), R (reno-urinary anomalies), and L (radial limb defect). Under this definition, 524 infants were ascertained by ECLAMC from almost 3,000,000 births examined from 1967 through 1990. Observed association rates among VACTERL components as well as between VACTERL and other defects were compared against randomly expected values obtained from 10,084 multiply malformed infants (casuistic method) from the same birth sample. Conclusions were: 1) Cardiac defects are not a part of VACTERL. 2) Single umbilical artery, ambiguous genitalia, abdominal wall defects, diaphragmatic hernia, and anomalies that are secondary to VACTERL components (intestinal and respiratory anomalies, and oligohydramnios sequence defects) are frequent enough to be considered an "extension" of VACTERL, and cardiac defects should be included in this category. 3) Neural tube defects are negatively associated with VACTERL which could not be explained by selection bias or any other operational artifact. High embryonic lethality or mutually exclusive pathogenetic mechanisms could be suitable explanations. 4) Results were not clear enough to determine whether VACTERL should be defined by at least two or three component defects.

Tracheal ligation does not correct the surfactant deficiency associated with congenital diaphragmatic hernia

INTRODUCTION

Experimental tracheal ligation (CDH + TL) has been shown to reverse the profound lung hypoplasia associated with congenital diaphragmatic hernia (CDH) and to normalize gas exchange. The aim of this study was to determine whether this experimental therapy would correct the surfactant deficiency present in the fetal lamb model of CDH.

METHODS

The CDH lamb model was created at 80 days' gestation, and tracheal ligation was performed at 110 days. At term, the lambs were delivered and were ventilated for 30 minutes. The lambs were killed, a pressure-volume curve performed, and the lungs lavaged to measure total phospholipid content. Finally, type II pneumocytes were isolated, and surfactant synthesis was assessed by the incorporation of tritiated choline into phosphatidylcholine.

RESULTS

CDH + TL resulted in a lung significantly larger than that of CDH alone. The lungs of the former also had better oxygenation and ventilation. However, lung compliance was reduced compared with controls. Total alveolar phospholipid was dramatically lower, with a decrease in the proportion of phosphatidylcholine present. Surfactant synthesis by the isolated type II pneumocyte was significantly impaired.

CONCLUSION

Occlusion of the fetal trachea produces a lung comparable in size to a normal control lung. However, broncheoalveolar lavage analysis shows a marked reduction in total phospholipid, with a decrease in surfactant synthesis by the type II pneumocyte. The normalization of gas exchange reported for this animal model may be only a transient phenomenon. Further studies are required to assess the impact of this surfactant deficiency on long-term lung function.

The fetal thorax: noncardiac chest anomalies

Fetal thoracic anomalies often lead to pulmonary hypoplasia with subsequent fetal or neonatal demise. Therefore, in utero sonographic identification of these anomalies is important. Unlike cardiac anomalies, most noncardiac thoracic abnormalities are easily detected with ultrasound. An unusually small thorax is usually obvious to the experienced sonographer, and thoracic masses are commonly observed on the routinely obtained four-chamber view of the heart. This article reviews the many causes of pulmonary hypoplasia with an emphasis placed on thoracic masses. Many examples of pathological fetal thoracic conditions are provided as well as a listing of differential considerations with regard to sonographic appearances of chest masses.

Congenital diaphragmatic hernia: associated malformations--cystic adenomatoid malformation, extralobular sequestration, and laryngotracheoesophageal cleft: two case reports

Two infants with unusual bronchopulmonary malformations associated with congenital diaphragmatic hernia (CDH) are presented. One infant had extralobular sequestration and cystic adenomatoid malformation of the lower lobe, in addition to a left-sided CDH. The second infant had a laryngotracheoesophageal cleft extending to the carina (type III) in addition to a left-sided CDH. These associated malformations can have major implications in terms of diagnosis, resuscitation, and surgical management of infants with CDH.

Recurrence of diaphragmatic agenesis associated with multiple midline defects: evidence for an autosomal gene regulating the midline

We report the familial occurrence of diaphragmatic agenesis in association with other midline anomalies in a brother and sister. Opitz and Gilbert [Am J Med Genet 1982, 12:443-455] introduced the concept of the midline as a developmental field, and there have been reports of pedigrees compatible with the hypothesis of an X-linked gene regulating the development of the midline. This family suggests that an autosomal gene also contributes to the morphogenesis of midline structures.