Congenital diaphragmatic hernia

Spontaneous Right-Sided Diaphragmatic Hernia: A Rare Cause of Small Bowel Obstruction

Diaphragmatic hernia (DH) is an uncommon cause of small bowel obstruction (SBO), particularly in the absence of trauma. This rarity can pose a diagnostic challenge, leading to significant delays in treatment and increased morbidity. We report a case of a 79-year-old male patient who presented with acute signs of small bowel obstruction. The patient had no reported history of trauma. Computed tomography (CT) of the abdomen revealed a diaphragmatic hernia causing small bowel obstruction. The patient underwent an initial laparoscopy, which was converted to laparotomy, small bowel resection, and subsequent hernia repair. The patient made a good recovery, and two weeks after his initial presentation, he was discharged home. This case highlights the importance of considering diaphragmatic hernia in differential diagnosis for small bowel obstruction, even in the absence of trauma.

Intravesical pressure: A new prognostic indicator in congenital diaphragmatic hernia

AIMS

To evaluate the usefulness of intravesical pressure as a prognostic indicator in congenital diaphragmatic hernia.

MATERIAL AND METHODS

In 25 cases, bladder pressure was measured intraoperatively during repair.

RESULTS

Cases were divided into three groups according to the intravesical pressure. Group 1: pressure <10 cm (n.9), Group 2: 10-15 cm (n.11) and Group 3: >15 cm (n.5). Number of ventilated days was tabulated against these groups. Median number of ventilated days for Group 1, with the lowest pressure, was 3 days, while that for Group 2 was 5 and for Group 3, with the highest pressure, was 10 days. This was significant, with a P-value of 0.016.

CONCLUSION

Measurement of intravesical pressure is a reliable prognostic indicator in newborns with congenital diaphragmatic hernia. It also helps in predicting postoperative ventilatory requirement.

Permissive hypercapnia in the management of congenital diaphragmatic hernia: our institutional experience

BACKGROUND

Congenital diaphragmatic hernia (CDH) is a potentially lethal anomaly associated with pulmonary hypoplasia and persistent pulmonary hypertension. Permissive hypercapnia is a strategy designed to reduce lung injury from mechanical ventilation in infants. It has been shown to be a potentially superior method of ventilator management for patients with CDH. In 2001, the Divisions of Neonatology and Pediatric Surgery at the University of Virginia Children's Hospital established permissive hypercapnia as the management strategy for treatment of CDH. We hypothesized that permissive hypercapnia would be associated with improved outcomes in this patient population.

STUDY DESIGN

This retrospective review compares outcomes of infants treated for CDH in the extracorporeal membrane oxygenation (ECMO) era before and after initiation of permissive hypercapnia at a single institution. Outcomes were compared using univariate statistical analysis.

RESULTS

Ninety-one patients were available for analysis and were divided into 2 groups: 42 (Group 1) treated before and 49 (Group 2) treated after implementation of permissive hypercapnia. Survival was higher in Group 2 (85.8% vs 54.8%; p = 0.001; relative risk [RR] 3.17). Morbidity was lower in Group 2 and approached statistical significance (65.3% vs 83.3%; p = 0.052). Patients in Group 2 were repaired later, had a lower rate of ECMO use, and were extubated earlier. There was no difference in hospital stay.

CONCLUSIONS

The use of permissive hypercapnia for infants with CDH was associated with decreased mortality, a longer period of ventilation before repair with a shorter period of ventilation after repair, a lower rate of ECMO use, and no lengthening of hospital stay. Permissive hypercapnia remains the standard of care for ventilation of infants with CDH at our institution.

[Congenital diaphragmatic hernia - mechanisms of pulmonary hypoplasia]

Congenital diaphragmatic hernia (CDH) is a common cause of severe neonatal respiratory distress. Mortality and morbidity are determined by the amount of pulmonary hypoplasia (PH) that occurs and by the development of therapy-resistant pulmonary hypertension. The pathogenesis and aetiology of CDH and its associated anomalies are still largely unknown despite all research efforts. The pathogenesis of CDH is based on an assumption linking herniation of abdominal viscera into the thorax with compression of the developing lung. PH, however, can also result from reduced distension of the developing lung secondary to impaired fetal breathing movements. Our understanding of CDH has also been aided by basic research with the use of dietary, teratogen-induced, and knockout models of CDH. These studies indicate that lung hypoplasia may involve disturbances of mitogenic signalling pathways fundamental to embryonic lung development. Recent data reveal the role of disruption of a retinoid-signalling pathway in the pathogenesis of CDH. Although multifactorial inheritance may best explain most cases of CDH in humans, much has been learned about the genetic factors that play a role in the development of CDH by studies of patients with CDH caused by specific genetic syndromes and chromosome anomalies. More research is warranted to improve our understanding of normal and abnormal lung development in relation to CDH. Such investigations will help in the design of new treatment strategies to improve the natural course or even to prevent this anomaly.

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.

Diaphragm development and congenital diaphragmatic hernia

Advances in the understanding of normal diaphragm embryogenesis have provided the necessary foundation for novel insights into the pathogenesis of congenital diaphragmatic hernia (CDH). Although diaphragm formation is still not completely understood, we have identified key structures and periods of development that are clearly abnormal in animal models of CDH. The pleuroperitoneal fold (PPF) is a transient structure which is the target for the neuromuscular component of the diaphragm. The PPF has been shown to be abnormal in multiple animal models of Bochdalek CDH; specifically, a malformation of the nonmuscular component of this tissue is thought to underlie the later defect in the complete diaphragm. Based on data from animal models and the examination of human postmortem tissue, we hypothesize that abnormal PPF development underlies Bochdalek CDH. Further, the understanding of the pathogenesis of rarer subtypes of CDH will be advanced by the study of various new animal models discussed in this review.

Effects of antenatal corticosteroid treatment on pulmonary ventilation and circulation in neonatal lambs with hypoplastic lungs

Our aim was to determine whether antenatal corticosteroids improve perinatal adaptation of the pulmonary circulation in lambs with lung hypoplasia (LH). LH was induced in 12 ovine fetuses between 105 and 140 days gestation (term approximately 147 days); in 6 of these the ewe was given a single dose of betamethasone (11.4 mg im) 24 hr before delivery (LH + B). All lambs, including a control group (n = 6), were delivered at approximately 140 days and ventilated for 2 hr during which arterial pressures, pulmonary blood flow (PBF), and ventilating pressure and flow were recorded. During ventilation, respiratory system compliance was lower in both LH + B and LH groups than in controls. Pulmonary vascular resistance (PVR) was lower in LH + B lambs than in LH lambs and similar to controls; PBF was reduced in LH lambs but was restored to control levels by betamethasone. The mean density of small arteries of LH + B lambs was similar to that of LH lambs (P = 0.06) and lower than in controls; the thickness of the media of small pulmonary arteries from LH + B lambs was similar to that in LH lambs and thicker than in controls. VEGF mRNA levels were not different between groups. PDGF mRNA levels in LH + B lambs were higher than in LH lambs; a similar trend (P = 0.06) was seen for PECAM-1. SP-C mRNA levels were greater in both LH and LH + B lambs than in controls. Effects of betamethasone were greater on indices of pulmonary circulation than ventilation. We conclude that a single dose of maternal betamethasone 24 hr prior to birth has significant favorable effects on the postnatal adaptation of the pulmonary circulation in lambs with LH.

Prenatal diagnosis and perinatal outcome of 38 cases with congenital diaphragmatic hernia: 8-year experience of a tertiary Brazilian center

PURPOSE

To evaluate the perinatal results for neonates with congenital diaphragmatic hernia diagnosed prenatally.

METHOD

We reviewed data from 38 cases of congenital diaphragmatic hernia diagnosed prenatally from January 1995 to December 2003 in the Fetal Medicine Unit of the Department of Obstetrics and Gynecology, São Paulo University Medical School. The main data analyzed were gestational age at diagnosis, fetal karyotyping, side of diaphragmatic defect, presence of associated structural malformations, hepatic herniation, and severe mediastinal shift. Perinatal outcomes were obtained by reviewing hospital documents or by directly calling the patients' immediate relatives.

RESULTS

Mean gestational age at diagnosis was 29 weeks (range, 16-37 weeks). Thirty (79%) cases had a left diaphragmatic defect and 8 (21%) had a right lesion. Associated structural malformations were observed in 21 (55%) cases, in which 12 fetuses had a normal karyotype and 9 had chromosomal abnormalities. Isolated congenital diaphragmatic hernia was confirmed in 17 (45%) cases. The overall perinatal mortality rate was 92%. Rates of fetal deaths, early neonatal deaths, late neonatal deaths, and survival were 42%, 50%, 0%, and 8%, respectively, in cases with associated structural malformations but normal karyotyping; 56%, 44%, 0%, and 0% for cases with chromosomal abnormalities; and, 0%, 76%, 12%, and 12% in cases with isolated congenital diaphragmatic hernia. The neonatal mortality rate was 89% in cases with isolated congenital diaphragmatic hernia.

CONCLUSION

Perinatal mortality was very high in prenatally diagnosed cases of congenital diaphragmatic hernia. Earlier perinatal deaths are associated with the presence of other structural defects or chromosomal abnormalities. In cases of isolated congenital diaphragmatic hernia, mortality is related to the presence of herniated liver, right-sided lesion, and major mediastinal shift.

Perinatal management of congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) retains high mortality due to lung hypoplasia and pulmonary hypertension. Efforts to improve survival and outcome have included fetal intervention, delivery at specialist centres, elective operation after stabilisation of labile physiology and minimising barotrauma. Permissive hypercapnea ('gentle ventilation') represents a significant advance in therapy gaining wider acceptance in centres worldwide. Human genetic studies are underway to identify candidate genes for the birth defect. Progress in the basic sciences may uncover critical aspects of developmental biology fundamental to CDH. Clinical trends in perinatal management of CDH are highlighted, which underpin the challenges of this lethal human anomaly.

Prevention of heart failure in the management of congenital diaphragmatic hernia by maintaining ductal patency. A case report

Congenital diaphragmatic hernia is a rare entity in childhood carrying a high mortality rate of 30% to 50%. Ipsilateral pulmonary hypoplasia, increased pulmonary vascular resistance, and potential cardiac failure complicate early postnatal life. Surgical correction can either be performed on the first day of life or be deferred to a time after stabilization of the infant. Our patient presented with a left-sided Bochdalek's hernia containing large and small bowel. She required intubation and resuscitation on day 1 of life, and surgical repair had to be postponed. Further respiratory deterioration required commencement of inhaled nitric oxide and high-frequency ventilation. Pulmonary artery pressure rose to suprasystemic level. Closure of the ductus arteriosus on day 8 resulted in imminent right-sided heart failure. Commencement of alprostadil (prostaglandin E1) reopened the ductus and stabilized the patient. Surgical repair was successful 3 days later. Alprostadil should be considered as an important component of therapy in severe cases of congenital diaphragmatic hernia, where deterioration of right-sided heart function occurs.

Congenital diaphragmatic hernia prevents absorption of distal air space fluid in late-gestation rat fetuses

We hypothesized that congenital diaphragmatic hernia (CDH) may decrease distal air space fluid absorption due to immaturity of alveolar epithelial cells from a loss of the normal epithelial Na+ transport, as assessed by amiloride and epithelial Na+ channel (ENaC) and Na-K-ATPase expression, as well as failure to respond to endogenous epinephrine as assessed by propranolol. Timed-pregnant dams were gavage fed 100 mg of nitrofen at 9.5-day gestation to induce CDH in the fetuses, and distal air space fluid absorption experiments were carried out on 22-day gestation (term) fetuses. Controls were nitrofen-exposed fetuses without CDH. Absorption of distal air space fluid was measured from the increase in 131I-albumin concentration in an isosmolar, physiological solution instilled into the developing lungs. In controls, distal air space fluid absorption was rapid and mediated by β-adrenoceptors as demonstrated by reversal to fluid secretion after propranolol. Normal lung fluid absorption was also partially inhibited by amiloride. In contrast, CDH fetuses continued to show lung fluid secretion, and this secretion was not affected by either propranolol or amiloride. CDH lungs showed a 67% reduction in α-ENaC and β-ENaC expression, but no change in α1-Na-K-ATPase expression. These studies demonstrate: 1) CDH delays lung maturation with impaired distal air space fluid absorption secondary to inadequate Na+ uptake by the distal lung epithelium that results in fluid-filled lungs at birth with reduced capacity to establish postnatal breathing, and 2) the main stimulus to lung fluid absorption in near-term control fetuses, elevated endogenous epinephrine levels, is not functional in CDH fetuses.

Bilateral congenital diaphragmatic hernia

Bilateral congenital diaphragmatic hernia (CDH) is a rare condition, with the literature suggesting a bleak prognosis. We describe a case of bilateral CDH that, despite confirming the challenges of diagnosis, demonstrates that the condition can have a favourable outcome.

Recent advances in congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a common birth defect which continues to challenge paediatric surgeons and intensivists. Affecting approximately 1:2500 births, a baby with CDH is born every 24-36 hours in the UK.

Fetal surgery for congenital diaphragmatic hernia: the North American experience

The role for fetal surgery in treating fetuses with congenital diaphragmatic hernia (CDH) is unclear. Two decades of investigation have improved our understanding of the prenatal natural history, pathophysiology, and outcomes of these patients. During this same period, there have been advances in fetal surgery techniques including improvements in fetal monitoring, maternal-fetal anesthesia, tocolysis, and improved instrumentation to permit increased application of videoscopic approaches. Because of technical challenges, open fetal repair of CDH has been abandoned. Fetal tracheal ligation has shown promise, but a recently published prospective, randomized trial failed to show a benefit of fetoscopic tracheal ligation compared with expert postnatal treatment. Although there is evidence that postnatal outcomes for infants with this disease have improved with the adoption of gentilation ventilator management, high-frequency ventilation, and ECMO, there continues to be a subset of infants with severe CDH that die or suffer serious long-term morbidity despite advanced surgical care. The purpose of this article is to review issues related to prenatal diagnosis, patient selection, and outcomes for fetal surgery; and ultimately to assess whether there is a role for fetal surgery in treating fetuses with CDH.

Effect of lung hypoplasia on birth-related changes in the pulmonary circulation in sheep

Lung hypoplasia (LH) is a serious cause of neonatal compromise, but little is known of its functional effects on the pulmonary circulation. Our aim was to characterize birth-related changes in the pulmonary circulation of newborn lambs with LH and to compare them with alterations in respiratory function. LH was induced in six ovine fetuses by the creation of a tracheo-amniotic shunt as well as amniotic fluid drainage starting at 105.6+/-1.5 (mean+/-SEM) days of gestation (term approximately 147 d). At 139.9+/-0.3 d, fetuses were exteriorized under anesthesia to implant vascular catheters and an ultrasonic flow probe around the left pulmonary artery. The lambs then were delivered and ventilated for 2 h, during which systemic and pulmonary artery pressures, left pulmonary blood flow, and measures of respiratory function were recorded. At autopsy, lungs were weighed and volume was measured at 20 cm H2O. In LH lambs, lung weight was 25% lower and respiratory system compliance was 30% lower than in controls. Mean pulmonary blood flow in LH lambs was 42% lower and pulmonary vascular resistance was 138% higher than in controls. Morphometry showed that volume density of pulmonary arteries in LH was 30% lower than in controls. We conclude that, in this LH model, changes in ventilatory indices were proportional to the change in lung size, whereas changes in the pulmonary circulation were greater than the change in lung size and were associated with reduced density of pulmonary arteries. LH severely impairs normal adaptation of the pulmonary circulation in the perinatal period.

Distal angiogenesis: a new concept for lung vascular morphogenesis

Although several molecular players have been described that play a role during the early phases of lung development, it is still unknown how the vasculature develops in relation to the airways. Two opposing models describe development of lung vasculature: one suggests that both vasculogenesis and angiogenesis are involved, whereas the second describes vasculogenesis as the primary mechanism. Therefore, we examined the development of the murine pulmonary vasculature through a morphological analysis from the onset of lung development [9.5 days postcoital (dpc)] until the pseudoglandular stage (13.5 dpc). We analyzed fetal lungs of Tie2-LacZ transgenic mice as well as serial sections of wild-type lungs stained with endothelial-specific antibodies (Flk-1, Fli-1, and PECAM-1). Embryos were processed with intact blood circulation to maintain the integrity of the vasculature; hence individual vessels could be identified with accuracy through serial section analysis. Furthermore, circulating primitive erythrocytes, formed exclusively by the blood islands in the yolk sac, are trapped in vessels during fixation, which proves the connection with the embryonic circulation. We report that from the first morphological sign of lung development, a clear vascular network exists that is in contact with the embryonic circulation. We propose distal angiogenesis as a new concept for early pulmonary vascular morphogenesis. In this model, capillary networks surround the terminal buds and expand by formation of new capillaries from preexisting vessels as the lung bud grows. The fact that at an early embryonic stage a complete vascular network exists may be important for the general understanding of embryonic development.

[Delayed discovery of congenital diaphragmatic hernia: diagnostic difficulties. A report of two cases]

Delayed revelation of congenital diaphragmatic hernias (CDH) is not uncommon and can represent 5-30% of total CDHs. Time before diagnosis may be prolonged, sometimes to the adult period. Respiratory and gastrointestinal symptoms are frequent but not specific. The clinical presentation of delayed CDH may thus mislead the practitioner. Diagnosis can be approached and/or confirmed by plain radiography. Outcome is usually favorable after surgery. We report two cases of delayed CDH and we discuss the difficulty of diagnosis.

The CDH Study Group and advances in the clinical care of the patient with congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) occurs in 1 of every 2000 to 4000 births and accounts for 8% of all major congenital anomalies. Recurrence risk for a subsequent pregnancy is estimated at 2%. The mortality rate for CDH when diagnosed antenatally, varies with fetal age and with the presence or absence of hydramnios and degree of pulmonary hypoplasia. The prognosis has improved dramatically in recent years, primarily due to advances in neonatal and surgical interventions. Neonatal survival rates with an antenatal diagnosis now exceed 80% in some centers. Treatment for infants with CDH reflects other pediatric surgical problems in that a majority of the clinical research that shapes treatment is retrospective in nature. Because CDH is a relatively rare disease, using a compilation of cases, such as the CDH database provides, greatly aids our understanding of this disease process. Moreover, the application of a quality assessment scale provides the practitioner with a knowledge base to critically evaluate the published retrospective data.

Apparent truth about congenital diaphragmatic hernia: a population-based database is needed to establish benchmarking for clinical outcomes for CDH

BACKGROUND

The authors hypothesize that recent single or multiinstitution-based reports of improved survival of congenital diaphragmatic hernia (CDH) patients are biased by patient selection, practice, and referral patterns. Here the authors report a population-based analysis of the clinical outcomes of CDH in the province of Ontario for 1996.

METHODS

A retrospective analysis of cross-sectional data from the Bureau of Vital Statistics of Ontario and all 5 pediatric surgical institutions in Ontario for 1996 was performed.

RESULTS

Twenty-four CDH-associated deaths were registered in Canada in 1996. Fourteen of 24 occurred in Ontario (58.3%). Of 30 institutionally identified CDH in Ontario, 8 patients died (26.7%). CDH-associated infant mortality rate was 6.6 of 100,000 live births in Canada compared with 10 of 100,000 live births for Ontario (Relative risk, 1.4; confidence interval, 0.5, 3.7; P >.01). Neonatal death (<28 postnatal days) accounted for the majority, 13 of 14 (92.8%) of deaths. Six of 14 (42.9%) CDH-associated deaths, however, were not accounted by the institutional-based reporting. In addition, institutional-based survival rates for CDH varied from 62.5% to 100%.

CONCLUSIONS

Our results indicate the existing bias associated with institution-based reporting and database of CDH. The "hidden mortality" associated with CDH is still present. A population-based database is needed to establish the benchmarking for management of CDH.