Prenatal intervention for congenital diaphragmatic hernia

Update on Congenital Diaphragmatic Hernia

Congenital diaphragmatic hernia (CDH) is a rare developmental defect of the diaphragm, characterized by herniation of abdominal contents into the chest that results in varying degrees of pulmonary hypoplasia and pulmonary hypertension (PH). Significant advances in the prenatal diagnosis and identification of prognostic factors have resulted in the continued refinement of the approach to fetal therapies for CDH. Postnatally, protocolized approaches to lung-protective ventilation, nutrition, prevention of infection, and early aggressive management of PH have led to improved outcomes in infants with CDH. Advances in our understanding of the associated left ventricular (LV) hypoplasia and myocardial dysfunction in infants with severe CDH have allowed for the optimization of hemodynamics and management of PH. This article provides a comprehensive review of CDH for the anesthesiologist, focusing on the complex pathophysiology, advances in prenatal diagnosis, fetal interventions, and optimal postnatal management of CDH.

Fetoscopic endoluminal tracheal occlusion (FETO) for congenital diaphragmatic hernia in Australia and New Zealand: are we willing, able, both or neither?

AIM

An estimated 140 pregnancies are diagnosed with congenital diaphragmatic hernia (CDH) in Australia and New Zealand each year, with these fetuses having a less than even chance of 1-year survival. Fetoscopic endoluminal tracheal occlusion (FETO) is a relatively new technique that offers a prenatal interventional strategy for selective cases of CDH. This is not routinely offered in Australia or New Zealand. The aim of this systematic review is to critically appraise controlled clinical trials investigating the role of FETO in moderate and severe isolated CDH and explore whether this treatment is justified within our region.

METHODS

A systematic literature search of multiple electronic databases was undertaken, with restrictions to human subjects and controlled clinical trials.

RESULTS

Nine relevant studies were identified. No current evidence was found in favour of FETO for moderate severity CDH. For severe CDH, the most recent evidence demonstrates significantly improved survival following FETO performed using contemporary percutaneous minimally invasive techniques. Optimum timing for balloon insertion, removal and occlusion duration remains conjectural. Substantial variation in survival rates observed among control groups highlights the impact of post-natal care in prenatally diagnosed CDH.

CONCLUSION

Until recently, evidence to support a role for FETO in prenatal CDH management was weak. Recently reported and ongoing controlled trials give cause for optimism, with improved FETO safety and increased survival reported for severe CDH cases. Should Australasia embrace FETO for selected CDH cases, a co-ordinated, evidence-informed service should be established under the guidance of experienced international partnerships.

[Videosurgery in infancy and childhood: state of the art. Experience with 1408 procedures in the Instituto da Criança "Pedro de Alcântara"]

The videosurgery in Pediatric Surgery has a large field of applications unfortunately still underexplored. There are few services that routinely use this techinic , and Brazilian articles published are scarce. The Institute of Children's Hospital of the Faculty of Medicine, University of São Paulo, has been using for fifteen years the videosurgery which is now the first choice of treatment, among other diseases as gastroesophageal reflux, the cholecystolithiasis, the nonpalpable undescended testicles and megaesophagus. In this article we report our experience in laparoscopic pediatric surgery, acquired with 1408 surgical procedures, to present this useful method, and beneficial to a large number of situations and still underused in Pediatric Surgery.

Recent advances in the management of congenital diaphragmatic hernia

The management of congenital diaphragmatic hernia (CDH) is undergoing continual change and refinement, fuelled by recent advances in this field. Although many studies have documented the benefits of these recent advances but definite recommendations are lacking. Also, injudicious use of some of these strategies may be counterproductive, underscoring the importance of evidence based treatment strategy. This article discusses the utility of the recent advances in the management of CDH.

Chronic fetal and maternal instrumentation in pregnant sheep: effect on gestation length and birthweight

The objective was to compare gestation length in chronically instrumented (laboratory) pregnant sheep (n = 131) and in the breeding flock (n = 476) that provided the experimental sheep. In the breeding flock, gestation length was normally distributed and varied between 141 and 151 days (mean = 147 +/- 0.1 days). In the laboratory sheep, gestation length varied between 128 and 151 days (mean = 142 +/- 1 day), and was bimodal, with 35.9% delivering preterm (<141 days). To examine potential factors that contributed to the preterm birth, a severity score was used, which comprised surgery characteristics, number of experiments and maternal or fetal complications. There was a significant inverse linear relationship (P < 0.001) between the total severity score and gestation length. The median values for the surgical (15 v. 12), overall complication (6 v. 2), maternal complication (2 v. 0) and fetal complication (2 v. 2) components were significantly greater in the preterm compared with the term groups. There was no relationship between fetal number and gestation length in either group. It is concluded that in chronic pregnant sheep preparations, there is a significant incidence of preterm birth and that this is associated with the severity of the surgical intervention and with several maternal and fetal complications.

Effect of prenatal tetrandrine administration on transforming growth factor-beta1 level in the lung of nitrofen-induced congenital diaphragmatic hernia rat model

PURPOSE

Tetrandrine (Tet) is a bisbenzylisoquinoline alkaloid isolated from the root of Stephania tetrandra, which has been used in traditional Chinese medicine to treat patients with silicosis, asthma, and pulmonary hypertension, and others and can be used as a pulmonary therapeutic agent. We hypothesized that it can also improve the lung growth in congenital diaphragmatic hernia (CDH) for its multiple biological effects. There are increasing evidences that suggest transforming growth factor beta1(TGF-beta1) plays a crucial role in fetal lung growth and morphogenesis. The aim of this study was to evaluate the effect of prenatal administration of Tet and to investigate its possible mechanism on the expression of TGF-beta1 in the lung of nitrofen-induced CDH rat model.

METHODS

A CDH model was induced in pregnant Sprague-Dawley rats by administration of nitrofen on day 9.5 of gestation (Ed9.5 term, day 22). Tetrandrine (30 mg/kg) was given through gavage (once a day, for 3 days) on Ed11.5. Accordingly, there were 3 groups as follows: control (n = 9), CDH (n = 9), and CDH + Tet (n = 9). All the fetuses were delivered by cesarean delivery on Ed16.5, 18.5, and 21.5, respectively, to check if diaphragmatic hernia existed on each fetus, then the lung tissue weight (LW) and body weight (BW) of each fetus were recorded. Histologic evaluations and TGF-beta1 immunohistochemistry staining in the lung sample were performed for image analysis.

RESULTS

Diaphragmatic hernia was observed in 95 of the 112 rat fetuses in CDH and CDH + Tet groups on Ed18.5 and Ed21.5 (84.8%), the incidence between the 2 groups had no statistical significance (P = .642). Lung weight/body weight in the CDH group and the CDH + Tet group were lower than that in the control group (P < .01), and LW/BW in the CDH group was lower than that in the CDH + Tet group (P < .05). Observed under the light microscope and electron microscope, marked hypoplasia of the lungs in fetuses among the CDH groups was observed, in contrast to improvement of the lungs in CDH + Tet fetuses. Statistical differences in morphological parameters (percentage of alveoli area, counting bronchus) were found even on Ed16.5 when diaphragm had not closed (P < .01). The number of type II pneumocytes and lamellar bodies in each group had no significant difference (P > .05). The immunoreactivity of TGF-beta1 in CDH group and CDH + Tet group were markedly stronger than that in the control group (P < .01). In addition, TGF-beta1 expression in the CDH group was stronger than that in the CDH + Tet group (P < .01).

CONCLUSION

Nitrofen can interfere with lung development early in the fetal rat development before and separate from diaphragm development, and increased expression of TGF-beta1 in the lung of CDH rat model may suppress lung growth and development. Prenatal treatment with Tet can improve the growth of the lung of the nitrofen-induced CDH fetuses and its mechanism seems to be involved in downregulating the expression of TGF-beta1. It is a likely new approach to treat CDH and its coexistent lung hypoplasia by maternal Tet administration.

Improvement in the outcome of patients with antenatally diagnosed congenital diaphragmatic hernia using gentle ventilation and circulatory stabilization

BACKGROUND/OBJECTIVES

No definitive treatment strategy has been established for patients with an antenatal diagnosed congenital diaphragmatic hernia (AD-CDH). From 1997 to 2003 in this department fetal stabilization (FS) was administered using both morphine and diazepam via the placenta just before delivery of the fetus by cesarean section. In contrast, from 2004 to the present, a combination of gentle ventilation (GV) and a delayed operation was selected, which was performed when the patient's circulatory stabilization (CS) was achieved.

PATIENTS AND METHODS

This study included 22 patients in the FS group and 16 patients in the GV + CS group, respectively. The outcomes in both groups were compared and the outcome in AD-CDH patients with a patch repaired operation, liver-up or lower lung-to-thorax transverse area ratio (L/T, <0.10) was further investigated in both groups.

RESULTS

The overall survival rate (SR) was 93.8% in the GV + CS group and 59.1% in the FS group, respectively (P = 0.04). For the patients with the lower L/T, the SR was 85.7% in GV + CS group and 53.8% in the FS group (P = 0.33). Regarding the patients using a patch and liver-up, the SR in GV + CS group was better than that in the FS group (patch: FS 44.4%, GV +/- CS 87.5%, P = 0.18; liver-up: FS 57.8 and 87.5%, P = 0.30).

CONCLUSION

Our strategy of using GV +/- CS might thus be considered to be more effective than that using FS in the treatment of AD-CDH patients.

Prenatal tetrandrine treatment can reverse the abnormal conditions in the lung of newborn with congenital diaphragmatic hernia

Pulmonary hypoplasia and persistent pulmonary hypertension are the most important reasons for the high morbidity and mortality of congenital diaphragmatic hernia (CDH). Despite surgical advances and advances in neonatal intensive care, the mortality still remains high. Then the research on how to improve prenatal fetal lung growth has become a focus. Some researches involved in fetal surgery, tracheal occlusion, prenatal use of corticosteroids etc., have been carried out in CDH animal models and humans. But the results either showed no benefit for the outcome of CDH or were unproved. Tetrandrine is a bisbenzylisoquinoline alkaloid isolated from the root of Stephania tetrandra. It has been used in traditional Chinese medicine for several decades to treat patients with silicosis, asthma and pulmonary hypertension etc. Some researches showed that prenatal tetrandrine administration can improve the lung development in CDH rat models. We hypothesize that prenatal treatment with tetrandrine can reverse the abnormal condition in the lung of newborn with CDH, and thus decrease the mortality.

The impact of strict infection control on survival rate of prenatally diagnosed isolated congenital diaphragmatic hernia

BACKGROUND/PURPOSE

Although the prognosis of congenital diaphragmatic hernia (CDH) is determined by the degree of pulmonary hypoplasia, there may be an occult contribution of infection to outcomes. The purpose of this study is to evaluate the effects of our new supportive therapy to prevent infectious complications on mortality and morbidity of CDH.

METHODS

Among 57 cases with CDH treated between 2002 and 2007, 43 prenatally diagnosed isolated cases were enrolled in this study. All patients were managed by a lung-protective strategy and delayed surgery. Since January 2006, we have optimized our perioperative care to reduce infectious complications by using peripherally inserted central catheters and restriction of invasive procedures including extracorporeal membranous oxygenation (ECMO). The survival rate, intubation period, maximum serum C-reactive protein (CRP) level, and complications were compared before and after the introduction of refined supportive therapy.

RESULTS

There were 25 cases (12 liver-up, 13 liver-down) treated before 2006 and 18 cases (8 liver-up, 10 liver-down) after 2006. ECMO was required for stabilization in five cases before 2006. The survival rates of total, liver-up, and liver-down cases improved from 60, 42, 77, to 83, 63, 100% after 2006, respectively. The intubation period was shortened from 37.8 +/- 24.3 to 22.2 +/- 10.8 days, and the maximum serum CRP level declined from 12.8 +/- 11.5 to 2.2 +/- 1.6 mg/dl after 2006. Nine cases developed sepsis before 2006 whereas no patients suffered from sepsis or pneumonia after 2006.

CONCLUSION

The new supportive therapy with strict infection control improved survival rate of prenatally diagnosed CDH without using ECMO.

Management of congenital diaphragmatic hernia

PURPOSE OF REVIEW

To evaluate the impact of recent research on the management of congenital diaphragmatic hernia in the light of new theories on embryological development, earlier antenatal diagnosis, fetal and postnatal interventions together with advances in perinatal intensive care.

RECENT FINDINGS

The year 2007 provided in excess of 200 publications that address various aspects of congenital diaphragmatic hernia. The genetic basis and the causes of pulmonary hypoplasia at the molecular level are slowly being unravelled. Fetal MRI of lung volume, lung-head ratio, liver position and size of diaphragmatic defect have all been evaluated as early predictors of outcome and with a view to prenatal counselling. The impact of fetal interventions such as fetal endoluminal tracheal occlusion, the mode of delivery, the surgical techniques and agents for treating pulmonary hypertension were evaluated. The influence of associated anomalies and therapeutic interventions on the outcome and quality of life of survivors continue to be appraised.

SUMMARY

Deferred surgery after stabilization with gentle ventilation and reversal of pulmonary hypertension remain the cornerstones of management. Optimal presurgery and postsurgery ventilatory settings remain unproven. Continued improvement in neonatal intensive care raises the bar against which any intervention such as fetal endoluminal tracheal occlusion and extracorporeal membrane oxygenation will be judged.

Congenital diaphragmatic hernia: advanced physiology and care concepts

Congenital diaphragmatic hernia (CDH) is a defect in the formation of the diaphragm of the fetus. The diaphragm is the muscle and tissue that separate the chest and the abdominal cavities. In CDH, abdominal organs push into the chest cavity through the defect or herniation, compressing the developing lungs. During the past 10 years, significant changes have occurred in the diagnosis and management of CDH. Despite advances in postnatal care, infants born with a CDH continue to suffer substantial morbidity and mortality. Healthcare providers continue to research therapeutic approaches that will improve the care and optimize survival in these infants. The purpose of this article is to offer an in-depth exploration of neonatal physiology and pathophysiology, providing advanced concepts that expand the scientific basis for neonatal care practices.