Treatment evolution in high-risk congenital diaphragmatic hernia: ten years' experience with diaphragmatic agenesis

Risk factors for and developmental relation of delayed oral nutrition in infants with congenital diaphragmatic hernia

PURPOSE

To identify risk factors for delayed oral nutrition in infants with a congenital diaphragmatic hernia (CDH) and its impact on developmental delay at 18 months of age.

METHODS

This retrospective single-center cohort study compared the clinical parameters in patients with isolated CDH born and treated at our hospital between 2006 and 2020. We evaluated clinical features significantly related to delayed oral nutrition (defined as taking ≥ 30 days from weaning from mechanical ventilation to weaning from tube feeding).

RESULTS

Twenty-six of the 80 cases had delayed oral nutrition. Univariate analyses showed significant differences. Multivariate analyses were performed on the three items of preterm delivery, defect size (over 50% to nearly entire defect), and ventilation for ≥ 9 days. We identified the latter two items as independent risk factors. The adjusted odds ratios were 4.65 (95% confidence interval, 1.27-7.03) and 6.02 (1.65-21.90), respectively. Delayed oral nutrition was related to a significantly higher probability of developmental delay at 18 months (crude odds ratio 4.16, 1.19-14.5).

CONCLUSION

In patients with CDH, a large defect and ventilatory management over 9 days are independent risk factors for delayed oral nutrition, which is a potent predictor of developmental delay that requires active developmental care.

Outcomes of neonatal congenital diaphragmatic hernia in a non-ECMO center in a middle-income country: a retrospective cohort study

BACKGROUND

Most studies examining survival of neonates with congenital diaphragmatic hernia (CDH) are in high-income countries. We aimed to describe the management, survival to hospital discharge rate, and factors associated with survival of neonates with unilateral CDH in a middle-income country.

METHODS

We retrospectively reviewed the medical notes of neonates with unilateral CDH admitted to a pediatric intensive care unit (PICU) in a tertiary referral center over a 15-year period, from 2003-2017. We described the newborns' respiratory care pathways and then compared baseline demographic, hemodynamic, and respiratory indicators between survivors and non-survivors. The primary outcome measure was survival to hospital discharge.

RESULTS

Altogether, 120 neonates were included with 43.3% (52/120) diagnosed antenatally. Stabilization occurred in 38.3% (46/120) with conventional ventilation, 13.3% (16/120) with high-frequency intermittent positive-pressure ventilation, and 22.5% (27/120) with high frequency oscillatory ventilation. Surgical repair was possible in 75.0% (90/120). The overall 30-day survival was 70.8% (85/120) and survival to hospital discharge was 66.7% (80/120). Survival to hospital discharge tended to improve over time (p > 0.05), from 56.0% to 69.5% before and after, respectively, a service reorganization. For those neonates who could be stabilized and operated on, 90.9% (80/88) survived to hospital discharge. The commonest post-operative complication was infection, occurring in 43.3%. The median survivor length of stay was 32.5 (interquartile range 18.8-58.0) days. Multiple logistic regression modelling showed vaginal delivery (odds ratio [OR] = 4.8; 95% confidence interval [CI] [1.1-21.67]; p = 0.041), Apgar score [Formula: see text] 7 at 5 min (OR = 6.7; 95% CI [1.2-36.3]; p = 0.028), and fraction of inspired oxygen (FiO₂) < 50% at 24 h (OR = 89.6; 95% CI [10.6-758.6]; p < 0.001) were significantly associated with improved survival to hospital discharge.

CONCLUSIONS

We report a survival to hospital discharge rate of 66.7%. Survival tended to improve over time, reflecting a greater critical volume of cases and multi-disciplinary care with early involvement of the respiratory team resulting in improved transitioning from PICU. Vaginal delivery, Apgar score [Formula: see text] 7 at 5 min, and FiO₂ < 50% at 24 h increased the likelihood of survival to hospital discharge.

Intra-Amniotic Sildenafil Treatment Promotes Lung Growth and Attenuates Vascular Remodeling in an Experimental Model of Congenital Diaphragmatic Hernia

BACKGROUND

Defective lung development resulting in lung hypoplasia and an attenuated and hypermuscularized pulmonary vasculature contributes to significant postnatal mortality in congenital diaphragmatic hernia (CDH). We hypothesize that deficient embryonic pulmonary blood flow contributes to defective lung development in CDH, which may therefore be ameliorated via enhancement of embryonic pulmonary blood flow.

METHODS

The mouse nitrofen model of CDH was utilized to measure embryonic pulmonary blood flow by in utero intracardiac injection of FITC-labeled tomato lectin and color-flow Doppler ultrasound. The effect of prenatal intra-amniotic treatment with sildenafil on survival, lung growth, and vascular morphology in the nitrofen model was determined.

RESULTS

Nitrofen-treated embryos exhibited decreased blood flow in the lung periphery compared to controls, and intra-amniotic sildenafil significantly improved embryonic pulmonary blood flow. Similar to nitrofen alone, pups delivered after nitrofen treatment and intra-amniotic injection of dextrose control exhibited respiratory distress and never survived beyond 6 h. Intra-amniotic sildenafil ameliorated respiratory distress in nitrofen-treated pups and improved postnatal survival to 82%. Following intra-amniotic sildenafil treatment at embryonic day (E)10.5, nitrofen-treated P0 lungs were larger with increased left lobe weight, reduced small pulmonary arterial wall muscularization, and increased airway branching complexity compared to controls. Intra-amniotic sildenafil treatment later at E15.5 also resulted in improved survival, lung growth, and attenuation of vascular remodeling in nitrofen-treated embryos.

CONCLUSIONS

Defective embryonic pulmonary blood flow may contribute to lung maldevelopment in CDH. Enhancement of embryonic pulmonary blood flow via intra-amniotic sildenafil results in lung growth and attenuation of pulmonary vascular remodeling and may have therapeutic potential for CDH.

Intra-amniotic Sildenafil Treatment Modulates Vascular Smooth Muscle Cell Phenotype in the Nitrofen Model of Congenital Diaphragmatic Hernia

The etiology of pulmonary vascular abnormalities in CDH is incompletely understood. Studies have demonstrated improvement in pulmonary vasculature with prenatal therapy in animal models. We hypothesize that prenatal sildenafil may attenuate defective pulmonary vascular development via modulation of vSMC phenotype from undifferentiated, proliferative phenotype to differentiated, contractile phenotype. We utilized the nitrofen model of CDH to examine the effect of IA sildenafil on pulmonary vSMC phenotype during lung development. Timed-pregnant CD-1 mice were gavage fed 25 mg nitrofen or olive oil (control) at E8.5 of gestation. Single IA injections of Sildenafil (Revatio; 10 µL of 4 mg/4 ml solution) or dextrose control were performed at E12.5. Mice were sacrificed on various gestational days for embryonic lung harvest. Markers of vSMC development of undifferentiated and differentiated phenotypes were analyzed by immunostaining and western blot. Across all time points in gestation, nitrofen-treated embryonic lungs demonstrated increased vSMC expression of NOTCH3, Hes-5, PDGFR-β, desmin and α-SMA and decreased expression of calponin and SMMHC, compared to oil controls. IA dextrose treatment had no effect on expression levels. However, IA Sildenafil treatment resulted in down-regulation of NOTCH3, Hes-5, PDGFR-β, desmin and α-SMA and upregulation of calponin and SMMHC, comparable to oil controls. In the nitrofen model, vSMC express markers consistent with more undifferentiated proliferative phenotype, resulting in hypermuscularization of intrapulmonary arterioles in CDH. A single dose of IA Sildenafil treatment early in gestation, results in sustained normalization of vSMC phenotype. Pharmacologic modulation of the vSMC phenotype at key gestational points may have therapeutic potential.

Treatment Strategies for Congenital Diaphragmatic Hernia: Change Sometimes Comes Bearing Gifts

OBJECTIVE

To report treatment strategies' evolution and its impact on congenital diaphragmatic hernia (CDH) outcome.

DESIGN

Registry-based cohort study using the CDH Study Group database, 1995-2013.

SETTING

International multicenter database.

PATIENTS

CDH patients entered into the registry. Late presenters or patients with very incomplete data were excluded. Patients were divided into three Eras (1995-2000; 2001-2006; 2007-2013).

MAIN OUTCOME MEASURES

Treatment strategies and outcomes. One-way ANOVA, X2 test, and X2 test for trend were used. A Sydak-adjusted p < 0.0027 was considered significant. Prevalence or mean (SE) are reported.

RESULTS

Patients: 8,603; included: 7,716; Era I: 2,146; Era II: 2,572; Era III: 2,998. From Era I to Era III, significant changes happened. Some severity indicators such as gestational age, prevalence of prenatal diagnosis, and inborn patients significantly worsened. Also, treatment strategies such as the use of prenatal steroids and inhaled nitric oxide, age at operation, prevalence of minimal access surgery, and the use of surfactant significantly changed. Finally, length of hospital stay became significantly longer and survival to discharge slightly but significantly improved, from 67.7 to 71.4% (p for trend 0.0019).

CONCLUSION

Treatment strategies for patients registered since 1995 in the CDH Study Group significantly changed. Survival to discharge slightly but significantly improved.

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.

Length of stay and cost analysis of neonates undergoing surgery at a tertiary neonatal unit in England

Introduction There is a lack of knowledge on the average length of stay (LOS) in neonatal units after surgical repair of common congenital anomalies. There are few if any publications reporting the activity performed by units undertaking neonatal surgery. Such activity is important for contracting arrangements, commissioning specialist services and counselling parents. The aim of this study was to describe postnatal LOS for infants admitted to a single tertiary referral neonatal unit with congenital malformations requiring surgery. Methods Data on nine conditions were collected prospectively for babies on the neonatal unit over a five-year period (2006-2011). For those transferred back to their local unit following surgery, the local unit was contacted to determine the total LOS. Only those babies who had surgery during their first admission to our unit and who survived to discharge were included in the study. Cost estimates were based on the tariffs agreed for neonatal care between our trust and the London specialised commissioning group in 2011-2012. Results The median LOS for the conditions studied was: gastroschisis 35 days (range: 19-154 days), oesophageal atresia 33 days (range: 9-133 days), congenital diaphragmatic hernia 28 days (range: 7-99 days), intestinal atresia 24 days (range: 6-168 days), Hirschsprung's disease 21 days (range: 15-36 days), sacrococcygeal teratoma 17 days (range: 12-55 days), myelomeningocoele 15.5 days (range: 8-24 days), anorectal malformation 15 days (range: 6-90 days) and exomphalos 12 days (range: 3-228 days). The total neonatal bed day costs for the median LOS ranged from £8,701 (myelomeningocoele) to £23,874 (gastroschisis). The cost of surgery was not included. Conclusions There is wide variation in LOS for the same conditions in a single neonatal unit. This can be explained by different types and severity within the same congenital anomalies, different surgeons and other clinical confounders (eg sepsis, surgical complications, associated anomalies). These data will enable us to give more detailed information to families following prenatal or postnatal diagnosis. They also allow more detailed planning of resource allocation for neonatal admissions.

Self-assessed physical health among children with congenital diaphragmatic hernia

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Initial oxygenation response to inhaled nitric oxide predicts improved outcome in congenital diaphragmatic hernia

BACKGROUND

Pulmonary hypertension (PH) is the most important complication of congenital diaphragmatic hernia (CDH) and still has a high mortality rate. The aim of this study was to evaluate the effectiveness of inhaled nitric oxide therapy in PH due to CDH.

METHODS

Hospital records of children who had undergone inhaled nitric oxide therapy for PH due to CDH between June 2009 and December 2011 were reviewed.

RESULTS

Twenty-nine patients had a diagnosis of CDH at the time of study, and eight of these patients underwent nitric oxide therapy because of failure of conventional ventilation techniques, which was successful in five of these patients. Patients who had a good overall outcome of nitric oxide therapy experienced rapid improvement (pretreatment, mean PaO2 = 44.8 mmHg; after the first hour of therapy, mean PaO2 = 96.8 mmHg), whereas patients with no response did not have a similar course (pretreatment, PaO2 = 37 mmHg; after the first hour, PaO2 = 54.6 mmHg).

CONCLUSION

Inhaled nitric oxide therapy seems to increase survival in PH due to CDH. No predictive parameters to orient patient selection could be identified; however, the early response seemed to predict the overall outcome. Good results in our series were attributed to routine use of sildenafil and dopamine, along with the nitric oxide inhalation.

Pulmonary support on day 30 as a predictor of morbidity and mortality in congenital diaphragmatic hernia

PURPOSE

Congenital diaphragmatic hernia (CDH) is associated with significant in-hospital mortality, morbidity and length-of-stay (LOS). We hypothesized that the degree of pulmonary support on hospital day-30 may predict in-hospital mortality, LOS, and discharge oxygen needs and could be useful for risk prediction and counseling.

METHODS

862 patients in the CDH Study Group registry with a LOS ≥ 30 days were analyzed (2007-2010). Pulmonary support was defined as (1) room-air (n=320) (2) noninvasive supplementation (n=244) (3) mechanical ventilation (n=279) and (4) extracorporeal membrane oxygenation (ECMO, n=19). Cox Proportional hazards and logistic regression models were used to determine the case-mix adjusted association of oxygen requirements on day-30 with mortality and oxygen requirements at discharge.

RESULTS

On multivariate analysis, use of ventilator (HR 5.1, p=.003) or ECMO (HR 19.6, p<.001) was a significant predictor of in-patient mortality. Need for non-invasive supplementation or ventilator on day-30 was associated with a respective 22-fold (p<.001) and 43-fold (p<.001) increased odds of oxygen use at discharge compared to those on room-air.

CONCLUSIONS

Pulmonary support on Day-30 is a strong predictor of length of stay, oxygen requirements at discharge and in-patient mortality and may be used as a simple prognostic indicator for family counseling, discharge planning, and identification of high-risk infants.

Defective pulmonary innervation and autonomic imbalance in congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is associated with significant mortality due to lung hypoplasia and pulmonary hypertension. The role of embryonic pulmonary innervation in normal lung development and lung maldevelopment in CDH has not been defined. We hypothesize that developmental defects of intrapulmonary innervation, in particular autonomic innervation, occur in CDH. This abnormal embryonic pulmonary innervation may contribute to lung developmental defects and postnatal physiological derangement in CDH. To define patterns of pulmonary innervation in CDH, human CDH and control lung autopsy specimens were stained with the pan-neural marker S-100. To further characterize patterns of overall and autonomic pulmonary innervation during lung development in CDH, the murine nitrofen model of CDH was utilized. Immunostaining for protein gene product 9.5 (a pan-neuronal marker), tyrosine hydroxylase (a sympathetic marker), vesicular acetylcholine transporter (a parasympathetic marker), or VIP (a parasympathetic marker) was performed on lung whole mounts and analyzed via confocal microscopy and three-dimensional reconstruction. Peribronchial and perivascular neuronal staining pattern is less complex in human CDH than control lung. In mice, protein gene product 9.5 staining reveals less complex neuronal branching and decreased neural tissue in nitrofen-treated lungs from embryonic day 12.5 to 16.5 compared with controls. Furthermore, nitrofen-treated embryonic lungs exhibited altered autonomic innervation, with a relative increase in sympathetic nerve staining and a decrease in parasympathetic nerve staining compared with controls. These results suggest a primary defect in pulmonary neural developmental in CDH, resulting in less complex neural innervation and autonomic imbalance. Defective embryonic pulmonary innervation may contribute to lung developmental defects and postnatal physiological derangement in CDH.

Pulmonary artery size has prognostic value in low birth weight infants with congenital diaphragmatic hernia

AIM

The aim of this study was to examine the relationship between birth weight, pulmonary artery (PA) size, and outcome in congenital diaphragmatic hernia (CDH) to establish if PA size has prognostic value.

METHODS

The subjects for this study were 39 consecutive left-sided CDH patients treated at our institution according to the same protocol from 2002 to 2009. Other CDH patients with concurrent anomalies that eventually caused death or who became symptomatic more than 6 h after birth were excluded. Birth weight was used to create two groups; low birth weight (LBW; birth weight ≤ 2,500 g; n = 15) and normal birth weight (NBW; birth weight >2,500 g; n = 24). Right PA (RPA) and left PA (LPA) were measured by echocardiography (EC) during late pregnancy (fetal; gestational age (GA): 32-34 weeks), and on days 0, and 2 of life and compared.

RESULTS

Mean birth weights were significantly different between the two groups; however, gender, mean GA, and outcome were similar. In LBW survivors, RPA was significantly larger than in non-survivors. PA size was not related to outcome in NBW.

CONCLUSION

We are the first to show that RPA size has prognostic value in low birth weight infants with left-sided CDH.

Single payer health insurance in pediatric surgery: US impressions and Canadian experience

CONTEXT

Some advocate single payer national health insurance, present in Canada, as a solution to problems in US health care.

METHOD

Pediatric surgeons in the US and Canada were surveyed regarding their attitudes (US) and experience (Canada) under a single payer by electronic mail regarding features of a single payer using a Likert scale (1-strongly disagree to 5-strongly agree) on quality, administration, organization, and economics.

RESULTS

Overall response rate of 22% (175/835), 153 US, 22 Canadian. US and Canadian respondents predicted a higher quality of care for both emergency (66 and 36%, respectively) and elective conditions (47 and 9%) under a single payer. Both groups recognized delays for elective surgery. Better access to surgical care under a single payer, seen by most Canadians (81%), was not predicted among Americans (44%, p = 0.00012). Americans (68%) did not believe a single payer would address workforce shortages, while Canadians (68%) disagreed (p = 0.00001). Both groups agree (p = 0.7) that personal income is decreased.

CONCLUSIONS

US surgeons anticipate benefits and problems that Canadian surgeons with direct experience with a single payer do not experience. This discrepancy must be recognized during the ongoing debate over the future of US health care.

Effect of insulin-like growth factors on lung development in a nitrofen-induced CDH rat model

PURPOSE

Both the mortality and morbidity associated with congenital diaphragmatic hernia (CDH) are mainly caused by pulmonary hypoplasia and persistent pulmonary hypertension. A previous study revealed that insulin-like growth factors (IGFs) play important roles in fetal lung development. The aim of this study was to investigate the effect of IGF-1 and IGF-2 on tissue cultures of fetal hypoplastic lungs obtained from nitrofen-induced CDH model rats.

METHODS

Pregnant rats were exposed to nitrofen on day 9 of gestation (D9). Fetuses were harvested on D18 by caesarian section. Lung specimens of the CDH (+) fetus were divided into three groups; control, IGF-1, and IGF-2. The specimens from the control group were cultured in culture medium without IGFs. The IGF-1 group specimens were cultured with IGF-1 (500 ng/ml), and those in the IGF-2 group were cultured with IGF-2 (500 ng/ml). The mRNA expression of TTF-1, T1α and α-SMA were analyzed in each group using real-time RT-PCR after 24 and 48 h of incubation. Immunohistochemical staining of these markers was also assessed for each of the cultured specimens.

RESULTS

There was a significant increase in the expression of both TTF-1 and T1α mRNA in the IGF-2 group, in comparison to the control group after 48 h of culture. Immunohistochemical staining revealed that the cell morphology was changed from cuboidal to squamous type in the IGF-2 group.

CONCLUSIONS

An increased mRNA expression of the markers related to type 1 and 2 alveolar epithelial cells, and morphological changes in the epithelial cells were observed in the IGF-2 group. The administration of IGF-2 to nitrofen-induced hypoplastic lungs might lead to alveolar maturation, which thus results in their improved development.

Congenital diaphragmatic hernia: outcome review of 2,173 surgical repairs in US infants

Congenital diaphragmatic hernia (CDH) remains one of the most challenging conditions to treat within the pediatric surgical and medical communities. In spite of modern treatment modalities, including extracorporeal membrane oxygenation (ECMO) and improved ventilatory support, mortality remains high. The present study analyzes a US database containing information from nearly 93 million discharges in the US. Infants with congenital diaphragmatic hernia who underwent surgical repair were identified by ICD-9 procedure code and inclusion criteria including an age at admission of less than 1 year. Variables of gender, race, age, geographic region, co-existing diagnoses and procedures, hospital type, hospital charges adjusted to 2006 dollars, length of stay, and inpatient mortality were collected. A total of 89% of patients were either treated initially or rapidly transferred to urban teaching hospitals for definitive treatment of CDH. The inpatient mortality rate was 10.4% with a median length of stay of 20 days (interquartile range of 9-40 days). The median inflation-adjusted total hospital charge was $116,210. Respiratory distress was the most common co-existing condition (68.8%) followed by esophageal reflux (27.8%). The most common concomitant procedures performed were ECMO (17.8%) and fundoplication (17.6%). This study, which represents the largest characterization of US infants who have undergone CDH repair using data from a nationally representative non-voluntary database, demonstrates that surgical repair is associated with significant mortality and morbidity.

Management of pulmonary hypertension in congenital diaphragmatic hernia: nitric oxide with prostaglandin-E1 versus nitric oxide alone

AIM

Prostaglandin-E1 (PGE1) is used at most centers for treating pulmonary hypertension (PH) in congenital diaphragmatic hernia (CDH) because it has been regarded as effective. The aim of this study was to investigate the role of PGE1 for treating PH in CDH.

METHODS

We reviewed 49 CDH cases with echocardiography-proven PH. PH was treated with PGE1 and nitric oxide (NO) and high frequency oscillatory ventilation (HFOV) from 1997 to 2001 (PG + NO; n = 19) and with NO and HFOV from 2002 to 2007 (NO; n = 30).

RESULTS

Subject demographics, severity of PH, and presence of other anomalies were not significantly different between the two groups. In the PG + NO group, 12/19 (63.2%) survived (PG + NO-s) and 7/19 (36.8%) died (PG + NO-d). In the NO group, 21/30 (70.0%) survived (NO-s) and 9/30 (30.0%) died (NO-d). Survival rates were not significantly different. In the NO-s group, spontaneous closure of the ductus arteriosus (DA) was significantly earlier compared with the PG + NO-s group (P < 0.01; 4.0 +/- 0.9 vs. 9.5 +/- 2.2 days after birth). DA diameters were significantly larger in groups that died compared with groups that survived (P < 0.01), and PH persisted in groups that died. In the NO-s group, surgery was possible significantly earlier compared with the PG + NO-s group (P < 0.01; 3.75 +/- 0.67 vs. 6.12 +/- 0.78 days after birth). No NO-s case developed a PH crisis even though PGE1 was not used. Hospital stay was significantly shorter in the NO-s group compared with the PG + NO-s group (P < 0.05; 39.9 +/- 19 vs. 53.2 +/- 23 days).

CONCLUSION

Nitric oxide alone would appear to simplify the management of CDH with PH and provide better outcome.

Teratogen-induced, dietary and genetic models of congenital diaphragmatic hernia share a common mechanism of pathogenesis

Congenital diaphragmatic hernia (CDH) is a frequently occurring, major congenital abnormality that has high mortality and significant morbidity in survivors. Currently, the pathogenesis of CDH is poorly understood. In this study, we have compared the anatomical characteristics of diaphragm defects in the well-described nitrofen model with the pathogenesis of CDH in vitamin A-deficient rats and wt1 null-mutant mice, representing teratogen-induced, dietary and genetic models of CDH, respectively. Our histological investigations, aided by three-dimensional reconstruction of the developing diaphragm, revealed a common pathogenic mechanism with regards to the location of the diaphragm defect in the foramen of Bochdalek (posterolateral diaphragm) and specific abnormalities within the primordial diaphragm. Furthermore, our analysis of postmortem specimens highlighted similarities in human cases of CDH and these animal models, supporting our hypothesis that CDH in humans arises from a defect in the primordial diaphragm. Immunohistochemical data were consistent with the defect in the primordial diaphragm being in the nonmuscular component. Importantly, these data show that very distinct models of CDH all share a common pathogenic mechanism and, together with supporting evidence from pathological specimens, highlight our proposed pathogenic model for CDH.