Neonatal and fetal therapy of congenital diaphragmatic hernia-related pulmonary hypertension

Hemodynamic management of congenital diaphragmatic hernia: the role of targeted neonatal echocardiography

Congenital diaphragmatic hernia (CDH) is a major congenital anomaly, resulting from the herniation of abdominal contents into the thoracic cavity, thereby impeding the proper development of the lungs and pulmonary vasculature. CDH severity correlates with a spectrum of pulmonary hypoplasia, pulmonary hypertension (PHT), and cardiac dysfunction, constituting the pathophysiological triad of this complex condition. The accurate diagnosis and effective management of PHT and cardiac dysfunction is pivotal to optimizing patient outcomes. Targeted neonatal echocardiography is instrumental in delivering real-time data crucial for the bespoke, pathophysiology-targeted hemodynamic management of CDH-associated PHT.

Long-term follow-up of patients with congenital diaphragmatic hernia

Neonates with congenital diaphragmatic hernia encounter a number of surgical and medical morbidities that persist into adulthood. As mortality improves for this population, these survivors warrant specialized follow-up for their unique disease-specific morbidities. Multidisciplinary congenital diaphragmatic hernia clinics are best positioned to address these complex long-term morbidities, provide long-term research outcomes, and help inform standardization of best practices in this cohort of patients. This review outlines long-term morbidities experienced by congenital diaphragmatic hernia survivors that can be addressed in a comprehensive follow-up clinic.

Arterial hypertension in infants with congenital diaphragmatic hernia following surgical repair

Pulmonary hypertension (PH) and cardiac dysfunction are established comorbidities of congenital diaphragmatic hernia (CDH). However, there is very little data focusing on arterial hypertension in CDH. This study aims to investigate the incidence of arterial hypertension in neonates with CDH at hospital discharge. Archived clinical data of 167 CDH infants who received surgical repair of the diaphragmatic defect and survived for > 60 days were retrospectively analyzed. Blood pressure (BP) values were averaged for the last 7 days before discharge and compared to standard BP values for sex, age, and height provided by the AHA in 2004. BP values reaching or extending the 95th percentile were defined as arterial hypertension. The use of antihypertensive medication was analyzed at discharge and during hospitalization. Arterial hypertension at discharge was observed in 19 of 167 infants (11.3%) of which 12 (63%) were not receiving antihypertensive medication. Eighty patients (47.9%) received antihypertensive medication at any point during hospitalization and 28.9% of 152 survivors (n = 44) received antihypertensive medication at discharge, although in 45.5% (n = 20) of patients receiving antihypertensive medication, the indication for antihypertensive medication was myocardial hypertrophy or frequency control. BP was significantly higher in ECMO compared to non-ECMO patients, despite a similar incidence of arterial hypertension in both groups (13.8% vs. 10.1%, p = 0.473). Non-isolated CDH, formula feeding, and minimal creatinine in the first week of life were significantly associated with arterial hypertension on univariate analysis. Following multivariate analysis, only minimal creatinine remained independently associated with arterial hypertension.   Conclusion: This study demonstrates a moderately high incidence of arterial hypertension in CDH infants at discharge and an independent association of creatinine values with arterial hypertension. Physicians should be aware of this risk and include regular BP measurements and test of renal function in CDH care and follow-up. What is Known: • Due to decreasing mortality, morbidity is increasing in surviving CDH patients. • Pulmonary hypertension and cardiac dysfunction are well-known cardiovascular comorbidities of CDH. What is New: • There is a moderately high incidence of arterial hypertension in CDH infants at discharge even in a population with frequent treatment with antihypertensive medication. • A more complicated hospital course (ECMO, higher degree of PH, larger defect size) was associated with a higher risk for arterial hypertension.

Prenatal treprostinil improves pulmonary arteriolar hypermuscularization in the rabbit model of congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a congenital malformation characterized by pulmonary hypoplasia, pulmonary hypertension, and cardiac dysfunction. Pulmonary hypertension represents the major cause of neonatal mortality and morbidity. Prenatal diagnosis allows assessment of severity and selection of foetal surgery candidates. We have shown that treprostinil, a prostacyclin analogue with an anti-remodelling effect, attenuates the relative hypermuscularization of the pulmonary vasculature in rats with nitrofen-induced CDH. Here we confirm these observations in a large animal model of surgically-created CDH. In the rabbit model, subcutaneous maternal administration of treprostinil at 150 ng/kg/min consistently reached target foetal concentrations without demonstrable detrimental foetal or maternal adverse effects. In pups with CDH, prenatal treprostinil reduced pulmonary arteriolar proportional medial wall thickness and downregulated inflammation and myogenesis pathways. No effect on alveolar morphometry or lung mechanics was observed. These findings provide further support towards clinical translation of prenatal treprostinil for CDH.

Pathological findings in congenital diaphragmatic hernia on necropsy studies: A single-center case series

INTRODUCTION

Congenital diaphragmatic hernia (CDH) is associated with high mortality rates and significant pulmonary morbidities. The objective of this study was to delineate the histopathological features observed in necropsies of CDH patients and correlate these with their clinical manifestations.

METHODS

We retrospectively reviewed the postmortem findings and corresponding clinical characteristics in eight CDH cases from 2017 to July 2022.

RESULTS

The median survival time was 46 (8-624) hours. Autopsy reports showed that diffuse alveolar damage (congestion and hemorrhage) and hyaline membrane formation were the primary pathological lung changes observed. Notably, despite significant reduction in lung volume, the lung development appeared normal in 50% of the cases, while lobulated deformities were present in three (37.5%) cases. All patients displayed a large patent ductus arteriosus (PDA) and a patent foramen ovale, resulting in increased right ventricle (RV) volume, and myocardial fibers appeared slightly congested and swollen. The pulmonary vessels indicated thickening of the arterial media and adventitia. Lung hypoplasia and diffuse lung damage resulted in impaired gas exchange, while PDA and pulmonary hypertension led to RV failure, subsequent organ dysfunction and ultimately death.

CONCLUSIONS

Patients with CDH typically succumb to cardiopulmonary failure, a condition driven by a complex interplay of pathophysiological factors. This complexity accounts for the unpredictable response to currently available vasodilators and ventilation therapies.

Prenatal management of congenital diaphragmatic hernia

Recently, two randomized controlled, prospective trials, the Tracheal Occlusion to Accelerate Lung Growth (TOTAL) trials, reported the outcomes on fetal endoluminal tracheal occlusion (FETO) for isolated left congenital diaphragmatic hernia (CDH). FETO significantly improved outcomes for severe hypoplasia. The effect in moderate cases, where the balloon was inserted later in pregnancy, did not reach significance. In a pooled analysis investigating the effect of the heterogeneity of the treatment effect by the time point of occlusion and severity, the difference may be explained by a difference in the duration of occlusion. Nevertheless, FETO carries a significant risk of preterm birth. The primary objective of this review is to provide an overview of the rationale for fetal intervention in CDH and the results of the randomized trials. The secondary objective is to discuss the technical aspects of FETO. Finally, recent developments of potential alternative fetal approaches will be highlighted.

Sildenafil during the 2nd and 3rd Trimester of Pregnancy: Trials and Tribulations

Sildenafil, a phosphodiesterase 5 inhibitor with a vasodilatory and anti-remodeling effect, has been investigated concerning various conditions during pregnancy. Per indication, we herein review the rationale and the most relevant experimental and clinical studies, including systematic reviews and meta-analyses, when available. Indications for using sildenafil during the second and third trimester of pregnancy include maternal pulmonary hypertension, preeclampsia, preterm labor, fetal growth restriction, oligohydramnios, fetal distress, and congenital diaphragmatic hernia. For most indications, the rationale for administering prenatal sildenafil is based on limited, equivocal data from in vitro studies and rodent disease models. Clinical studies report mild maternal side effects and suggest good fetal tolerance and safety depending on the underlying pathology.

Pulmonary hypertension in congenital diaphragmatic hernia: ANTENATAL PREDICTION AND IMPACT ON NEONATAL MORTALITY

OBJECTIVE

To determine the prevalence of pulmonary hypertension(PAH) in left-sided congenital diaphragmatic hernia(CDH); how we could predict it; and how PAH contributed to the model for mortality prediction.

STUDY DESIGN

Retrospective analysis in three European centers. The primary outcome was the presence of PAH on postnatal day(d)1,7, and at discharge. Studied predictors of PAH were: observed/expected-lung/head-ratio(o/e LHR), liver-herniation, FETO, and gestational age(GA) at delivery. The combined effect of pre-and postnatal variables on mortality was modeled by Cox regression.

RESULTS

Of the 197 neonates, 56(28.4%) died. At d1, 67.5%(133/197) had PAH and 61.9% (101/163) by d7. Overall, 6.4% (9/141) had PAH at discharge.At d1, o/eLHR(OR 0.96) and FETO(OR 2.99) independently correlated to PAH(AUC:0.74). At d7, PAH significantly correlated only with the use of FETO (OR 3.9;AUC:0.65). None were significant for PAH at discharge.Combining the occurrence of PAH with antenatal biomarkers improved mortality prediction(p=0.02), in a model including o/eLHR(HR:0.94), FETO(HR:0.35), liver herniation(HR:16.78), and PAH(HR:15.95).

CONCLUSIONS

Antenatal prediction of PAH was only moderate. The postnatal occurrence of PAH further increases the risk of death. Whereas this may be used to counsel parents in the postnatal period, our study demonstrates there is a need to find more accurate antenatal predictors for PAH. This article is protected by copyright. All rights reserved.

The heart in congenital diaphragmatic hernia: Knowns, unknowns, and future priorities

There is growing recognition that the heart is a key contributor to the pathophysiology of congenital diaphragmatic hernia (CDH), in conjunction with developmental abnormalities of the lung and pulmonary vasculature. Investigations to date have demonstrated altered fetal cardiac morphology, notably relative hypoplasia of the fetal left heart, as well as early postnatal right and left ventricular dysfunction which appears to be independently associated with adverse outcomes. However, many more unknowns remain, not least an understanding of the genetic and cellular basis for cardiac dysplasia and dysfunction in CDH, the relationship between fetal, postnatal and long-term cardiac function, and the impact on other parts of the body especially the developing brain. Consensus on how to measure and classify cardiac function and pulmonary hypertension in CDH is also required, potentially using both non-invasive imaging and biomarkers. This may allow routine assessment of the relative contribution of cardiac dysfunction to individual patient pathophysiological phenotype and enable better, individualized therapeutic strategies incorporating targeted use of fetal therapies, cardiac pharmacotherapies, and extra-corporeal membrane oxygenation (ECMO). Collaborative, multi-model approaches are now required to explore these unknowns and fully appreciate the role of the heart in CDH.