Fetal tracheal occlusion for congenital diaphragmatic hernia

Congenital diaphragmatic hernia-associated pulmonary hypertension

Congenital diaphragmatic hernia (CDH) is characterized by a developmental insult which compromises cardiopulmonary embryology and results in a diaphragmatic defect, allowing abdominal organs to herniate into the hemithorax. Among the significant pathophysiologic components of this condition is pulmonary hypertension (PH), alongside pulmonary hypoplasia and cardiac dysfunction. Fetal pulmonary vascular development coincides with lung development, with the pulmonary vasculature evolving alongside lung maturation. However, in CDH, this embryologic development is impaired which, in conjunction with external compression, stifle pulmonary vascular maturation, leading to reduced lung density, increased muscularization of the pulmonary vasculature, abnormal vascular responsiveness, and altered molecular signaling, all contributing to pulmonary arterial hypertension. Understanding CDH-associated PH (CDH-PH) is crucial for development of novel approaches and effective management due to its significant impact on morbidity and mortality. Antenatal and postnatal diagnostic methods aid in CDH risk stratification and, specifically, pulmonary hypertension, including fetal imaging and gas exchange assessments. Management strategies include lung protective ventilation, fluid optimization, pharmacotherapies including pulmonary vasodilators and hemodynamic support, and extracorporeal life support (ECLS) for refractory cases. Longitudinal re-evaluation is an important consideration due to the complexity and dynamic nature of CDH cardiopulmonary physiology. Emerging therapies such as fetal endoscopic tracheal occlusion and pharmacological interventions targeting key CDH pathophysiological mechanisms show promise but require further investigation. The complexity of CDH-PH underscores the importance of a multidisciplinary approach for optimal patient care and improved outcomes.

Prenatal diagnostic and intervention considerations in congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a life-threatening birth defect with significant morbidity and mortality. The prenatal management of a pregnancy with a fetus affected with CDH is complex and requires a multi-disciplinary team approach. An improved understanding of prenatal diagnosis and management is essential to developing strategies to optimize outcomes for these patients. In this review, we explore the current knowledge on diagnosis, severity stratification, prognostic prediction, and indications for fetal intervention in the fetus with CDH.

Organization of care of infants with congenital diaphragmatic hernia-Building a high-functioning CDH program

Infants born with congenital diaphragmatic hernia have high mortality and morbidity and require coordinated multidisciplinary care for optimal outcomes. Over the past several decades numerous articles have been published on the technical aspects of the care of these patients demonstrating both the variation in management across institutions as well as the desirability and need for standardization of care. Unfortunately, none have focused on the organization of care for CDH patients encompassing the range from early prenatal diagnosis to long-term postnatal care. However, to achieve optimal care and optimal outcomes, it is important to not only have excellent technical surgical and medical care but also to have an organized, systematic, and purposefully designed program for the delivery of healthcare to infants with this condition. In this article, based on our experience and drawing on general principles of building clinical programs, we describe the important elements of an ideal CDH program.

Hemolysis during Venovenous Extracorporeal Membrane Oxygenation in Neonates with Congenital Diaphragmatic Hernia: A Prospective Observational Study

OBJECTIVE

To investigate the incidence of hemolysis and its association with outcome in neonates with congenital diaphragmatic hernia (CDH) requiring venovenous extracorporeal membrane oxygenation (ECMO) treatment using a Medos Deltastream circuit with a DP3 pump, a hilite 800 LT oxygenator system, and a ¼' tubing.

STUDY DESIGN

Plasma free hemoglobin (PFH) was prospectively measured once daily during ECMO using spectrophotometric testing. Patients (n = 62) were allocated into two groups according to presence or absence of hemolysis. Hemolysis was defined as PFH ≥ 50 mg/dL on at least 2 consecutive days during ECMO treatment. Hemolysis was classified as either moderate with a maximum PFH of 50-100 mg/dL or severe with a maximum PFH >100 mg/dL.

RESULTS

Hemolysis was detected in 14 patients (22.6%). Mortality was 100% in neonates with hemolysis compared with 31.1% in neonates without hemolysis (P < .001). In 21.4% hemolysis was moderate and in 78.6% severe. Using multivariable analysis, hemolysis (hazard ratio: 6.8; 95%CI: 1.86-24.86) and suprasystemic pulmonary hypertension (PH) (hazard ratio: 3.07; 95%CI: 1.01-9.32) were independently associated with mortality. Hemolysis occurred significantly more often using 8 French (Fr) cannulae than 13 Fr cannulae (43% vs 17%; P = .039). Cutoff for relative ECMO flow to predict hemolysis were 115 ml/kg/ minute for patients with 8 Fr cannulae (Area under the curve [AUC] 0.786, P = .042) and 100 ml/kg/ minute for patients with 13 Fr cannulae (AUC 0.840, P < .001).

CONCLUSIONS

Hemolysis in CDH neonates receiving venovenous ECMO is independently associated with mortality.

Intra-amniotic sildenafil treatment improves lung blood flow and pulmonary hypertension in congenital diaphragmatic hernia rats

Pulmonary hypertension associated with congenital diaphragmatic hernia (CDH) is a critical factor in determining prognosis. We propose that intra-amniotic sildenafil administration is an effective prenatal therapy for CDH-induced pulmonary hypertension. To assess the efficacy of this treatment, we administered sildenafil to nitrofen-induced congenital diaphragmatic hernia fetuses and control fetuses via an intra-amniotic injection after a laparotomy on the pregnant dam at either E13.5 or E15.5. Intra-amniotic sildenafil treatment attenuated peripheral vascular muscularization, enhanced pulmonary blood flow, and increased the ratio of pulmonary artery size to aortic size in congenital diaphragmatic hernia fetuses after both E13.5 and E15.5 treatments. E13.5-treated congenital diaphragmatic hernia fetuses showed a higher and more prolonged expression of cyclic guanosine monophosphate (cGMP)-dependent protein kinase and more production of vascular endothelial growth factor, resulting in a significant improvement in lung architecture. The E13.5-treated congenital diaphragmatic hernia fetuses also had an increase in lung weight-to-body weight ratio and an improved fetal survival. Intra-amniotic sildenafil treatment did not show any detectable negative effects in control fetuses. Intra-amniotic sildenafil treatment for rats attenuates CDH-induced pulmonary hypertension and enhanced peripheral pulmonary blood flow. Moreover, early intervention may be preferable to better accelerate lung development and improve prognosis. Direct sildenafil administration via an intra-amniotic injection may be a promising option in congenital diaphragmatic hernia prenatal therapy.

Intra-amniotic sildenafil administration in rabbits: Safety, pharmacokinetics, organ distribution and histologic evaluation

BACKGROUND

The effectiveness of sildenafil in the management of pulmonary hypertension in congenital diaphragmatic hernia (CDH) has been reported but has not been systematically evaluated. Our studies have also demonstrated that intra-amniotic (IA) sildenafil administration improves pulmonary hypertension in CDH.

METHODS

We evaluated the pharmacokinetics of sildenafil after IA administration in pregnant rabbits. Following maternal laparotomy, fetuses received IA injection of 0.8 mg of sildenafil. Maternal blood, amniotic fluid, and fetal tissues were collected at various time points. The concentrations of sildenafil and its major metabolite in samples were analyzed by liquid chromatography-mass spectrometry. To assess organ toxicity, 7 days after IA sildenafil administration, fetal organs were examined histologically.

RESULTS

After IA dosing, sildenafil was absorbed quickly with an absorption half-life of 0.03-0.07 h into the fetal organs. All the organs showed a maximum concentration within 1 h and the disposition half-life ranged from 0.56 to 0.73 h. Most of the sildenafil was eliminated from both mothers and fetuses within 24 h after a single dose. There was no histological evidence of organ toxicity in the fetuses after a single dose of IA administration of sildenafil.

CONCLUSION

IA sildenafil is rapidly absorbed into the fetus, distributes into the mother and is eliminated by the mother without accumulation or fetal organ toxicity. This study confirms the feasibility and the safety of IA administration of sildenafil and enables future applications in the treatment of CDH fetuses.

Neuraxial anesthesia in ex utero intrapartum therapy for parturients with fetal congenital diaphragm hernia: a prospective observational study

BACKGROUND

Congenital diaphragmatic hernia (CDH) is characterized by defects in the fetal diaphragm and thoracic herniation of the abdominal viscera. The ex utero intrapartum treatment (EXIT) procedure is used to establish the fetal airway while on placental support. These EXIT procedures are commonly performed under general anesthesia, which increases maternal bleeding and the risk of insufficient placental perfusion subsequently. This study investigated the feasibility of performing neuraxial anesthesia for the EXIT procedure for fetal congenital diaphragmatic hernia to improve outcomes.

METHODS

Parturients with fetal CDH who underwent an EXIT procedure between January 2019 and May 2021 in our institution were recruited. Variables evaluated included gestational age, surgical time, intra-operative blood loss, peri-operative hemoglobin, maternal complications, fetal lung-to-head ratio, time on placental bypass, and postnatal outcome.

RESULTS

Twenty-two cases were included. All procedures were performed under neuraxial anesthesia. The median gestational age at the time of the EXIT procedure was 37 weeks. The median estimated blood loss was 200 mL. There was no report of an adverse maternal event. The placental bypass time was 142.9 ± 72.6 s, and access to the airway was successfully established within the bypass time. Twenty-one neonates reached an Apgar score of 9 at 5 min. In the first two hours after birth, the average pH of neonatal peripheral arterial blood was 7.35 ± 0.07 (n=19), and lactate level 1.85 ± 0.71 mmol/L (n=19).

CONCLUSIONS

In the EXIT procedure to establish an airway for fetal CDH, neuraxial anesthesia proved a feasible technique for maternal anesthesia.

Imaging Assessment of Prognostic Parameters in Cases of Isolated Congenital Diaphragmatic Hernia: Integrative Review

OBJECTIVE

 Antenatal recognition of severe cases of congenital diaphragmatic hernia (CDH) by ultrasound (US) and magnetic resonance imaging (MRI) may aid decisions regarding the indication of fetal endoscopic tracheal occlusion.

METHODS

 An integrative review was performed. Searches in MEDLINE and EMBASE used terms related to CDH, diagnosis, MRI, and US. The inclusion criteria were reviews and guidelines approaching US and MRI markers of severity of CDH published in English in the past 10 years.

RESULTS

 The search retrieved 712 studies, out of which 17 publications were included. The US parameters were stomach and liver positions, lung-to-head ratio (LHR), observed/expected LHR (o/e LHR), and quantitative lung index. The MRI parameters were total fetal lung volume (TFLV), observed/expected TFLV, relative fetal or percent predicted lung volumes, liver intrathoracic ratio, and modified McGoon index. None of the parameters was reported to be superior to the others.

CONCLUSION

 The most mentioned parameters were o/e LHR, LHR, liver position, o/e TFLV, and TFLV.

Survival and decannulation across indications for infant tracheostomy: a twelve-year single-center cohort study

OBJECTIVE

Describe survival and decannulation following infant tracheostomy based on indication for tracheostomy placement.

STUDY DESIGN

Retrospective cohort study of infants who received tracheostomy at a single pediatric hospital over a twelve-year period. Primary and secondary indications were categorized into pulmonary, anatomic, cardiac, neurologic/musculoskeletal, and others.

RESULTS

A total of 378 infants underwent tracheostomy; 323 had sufficient data to be included in analyses of post-discharge outcomes. Overall mortality was 26.3%; post-operative and post-discharge mortality differed across primary indications (P = 0.03 and P = 0.005). Among survivors, 69.3% decannulated at a median age of 3.0 years (IQR 2.3, 4.5 years). Decannulation among survivors varied across primary indications (P = 0.002), ranging from 17% to 75%. In multivariable analysis, presence of a neurologic or musculoskeletal indication for tracheostomy was a significant negative predictor of future decannulation (aOR 0.10 [95% CI 0.02-0.44], P = 0.003).

CONCLUSIONS

Early childhood outcomes vary across indications for infant tracheostomy.

Developmental Pathways Underlying Lung Development and Congenital Lung Disorders

Lung organogenesis is a highly coordinated process governed by a network of conserved signaling pathways that ultimately control patterning, growth, and differentiation. This rigorously regulated developmental process culminates with the formation of a fully functional organ. Conversely, failure to correctly regulate this intricate series of events results in severe abnormalities that may compromise postnatal survival or affect/disrupt lung function through early life and adulthood. Conditions like congenital pulmonary airway malformation, bronchopulmonary sequestration, bronchogenic cysts, and congenital diaphragmatic hernia display unique forms of lung abnormalities. The etiology of these disorders is not yet completely understood; however, specific developmental pathways have already been reported as deregulated. In this sense, this review focuses on the molecular mechanisms that contribute to normal/abnormal lung growth and development and their impact on postnatal survival.

Delivery Room Intensive Care Unit: 5 Years' Experience in Assistance of High-Risk Newborns at a Referral Center

Objective: The aim of the study is to describe a delivery room intensive care unit (DRICU) model and evaluate its effectiveness in preventing morbidity and mortality in high-risk newborns. Design: This retrospective case series includes all DRICU procedures performed from 2016 to 2020. Setting: Gaslini Children's Hospital is a major pediatric tertiary care center where high-risk pregnancies are centralized. The Neonatal and Pediatric Intensive Care Unit admits every year about 100 high-risk newborns. Patients: The selected patients are newborns at risk of critical conditions immediately after birth for respiratory or cardiovascular congenital disorders. Interventions: The perinatal plan is defined by the multidisciplinary team of Fetal and Perinatal Medicine. The DRICU procedure provides highly specialized care through a protocol that includes logistics, personnel, equipment, and clinical pathways. Main Outcome Measures: The primary outcome is the prevention of acute complications and mortality in the delivery room and early neonatal period. Results: From 2016 to 2020, 40 DRICU procedures were performed. The main prenatal diagnoses included congenital heart disease with a high risk of life-threatening events immediately after birth (38%), congenital diaphragmatic hernia (35%), and fetal hydrops/hydrothorax (23%). Mean gestational age was 35.9 weeks (range: 31-39), and mean birth weight was 2,740 grams (range: 1,480-3,920). DRICU assistance completed in all patients by neonatal intensivists included tracheal intubation and arterial and central venous cannulation; complex procedures such as ex-utero intrapartum technique and extracorporeal membrane oxygenation cannulation are described. No deaths nor severe acute complications occurred in the delivery room or in the immediate postnatal period. Conclusions: The outcome in critical newborns is potentially affected by planned assistance strategies and specialized competencies through the implementation of a DRICU protocol.