Correction of congenital diaphragmatic hernia in utero VIII: Response of the hypoplastic lung to tracheal occlusion

Predicting the Difficult Neonatal Airway in Fetuses With Micrognathia, Oropharyngeal or Neck Mass Lesions: Two-Center Experience With Fetal MRI

OBJECTIVE

Neonatal airway compromise requiring intubation, due to micrognathia or a mass lesion obstructing the fetal airway, remains difficult but important to predict prenatally. We aimed to validate MR predictors of difficult neonatal airway (DNA) in a multicentre retrospective cohort of fetuses with micrognathia and oropharyngeal/neck masses.

METHOD

The radiology databases of two large Australian maternal-fetal medicine centers were searched for subjects meeting inclusion criteria: Pregnancies of > 18 weeks' gestation evaluated with prenatal ultrasound and MRI between 2007 and 2022 where either fetal micrognathia or a fetal cervical, oral or oropharyngeal mass was identified on prenatal ultrasound and MRI, and details of delivery/postnatal course were available including: nature of delivery, need for the fetal airway to be secured at delivery, degree of difficulty in airway securement, survival > 24 h postnatally. Imaging predictors of a difficult neonatal airway (DNA) were assessed blinded to these neonatal outcomes.

RESULTS

Twenty-six fetuses met the inclusion criteria. Oropharyngeal and neck mass location with polyhydramnios was 100% sensitive and 82% specific for DNA. JI < 5th centile with polyhydramnios was 83% sensitive and 70% specific. JI < 5th centile with polyhydramnios was associated with DNA in 80% of cases delivered by ex utero intrapartum (EXIT) delivery and none with non-EXIT delivery mode.

CONCLUSION

A cervical or oropharyngeal mass with polyhydramnios predicted a difficult neonatal airway. Polyhydramnios with jaw index < 5th centile was less sensitive and less specific for a difficult neonatal airway.

Ex utero intrapartum treatment (EXIT) procedure for the second twin with neck mass in a twin pregnancy with vertex/breech presentation

We report a case of a dichorionic diamniotic twin pregnancy where twin B was diagnosed with a large multi-loculated exophytic cystic neck mass arising from the right side with involvement of the right proximal upper limb and significant mass effect on the trachea diagnosed during antenatal MRI. After multidisciplinary discussion, an ex utero intrapartum treatment (EXIT) procedure was planned given concerns about airway obstruction in twin B. Successful EXIT was performed with the delivery of twin A first, followed by an intraoperative external cephalic version of twin B and subsequent delivery of the fetal head and intubation on maternal circulation.

Feasibility, safety, and outcome of fetoscopic endoluminal tracheal occlusion for severe congenital diaphragmatic hernia at a low case-load center: one center's experience

BACKGROUND

Antenatal fetoscopic endoluminal tracheal occlusion (FETO) has been introduced as an effective intervention to improve the outcome of severe congenital diaphragmatic hernia (CDH).

OBJECTIVE

We report our early experience with FETO.

DESIGN

A retrospective chart review of case series.

SETTING

Tertiary health care center.

PATIENTS AND METHODS

18-45 years old, with single fetuses diagnosed with left severe CDH (lung-head ratio <1 measured between 27-29 weeks of gestational age (GA) and liver up or observed/expected lung-to-head ratio <25%, normal echocardiogram and karyotype were included. FETO was performed between 28-30 weeks of gestation and removed after 4-6 weeks or at birth during an ex utero intrapartum treatment (EXIT) procedure.

MAIN OUTCOME MEASURES

FETO represents a viable option for severe type of CDH fetuses with reasonable outcomes. FETO performance in low volume centers may be feasible with reasonable outcomes. Good outcome of postnatal care with no potential antenatal complications may affect FETO adoption in some societies.

SAMPLE SIZE

5.

RESULTS

14 pregnant women were referred for assessment and only 7 met the inclusion criteria. Two were excluded initially (late referral and spouse refusal) and a 3rd excluded later due to failure of FETO due to faulty balloons. The median age of the mothers was 28 years and the gestational age was 29 weeks. Median observed/expected lung-to-head ratio was 23%. Among patients who had successful FETO, one had the balloon removed fetoscopically 4 weeks after insertion and one was removed 8 weeks after insertion during an elective EXIT procedure and both have survived. The other two had premature labor after 1 and 5 weeks after FETO and balloon removed during an emergency EXIT procedures, and both died within 24 hours of birth.

CONCLUSION

FETO represents a viable option for severe type of CDH fetuses with reasonable outcome. FETO performance in a low volume centers may be feasible with reasonable outcomes. Good outcome of postnatal care with no potential antenatal complications may affect FETO adoption in some societies.

LIMITATIONS

Retrospective nature of the study may imply inaccuracy, but we believe data from electronic medical records is highly accurate.

Diagnosis and management of congenital diaphragmatic hernia: a 2023 update from the Canadian Congenital Diaphragmatic Hernia Collaborative

OBJECTIVE

The Canadian Congenital Diaphragmatic Hernia (CDH) Collaborative sought to make its existing clinical practice guideline, published in 2018, into a 'living document'.

DESIGN AND MAIN OUTCOME MEASURES

Critical appraisal of CDH literature adhering to Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. Evidence accumulated between 1 January 2017 and 30 August 2022 was analysed to inform changes to existing or the development of new CDH care recommendations. Strength of consensus was also determined using a modified Delphi process among national experts in the field.

RESULTS

Of the 3868 articles retrieved in our search that covered the 15 areas of CDH care, 459 underwent full-text review. Ultimately, 103 articles were used to inform 20 changes to existing recommendations, which included aspects related to prenatal diagnosis, echocardiographic evaluation, pulmonary hypertension management, surgical readiness criteria, the type of surgical repair and long-term health surveillance. Fifteen new CDH care recommendations were also created using this evidence, with most related to the management of pain and the provision of analgesia and neuromuscular blockade for patients with CDH.

CONCLUSIONS

The 2023 Canadian CDH Collaborative's clinical practice guideline update provides a management framework for infants and children with CDH based on the best available evidence and expert consensus.

Surfactant Therapy in Congenital Diaphragmatic Hernia and Fetoscopic Endoluminal Tracheal Occlusion

INTRODUCTION

Congenital diaphragmatic hernia (CDH) is a complex pathology with severe pulmonary morbidity. Administration of surfactant in CDH is controversial, and the advent of fetoscopic endoluminal tracheal occlusion (FETO) has added further complexity. While FETO has been shown to improve survival outcomes, there are risks of prematurity and potential surfactant deficiency. We aim to evaluate the characteristics and outcomes of surfactant administration for CDH infants and elucidate potential benefits or risks in this unique population.

METHODS

A single-center retrospective cohort review of patients with unilateral CDH from September 2015 to July 2022 was performed. Demographics, prognostic perinatal imaging features, and outcomes were collected. Patients were stratified by surfactant administration and history of FETO. Data were analyzed with descriptive statistics, two-sample t-tests, chi-squared analyses, and logistic regression.

RESULTS

Of 105 included patients, 19 (18%) underwent FETO and 25 (24%) received surfactant. Overall, surfactant recipients were born at earlier gestational ages and lower birthweights regardless of FETO history. Surfactant recipients possessed significantly worse prenatal prognostic features such as observed to expected total fetal lung volume, observed to expected lung to head ratio, and percent liver herniation. In CDH patients without FETO history, surfactant recipients demonstrated worse outcomes than nonrecipients. This association is notably absent in the FETO population, where surfactant recipients have more favorable survival and comparable outcomes. When controlling for defect severity or surfactant usage, as a proxy for respiratory status, surfactant recipients that underwent FETO trended toward improved survival and decreased ECMO use.

CONCLUSIONS

Surfactant administration is not associated with increased morbidity and mortality and may be beneficial in CDH patients that have undergone FETO.

Unique Cardiopulmonary Interactions in Congenital Diaphragmatic Hernia: Physiology and Therapeutic Implications

Congenital diaphragmatic hernia (CDH) results in abdominal contents entering the thoracic cavity, affecting both cardiac and pulmonary development. Maldevelopment of the pulmonary vasculature occurs within both the ipsilateral lung and the contralateral lung. The resultant bilateral pulmonary hypoplasia and associated pulmonary hypertension are important components of the pathophysiology of this disease that affect outcomes. Despite prenatal referral to specialized high-volume centers, advanced ventilation strategies, pulmonary hypertension management, and the option of extracorporeal membrane oxygenation, overall CDH mortality remains between 25% and 30%. With increasing recognition that cardiac dysfunction plays a large role in morbidity and mortality in patients with CDH, it becomes imperative to understand the different clinical phenotypes, thus allowing for individual patient-directed therapies. Further research into therapeutic interventions that address the cardiopulmonary interactions in patients with CDH may lead to improved morbidity and mortality outcomes.

Perinatal management of the anticipated difficult airway

The ex-utero intrapartum treatment (EXIT) procedure was originally developed to reverse tracheal occlusion in fetuses with severe congenital diaphragmatic hernia that underwent fetal tracheal occlusion. The EXIT procedure has since been applied to a wide range of indications, but the primary indication remains securing a patent airway and providing respiratory support in fetuses with anticipated difficult airways. The authors review perinatal management of the anticipated difficult airway and their single-institution's experience with the EXIT procedure.

Maternal-fetal surgery as part of pediatric palliative care

Maternal-fetal surgical interventions have become a more common part of prenatal care. This third option, beside termination or post-natal interventions, complicates prenatal decision-making: while interventions may be lifesaving, survivors may face a life with disability. Pediatric palliative care (PPC) is more than end of life or hospice care, it aims at helping patients with complex medical conditions live well. In this paper, we briefly discuss maternal-fetal surgery, challenges regarding counseling and benefit-risk evaluation, argue that PPC should be a routine part of prenatal consultation, discuss the pivotal role of the maternal-fetal surgeon in the PCC-team, and finally discuss some of the ethical considerations of maternal-fetal surgery. We illustrate this with a case example of an infant diagnosed with congenital diaphragmatic hernia (CDH).

In Utero Therapy for Congenital Diaphragmatic Hernia

Congenital diaphragmatic hernia is an anomaly that is often prenatally diagnosed and spans a wide spectrum of disease, with high morbidity and mortality associated with fetuses with severe defects. Congenital diaphragmatic hernia is thus an ideal target for fetal intervention. We review the literature on prenatal diagnosis, describe the history of fetal intervention for congenital diaphragmatic hernia, and discuss fetal endoscopic tracheal occlusion and the Tracheal Occlusion To Accelerate Lung growth trial results. Finally, we present preclinical studies for potential future directions.

Impact of fetal treatments for congenital diaphragmatic hernia on lung development

The extent of lung hypoplasia impacts the survival and severity of morbidities associated with congenital diaphragmatic hernia (CDH). The alveoli of CDH infants and in experimental models of CDH have thickened septa with fewer type II pneumocytes and capillaries. Fetal treatments of CDH-risk preterm birth. Therefore, treatments must aim to balance the need for increased gas exchange surface area with the restoration of pulmonary epithelial type II cells and the long-term respiratory and neurodevelopmental consequences of prematurity. Achievement of sufficient lung development in utero for successful postnatal transition requires adequate intra-thoracic space for lung growth, maintenance of sufficient volume and appropriate composition of fetal lung fluid, regular fetal breathing movements, appropriate gas exchange area, and ample surfactant production. The review aims to examine the rationale for current and future therapeutic strategies to improve postnatal outcomes of infants with CDH.

Ex utero intrapartum therapy in infants with congenital diaphragmatic hernia: a propensity score matching analysis

Objective

Previous studies have shown that ex utero intrapartum therapy (EXIT) is safe and feasible for newborns with congenital diaphragmatic hernia (CDH). This study reports our experience with EXIT in fetuses with CDH in an attempt to explore the efficacy of EXIT on the survival rate of this population.

Methods

A retrospective analysis of the clinical data of 116 children with CDH was conducted. The children were assigned to EXIT and non-EXIT groups. Propensity score matching (PSM) toward clinical data was performed, and the clinical characteristics and outcomes were compared. Taking survival at discharge as the main outcome, logistic regression analysis was carried out to explore the efficacy of EXIT on survival.

Results

During the study period, 30 of 116 children received EXIT. After PSM, the survival rates of the EXIT group and the non-EXIT group were 82.76% (24/29) and 48.28% (14/29), respectively (p=0.006). EXIT (OR=0.083, 95% CI=0.013to 0.525, p=0.008), liver herniation (OR=16.955, 95% CI=2.342 to 122.767, p=0.005), and gestational age at diagnosis (OR=0.662, 95% CI=0.497 to 0.881, p=0.005) were independent mortality-related risk factors of all children with CDH. Ninety-nine of 116 children underwent surgery. After PSM, the postoperative survival rates of the EXIT group and non-EXIT group were 84.6% (22/26) and 76.9% (20/26), respectively (p=0.754). Liver herniation (OR=10.451, 95% CI=1.641 to 66.544, p=0.013) and gestational age at diagnosis (OR=0.736, 95% CI=0.577 to 0.938, p=0.013) were independent mortality-related risk factors of children after surgery.

Conclusion

EXIT can be performed safely for selected prenatally diagnosed CDH neonates with potentially better survival and does not cause more maternal complications compared with traditional cesarean section.

Congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a rare birth defect characterized by incomplete closure of the diaphragm and herniation of fetal abdominal organs into the chest that results in pulmonary hypoplasia, postnatal pulmonary hypertension owing to vascular remodelling and cardiac dysfunction. The high mortality and morbidity rates associated with CDH are directly related to the severity of cardiopulmonary pathophysiology. Although the aetiology remains unknown, CDH has a polygenic origin in approximately one-third of cases. CDH is typically diagnosed with antenatal ultrasonography, which also aids in risk stratification, alongside fetal MRI and echocardiography. At specialized centres, prenatal management includes fetal endoscopic tracheal occlusion, which is a surgical intervention aimed at promoting lung growth in utero. Postnatal management focuses on cardiopulmonary stabilization and, in severe cases, can involve extracorporeal life support. Clinical practice guidelines continue to evolve owing to the rapidly changing landscape of therapeutic options, which include pulmonary hypertension management, ventilation strategies and surgical approaches. Survivors often have long-term, multisystem morbidities, including pulmonary dysfunction, gastroesophageal reflux, musculoskeletal deformities and neurodevelopmental impairment. Emerging research focuses on small RNA species as biomarkers of severity and regenerative medicine approaches to improve fetal lung development.

The Cellular and Molecular Effects of Fetoscopic Endoluminal Tracheal Occlusion in Congenital Diaphragmatic Hernia

Congenital diaphragmatic hernia (CDH) is a complex disease associated with pulmonary hypoplasia and pulmonary hypertension. Great strides have been made in our ability to care for CDH patients, specifically in the prenatal improvement of lung volume and morphology with fetoscopic endoluminal tracheal occlusion (FETO). While the anatomic effects of FETO have been described in-depth, the changes it induces at the cellular and molecular level remain a budding area of CDH research. This review will delve into the cellular and molecular effects of FETO in the developing lung, emphasize areas in which further research may improve our understanding of CDH, and highlight opportunities to optimize the FETO procedure for improved postnatal outcomes.

Fetal endoscopic tracheal occlusion for congenital diaphragmatic hernia: a narrative review of the history, current practice, and future directions

Fetal intervention for fetuses with congenital diaphragmatic hernia (CDH) has been investigated for over 30 years and is summarized in this manuscript. The review begins with a discussion of the history of fetal intervention for this severe congenital anomaly beginning with open fetal surgery with repair of the anatomical defect, shifting towards tracheal occlusion via open surgery techniques, and finally fetoscopic endoluminal balloon tracheal occlusion using a percutaneous approach. The current technique of fetal endoscopic tracheal occlusion (FETO) is described in detail with steps of the procedure and complementary figures. The main outcomes of single-institutional studies and multiple systematic reviews are examined and discussed. Despite these studies, the fetal community agrees that FETO remains investigational at this time as there is insufficient evidence to recommend it as the standard of care for CDH. A randomized controlled trial, The Tracheal Occlusion to Accelerate Lung Growth (TOTAL) trial, has been designed to attempt to answer this question in an elaborate, international, multi-institutional study and is described in the text. Finally, future directions of fetal intervention for antenatally diagnosed CDH are discussed, including options for non-isolated CDH, the Smart-TO balloon for nonoperative reversal of occlusion, and transplacental sildenafil for treatment of pulmonary hypertension prior to birth.

Modern fetal surgery-a historical review of the happenings that shaped modern fetal surgery and its practices

The history of fetal surgery is one of constant evolution. Over the last 50 years, fetal surgery has progressed from a mere idea to an internationally respected innovative field of surgery. This article aims to provide a historical review of how the enterprise of maternal-fetal surgery came to be its modern version. This review is less focused on the history of specific therapies for a relatively small number of conditions, and more on how the whole field of maternal-fetal surgery evolved. The various internal and external influences that steered the field's evolution are discussed in chronologic order. Since the start of modern fetal surgery in the 1980s, large paradigm shifts have characterized the growth of the field as a whole. Innovative interventions are now based on physiologic manipulation as opposed to simple anatomic repair, fetoscopy has become the more frequently preferred surgical approach, and rigorous scientific evaluation with randomized controlled trials is now the standard expected by the community. In a very similar fashion to when the field first began in the early 1980s, recently community's leaders have risen to protect the integrity of maternal-fetal surgery by publishing ethical guidelines for innovation and clinical practice. This incredible history of innovation, rigorous science and ethical contemplation is the foundation on which modern maternal-fetal surgery rests.

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.

Current perspective and scope of fetal therapy: part 1

Fetal therapy term has been described for any therapeutic intervention either invasive or noninvasive for the purpose of correcting or treating any fetal malformation or condition. Fetal therapy is a rapidly evolving specialty and has gained pace in last two decades and now fetal intervention is being tried in many malformations with rate of success varying with the type of different fetal conditions. The advances in imaging techniques have allowed fetal medicine persons to make earlier and accurate diagnosis of numerous fetal anomalies. Still many fetal anomalies are managed postnatally because the fetal outcomes have not changed significantly with the use of fetal therapy and this approach avoids unnecessary maternal risk secondary to inutero intervention. The short-term maternal risk associated with fetal surgery includes preterm labor, premature rupture of membranes, uterine wall bleeding, chorioamniotic separation, placental abruption, chorioamnionitis, and anesthesia risk. Whereas, maternal long-term complications include risk of infertility, uterine rupture, and need for cesarean section in future pregnancies. The decision for invasive fetal therapy should be taken after discussion with parents about the various aspects like postnatal fetal outcome without fetal intervention, possible outcome if the fetal intervention is done, available postnatal intervention for the fetal condition, and possible short-term and long-term maternal complications. The center where fetal intervention is done should have facility of multi-disciplinary team to manage both maternal and fetal complications. The major issues in the development of fetal surgery include selection of patient for intervention, crafting effective fetal surgical skills, requirement of regular fetal and uterine monitoring, effective tocolysis, and minimizing fetal and maternal fetal risks. This review will cover the surgical or invasive aspect of fetal therapy with available evidence and will highlight the progress made in the management of fetal malformations in last two decades.

Ex-Utero Intrapartum Treatment (EXIT): indications and outcome in fetal cervical and oropharyngeal masses

Background

The “Ex-Utero Intrapartum Treatment” (EXIT) procedure allows to ensure fetal airway before completion of delivery and umbilical cord clamping while keeping uteroplacental circulation. Airway obstruction in fetal oropharyngeal and cervical masses can be life-threatening at birth. In those situations, controlled access to fetal airway performed by a trained multidisciplinary team allows safe airway management, while feto-maternal circulation is preserved. We aim to review the indications and outcome of the EXIT procedure in a case series of fetal cervical and oropharyngeal masses.

Methods

We have carried out a retrospective review of all patients with fetal cervical and oropharyngeal masses who underwent an EXIT procedure between 2008 and 2019. Variables evaluated included indication for EXIT, ultrasound and MRI findings, the need of amnioreduction, gestational age at EXIT, birth weight, complications, operative time, survival rate, pathological findings, and postnatal evolution. Five patients are included in this series. One additional case has already been published.

Results

The diagnosis were cervical teratoma (n = 1), epulis (n = 1) and lymphangioma (n = 3). Polyhydramnios was present in 2 patients, requiring amnioreduction in one of them. Mean gestational age at EXIT was 36–37 weeks (range, 34–38 weeks). Median EXIT time in placental support was 9 min (range, 3–22 min). Access to airway was successfully established in EXIT in all cases. All children born by EXIT are currently healthy and without complications.

Conclusion

The localization and characteristics of the mass, its relationship to the airway, and the presence of polyhydramnios seem to be major factors determining indications for EXIT and clinical outcome.

Prenatal regenerative fetoscopic interventions for congenital anomalies

Fetal intervention has progressed in the past two decades from experimental proof-of-concept to practice-adopted, life saving interventions in human fetuses with congenital anomalies. This progress is informed by advances in innovative research, prenatal diagnosis, and fetal surgical techniques. Invasive open hysterotomy, associated with notable maternal-fetal risks, is steadily replaced by less invasive fetoscopic alternatives. A better understanding of the natural history and pathophysiology of congenital diseases has advanced the prenatal regenerative paradigm. By altering the natural course of disease through regrowth or redevelopment of malformed fetal organs, prenatal regenerative medicine has transformed maternal-fetal care. This review discusses the uses of regenerative medicine in the prenatal diagnosis and management of three congenital diseases: congenital diaphragmatic hernia, lower urinary tract obstruction, and spina bifida.

Fetal tracheal occlusion for congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) remains one of the most elusive birth defects to treat. Despite greater knowledge of disease and advances in technology, approximately one-third of CDH children born today still die. Consequently, clinicians and researchers have struggled to find the optimal treatment strategies for CDH. Without further innovations in postnatal treatment, many have focused an antenatal approach to improve pulmonary function. Fetoscopic Endoluminal Tracheal Occlusion (FETO) for CDH has evolved to the bedside after decades of research. While still under clinical investigation, FETO remains a promising adjunct to the treatment of CDH.

Clinical outcomes of ex utero intrapartum treatment for fetal airway obstruction

PURPOSE

The aim of this study was to evaluate the indications and the clinical outcomes of the fetuses managed with ex utero intrapartum treatment (EXIT) procedures.

METHODS

We retrospectively reviewed the medical records of all fetuses who underwent EXIT procedures between 2003 and 2018.

RESULTS

EXIT procedures were performed in nine cases. The prenatal diagnosis of the neonates was congenital high airway obstruction syndrome in four cases, the neck masse in five cases. Although the airway management under the EXIT procedure was successful in eight cases, the airway management failed in one case. During the EXIT procedures, the airway was managed by endotracheal intubation in two cases, whereas six cases underwent tracheostomy. Six cases with fetal airway obstruction survived to discharge, whereas three cases died due to airway management failure or complications of the underlying disease. A case with a cervical teratoma underwent tumor resection the day after birth due to rapid enlargement of the neck mass. Long-term survival was achieved in five cases.

CONCLUSIONS

We concluded that the EXIT procedure was effective and could be performed safely in the airway management of fetuses with suspected airway obstruction. The treatment strategy for the neck masses should be planned before birth.

Fetal intervention for congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a condition that results from incomplete diaphragm formation during embryogenesis. The diaphragmatic defect allows for herniation of abdominal viscera into the chest, and the resulting pulmonary hypoplasia and pulmonary hypertension can lead to cardiorespiratory failure in the neonatal period. There is a wide spectrum of disease severity in CDH, and while advances in neonatal care and the introduction of extracorporeal membrane oxygenation have improved outcomes in many cases, the most severe defects are still associated with high morbidity and mortality. Improvements in prenatal diagnostic and prognostic capabilities have created an opportunity to select high risk patients for fetal intervention. Three decades of refinements in the fetal surgical therapy for CDH have led to the current technique of Fetoscopic Endoluminal Tracheal Occlusion (FETO). Herein, we review the current considerations for selecting patients for fetal intervention, and the contemporary fetal surgical operation for CDH, FETO, with a focus on early outcomes and ongoing studies.

Predictive Factors for Perinatal Outcomes of Infants Diagnosed With Micrognathia Antenatally

INTRODUCTION

Advances in fetal imaging have allowed us to identify abnormalities previously not appreciated. With this study, we hope to identify factors predicting a difficult airway at birth and review the perinatal outcomes of these patients.

METHODS

Sixteen patients with antenatally diagnosed micrognathia were reviewed from a tertiary care hospital database from 2011 to 2016. Jaw index (JI), amniotic fluid index (AFI), glossoptosis, gastric size, and oropharynx obliteration were assessed. The airway support required at birth, specialist team involvement, and outcomes were evaluated.

RESULTS

Nine (56.3%) of 16 patients had JI <5th percentile, 3 (33.3%) of 9 had difficult intubation, 2 (22.2%) of 9 needed an emergency tracheostomy, and 1 (11.1%) of 9 died. Seven patients had polyhydramnios, 2 (28.6%) of 7 had difficult intubation, 2 (28.6%) of 7 required tracheostomy, and 1 (14.3%) of 7 died. Twelve patients had either JI <5th percentile or abnormal AFI, 5 (41.7%) of 12 had difficult intubation, 2 (16.7%) of 12 required tracheostomy, and 1 (8.33%) of 12 died. For the group without otolaryngology consultation, 8 (50%) of 16, 1 (12.5%) of 8 had difficult intubation and 1 (12.5%) of 8 died because airway was not secured after 45 minutes of resuscitation.

CONCLUSION

Jaw index <5th percentile or abnormal AFI predicts a difficult airway. A multidisciplinary approach with otolaryngology involvement for airway intervention may be required at birth.

Prenatal intervention for the management of congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is the result of incomplete formation of the diaphragm that occurs during embryogenesis. The defect in the diaphragm permits the herniation of abdominal organs into the thoracic cavity contributing to the impairment of normal growth and development of the fetal lung. In addition to the hypoplastic lung, anomalies of the pulmonary arterioles worsen the pulmonary hypertension that can have detrimental effects in severe cases. Most cases of CDH can be effectively managed postnatally. Advances in neonatal and surgical care have resulted in improved outcomes over the years. When available, extracorporeal membrane oxygenation can provide temporary cardiorespiratory support for those not effectively supported by mechanical ventilation. In spite of these advances, very severe cases of CDH still carry a very high mortality and morbidity rate. Advances in imaging and evaluation now allow for early and accurate prenatal diagnosis of CDH, thereby identifying those at greatest risk who may benefit from prenatal intervention. This review article discusses some of the surgical and non-surgical prenatal interventions in the management of isolated severe congenital diaphragmatic hernia.

Lessons from the Barn to the Operating Suite: A Comprehensive Review of Animal Models for Fetal Surgery

The International Fetal Medicine and Surgery Society was created in 1982 and proposed guidelines for fetal interventions that required demonstrations of the safety and feasibility of intended interventions in animal models prior to application in humans. Because of their short gestation and low cost, small animal models are useful in early investigation of fetal strategies. However, owing to the anatomic and physiologic differences between small animals and humans, repeated studies in large animal models are usually needed to facilitate translation to humans. Ovine (sheep) models have been used the most extensively to study the pathophysiology of congenital abnormalities and to develop techniques for fetal interventions. However, nonhuman primates have uterine and placental structures that most closely resemble those of humans. Thus, the nonhuman primate is the ideal model to develop surgical and anesthetic techniques that minimize obstetrical complications.

Evaluation of alveolar epithelial cells in the sheep model of congenital diaphragmatic hernia: Type 1 alveolar epithelial cells and histopathological image analysis

BACKGROUND

There are few reports comparing type 1 alveolar epithelial cell development with histopathological image analysis. We investigated these as indicators of maturity in fetal lambs' lungs in a congenital diaphragmatic hernia (CDH) model.

METHODS

We created left CDH in 4 fetal lambs at 75 or 76days' gestation (Group A). Controls were 5 sham-operated lambs (Group B); both groups delivered at term. The right lower lung lobe (RLL) and left lower lobe (LLL) were sampled. Using histopathological image analysis, alveoli/air sacs count (AC), alveoli/air sacs area percentage (AP), average area (AA), total area (TA), and perimeter (PM) were determined. We also evaluated total lung volumes, radial alveolar count (RAC), and Type 1 alveolar epithelial cells ratio (AT1 ratio), which we previously reported. Regression analysis was performed, with p<0.05 considered significant.

RESULTS

RLL and LLL AT1 ratio and LLL RAC in Group A were lower than in Group B. There are no significant differences demonstrated by histopathological image analysis. In Group A, the AT1 ratio in the LLL was lower than in the RLL. There were no differences between LLL and RLL in Group B.

CONCLUSION

AT1 ratio was superior to the other indicators evaluating lung maturity.

Minimally Invasive Fetal Surgery

Fetal surgery corrects severe congenital anomalies in utero to prevent their severe consequences on fetal development. The significant risk of open fetal operations to the pregnant mother has driven innovation toward minimally invasive procedures that decrease the risks inherent to hysterotomy. In this article, we discuss the basic principles of minimally invasive fetal surgery, the general history of its development, specific conditions and procedures used to treat them, and the future of the field.

Long-term morbidity of congenital diaphragmatic hernia: A plea for standardization

Congenital diaphragmatic hernia (CDH) survivors present long-term morbidities in several systems, including the neurodevelopmental, gastrointestinal, pulmonary, and musculoskeletal ones, and CDH long-term sequelae are increasingly being recognized. Due to high co-morbidity, health related quality of life in a significant proportion of CDH patients might be compromised. As a consequence of consciousness on the long-term sequelae of CDH survivors, and their consequences for life, several follow-up programs were brought to life worldwide. In this review, we will summarize the long-term sequelae of CDH survivors, the impact of new treatments, and analyze the consistency of follow-up programs.

Fetal imaging and therapy for CDH-Current status

In congenital diaphragmatic hernia (CDH), herniation of the abdominal organs into the fetal chest causes pulmonary hypoplasia and pulmonary hypertension, the main causes of neonatal mortality. As antenatal ultrasound screening improves, the risk of postnatal death can now be better predicted, allowing for the identification of fetuses that might most benefit from a prenatal intervention. Fetoscopic tracheal occlusion is being evaluated in a large international randomized controlled trial. We present the antenatal imaging approaches that can help identify fetuses that might benefit from antenatal therapy, and review the evolution of fetal surgery for CDH to date.

Fetal surgery: a critical review

Therapeutic fetal surgical procedures are predicated upon the ability to make an accurate fetal diagnosis. The earliest open fetal surgical procedures were introduced in the 1960s to treat Rh isoimmunisation. They were introduced when it became possible to predict impending fetal demise. Open procedures were abandoned when percutaneous approaches proved superior. The introduction of fetal ultrasound allowed the diagnosis of other congenital anomalies, some being amenable to fetal interventions. Open fetal surgical procedures were initially utilised, with significant maternal morbidity. For some anomalies, percutaneous approaches became favoured. In general, all of these procedures involved significant risks to the mother, to save a baby that was likely to die before or shortly after birth without fetal intervention. Fetal repair for myelomeningocele was a "sea change" in approach. The same maternal risks were taken to improve the quality of life of the affected fetus, not save its life. The completion of the "MOMs Trial" has occasioned a "tsunami" of centres in North America applying this approach. Others are attempting percutaneous repairs, with mixed results. This paper reviews the history of fetal surgery, focusing on the themes of the tension between accurate diagnosis and prognosis and open versus "minimally invasive" approaches.

Immediate operative management of the fetus with airway anomalies resulting from congenital malformations

Prenatal diagnosis has transformed the outcome of fetuses with airway obstruction. The thorough evaluation of prenatal imaging allows for categorizing fetuses with airway compromise into those who will require a special mode of delivery and those who can be delivered without any special resources. The ex-utero intrapartum treatment (EXIT) approach allows accessing the airway while the fetus is under placental support, converting a potentially catastrophic situation into a controlled one. An expert multidisciplinary team is the key to success.

Management of fetal teratomas

Fetal teratomas are the most common tumors diagnosed prenatally. The majority of these tumors are benign and cured by complete resection of the mass during the neonatal period. Prenatal diagnosis has improved the perinatal management of these lesions and especially for the teratomas that might benefit from fetal intervention. A comprehensive prenatal evaluation including conventional ultrasounds, Doppler, echocardiography and fetal MRI, is essential for an effective counseling and perinatal management. Antenatal counseling helps the parents to better understand the natural history, fetal intervention, and perinatal management of these tumors, which differ dramatically depending on their size and location. Fetal surgical debulking improves survival in cases of sacrococcygeal teratoma with cardiac decompensation. Additionally, the use of an EXIT procedure reduces the morbidity and mortality if a complicated delivery in cases of cervical and mediastinal teratomas. Here, we offer an overview of all fetal teratomas and their recommended management, with emphasis on in utero treatment options.

Prenatal and Postnatal Management of Congenital Pulmonary Airway Malformation

Congenital pulmonary airway malformation (CPAM) is one of the most common lung lesions detected prenatally. Despite the research efforts made in the past few years, controversy and lack of clarity in the literature still exist regarding nomenclature, classification, pathogenesis and the management of CPAM. Therefore, it is of greatest importance to delineate the natural history of CPAMs and to create a consensus to guide the management and follow-up of these lesions. This review will focus on classification systems, highlighting the most recent advancements in pathogenesis, and current practice in the prenatal diagnosis of CPAM. Strategies of prenatal management and postnatal management will be reviewed. Long-term follow-up, including lung cancer risk, is discussed and an outcome perspective is presented.

Management of the critical airway when an EXIT procedure is not an option: A case report

Perinatal imaging facilitates detection of congenital head and neck masses to plan fetal procedures which secure the airway. Ex utero intrapartum therapy (EXIT) procedures are preferred to protect the neonatal airway. Herein we present a case in which a neonate with a large oropharyngeal lymphovascular malformation was delivered and the airway successfully managed without an EXIT procedure using a multidisciplinary approach. Preparations for the non-EXIT delivery and critical airway management are described.

Fetal surgery: principles, indications, and evidence

Since the first human fetal surgery was reported in 1965, several different fetal surgical procedures have been developed and perfected, resulting in significantly improved outcomes for many fetuses. The currently accepted list of fetal conditions for which antenatal surgery is considered include lower urinary tract obstruction, twin-twin transfusion syndrome, myelomeningocele, congenital diaphragmatic hernia, neck masses occluding the trachea, and tumors such as congenital cystic adenomatoid malformation or sacrococcygeal teratoma when associated with developing fetal hydrops. Until recently, it has been difficult to determine the true benefits of several fetal surgeries because outcomes were reported as uncontrolled case series. However, several prospective randomized trials have been attempted and others are ongoing, supporting a more evidence-based approach to antenatal intervention. Problems that have yet to be completely overcome include the inability to identify ideal fetal candidates for antenatal intervention, to determine the optimal timing of intervention, and to prevent preterm birth after fetal surgery. Confronting a fetal abnormality raises unique and complex issues for the family. For this reason, in addition to a maternal-fetal medicine specialist experienced in prenatal diagnosis, a pediatric surgeon, an experienced operating room team including a knowledgeable anesthesiologist, and a neonatologist, the family considering fetal surgery should have access to psychosocial support and a bioethicist.

Ex utero intrapartum treatment (EXIT) in the management of cervical lymphatic malformation

PURPOSE

The purpose of this study was to review the outcomes and technical details of EXIT procedures performed in fetuses with large cervical lymphatic malformations.

METHODS

A retrospective chart review of fetuses with a prenatal diagnosis of cervical lymphatic malformation evaluated at our center between 1995 and 2013 was performed.

RESULTS

We evaluated a total of 112 fetuses with a prenatal diagnosis of cervical lymphatic malformation. Thirteen of the 112 fetuses (11%) were delivered by an EXIT procedure. Criteria to deliver by EXIT were: 1) deviation/compression/obstruction of the airway, and 2) involvement of the floor of the mouth. Two fetuses developed hydrops. Five fetuses developed polyhydramnios. Eleven EXITs were performed electively at term (n=7; 37-38 weeks) or late pre-term (n=4; 34-36/6 weeks), whereas two patients underwent emergency EXIT at 33 and 38 weeks, respectively. The airway was accessed successfully in 12 of 13 cases. Laryngoscopy only was sufficient in 7, rigid bronchoscopy was required in 4, and 1 required a tracheostomy. In one case with a massive lymphatic malformation of the face, neck, and airway, a tracheostomy was not attempted, and the fetus expired. Four patients had invasion of the larynx by the lymphatic malformation. Five patients required a tracheostomy later. Median time from fetal exposure to intubation was 8 (2-29) min. Median total EXIT time was 105.5 (67-142) min. Median maternal blood loss was 800 (300-1000) ml. Median maternal hospital stay was 4 (3-6) days.

CONCLUSION

The EXIT procedure allows controlled airway access in fetuses with cervical lymphatic malformations and evidence of airway impairment on prenatal images.

Prenatal diagnosis of obstructive head and neck masses and perinatal airway management: the ex utero intrapartum treatment procedure

Advances in prenatal imaging in the last 20 years have enabled prenatal diagnosis of obstructive head and neck masses. These advances, coupled with improvements in maternal-fetal anesthesia, have made possible the development of the ex utero intrapartum treatment (EXIT) procedure for management of obstructive head and neck masses, during which the airway is managed in a controlled fashion while maintaining fetal circulation for oxygenation. This review addresses the preoperative and perioperative assessment and management of patients with prenatally diagnosed airway obstruction, indications and contraindications for the EXIT procedure, technical details of the procedure, and outcomes.

EXIT procedure in twin pregnancy: a series of three cases from a single center

Background

Indications for the ex utero intrapartum therapy (EXIT) procedure have evolved and nowadays in addition to secure the airway, obtain vascular access, administer surfactant and other resuscitation medications, EXIT is used to resect cervical or thoracic masses, for extracorporeal membrane circulation (ECMO) cannulation, as well as to rescue maximum intra-thoracic space for ventilation of the remaining functional lung tissue or in cases in which resuscitation of the neonate may be compromised. EXIT procedure in twin pregnancy has been rarely reported and some doubts have been raised about its strategy and safety in such cases.

Methods

We reviewed the medical records of 3 twin pregnancy cases where the EXIT procedure have been performed in our center.

Results

The mean gestational age at EXIT procedure was 34 + 4 weeks. In two out the three EXIT procedures, the affected twin was delivered first. The average time on placental bypass was 9 minutes. There were no fetal or maternal complications related to the EXIT procedure. All newborns are currently doing well.

Conclusion

In twin pregnancies, prenatal diagnosis combined with the EXIT procedure permits the formulation of a controlled delivery strategy to secure both newborns outcome. In those pregnancies, if intervention can be accomplished without compromise of the normal twin, EXIT can be considered. Our results support that EXIT procedure, if properly planned, safely provides a good outcome for both the fetuses as well as the mother.

Tracheomegaly in infants with severe congenital diaphragmatic hernia treated with fetal endoluminal tracheal occlusion

OBJECTIVE

To measure and evaluate the effects of tracheal dimensions on survival and ventilation in a large series of infants with congenital diaphragmatic hernia (CDH) treated antenatally with fetal endoluminal tracheal occlusion (FETO).

STUDY DESIGN

Tracheal dimensions on chest radiograph (CR) were measured by 2 blinded radiologists. Survival, day 1 best oxygenation index and duration of ventilation, continuous positive airway pressure, and hospital stay were recorded. Survivors with a minimum 12-month follow-up were longitudinally compared for incidence of gastroesophageal reflux, chest infections, chest deformities, and hernia recurrence.

RESULTS

Seventy infants with CDH (41 who underwent FETO) were treated between 2004 and 2010. Hernia repair was performed in 26 infants without FETO (8 with patch repair) and 35 infants with FETO (26 with patch repair; P = .0015). Infants with FETO had a wider trachea than those without FETO at T1 (P < .0001) and between T1 and the carina (P < .0001). Tracheal diameter was similar in survivors and nonsurvivors in the FETO group. Tracheal size was not correlated with day 1 best oxygenation index in the FETO group (R2 = 0.17) or the non-FETO group (R2 = 0.07). There were no between-group differences in duration of mechanical ventilation (P = .30), continuous positive airway pressure (P = .20), or hospital stay (P = .30). In the longitudinal study, tracheal widths were larger on the last CR than on preoperative CR in patients without FETO (T1, P = .02; widest point, P = .001; carina, P = .0001), and for patients with FETO at the widest point (P < .0001) and at the carina (P < .0001), but not at T1 (P = .12). There were no differences in clinical variables between the FETO and non-FETO groups.

CONCLUSION

FETO has a significant impact on tracheal size of infants with CDH; however, tracheal size does not affect survival or the requirement for early respiratory support.

The ex utero intrapartum treatment (EXIT) procedure: application of a new therapeutic paradigm

The ex utero intrapartum treatment (EXIT) procedure is a term given to a technique that can transform a potentially fatal neonatal emergency to a controlled intervention with an improved outcome. It has revolutionised the care of prenatally diagnosed congenital malformations in which severe upper airway obstruction is anticipated. An extended period of utero-placental circulation can be utilised to avoid profound cardiopulmonary compromise. Its therapeutic applications have been broadened to include fetuses with congenital diaphragmatic hernia after tracheal plugging, high-risk intrathoracic masses, severe cardiac malformations and conjoined twins. It requires the co-ordination of a highly skilled and experienced multidisciplinary team. The recent enthusiasm for the EXIT procedure needs to be balanced against maternal morbidity. Specific indications and guidelines are likely to be refined as a consequence of ongoing advances in fetal intervention and antenatal imaging.

Pulmonary alveolar and vascular morphometry after gel plug occlusion of the trachea in a fetal rabbit model of CDH

PURPOSE

Tracheal occlusion (TO) induces lung growth in congenital diaphragmatic hernia (CDH) but is also associated with drawbacks. We devised a temporary gel plug that induced lung growth when placed in the fetal trachea. This study evaluates the effects of temporary versus permanent TO on histologic radial alveolar count (RAC) and vascular morphometrics.

METHODS

Experimental CDH was created surgically in 64 New Zealand White rabbit fetuses on gestational day (GD) 24. On GD 27, these fetuses were randomized to intratracheal instillation of a fibrin gel plug (GP), tracheal suture ligation (SL), intratracheal instillation of normal saline (NS), or sham amniotomy (SH). Non-manipulated fetuses served as controls (NM). Histologic lung sections were assessed blindly for RAC and relative arterial adventitial thickness (%AT) as a variable for vascular remodelling. Results were statistically compared.

RESULTS

RAC was significantly lower in the ipsilateral lung of SH fetuses than in the contralateral lung (p = 0.011). Mean RAC was higher after SL (p < 0.001) and GP (p = 0.03) compared to SH. Furthermore, %AT was higher in GP (50 ± 28, p < 0.001) and SL (45 ±2 6, p = 0.003) fetuses than in controls (36 ± 19).

CONCLUSION

Temporary and permanent TO leads to increased RAC; this effect was more pronounced with permanent TO. Both interventions were associated with an increased %AT. These findings may explain the adverse clinical effects of TO, despite causing accelerated lung growth.

Management of prenatally diagnosed congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a congenital anomaly that presents with a broad spectrum of severity that is dependent upon components of pulmonary hypoplasia and pulmonary hypertension. While advances in neonatal care have improved the overall survival of CDH in experienced centers, mortality and morbidity remain high in a subset of CDH infants with severe CDH. Prenatal predictors have been refined for the past two decades and are the subject of another review in this issue. So far, all randomized trials comparing prenatal intervention to standard postnatal therapy have shown no benefit to prenatal intervention. Although recent non-randomized reports of success with fetoscopic endoluminal tracheal occlusion (FETO) and release are promising, prenatal therapy should not be widely adopted until a well-designed prospective randomized trial demonstrating efficacy is performed. The increased survival and subsequent morbidity of CDH survivors has resulted in the need to provide resources for the long-term follow up and support of the CDH population.

Ex Utero Intrapartum Therapy

The Ex Utero Intrapartum Therapy (EXIT) procedure was initially developed to secure the airway in fetuses at delivery after they had undergone in utero tracheal occlusion for congenital diaphragmatic hernia. Indications for the EXIT procedure have been expanded to include any delivery in which prenatal diagnosis is concerned for neonatal airway compromise, such as large neck masses and Congenital High Airway Obstruction Syndrome, or when a difficult resuscitation is anticipated such as with large lung lesions. Uteroplacental blood flow and gas exchange are maintained through the use of inhalational anesthetics to allow optimal uterine relaxation with partial delivery of the fetus and amnioinfusion to sustain uterine distension. Using the EXIT procedure, sufficient time is provided on placental bypass to perform life-saving procedures such as bronchoscopy, laryngoscopy, endotracheal intubation, tracheostomy, cannulation for extracorporeal membrane oxygenation, and resection of lung masses or resection of neck masses in a controlled setting, thus avoiding a potential catastrophe.

Evaluation of histological changes after tracheal occlusion at different gestational ages in a fetal rat model

OBJECTIVES

To evaluate the histological changes of tracheal cartilage and epithelium caused by tracheal occlusion at different gestational ages in a fetal rat model.

METHODS

Rat fetuses were divided into two groups: a) External control, composed of non-operated rats, and b) Interventional group, composed of rats operated upon on gestational day 18.5 (term = 22 days), divided into triads: 1) Tracheal occlusion, 2) Internal control and 3) Sham (manipulated but not operated). Morphological data for body weight, total lung weight and total lung weight/body weight ratio were collected and measured on gestational days 19.5, 20.5 and 21.5. Tracheal samples were histologically processed, and epithelial, chondral and total tracheal thicknesses were measured on each gestational day.

RESULTS

The tracheal occlusion group exhibited an increase in total lung weight/body weight ratio (p<0.001). Histologically, this group had a thicker epithelial thickness (p<0.05) and thinner chondral (p<0.05) and total tracheal thicknesses (p<0.001). These differences were more prominent on gestational days 20.5 and 21.5.

CONCLUSION

Tracheal occlusion changed tracheal morphology, increased epithelial thickness and considerably decreased total tracheal thickness. These changes in the tracheal wall could explain the development of tracheomegaly, recently reported in some human fetuses subjected to tracheal occlusion.