The plug-unplug sequence: an important step to achieve type II pneumocyte maturation in the fetal lamb model

Fetoscopic endoluminal tracheal occlusion vs expectant management for fetuses with severe left-sided congenital diaphragmatic hernia

BACKGROUND

The treatment of fetuses with a congenital diaphragmatic hernia is challenging, but there is evidence that fetoscopic endoluminal tracheal occlusion has a benefit over expectant care. In addition, standardization and expertism have a great impact on survival and are probably crucial in centers that rely on expectant management with extracorporeal membrane oxygenation after birth.

OBJECTIVE

This study aimed to examine the survival and morbidity rates of fetuses with a severe isolated left-sided congenital diaphragmatic hernia who underwent fetoscopic endoluminal tracheal occlusion vs expectant management in high-volume centers.

STUDY DESIGN

This was a multicenter, retrospective study that included all consecutive fetuses with severe isolated left-sided congenital diaphragmatic hernia who were expectantly managed in a German center or who underwent fetoscopic endoluminal tracheal occlusion in 3 other European centers (Belgium, France, and Italy). Severe congenital diaphragmatic hernia was defined as having an observed to expected total fetal lung volume ≤35% with intrathoracic position of the liver diagnosed with magnetic resonance imaging. All magnetic resonance images were centralized, and lung volumes were measured by 2 experienced operators who were blinded to the pre- and postnatal data. Multiple logistic regression analyses were performed to examine the effect of the management strategy in the 2 groups on the short- and long-term outcomes.

RESULTS

A total of 147 patients who were managed expectantly and 47 patients who underwent fetoscopic endoluminal tracheal occlusion were analyzed. Fetuses who were managed expectantly had lower observed to expected total fetal lung volumes (20.6%±7.5% vs 23.7%±6.8%; P=.013), higher gestational age at delivery (median weeks of gestation, 37.4; interquartile range, 36.6-38.00 vs 35.1; interquartile range, 33.1-37.2; P<.001), and more frequent use of extracorporeal membrane oxygenation (55.8% vs 4.3%; P<.001) than the fetuses who underwent fetoscopic endoluminal tracheal occlusion. The survival rates at discharge and at 2 years of age in the expectant management group were higher than the survival rates of the fetoscopic endoluminal tracheal occlusion group (74.3% vs 44.7%; P=.001 and 72.8% vs 42.5%; P=.001, respectively). After adjustment for maternal age, gestational age at birth, observed to expected total fetal lung volume, and birth weight Z-score, the odds ratios were 4.65 (95% confidence interval, 1.9-11.9; P=.001) and 4.37 (95% confidence interval, 1.8-11.0; P=.001), respectively.

CONCLUSION

Fetuses with a severe isolated left-sided congenital diaphragmatic hernia had a higher survival rate when treated in an experienced center in Germany with antenatal expectant management and frequent use of extracorporeal membrane oxygenation during the postnatal period than fetuses who were treated with fetoscopic endoluminal tracheal occlusion in 3 centers in Belgium, France, and Italy.

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).

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.

Meconium Aspiration Syndrome in Animal Models: Inflammatory Process, Apoptosis, and Surfactant Inactivation

Meconium Aspiration Syndrome is a condition that causes respiratory distress in newborns due to occlusion and airway inflammation, and surfactant inactivation by meconium. This condition has been described in animal species such as canids, sheep, cattle, horses, pigs, and marine mammals. In its pathogenesis, the pulmonary epithelium activates a limited inflammatory response initiated by cytokines causing leukocyte chemotaxis, inhibition of phagocytosis, and pathogen destruction. Likewise, cytokines release participates in the apoptosis processes of pneumocytes due to the interaction of angiotensin with cytokines and the caspase pathway. Due to these reactions, the prevalent signs are lung injury, hypoxia, acidosis, and pneumonia with susceptibility to infection. Given the importance of the pathophysiological mechanism of meconium aspiration syndrome, this review aims to discuss the relevance of the syndrome in veterinary medicine. The inflammatory processes caused by meconium aspiration in animal models will be analyzed, and the cellular apoptosis and biochemical processes of pulmonary surfactant inactivation will be discussed.

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.

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.

Antenatal Management of Congenital Diaphragmatic Hernia: what's next ?

Congenital diaphragmatic hernia (CDH) can be diagnosed in the prenatal period and its severity can be measured by fetal imaging. There is now level I evidence that, in selected cases, Fetoscopic Endoluminal Tracheal Occlusion (FETO) increases survival to discharge from the neonatal unit as well as the risk for prematurity. Both effects are dependent on the time point of tracheal occlusion. FETO may also lead to iatrogenic death when done in unexperienced centres. The implementation of the findings from our clinical studies, may also vary based on local conditions. These may be different in terms of available skill set, access to fetal therapy, as well as outcome based on local neonatal management. We encourage prior benchmarking of local outcomes with optimal postnatal management, based on large enough numbers and using identical criteria as in the recent trials. We propose to work further on prenatal prediction methods, and the improvement of fetal intervention. In this manuscript, we describe a research agenda from a fetal medicine perspective. This research should be in parallel with innovation in neonatal and pediatric (surgical) management of this condition. This article is protected by copyright. All rights reserved.

How should fetal surgery for congenital diaphragmatic hernia be implemented in the post-TOTAL trial era: a discussion. Prenat Diagn 2022;42:301-309. [PMID: 35032132 DOI: 10.1002/pd.6091]

Following prenatal diagnosis of congenital diaphragmatic hernia, severity can be predicted based on the presence of associated abnormalities, and in isolated cases, on lung size and position of the liver. Severe hypoplasia is defined by a contralateral lung size < 25% on ultrasound; moderate hypoplasia is when that lung measures between 25 and 45% of the normal. In fetuses with predicted poor postnatal outcome a procedure that reverses pulmonary hypoplasia may be considered. In uncontrolled studies, fetoscopic endoluminal tracheal occlusion (FETO) improved neonatal outcome. Recently, two randomized controlled trials compared the neonatal and infant outcomes in fetuses with isolated CDH (www.totaltrial.eu). In severe cases, FETO was carried out at 27⁺⁰ -29⁺⁶ weeks' gestation (referred to as "early") and in moderate at 30⁺⁰ -31⁺⁶ weeks ("late"). Survival to discharge from the neonatal intensive care unit increased by 25% (95%-CI:+6 - +46; P=.0091) and 13% (-1 - +28; P=.059), in fetuses with severe and moderate cases, respectively. Following FETO gestational age at delivery was on average 3.2 (2.3-4.1) weeks earlier following early and 1.7 (1.1 - 2.3) following late FETO. Here the strengths and weaknesses of the TOTAL trials and their translation to the clinic are debated. Discussants are the lead for the trial (JD) and a colleague (AF) not involved. The discussant notes that the observed survival, both in treated and expectantly managed fetuses, was overall less than what is reported by some high volume centers, particularly in North America. Additional criticisms are the potential effects of prematurity on the long term, the inclusion of low-volume centers, and the potential of FETO for severe iatrogenic complications. Therefore results may not be generalizable. The discussants concluded that although FETO may have its value it remains a procedure with a high risk for prematurity and it can be lethal when the balloon cannot be removed prior to delivery. This article is protected by copyright. All rights reserved.

Stretch increases alveolar type 1 cell number in fetal lungs through ROCK-Yap/Taz pathway

Accurate fluid pressure in the fetal lung is critical for its development, especially at the beginning of the saccular stage when alveolar epithelial type 1 (AT1) and type 2 (AT2) cells differentiate from the epithelial progenitors. Despite our growing understanding of the role of physical forces in lung development, the molecular mechanisms that regulate the transduction of mechanical stretch to alveolar differentiation remain elusive. To simulate lung distension, we optimized both an ex vivo model with precision cut lung slices and an in vivo model of fetal tracheal occlusion. Increased mechanical tension showed to improve alveolar maturation and differentiation toward AT1. By manipulating ROCK pathway, we demonstrate that stretch-induced Yap/Taz activation promotes alveolar differentiation toward AT1 phenotype via ROCK activity. Our findings show that balanced ROCK-Yap/Taz signaling is essential to regulate AT1 differentiation in response to mechanical stretching of the fetal lung, which might be helpful in improving lung development and regeneration.

Maternal Fetal Surgery: Intervention and Management

Congenital malformations occur in about 3% of all live births and are a leading cause of perinatal morbidity and mortality. An evolving understanding of the developing human fetus, advances in imaging, availability of cutting-edge instrumentation, and enhanced understanding of fetal pathophysiology, have allowed for prenatal surgical interventions to improve fetal diseases and neonatal outcomes. Fetal surgical therapy is no longer restricted to life-threatening prenatal diagnoses and can be categorized into either open surgical techniques or minimally invasive endoscopic/ultrasound-guided techniques. Patient selection requires a thorough multidisciplinary evaluation and shared decision-making process.

Randomized Trial of Fetal Surgery for Moderate Left Diaphragmatic Hernia

BACKGROUND

Fetoscopic endoluminal tracheal occlusion (FETO) has been associated with increased postnatal survival among infants with severe pulmonary hypoplasia due to isolated congenital diaphragmatic hernia on the left side, but data are lacking to inform its effects in infants with moderate disease.

METHODS

In this open-label trial conducted at many centers with experience in FETO and other types of prenatal surgery, we randomly assigned, in a 1:1 ratio, women carrying singleton fetuses with a moderate isolated congenital diaphragmatic hernia on the left side to FETO at 30 to 32 weeks of gestation or expectant care. Both treatments were followed by standardized postnatal care. The primary outcomes were infant survival to discharge from a neonatal intensive care unit (NICU) and survival without oxygen supplementation at 6 months of age.

RESULTS

In an intention-to-treat analysis involving 196 women, 62 of 98 infants in the FETO group (63%) and 49 of 98 infants in the expectant care group (50%) survived to discharge (relative risk , 1.27; 95% confidence interval [CI], 0.99 to 1.63; two-sided P = 0.06). At 6 months of age, 53 of 98 infants (54%) in the FETO group and 43 of 98 infants (44%) in the expectant care group were alive without oxygen supplementation (relative risk, 1.23; 95% CI, 0.93 to 1.65). The incidence of preterm, prelabor rupture of membranes was higher among women in the FETO group than among those in the expectant care group (44% vs. 12%; relative risk, 3.79; 95% CI, 2.13 to 6.91), as was the incidence of preterm birth (64% vs. 22%, respectively; relative risk, 2.86; 95% CI, 1.94 to 4.34), but FETO was not associated with any other serious maternal complications. There were two spontaneous fetal deaths (one in each group) without obvious cause and one neonatal death that was associated with balloon removal.

CONCLUSIONS

This trial involving fetuses with moderate congenital diaphragmatic hernia on the left side did not show a significant benefit of FETO performed at 30 to 32 weeks of gestation over expectant care with respect to survival to discharge or the need for oxygen supplementation at 6 months. FETO increased the risks of preterm, prelabor rupture of membranes and preterm birth. (Funded by the European Commission and others; TOTAL ClinicalTrials.gov number, NCT00763737.).

Randomized Trial of Fetal Surgery for Severe Left Diaphragmatic Hernia

BACKGROUND

Observational studies have shown that fetoscopic endoluminal tracheal occlusion (FETO) has been associated with increased survival among infants with severe pulmonary hypoplasia due to isolated congenital diaphragmatic hernia on the left side, but data from randomized trials are lacking.

METHODS

In this open-label trial conducted at centers with experience in FETO and other types of prenatal surgery, we randomly assigned, in a 1:1 ratio, women carrying singleton fetuses with severe isolated congenital diaphragmatic hernia on the left side to FETO at 27 to 29 weeks of gestation or expectant care. Both treatments were followed by standardized postnatal care. The primary outcome was infant survival to discharge from the neonatal intensive care unit. We used a group-sequential design with five prespecified interim analyses for superiority, with a maximum sample size of 116 women.

RESULTS

The trial was stopped early for efficacy after the third interim analysis. In an intention-to-treat analysis that included 80 women, 40% of infants (16 of 40) in the FETO group survived to discharge, as compared with 15% (6 of 40) in the expectant care group (relative risk, 2.67; 95% confidence interval [CI], 1.22 to 6.11; two-sided P = 0.009). Survival to 6 months of age was identical to the survival to discharge (relative risk, 2.67; 95% CI, 1.22 to 6.11). The incidence of preterm, prelabor rupture of membranes was higher among women in the FETO group than among those in the expectant care group (47% vs. 11%; relative risk, 4.51; 95% CI, 1.83 to 11.9), as was the incidence of preterm birth (75% vs. 29%; relative risk, 2.59; 95% CI, 1.59 to 4.52). One neonatal death occurred after emergency delivery for placental laceration from fetoscopic balloon removal, and one neonatal death occurred because of failed balloon removal. In an analysis that included 11 additional participants with data that were available after the trial was stopped, survival to discharge was 36% among infants in the FETO group and 14% among those in the expectant care group (relative risk, 2.65; 95% CI, 1.21 to 6.09).

CONCLUSIONS

In fetuses with isolated severe congenital diaphragmatic hernia on the left side, FETO performed at 27 to 29 weeks of gestation resulted in a significant benefit over expectant care with respect to survival to discharge, and this benefit was sustained to 6 months of age. FETO increased the risks of preterm, prelabor rupture of membranes and preterm birth. (Funded by the European Commission and others; TOTAL ClinicalTrials.gov number, NCT01240057.).

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.

Safety and efficacy of smart tracheal occlusion device in diaphragmatic hernia lamb model

OBJECTIVE

To investigate the efficacy and safety of the 'smart' tracheal occlusion (Smart-TO) device in fetal lambs with diaphragmatic hernia (DH).

METHODS

DH was created in fetal lambs on gestational day 70 (term, 145 days). Fetuses were allocated to either pregnancy continuation until term (DH group) or fetoscopic endoluminal tracheal occlusion (TO), performed using the Smart-TO balloon on gestational day 97 (DH + TO group). On gestational day 116, the presence of the balloon was confirmed on ultrasound, then the ewe was walked around a 3.0-Tesla magnetic resonance scanner for balloon deflation, which was confirmed by ultrasound immediately afterwards. At term, euthanasia was performed and the fetus retrieved. Efficacy of occlusion was assessed by the lung-to-body-weight ratio (LBWR) and lung morphometry. Safety parameters included tracheal side effects assessed by morphometry and balloon location after deflation. The unoccluded DH lambs served as a comparator.

RESULTS

Six fetuses were included in the DH group and seven in the DH + TO group. All balloons deflated successfully and were expelled spontaneously from the airways. In the DH + TO group, in comparison to controls, the LBWR at birth was significantly higher (1.90 (interquartile range (IQR), 1.43-2.55) vs 1.07 (IQR, 0.93-1.46); P = 0.005), while on lung morphometry, the alveolar size was significantly increased (mean linear intercept, 47.5 (IQR, 45.6-48.1) vs 41.9 (IQR, 38.8-46.1) μm; P = 0.03); whereas airway complexity was lower (mean terminal bronchiolar density, 1.56 (IQR, 1.0-1.81) vs 2.23 (IQR, 2.14-2.40) br/mm² ; P = 0.005). Tracheal changes on histology were minimal in both groups, but more noticeable in fetal lambs that underwent TO than in unoccluded lambs (tracheal score, 2 (IQR, 1-3) vs 0 (0-1); P = 0.03).

CONCLUSIONS

In fetal lambs with DH, TO using the Smart-TO balloon is effective and safe. Occlusion can be reversed non-invasively and the deflated intact balloon expelled spontaneously from the fetal upper airways. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

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.

Single-Center Outcome of Fetoscopic Tracheal Balloon Occlusion for Severe Congenital Diaphragmatic Hernia

OBJECTIVE

To assess feasibility and maternal and infant outcome after fetoscopic tracheal balloon occlusion in patients with severe congenital diaphragmatic hernia.

METHODS

We conducted a prospective cohort study of fetuses with congenital diaphragmatic hernia and observed/expected lung/head ratio less than 30%. Eligible women had planned fetoscopic tracheal balloon occlusion at 26 0/7-29 6/7 weeks of gestation and balloon removal 4-6 weeks later. Standardized prenatal and postnatal care was at a single institution. Fetoscopic tracheal balloon occlusion details, lung growth, obstetric complications, birth outcome, and infant outcome details until discharge were evaluated.

RESULTS

Of 57 women screened, 14 (25%) were enrolled between 2015 and 2019. The congenital diaphragmatic hernia was left in 12 (86%); the pre-fetoscopic tracheal balloon occlusion observed/expected lung/head ratio was 23.2% (range 15.8-29.0%). At a median gestational age of 28 5/7 weeks (range 27 3/7-29 6/7), fetoscopic tracheal balloon occlusion was successful in all cases, and balloons remained in situ. Removal was elective in 10 (71%) patients, by ultrasound-guided needle puncture in eight (57%), and occurred at a median of 33 4/7 weeks of gestation (range 32 1/7-34 4/7; median occlusion 34 days, range 17-44). The post-fetoscopic tracheal balloon occlusion observed/expected lung/head ratio increased to a median of 62.8% (44.0-108) and fell to a median of 46.6% (range 30-92) after balloon removal (all Mann Whitney U, P<.003). For prevention of preterm birth, all patients received vaginal progesterone; 11 (79%) required additional tocolytics, three (21%) had vaginal pessary placement for cervical shortening, and five (36%) had amnioreduction for polyhydramnios. Median gestational age at birth was 39 2/7 weeks (range 33 6/7-39 4/7), with term birth in eight (57%) patients. Twelve (86%) neonates required high-frequency ventilation, and seven (50%) required extracorporeal membrane oxygenation for a median of 7 days (range 3-19). All neonates needed patch repair. Neonatal survival was 93% (n=13, 95% CI 49-100%), and survival to hospital discharge was 86% (n=12, 95% CI 44-100%).

CONCLUSION

Fetoscopic tracheal balloon occlusion for severe congenital diaphragmatic hernia was feasible in our single-center setting, with few obstetric complications and favorable infant outcome.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT02710968.

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.

Congenital diaphragmatic hernia: current management strategies from antenatal diagnosis to long-term follow-up

Congenital diaphragmatic hernia (CDH) is a developmental birth defect consisting of a diaphragmatic defect and abnormal lung development. CDH complicates 2.3-2.8 per 10,000 live births. Despite efforts to standardize clinical practice, management of CDH remains challenging. Frequent re-evaluation of clinical practices in CDH reveals that management of CDH is evolving from one of postnatal stabilization to prenatal optimization. Translational research reveals promising avenues for in utero therapeutic intervention, including fetoscopic endoluminal tracheal occlusion. These remain highly experimental and demand improved antenatal diagnostics. Timely diagnosis of CDH and identification of severely affected fetuses allow time for delivery planning or in utero therapeutics. Optimal perinatal care and surgical treatment strategies are highly debated. Improved CDH mortality rates have placed increased emphasis on identifying and monitoring the long-term sequelae of disease throughout childhood and into adulthood. We review the current management strategies for CDH, highlighting where progress has been made, and where future developments have the potential to revolutionize care in this vulnerable patient population.

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.

Effects of tracheal occlusion on the neonatal cardiopulmonary transition in an ovine model of diaphragmatic hernia

OBJECTIVE

Fetoscopic endoluminal tracheal occlusion (FETO) aims to reverse pulmonary hypoplasia associated with congenital diaphragmatic hernia (CDH) and mitigate the associated respiratory insufficiency and pulmonary hypertension after birth. We aimed to determine whether FETO improves the cardiopulmonary transition at birth in an ovine model of CDH.

METHODS

In 12 ovine fetuses with surgically induced diaphragmatic hernia (DH; 80 dGA), an endotracheal balloon was placed tracheoscopically at ≈110 dGA and removed at ≈131 dGA (DH+FETO), while 10 were left untreated (DH). At ≈138 dGA, all lambs (survival at delivery: 67% [DH+FETO], 70% [DH]) were delivered via caesarean section and ventilated for 2 hours. Physiological and ventilation parameters were continuously recorded, and arterial blood-gas values were measured.

RESULTS

Compared with DH, DH+FETO lambs had increased wet lung-to-body-weight ratio (0.031±0.004 vs 0.016±0.002) and dynamic lung compliance (0.7±0.1 vs 0.4±0.1 mL/cmH₂O). Pulmonary vascular resistance was lower in DH+FETO lambs (0.44±0.11 vs 1.06±0.17 mm Hg/[mL/min]). However, after correction for lung weight, pulmonary blood flow was not significantly different between the groups (4.19±0.57 vs 4.05±0.60 mL/min/g). Alveolar-arterial difference in oxygen tension was not significantly different between DH+FETO and DH (402±41mm Hg vs 401±45 mm Hg).

CONCLUSIONS

FETO accelerated lung growth in fetuses with CDH and improved neonatal respiratory function during the cardiopulmonary transition at birth. However, despite improved lung compliance and reduced pulmonary vascular resistance, there were less pronounced benefits for gas exchange during the first 2 hours of life.

Long tail balloon as a new approach for fetoscopic tracheal occlusion for a treatment of severe congenital diaphragmatic hernia

Severe congenital diaphragmatic hernia (CDH) remains a significant challenge for neonatal specialists. In order to reduce complications during extraction of the surgical balloon after fetoscopic tracheal occlusion (FETO) CDH, we have developed a FETO with a ‘long tail balloon’ of 2.5 mL volume. Here we describe two successful uses of the device with observed/expected total fetal lung volume (o/e TFLV) of 15% and with o/e TFLV of 24% and ‘liver up’. The o/e TFLV increased to 134% in first case and to 47% in second fetus. The balloon was successfully extracted at 34 weeks' gestation by pulling the long tail suture during second fetoscopy. In the second case the fetus pulled out the balloon from trachea itself by traction onto the balloon's long tail. Both neonates were operated on for their CDH with a good outcome. This work showed the feasibility of this long tail balloon for FETO to reduce the technical difficulty of the balloon extraction and the possibility that fetuses are able to extract the balloon by itself by pulling the balloons' long tail. Further development of long tail balloon for FETO could facilitate its extraction thereby reducing neonatal complications.

Prenatal diagnosis and management of congenital diaphragmatic hernia

Congenital diaphragmatic hernia is characterized by failed closure of the diaphragm, thereby allowing abdominal viscera to herniate into the thoracic cavity and subsequently interfering with normal lung development. At birth, pulmonary hypoplasia leads to respiratory insufficiency and persistent pulmonary hypertension (PHT), that is lethal in up to 32% of patients. In isolated cases, the outcome may be predicted prenatally by medical imaging and advanced genetic testing. In those fetuses with a predicted poor outcome, fetoscopic endoluminal tracheal occlusion may be offered. This procedure is currently being evaluated in a global randomized clinical trial (www.TOTALtrial.eu). We are currently investigating alternative strategies including transplacental sildenafil administration to reduce the occurrence of persistent PHT.

Characterization of a reversible thermally-actuated polymer-valve: A potential dynamic treatment for congenital diaphragmatic hernia

BACKGROUND

Congenital diaphragmatic hernia (CDH) is a fetal defect comprising an incomplete diaphragm and the herniation of abdominal organs into the chest cavity that interfere with fetal pulmonary development. Though the most promising treatment for CDH is via interventional fetoscopic tracheal occlusion (TO) surgery in-utero, it has produced mixed results due to the static nature of the inserted occlusion. We hypothesize that a suitable noninvasively-actuatable, cyclic-release tracheal occlusion device can be developed to enable dynamic tracheal occlusion (dTO) implementation.

OBJECTIVE

To conduct an in-vitro proof-of-concept investigation of the construction of thermo-responsive polymer valves designed for targeted activation within a physiologically realizable temperature range as a first step towards potential development of a noninvasively-actuatable implantable device to facilitate dynamic tracheal occlusion (dTO) therapy.

METHODS

Six thermo-responsive polymer valves, with a critical solution temperature slightly higher than normal physiological body temperature of 37°C, were fabricated using a copolymer of n-isopropylacrylamide (NIPAM) and dimethylacrylamide (DMAA). Three of the valves underwent ethylene oxide (EtO) sterilization while the other three served as controls for EtO-processing compatibility testing. Thermal response actuation of the valves and their steady-state flow performances were evaluated using water and caprine amniotic fluid.

RESULTS

All six valves consisting of 0.3-mole fraction of DMAA were tested for thermal actuation of caprine amniotic fluid flow at temperatures ranging from 30-44°C. They all exhibited initiation of valve actuation opening at ~40°C with full completion at ~44°C. The overall average coefficient of variation (CV) for the day-to-day flow performance of the valves tested was less than 12%. Based on a Student t-test, there was no significant difference in the operational characteristics for the EtO processed versus the non-EtO processed valves tested.

CONCLUSIONS

We successfully fabricated and demonstrated physiological realizable temperature range operation of thermo-responsive polymer valves in-vitro and their suitability for standard EtO sterilization processing, a prerequisite for future in-vivo surgical implantation testing.

Fetoscopic endoluminal tracheal occlusion and reestablishment of fetal airways for congenital diaphragmatic hernia

Background

Congenital diaphragmatic hernia (CDH) is a congenital anomaly with high mortality and morbidity mainly due to pulmonary hypoplasia and hypertension. Temporary fetal tracheal occlusion to promote prenatal lung growth may improve survival. Entrapment of lung fluid stretches the airways, leading to lung growth.

Methods

Fetal endoluminal tracheal occlusion (FETO) is performed by percutaneous sono-endoscopic insertion of a balloon developed for interventional radiology. Reversal of the occlusion to induce lung maturation can be performed by fetoscopy, transabdominal puncture, tracheoscopy, or by postnatal removal if all else fails.

Results

FETO and balloon removal have been shown safe in experienced hands. This paper deals with the technical aspects of balloon insertion and removal. While FETO is invasive, it has minimal maternal risks yet can cause preterm birth potentially offsetting its beneficial effects.

Conclusion

For left-sided severe and moderate CDH, the procedure is considered investigational and is currently being evaluated in a global randomized clinical trial (https://www.totaltrial.eu/). The procedure can be clinically offered to fetuses with severe right-sided CDH.

Pulmonary vascular development in congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a rare congenital anomaly characterised by a diaphragmatic defect, persistent pulmonary hypertension (PH) and lung hypoplasia. The relative contribution of these three elements can vary considerably in individual patients. Most affected children suffer primarily from the associated PH, for which the therapeutic modalities are limited and frequently not evidence based. The vascular defects associated with PH, which is characterised by increased muscularisation of arterioles and capillaries, start to develop early in gestation. Pulmonary vascular development is integrated with the development of the airway epithelium. Although our knowledge is still incomplete, the processes involved in the growth and expansion of the vasculature are beginning to be unravelled. It is clear that early disturbances of this process lead to major pulmonary growth abnormalities, resulting in serious clinical challenges and in many cases death in the newborn. Here we provide an overview of the current molecular pathways involved in pulmonary vascular development. Moreover, we describe the abnormalities associated with CDH and the potential therapeutic approaches for this severe abnormality.

Current and future antenatal management of isolated congenital diaphragmatic hernia

Congenital diaphragmatic hernia is surgically correctable, yet the poor lung development determines mortality and morbidity. In isolated cases the outcome may be predicted prenatally by medical imaging. Cases with a poor prognosis could be treated before birth. However, prenatal modulation of lung development remains experimental. Fetoscopic endoluminal tracheal occlusion triggers lung growth and is currently being evaluated in a global clinical trial. Prenatal transplacental sildenafil administration may in due course be a therapeutic approach, reducing the occurrence of persistent pulmonary hypertension, either alone or in combination with fetal surgery.

Foetoscopic endotracheal occlusion (FETO) for severe isolated left-sided congenital diaphragmatic hernia: single center Polish experience

OBJECTIVE

To present early experience with foetoscopic endotracheal occlusion (FETO) for congenital diaphragmatic hernia (CDH) in a new center in Poland.

METHODS

This was a prospective study in singleton pregnancies with CDH treated by FETO between 2014 and 2016 in the Medical University of Warsaw, Poland. FETO was carried out at 25.6-30.1 (median 27.7) weeks' gestation in 28 consecutive cases of isolated left-sided CDH with observed over expected lung area to head circumference ratio (o/e LHR) of 20.7-22.6 (median 18.9).

RESULTS

Neonatal survival rate was 46.4% (13/28) at the time of discharge. The median o/e LHR the day before balloon removal was 33.4 (19.7-57.5) and median gestational age at delivery was 34.7 (29.0-38.1) weeks. Comparison of the survivors and perinatal deaths showed no significant differences in median gestational age at FETO or median o/e LHR before FETO, but higher median gestational age at delivery (35.9, range 32.7-38.1 weeks vs. 33.2, range 29.0-37.7 weeks; p = .007) and o/e LHR before balloon removal (33.7, range 28.3-57.5 vs. 30.9, range 19.7-37.5; p = .017).

CONCLUSIONS

FETO was implemented successfully in Poland and the survival rate (46.4%) is similar to that reported in other centers. Important determinants of survival were gestational age at delivery and pulmonary response to FETO. The rate of preterm prelabor rupture of membranes (PPROM) in our series is similar to the larger series treated with FETO in the pioneering centers of this technique.

Balloon removal after fetoscopic endoluminal tracheal occlusion for congenital diaphragmatic hernia

BACKGROUND

Isolated congenital diaphragmatic hernia defect allows viscera to herniate into the chest, competing for space with the developing lungs. At birth, pulmonary hypoplasia leads to respiratory insufficiency and persistent pulmonary hypertension that is lethal in up to 30% of patients. Antenatal measurement of lung size and liver herniation can predict survival after birth. Prenatal intervention aims at stimulating lung development, clinically achieved by percutaneous fetal endoscopic tracheal occlusion under local anesthesia. This in utero treatment requires a second intervention to reestablish the airway, either before birth or at delivery.

OBJECTIVE

To describe our experience with in utero endotracheal balloon removal.

MATERIALS AND METHODS

This is a retrospective analysis of prospectively collected data on consecutive patients with congenital diaphragmatic hernia treated in utero by fetal endoscopic tracheal occlusion from 3 centers. Maternal and pregnancy-associated variables were retrieved. Balloon removal attempts were categorized as elective or emergency and by technique (in utero: ultrasound-guided puncture; fetoscopy; ex utero: on placental circulation or postnatal tracheoscopy).

RESULTS

We performed 351 balloon insertions during a 144-month period. In 9 cases removal was attempted outside fetal endoscopic tracheal occlusion centers, 3 of which were deemed impossible and led to neonatal death. We attempted 302 in-house balloon removals in 292 fetuses (217 elective [71.8%], 85 emergency [28.2%]) at 33.4 ± 0.1 weeks (range: 28.9-37.1), with a mean interval to delivery of 16.6 ± 0.8 days (0-85). Primary attempt was by fetoscopy in 196 (67.1%), by ultrasound-guided puncture in 62 (21.2%), by tracheoscopy on placental circulation in 30 (10.3%), and postnatal tracheoscopy in 4 cases (1.4%); a second attempt was required in 10 (3.4%) cases. Each center had different preferences for primary technique selection. In elective removals, we found no differences in the interval to delivery between fetoscopic and ultrasound-guided puncture removals. Difficulties during fetoscopic removal led to the development of a stylet to puncture the balloon, leading to shorter operating time and easier reestablishment of airways.

CONCLUSION

In these fetal treatment centers, the balloon could always be removed successfully. In 90% this was in utero, with the use of fetoscopy preferred over ultrasound-guided puncture. Ex utero removal was a fall-back procedure. In utero removal does not seem to precipitate immediate membrane rupture, labor, or delivery, although the design of the study did not allow for a formal conclusion. For fetoscopic removals, the introduction of a stylet facilitated retrieval. Successful removal may rely on a permanently prepared team with expertise in all possible techniques.

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.

[Fetoscopic tracheal occlusion for severe congenital diaphragmatic hernia: retrospective study]

BACKGROUND AND OBJECTIVES

The temporary fetal tracheal occlusion performed by fetoscopy accelerates lung development and reduces neonatal mortality. The aim of this paper is to present an anesthetic experience in pregnant women, whose fetuses have diaphragmatic hernia, undergoing fetoscopic tracheal occlusion (FETO).

METHOD

Retrospective, descriptive study, approved by the Institutional Ethics Committee. Data were obtained from medical and anesthetic records.

RESULTS

FETO was performed in 28 pregnant women. Demographic characteristics: age 29.8±6.5; weight 68.64±12.26; ASA I and II. Obstetric: IG 26.1±1.10 weeks (in FETO); 32.86±1.58 (reversal of occlusion); 34.96±2.78 (delivery). Delivery: cesarean section, vaginal delivery. Fetal data: Weight (g) in the occlusion and delivery times, respectively (1045.82±222.2 and 2294±553); RPC in FETO and reversal of occlusion: 0.7±0.15 and 1.32±0.34, respectively. Preoperative maternal anesthesia included ranitidine and metoclopramide, nifedipine (VO) and indomethacin (rectal). Preanesthetic medication with midazolam IV. Anesthetic techniques: combination of 0.5% hyperbaric bupivacaine (5-10mg) and sufentanil; continuous epidural predominantly with 0.5% bupivacaine associated with sufentanil, fentanyl, or morphine; general. In 8 cases, there was need to complement via catheter, with 5 submitted to PC and 3 to BC. Thirteen patients required intraoperative sedation; ephedrine was used in 15 patients. Fetal Anesthesia: fentanyl 10 to 20mg·kg^-1 and pancuronium 0,1-0,2mg·kg^-1 (IM). Neonatal survival rate was 60.7%.

CONCLUSION

FETO is a minimally invasive technique for severe congenital diaphragmatic hernia repair. Combined blockade associated with sedation and fetal anesthesia proved safe and effective for tracheal occlusion.

In vivo evidence by magnetic resonance volumetry of a gestational age dependent response to tracheal occlusion for congenital diaphragmatic hernia

OBJECTIVE

We aimed to assess in vivo changes in lung and liver volumes in fetuses with isolated congenital diaphragmatic hernia, either expectantly managed or treated in utero.

METHOD

This is a secondary analysis of prospectively collected data at two fetal therapy centers. We used archived magnetic resonance images of fetuses taken ≥7 days apart, creating paired observations in 20 expectantly managed cases, 41 with a second magnetic resonance prior to balloon reversal and 64 after balloon removal. We measured observed to expected total fetal lung volume (O/E TFLV) and liver-to-thoracic volume ratio. We calculated changes in volume as compared with the initial measurement and its rate as a function of gestational age (GA) at occlusion.

RESULTS

The liver-to-thoracic volume ratio did not change in either group. In expectantly managed fetuses, O/E TFLV did not increase with gestation. In fetuses undergoing tracheal occlusion, the measured increase in volume was 2.6 times larger with balloon in place as compared with that after its removal. GA at tracheal occlusion was an independent predictor of the O/E TFLV. The net rate seems to initially increase and plateau at a maximum of 1.5% per week by 35 to 45 days after occlusion.

CONCLUSIONS

Tracheal occlusion induces a net increase in volume, its magnitude essentially dependent on the GA at occlusion.

Experimental Evaluation of Tracheo-Amniotic Shunting for Induced Congenital High Airway Obstruction in a Sheep Model

Objective: To evaluate the feasibility of tracheo-amniotic shunting in a sheep model for congenital high airway obstruction syndrome. Material and Methods: High airway obstruction was induced around day 95 (term = 145 days) in 10 lamb fetuses by tracheal clipping. Five days later, ultrasound-guided tracheoamniotic shunting was done using either the Harrison double-pigtail bladder stent (HS) or a double-basket device (BS). Caesarean section (CS) was done around day 110. At each time point, the cardiothoracic index (CTI) was measured. Lung-to-body weight ratio (LBWR) was calculated at fetal necropsy. The primary endpoint was successful shunting defined as anatomically correct placement and functional airway decompression; the secondary endpoint was survival until CS. Results: Two sheep aborted 3 fetuses after tracheal occlusion. Overall, the median CTI at CS was significantly smaller compared to baseline [0.52 (interquartile range, IQR: 0.52-0.54) vs. 0.58 (IQR: 0.54-0.63); p = 0.01]. In the HS group (n = 4), none of the shunts were correctly positioned. In the BS group (n = 3), there was 1 correct shunt placement; however, this fetus was stillborn. Median LBWR suggested pulmonary overgrowth [0.10 (IQR: 0.08-0.11)]. Conclusion: In our hands, using this model with a long and mobile neck and relative oligohydramnios, tracheoamniotic shunting for airway obstruction has a high failure rate. If further pursued, alternative techniques or different models should be considered.

Prenatal management of the fetus with isolated congenital diaphragmatic hernia in the era of the TOTAL trial

Congenital diaphragmatic hernia (CDH) may be isolated or associated with other structural anomalies, the latter with poor prognosis. The defect allows viscera to herniate through the defect into the chest, competing for space with the developing lungs. At birth, pulmonary hypoplasia leads to respiratory insufficiency and persistent pulmonary hypertension that is lethal in up to 30% of patients. When isolated, survival chances can be predicted by antenatal measurement of lung size and liver herniation. Chromosomal microarrays and exome sequencing contribute to understanding genetic factors underlying isolated CDH. Prenatal intervention aims at stimulating lung development, clinically achieved by percutaneous fetal endoscopic tracheal occlusion (FETO) under local anesthesia. The Tracheal Occlusion To Accelerate Lung growth trial (www.totaltrial.eu) is an international randomized trial investigating the role of fetal therapy for severe and moderate pulmonary hypoplasia. Despite an apparent increase in survival following FETO, the search for lesser invasive and more potent prenatal interventions must continue.

New Insights into Congenital Diaphragmatic Hernia - A Surgeon's Introduction to CDH Animal Models

In recent decades, new research into the developmental defects and pathophysiological basis of congenital diaphragmatic hernia (CDH) has revealed opportunities for the development of innovative therapies. Importantly, the use of animal models to represent this anomaly in the laboratory has resulted in the discovery of many important genetic, epigenetic, and other molecular contributors to this condition. In this review, the most commonly used and newly devised animal models of CDH are presented to familiarize the reader with the latest innovations in the basic sciences.

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.

Predictors of neonatal morbidity in fetuses with severe isolated congenital diaphragmatic hernia undergoing fetoscopic tracheal occlusion

OBJECTIVES

To investigate neonatal morbidity in fetuses with severe congenital diaphragmatic hernia (CDH) treated with fetoscopic endoluminal tracheal occlusion (FETO) and compare it with historical controls with less severe forms of CDH that were managed expectantly.

METHODS

This was a prospective, multicenter study on neonatal outcomes and prenatal predictors in 90 FETO survivors (78 left-sided, 12 right) and 41 controls from the antenatal CDH registry with either severe or moderate hypoplasia who were managed expectantly. We also investigated early neonatal morbidity indicators, including the need for patch repair, duration of mechanical ventilation and supplemental oxygen, age at full enteral feeding and incidence of pulmonary hypertension.

RESULTS

Gestational age at delivery was predictive of duration of assisted ventilation (P = 0.046), days on supplemental oxygen (P = 0.019) and age at full enteral feeding (P = 0.020). When delivery took place after 34 weeks' gestation, neonatal morbidity of FETO cases was comparable with that of expectantly managed cases with moderate hypoplasia.

CONCLUSIONS

Fetal intervention for severe CDH is associated with neonatal morbidity that is comparable with that of an expectantly managed group with less severe disease.

Fetal pulmonary response after fetoscopic tracheal occlusion for severe isolated congenital diaphragmatic hernia

OBJECTIVE

To estimate the response in lung growth and vascularity after fetal endoscopic tracheal occlusion for severe congenital diaphragmatic hernia in the prediction of neonatal survival.

METHODS

Between January 2006 and December 2010, fetal lung parameters (observed-to-expected lung-to-head ratio; observed-to-expected lung volume; and contralateral lung vascularization index) were evaluated before fetal tracheal occlusion and were evaluated longitudinally every 2 weeks in 72 fetuses with severe isolated congenital diaphragmatic hernia. Thirty-five fetuses underwent fetal endoscopic tracheal occlusion and 37 cases did not.

RESULTS

Survival rate was significantly higher in the fetal endoscopic tracheal occlusion group (54.3%) than in the no fetal endoscopic tracheal occlusion group (5.4%, P<.01). Fetal endoscopic tracheal occlusion resulted in a significant improvement in fetal lung size and pulmonary vascularity when compared with fetuses that did not go to the fetal intervention (increase of the observed-to-expected lung-to-head ratio, observed-to-expected total lung volume, and contralateral pulmonary vascularization index 56.2% compared with 0.3%, 37.9% compared with 0.1%, and 98.6% compared with 0.0%, respectively; P<.01). Receiver operating characteristic curves indicated that the observed-to-expected total fetal lung volume was the single best predictor of neonatal survival before fetal endoscopic tracheal occlusion (cutoff 0.23, area under the curve [AUC] 0.88, relative risk 5.3, 95% confidence interval [CI] 1.4-19.7). However, the contralateral lung vascularization index at 4 weeks after fetal endoscopic tracheal occlusion was more accurate in the prediction of neonatal outcome (cutoff 24.0%, AUC 0.98, relative risk 9.9, 95% CI 1.5-66.9) with the combination of observed-to-expected lung volumes and contralateral lung vascularization index at 4 weeks being the best predictor of outcome (AUC 0.98, relative risk 16.6, 95% CI 2.5-112.3).

CONCLUSION

Fetal endoscopic tracheal occlusion improves survival rate by increasing the lung size and pulmonary vascularity in fetuses with severe congenital diaphragmatic hernia. The pulmonary response after fetal endoscopic tracheal occlusion can be used to predict neonatal survival.