Fetal endoscopic tracheal occlusion for congenital diaphragmatic hernia: systematic review and meta-analysis

Observed/Expected Lung-To-Head Ratio and Total Lung Volumes That Identify Fetuses With Severe Congenital Diaphragmatic Hernia in a North American Fetal Center

OBJECTIVE

To define the ultrasound observed/expected lung-to-head ratio (O/E LHR) and magnetic resonance imaging (MRI) observed/expected total lung volume (O/E TLV) cut-offs associated with survival and lack of extracorporeal membrane oxygenation (ECMO) utilization to determine the most severe cohort that may benefit from fetal intervention.

METHODS

Retrospective review of patients with a prenatal diagnosis of isolated left or right congenital diaphragmatic hernia (L CDH, R CDH) seen and delivered at our level III fetal center from January 2013-July 2023. Data were extracted from our clinical outcome database. Characteristics of survivors and non-survivors were compared for both the L CDH and R CDH groups. For both O/E LHR and O/E TLV, the Youden criteria were then used to determine a good sensitivity and specificity for predicting survival and ECMO utilization for L and R CDH, respectively, in Receiver Operator Characteristic (ROC) curve analysis.

RESULTS

340 patients were included in the study, including 283 (83.2%) with L CDH and 57 (16.8%) with R CDH. The median [interquartile range, IQR] O/E LHR for L and R CDH was 37.9 [28.7-47.3] and 49.0 [40.0-64.5], respectively. The median O/E TLV for L and R CDH was 36.0 [28.0-48.0] and 25.3 [23.6-29.8], respectively. For survival, an O/E LHR of 28.1% and O/E TLV of 34.0% and an O/E LHR of 46.8% and O/E TLV of 17.6% were the best cut-offs for L and R CDH, respectively. For ECMO utilization, an O/E LHR of 32.8% and O/E TLV of 35.3% and an O/E LHR of 47.0% and O/E TLV of 22.0% were the best cut-offs for L and R CDH, respectively.

CONCLUSION

We report the best ultrasound O/E LHR and MRI TLV cut-offs associated with survival and lack of ECMO utilization in our cohort.

The Fall Out of the 2017 European Medical Device Regulation for Tracheal Occlusion

OBJECTIVE

The use of the Balt Goldbal-balloon and Baltacci-catheter in Fetoscopic Endoluminal Tracheal Occlusion is affected by the 2017-European Medical Device Regulation, which necessitates recertification even for devices long considered safe. This regulation has led the manufacturer to stop distributing these devices in Europe. We alert fetal surgery centers to these challenges and regulators to the broader impact on the availability of fetal therapy devices in Europe.

METHODS

We surveyed 50 fetal surgery centers worldwide and communicated directly with the manufacturer. Additionally, we provide updates on a new device under evaluation.

RESULTS

The response rate among 39 balloon users was 95% (n = 37). Currently, all balloons in Europe are expired. Supply issues exist in Australasia and South-America, with some distributors reporting discontinuation despite the manufacturer's communications on its sustained availability. Some centers manage shortages by importing from other countries. Balt has agreed to supply devices to European centers that obtain derogation by the national competent authorities, for which we cannot provide a generic procedure. An alternative device is unlikely to be marketed before 2026.

CONCLUSION

This scenario highlights the unintended consequences of stringent medical device regulations, leading to their unavailability for beneficial procedures or complicated administrative processes, even as these devices remain available outside the EU.

Recent advancements in fetal anesthesia

PURPOSE OF REVIEW

Fetal surgery has evolved into a transformative field, offering hope for the management of complex prenatal conditions. The purpose of this review is two-fold: to provide a brief overview of fetal anesthetic considerations, and to examine recent advancements which have significantly improved maternal safety and expanded the scope of treatable fetal anomalies.

RECENT FINDINGS

Enhanced imaging technologies, such as high-resolution ultrasound and fetal MRI, have enabled precise diagnoses and surgical planning to improve outcomes. Innovations in techniques, expanded indications for fetal surgery, and adoption of maternal anesthesia protocols have all helped to minimize complications and enhance recovery. Placental research shows no immune response or pathology from fetal surgery, suggesting it does not contribute to preterm delivery.

SUMMARY

Advancements in fetal intervention collectively underscore the field's commitment to delivering optimal outcomes for both mother and child while paving the way for future breakthroughs in prenatal care.

Congenital Chest Lesions and Interventions

Anomalies of the fetal chest require advanced imaging with ultrasound and MR imaging as well as expertise on the part of the interpreting pediatric radiologist. Congenital diaphragmatic hernia and congenital lung malformation are the most frequently seen, and in both conditions, the radiologist should provide both detailed anatomic description and measurement data for prognostication. This article provides a detailed approach to imaging the anatomy, in-depth explanation of available measurements and prognostic value, and keys to identifying candidates for fetal intervention. Less common congenital lung tumors and mediastinal and chest wall masses are also reviewed.

Intra-Amniotic Sildenafil and Rosiglitazone Late in Gestation Ameliorate the Pulmonary Hypertension Phenotype in Congenital Diaphragmatic Hernia

BACKGROUND

Pulmonary hypertension remains difficult to manage in congenital diaphragmatic hernia (CDH). Prenatal therapy may ameliorate postnatal pulmonary hypertension. We hypothesized that intra-amniotic (IA) injection of either sildenafil, a phosphodiesterase 5 inhibitor, or rosiglitazone, a PPAR-γ agonist, or both late in gestation would decrease the detrimental pulmonary vascular remodeling seen in CDH and improve peripheral pulmonary blood flow.

METHODS

Pregnant rats were gavaged with nitrogen on embryonic day (E) 9.5 to induce fetal CDH. Sildenafil and/or rosiglitazone were administered to each fetus via an intra-amniotic injection after laparotomy on the pregnant dam at E19.5, and fetuses delivered at E21.5. Efficacy measures were gross necropsy, histology, peripheral blood flow assessment using intra-cardiac injection of a vascular tracer after delivery, and protein expression analysis.

RESULTS

Intra-amniotic injections did not affect fetal survival, the incidence of CDH, or lung weight-to-body weight ratio in CDH fetuses. IA sildenafil injection decreased pulmonary vascular muscularization, and rosiglitazone produced an increase in peripheral pulmonary blood flow distribution. The combination of sildenafil and rosiglitazone decreased pulmonary artery smooth muscle cell proliferation. These intra-amniotic treatments did not show any negative effects in either CDH fetuses or control fetuses.

CONCLUSION

IA injection of sildenafil and rosiglitazone late in gestation ameliorates the pulmonary hypertensive phenotype of CDH and may have utility in clinical translation.

LEVEL OF EVIDENCE

Not applicable.

Abdominal wall muscle weakness outcomes after split abdominal flap repair of large congenital diaphragmatic hernias in newborn

PURPOSE

Split abdominal wall muscle flap (SAWMF) is a technique to repair large defects in congenital diaphragmatic hernia (CDH). A possible objection to this intervention could be any associated abdominal muscle weakness. Our aim is to analyze the evolution of this abdominal muscle wall weakness.

METHODS

Retrospective review of CDH repair by SAWMF (internal oblique muscle and transverse) from 2004 to 2023 focusing on the evolution of muscle wall weakness.

RESULTS

Eighteen neonates of 148 CDH patients (12,1%) were repaired using SAWMF. Mean gestational age and birth weight were 35.7 ± 3.5 weeks and 2587 ± 816 g. Mean lung-to-head ratio was 1.49 ± 0.28 and 78% liver-up. Seven patients (38%) were prenatally treated by tracheal occlusion. Ninety-four percent of the flaps were used for primary repair and one to repair a recurrence. One patient (5.6%) experienced recurrence. Abdominal muscle wall weakness was present in the form of a bulge. Resolution of weakness at 1, 2 and 3 years was 67%, 89% and 94%, respectively. No patient required treatment for weakness or died.

CONCLUSIONS

Abdominal muscular weakness after a split abdominal wall muscle flap repair is not a limitation for its realization since it is asymptomatic and presents a prompt spontaneous resolution.

LEVEL OF EVIDENCE

IV.

Fetoscopic Tracheal Occlusion for Isolated Severe Left Diaphragmatic Hernia: A Systematic Review and Meta-Analysis

Background: We aimed to conduct a systematic review and meta-analysis to evaluate the fetoscopic tracheal occlusion in patients with isolated severe and left-sided diaphragmatic hernia. Methods: Cochrane Library, Embase, and PubMed (Medline) databases were searched from inception to February 2024 with no filters or language restrictions. We included studies evaluating the outcomes of fetoscopic intervention compared to expectant management among patients with severe congenital diaphragmatic hernia exclusively on the left side. A random-effects pairwise meta-analysis was performed using RStudio version 4.3.1. Results: In this study, we included 540 patients from three randomized trials and five cohorts. We found an increased likelihood of neonatal survival associated with fetoscopic tracheal occlusion (Odds Ratio, 5.07; 95% Confidence Intervals, 1.91 to 13.44; p < 0.01) across general and subgroup analyses. Nevertheless, there were higher rates of preterm birth (OR, 5.62; 95% CI, 3.47-9.11; p < 0.01) and preterm premature rupture of membranes (OR, 7.13; 95% CI, 3.76-13.54; p < 0.01) in fetal endoscopic tracheal occlusion group compared to the expectant management. Conclusions: Our systematic review and meta-analysis demonstrated the benefit of fetoscopic tracheal occlusion in improving neonatal and six-month postnatal survival in fetuses with severe left-sided CDH. Further studies are still necessary to evaluate the efficacy of tracheal occlusion for isolated right-sided CDH, as well as the optimal timing to perform the intervention.

Plugging membranes after fetoscopy in congenital diaphragmatic hernia: early cost-effectiveness analysis

OBJECTIVES

Fetal endoscopic tracheal occlusion (FETO) improves neonatal survival of fetuses with congenital diaphragmatic hernia (CDH). However, FETO also increases the risk of preterm prelabor rupture of membranes (PPROM) and preterm delivery (PTD), as fetal membrane defects after fetoscopy do not heal. To solve this issue, an advanced sealing plug for closing the membrane defect is being developed. Using early-stage health economic modeling, we aimed to estimate the potential value of this innovative plug in terms of costs and effects, and to determine the properties required for it to become cost-effective.

METHODS

Early-stage health economic modeling was applied to the case of performing FETO in women with a singleton pregnancy whose fetus is diagnosed prenatally with CDH. We simulated a cohort of patients using a state-transition model over a 45-year time horizon. In our best-case-scenario analysis, we compared the current-care strategy with the perfect-plug strategy, which reduces the risk of PPROM and PTD by 100%, to determine the maximum quality-adjusted life years (QALYs) gained and costs saved. Using threshold analysis, we determined the minimum percentage reduction in the risk of PPROM and PTD required for the plug to be considered cost-effective. The impact of model parameters on outcome was investigated using a sensitivity analysis.

RESULTS

Our model indicated that a perfect-plug strategy would yield on average an additional 1.94 QALYs at a cost decrease of €2554 per patient. These values were influenced strongly by the percentage of cases with early PTD (27-34 weeks). Threshold analysis showed that, for €500 per plug, the plug strategy needs a minimum percentage reduction of 1.83% in the risk of PPROM and PTD (i.e. reduction in the risk from 47.50% to 46.63% for PPROM and from 71.50% to 70.19% for PTD) to be cost-effective.

CONCLUSIONS

Our model-based approach showed clear potential of the plug strategy when applied in the context of FETO for CDH fetuses, as only a minor reduction in the risk of PPROM and PTD is needed for the plug to be cost-effective. Its value is expected to be even higher when used in conditions associated with a higher rate of early PTD. Continued investment in research and development of the plug strategy appears to provide value for money. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.