Prenatal assessment of pulmonary vasculature development in fetuses with congenital diaphragmatic hernia: A literature review

Pathophysiological studies have shown that pulmonary vascular development is impaired in fetuses with a congenital diaphragmatic hernia (CDH), leading to a simplified vascular tree and increased vascular resistance. Multiple studies have described prenatal ultrasound parameters for the assessment of the pulmonary vasculature, but none of these parameters are used in daily clinical practice. We provide a comprehensive review of the literature published between January 1990 and February 2022 describing these parameters, and aim to explain the clinical relevance of these parameters from what is known from pathophysiological studies. Prenatal detection of a smaller diameter of the contralateral (i.e. contralateral to the diaphragmatic defect) first branch of the pulmonary artery (PA), higher pulsatility indices (PI), higher peak early diastolic reverse flow values, and a lower vascularization index seem of added value for the prediction of survival and, to a lesser extent, morbidity. Integration within the routine evaluation is complicated by the lack of uniformity of the methods used. To address the main components of the pathophysiological changes, we recommend future prenatal studies in CDH with a focus on PI values, PA diameters and pulmonary vascular branching.

Do FETO CDH survivors need the same follow-up program as non-FETO patients?

Congenital diaphragmatic hernia (CDH) survivors are at risk of developing significant chronic health conditions and disabilities. The main purpose of this study was to compare the outcomes of CDH infants at 2 years of age (2y) according to whether the infants had undergone fetoscopic tracheal occlusion (FETO) during the prenatal period and characterize the relationship between morbidity at 2y and perinatal characteristics. Retrospective cohort single center study. Eleven years of clinical follow-up data (from 2006 to 2017) were collected. Prenatal and neonatal factors as well as growth, respiratory, and neurological evaluations at 2y were analyzed. One hundred and fourteen CDH survivors were evaluated. Failure to thrive (FTT) was present in 24.6% of patients, gastroesophageal reflux disease (GERD) in 22.8%, 28.9% developed respiratory problems, and 22% had neurodevelopment disabilities. Prematurity and birth weight < 2500 g were related to FTT and respiratory morbidity. Time to reach full enteral nutrition and prenatal severity markers seemed to influence all outcomes, but FETO therapy itself only had an effect on respiratory morbidity. Some variables related to postnatal severity (ECMO, patch closure, days on mechanic ventilation, and vasodilator treatment) were associated with almost all outcomes.  Conclusion: CDH patients have specific morbidities at 2y, most of them related to lung hypoplasia severity. Only respiratory problems were related to FETO therapy itself. The implementation of a specific multidisciplinary follow-up program for CDH patients is essential to provide them the best standard of care, but, more severe patients, regardless of whether they received prenatal therapy, need a more intensive follow-up. What is Known: • Antenatal fetoscopic endoluminal tracheal occlusion (FETO) increases survival in more severe congenital diaphragmatic hernia patients. • Congenital diaphragmatic hernia survivors are at risk of developing significant chronic health conditions and disabilities. Very limited data are available about the follow-up in patients with congenital diaphragmatic hernia and FETO therapy. What is New: • CDH patients have specific morbidities at 2 years of age, most of them related to lung hypoplasia severity. • FETO patients present more respiratory problems at 2 years of age but they don't have an increased incidence of other morbidities. More severe patients, regardless of whether they received prenatal therapy, need a more intensive follow-up.

Perinatal Outcomes after Fetal Endoscopic Tracheal Occlusion for Isolated Congenital Diaphragmatic Hernia: Rapid Review

OBJECTIVE

 To compare the perinatal outcomes of fetuses with isolated congenital diaphragmatic hernia after fetal endoscopic tracheal occlusion (FETO) and antenatal expectant management.

DATA SOURCES

 In this rapid review, searches were conducted in the MEDLINE, PMC, EMBASE and CENTRAL databases between August 10th and September 4th, 2020. Randomized controlled trials (RCTs), quasi-RCTs or cluster-RCTs published in English in the past ten years were included.

STUDY SELECTION

 We retrieved 203 publications; 180 studies were screened by abstract. Full-text selection was performed for eight studies, and 1 single center RCT met the inclusion criteria (41 randomized women; 20 in the FETO group, and 21 in the control group).

DATA COLLECTION

 Data collection was performed independently, by both authors, in two steps (title and abstract and full-text reading).

DATA SYNTHESIS

 There were no cases of maternal mortality. The mean gestational age at delivery was of 35.6 ±  2.4 weeks in the intervention group, and of 37.4 ±  1.9 weeks among the controls (p < 0.01). Survival until 6 months of age was reported in 50% of the intervention group, and in 5.8% of the controls (p < 0.01; relative risk: 10.5; 95% confidence interval [95%CI]: 1.5-74.7). Severe postnatal pulmonary hypertension was found in 50% of the infants in the intervention group, and in 85.7% of controls (p = 0.02; relative risk: 0.6; 95%CI: 0.4-0.9). An analysis of the study indicated some concerns of risk of bias. The quality of evidence was considered moderate to low.

CONCLUSION

 Current evidence is limited but suggests that FETO may be an effective intervention to improve perinatal outcomes.

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.

Dual-Imaging Modality Approach to Evaluate Cerebral Hemodynamics in Growth-Restricted Fetuses: Oxygenation and Perfusion

OBJECTIVE

To evaluate a dual-imaging modality approach to obtain a combined estimation of venous blood oxygenation (SνO2) using susceptibility-weighted magnetic resonance imaging (SWI-MRI), and blood perfusion using power Dopp-ler ultrasound (PDU) and fractional moving blood volume (FMBV) in the brain of normal growth and growth-restricted fetuses.

METHODS

Normal growth (n = 33) and growth-restricted fetuses (n = 10) from singleton pregnancies between 20 and 40 weeks of gestation were evaluated. MRI was performed and SνO2 was calculated using SWI-MRI data obtained in the straight section of the superior sagittal sinus. Blood perfusion was estimated using PDU and FMBV from the frontal lobe in a mid-sagittal plane of the fetal brain. The association between fetal brain SνO2 and FMBV, and the distribution of SνO2 and FMBV values across gestation were calculated for both groups.

RESULTS

In growth-restricted fetuses, the brain SνO2 values were similar, and the FMBV values were higher across gestation as compared to normal growth fetuses. There was a significantly positive association between SνO2 and FMBV values (slope = 0.38 ± 0.12; r = 0.7; p = 0.02) in growth-restricted fetuses. In normal growth fetuses, SνO2 showed a mild decreasing trend (slope = -0.7 ± 0.4; p = 0.1), whereas FMBV showed a mild increasing trend (slope = 0.2 ± 0.2; p = 0.2) with advancing gestation, and a mild but significant negative association (slope = -0.78 ± 0.3; r = -0.4; p = 0.04) between these two estimates.

CONCLUSION

Combined MRI (SWI) and ultrasound (FMBV) techniques showed a significant association between cerebral blood oxygenation and blood perfusion in normal growth and growth-restricted fetuses. This dual-imaging approach could contribute to the early detection of fetal "brain sparing" and brain oxygen saturation changes in high-risk pregnancies.

Providing direction improves function: Comparison of a radial pore-orientated acellular collagen scaffold to clinical alternatives in a surgically induced rabbit diaphragmatic tissue defect model

Gore-Tex® is a widely used durable patch for repair of congenital diaphragmatic defects yet may result in complications. We compared Gore-Tex with a composite of a radial pore-orientated collagen scaffold (RP-Composite) and clinically used porcine small intestinal submucosa (SIS; Surgisis®) in a rabbit model for diaphragmatic hernia. The growing rabbit mimics the rapid rib cage growth and reherniation rates seen in children. We created and immediately repaired left hemidiaphragmatic defects in 6-week-old rabbits with Gore-Tex, SIS, and an RP-Composite scaffold. An additional group of rabbits had a sham operation. At 90 days, survivors more than doubled in weight. We observed few reherniations or eventrations in Gore-Tex (17%) and RP-Composite (22%) implanted animals. However, SIS failed in all rabbits. Maximum transdiaphragmatic pressure was lower in Gore-Tex (71%) than RP-Composite implanted animals (112%) or sham (134%). Gore-Tex repairs were less compliant than RP-Composite, which behaved as sham diaphragm (p < 0.01). RP-Composite induced less foreign body giant cell reaction than Gore-Tex (p < 0.05) with more collagen deposition (p < 0.001), although there was a tendency for the scaffold to calcify. Unlike Gore-Tex, the compliance of diaphragms reconstructed with RP-Composite scaffolds were comparable with native diaphragm, whereas reherniation rates and transdiaphragmatic pressure measurements were similar.

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.

A growing animal model for neonatal repair of large diaphragmatic defects to evaluate patch function and outcome

Objectives

We aimed to develop a more representative model for neonatal congenital diaphragmatic hernia repair in a large animal model, by creating a large defect in a fast-growing pup, using functional pulmonary and diaphragmatic read outs.

Background

Grafts are increasingly used to repair congenital diaphragmatic hernia with the risk of local complications. Growing animal models have been used to test novel materials.

Methods

6-week-old rabbits underwent fiberoptic intubation, left subcostal laparotomy and hemi-diaphragmatic excision (either nearly complete (n = 13) or 3*3cm (n = 9)) and primary closure (Gore-Tex patch). Survival was further increased by moving to laryngeal mask airway ventilation (n = 15). Sham operated animals were used as controls (n = 6). Survivors (90 days) underwent chest X-Ray (scoliosis), measurements of maximum transdiaphragmatic pressure and breathing pattern (tidal volume, Pdi). Rates of herniation, lung histology and right hemi-diaphragmatic fiber cross-sectional area was measured.

Results

Rabbits surviving 90 days doubled their weight. Only one (8%) with a complete defect survived to 90 days. In the 3*3cm defect group all survived to 48 hours, however seven (78%) died later (16–49 days) from respiratory failure secondary to tracheal stricture formation. Use of a laryngeal mask airway doubled 90-day survival, one pup displaying herniation (17%). Cobb angel measurements, breathing pattern, and lung histology were comparable to sham. Under exertion, sham animals increased their maximum transdiaphragmatic pressure 134% compared to a 71% increase in patched animals (p<0.05). Patched animals had a compensatory increase in their right hemi-diaphragmatic fiber cross-sectional area (p<0.0001).

Conclusions

A primarily patched 3*3cm defect in growing rabbits, under laryngeal mask airway ventilation, enables adequate survival with normal lung function and reduced maximum transdiaphragmatic pressure compared to controls.

Prediction of Neonatal Respiratory Function and Pulmonary Hypertension in Fetuses with Isolated Congenital Diaphragmatic Hernia in the Fetal Endoscopic Tracleal Occlusion Era: A Single-Center Study

Objective: To correlate prenatal indicators of pulmonary hypoplasia with neonatal lung function and pulmonary hypertension (PHT) in isolated congenital diaphragmatic hernia (iCDH). Materials and Methods: Prospective single-center study on 40 fetuses with iCDH either expectantly managed (n = 13) or undergoing tracheal occlusion (n = 27). Prenatal predictors included observed/expected lung-head ratio (O/E LHR), observed/expected total fetal lung volume, fetal pulmonary reactivity to maternal O2 administration (Δpulsatility index, ΔPI) and liver-to-thorax ratio (LiTR) as measured in the second and third trimesters. Postnatal outcome measures included survival until discharge, best oxygenation index (OI) and alveolar-arterial oxygen gradient [D(A-a)O2] in the first 24 h of life and the occurrence of PHT in the first 28 days of life. Results: Median gestational age (GA) at evaluations was 27.2 and 34.3 weeks. GA at delivery was 36.0 weeks, and overall survival was 55%. In the second trimester, measurement of lung size, LiTR and pulmonary reactivity were significantly related to survival and the best OI and D(A-a)O2.The occurrence of PHT was better predicted by ΔPI and LiTR. Conclusions: O/E LHR, LiTR and vascular reactivity correlate with ventilatory parameters in the first 24 h of life. Occurrence of PHT at ≥28 days was best predicted by LiTR and ΔPI, but not by lung size.

High temporal versus high spatial resolution in MR quantitative pulmonary perfusion imaging of two-year old children after congenital diaphragmatic hernia repair

OBJECTIVES

Congenital diaphragmatic hernia (CDH) leads to lung hypoplasia. Using dynamic contrast-enhanced (DCE) MR imaging, lung perfusion can be quantified. As MR perfusion values depend on temporal resolution, we compared two protocols to investigate whether ipsilateral lung perfusion is impaired after CDH, whether there are protocol-dependent differences, and which protocol is preferred.

METHODS

DCE-MRI was performed in 36 2-year old children after CDH on a 3 T MRI system; protocol A (n = 18) based on a high spatial (3.0 s; voxel: 1.25 mm(3)) and protocol B (n = 18) on a high temporal resolution (1.5 s; voxel: 2 mm(3)). Pulmonary blood flow (PBF), pulmonary blood volume (PBV), mean transit time (MTT), and peak-contrast-to-noise-ratio (PCNR) were quantified.

RESULTS

PBF was reduced ipsilaterally, with ipsilateral PBF of 45 ± 26 ml/100 ml/min to contralateral PBF of 63 ± 28 ml/100 ml/min (p = 0.0016) for protocol A; and for protocol B, side differences were equivalent (ipsilateral PBF = 62 ± 24 vs. contralateral PBF = 85 ± 30 ml/100 ml/min; p = 0.0034). PCNR was higher for protocol B (30 ± 18 vs. 20 ± 9; p = 0.0294). Protocol B showed higher values of PBF in comparison to protocol A (p always <0.05).

CONCLUSIONS

Ipsilateral lung perfusion is reduced in 2-year old children following CDH repair. Higher temporal resolution and increased voxel size show a gain in PCNR and lead to higher perfusion values. Protocol B is therefore preferred.

KEY POINTS

• Quantitative lung perfusion parameters depend on temporal and spatial resolution. • Reduction of lung perfusion in CDH can be measured with different MR protocols. • Temporal resolution of 1.5 s with spatial resolution of 2 mm (3) is suitable.

Use of fetal analgesia during prenatal surgery

OBJECTIVE

Recent progresses in fetal surgery have raised concern on fetal pain, its long-term consequences and the risks of sudden fetal movements induced by pain. In several studies, surgeons have directly administered opioids to the fetus, while others have considered sufficient the maternally administered analgesics. We performed a review of the literature to assess the state of the art.

METHODS

We performed a PubMed search to retrieve the papers that in the last 10 years reported studies of human fetal surgery and that described whether any fetal analgesia was administered.

RESULTS

We retrieved 34 papers. In three papers, the procedure did not hurt the fetus, being performed on fetal annexes, in two papers, it was performed in the first half of pregnancy, when pain perception is unlikely. In 10 of the 29 remaining papers, fetal surgery was performed using direct fetal analgesia, while in 19, analgesia was administered only to the mother. In most cases, fetal direct analgesia was obtained using i.m. opioids, and muscle relaxant. Rare drawbacks on either fetuses or mothers due to fetal analgesia were reported.

CONCLUSION

Fetal direct analgesia is performed only in a minority of cases and no study gives details about fetal reactions to pain. More research is needed to assess or exclude its possible long-term drawbacks, as well as the actual consequences of pain during surgery.

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.

Results of fetal endoscopic tracheal occlusion for congenital diaphragmatic hernia and the set up of the randomized controlled TOTAL trial

In isolated congenital diaphragmatic hernia, lung size and/or the position of the liver are predictive of neonatal outcome. Percutaneous Fetal Endoscopic Tracheal Occlusion (FETO) by a balloon can be undertaken to prompt lung growth in the worst cases. The feasibility and safety of FETO is no longer at stake, and it is associated with an apparent increase in neonatal survival. The gestational age at birth, the pre-existing lung size, the ability to remove the balloon prior to birth, and the lung response are predicting outcome. The most frequent complication is preterm premature rupture of the membranes, and as a consequence preterm delivery, which also complicates balloon removal. We have set up a randomized trial for the formal evaluation of FETO in Europe, including criteria for fetoscopy centers. Training of European as well as North American centers is taking place, so that the procedure could be safely and more widely offered.

Frontotemporal dementia: change of familial caregiver burden and partner relation in a Dutch cohort of 63 patients

BACKGROUND/AIMS

The current study examined the change of caregiver burden and the development of the quality of the partner relation in frontotemporal dementia (FTD).

METHODS

During a 2-year period, deterioration, behavioural problems, caregiver burden, general psychopathology, quality of life, social support, coping strategies and relationship quality were inspected in 63 FTD caregiver-care recipient dyads.

RESULTS

After 2 years patients reached maximum dementia severity with stable Neuropsychiatric Inventory levels. Contrary to expectations, caregiver burden decreased and psychological well-being remained stable. Coping style and social support changed unfavourably. Relationship closeness and getting along were preserved, whereas communication and sharing viewpoint on life were dramatically reduced.

CONCLUSIONS

FTD caregivers need support in coping with the increasingly hopeless situation of their patients. Future research methods into caregiver burden should address response shift as a means for psychological adjustment.