In utero intervention for severe congenital heart disease

Fetal Cardiac Intervention: A Comprehensive Review of Current Evidence

Fetal cardiac intervention consists of a novel and evolving technique for the intrauterine treatment of a subset of patients with congenital heart diseases, which aims to improve hemodynamics, reduce secondary damage, and achieve better postnatal outcomes. Nevertheless, the risks and benefits of this therapy remains subject to controversy. This review describes the rationale, selection criteria, and technical features for the most frequently performed fetal cardiac interventions. In addition, we provide a comprehensive overview of the medical literature, exploring the clinical implications of each therapy.

Epicardial pacing lead implantation for congenital complete atrioventricular block immediately after birth: a case report

BACKGROUND

The incidence of congenital complete atrioventricular block is estimated to be 1 per 20,000 deliveries. In the fetal period, the fetal mortality rate is high, but the treatment strategy has not yet been established. In severe cases, early postnatal pacing therapy is necessary.

CASE PRESENTATION

A 0-day-old Japanese baby girl was diagnosed with fetal congenital complete atrioventricular block during a prenatal physical examination. A joint conference was held preoperatively among multidisciplinary departments, and a cesarean section was performed at 37 weeks pregnancy, immediately followed by scheduled internal ventricular pacing lead implantation in an adjacent room. Percutaneous pacing was ineffective. The epicardial pacing lead was sutured at 17.5 minutes after birth, and perioperative management was successful with a heart rate and pulse rate of 150 beats per minute.

CONCLUSION

The infant with a congenital complete atrioventricular block was rescued by an uneventful epicardial lead implantation.

Perioperative pharmacological interventions for fetal immobilisation during fetal surgery and invasive procedures

BACKGROUND

Developments in ultrasound assessment of pregnancy has resulted in the increasing diagnosis of antenatal fetal issues. Many structural fetal conditions as well as complications associated with multiple pregnancies have the potential for in-utero treatment to improve both pregnancy and neonatal outcomes. Procedures such as laser ablation for twin-twin syndrome or cord occlusion for selective fetal termination require fetal immobilisation. Immobilisation of the fetus can occur through administration of medication to the mother or directly to the fetus. This improves procedural success and reduces the ongoing risk to the pregnancy. Evidence regarding the best medication and mode of delivery helps to ensure the optimal decision is made for both the mother and the fetus.

OBJECTIVES

To assess the effects of perioperative pharmacological interventions for fetal immobilisation during fetal surgery and invasive procedures on fetal, neonatal, and maternal outcomes.  SEARCH METHODS: We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (10 May 2021), and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs (including published abstracts) which compared different classes of medication administered to the mother or fetus to allow in-utero procedures to be performed. We also included cluster-randomised trials but excluded cross-over trials.

DATA COLLECTION AND ANALYSIS

We used the standard Cochrane Pregnancy and Childbirth methods for data collection and analysis. Two review authors independently assessed trials for inclusion and risk of bias, extracted data, and checked them for accuracy.

MAIN RESULTS

One study with three trial reports met the inclusion criteria. This involved 54 women with a multiple pregnancy. The study was conducted in a tertiary European hospital maternal-fetal medicine unit and compared remifentanil to diazepam for fetal immobilisation and maternal sedation during fetoscopic surgery.   Low-certainty evidence suggested that remifentanil may reduce fetal movement more than diazepam for two outcomes of fetal movement, one of fetal immobilisation at 40 minutes using a visual analogue score (VAS) (where 0 = immobile and 100 = baseline mobility), and one of gross body and limb movements (score was absolute number of movements), both assessed by a sonographer evaluating a taped ultrasound sequence (mean difference (MD) -65.00, 95% confidence interval (CI) -69.38 to -60.62 and MD -10.00, 95% CI -11.62 to -8.38; 1 study, 50 women).  Surgeons may also report being more satisfied with the procedure when using remifentanil rather than diazepam (risk ratio (RR) 2.88, 95% CI 1.60 to 5.15; 1 study, 50 women; low-certainty evidence). However, maternal respiratory rate may decrease more during the surgical procedure with remifentanil compared with diazepam (MD -6.00, 95% CI -8.29 to -3.71; 1 study, 50 women; low-certainty evidence). Maternal sedation may also be worse with remifentanil compared with diazepam (RR 0.09, 95% CI 0.01 to 0.65; 1 study, 50 women; low-certainty evidence) measured using an observer assessment of alertness/sedation (where a score of < 4 equates to profound sedation and > 4 equates to insufficient sedation). Perinatal mortality and time taken to perform the procedure were not reported in the trial.  We prespecified 20 outcomes and planned to use GRADE for 6 of them, all other outcomes were not able to be reported against for the purpose of meta-analysis due to data not being provided or unable to be interpreted. We assessed the included study at low risk of selection bias (appropriate random sequence generation and allocation concealment), performance bias (blinding of participants and personnel), detection bias (outcome assessors were blinded), attrition bias (incomplete outcome data minimal), and reporting bias.  Our GRADE assessment for certainty of the evidence indicates that there is low certainty of the evidence.

AUTHORS' CONCLUSIONS

We were only able to include one study with a small number of women, from a single centre, a European tertiary hospital. This study was published in 2005 with an abstract of this trial published in 2004. This study evaluated two intravenous medications administered to the mother - remifentanil and diazepam. This study reported our prespecified primary outcome but only evaluated several of our secondary outcomes, which limited further assessment. Low-certainty evidence suggested that remifentanil may be better at reducing fetal movements and surgeons were more satisfied with the procedure. However, maternal sedation and depression of breathing may be worse with remifentanil.  Further high-quality RCTs assessing both fetal and maternal medications are required to evaluate their efficacy for fetal immobilisation as well as safety for both mother and fetus.

Mending a broken heart: In vitro, in vivo and in silico models of congenital heart disease

Birth defects contribute to ∼0.3% of global infant mortality in the first month of life, and congenital heart disease (CHD) is the most common birth defect among newborns worldwide. Despite the significant impact on human health, most treatments available for this heterogenous group of disorders are palliative at best. For this reason, the complex process of cardiogenesis, governed by multiple interlinked and dose-dependent pathways, is well investigated. Tissue, animal and, more recently, computerized models of the developing heart have facilitated important discoveries that are helping us to understand the genetic, epigenetic and mechanobiological contributors to CHD aetiology. In this Review, we discuss the strengths and limitations of different models of normal and abnormal cardiogenesis, ranging from single-cell systems and 3D cardiac organoids, to small and large animals and organ-level computational models. These investigative tools have revealed a diversity of pathogenic mechanisms that contribute to CHD, including genetic pathways, epigenetic regulators and shear wall stresses, paving the way for new strategies for screening and non-surgical treatment of CHD. As we discuss in this Review, one of the most-valuable advances in recent years has been the creation of highly personalized platforms with which to study individual diseases in clinically relevant settings.

Fetal Cardiac Interventions-Are They Safe for the Mothers?

The aim of fetal cardiac interventions (FCI), as other prenatal therapeutic procedures, is to bring benefit to the fetus. However, the safety of the mother is of utmost importance. The objective of our study was to evaluate the impact of FCI on maternal condition, course of pregnancy, and delivery. 113 mothers underwent intrauterine treatment of their fetuses with critical heart defects. 128 percutaneous ultrasound-guided FCI were performed and analyzed. The patients were divided into four groups according to the type of FCI: balloon aortic valvuloplasty (fBAV), balloon pulmonary valvuloplasty (fBPV), interatrial stent placement (IAS), and balloon atrioseptoplasty (BAS). Various factors: maternal parameters, perioperative data, and pregnancy complications, were analyzed. There was only one major complication—procedure-related placental abruption (without need for blood products transfusion). There were no cases of: procedure-related preterm prelabor rupture of membranes (pPROM), chorioamnionitis, wound infection, and anesthesia associated complications. Tocolysis was only necessary only in two cases, and it was effective in both. None of the patients required intensive care unit admission. The procedure was effective in treating polyhydramnios associated with fetal heart failure in six out of nine cases. Deliveries occurred at term in 89%, 54% were vaginal. The results showed that FCI had a negligible impact on a further course of pregnancy and delivery.

Fetal acute cerebral vasoreactivity to maternal hyperoxia in low-risk pregnancies: a cross-sectional study

OBJECTIVE

To establish whether fetal cerebral vasoreactivity (CVR_O2 ), following maternal hyperoxia, is predicted by fetal cerebral and uteroplacental Doppler pulsatility indices (PI) at baseline, fetal pulmonary vasoreactivity to oxygen (PVR_O2 ), gestational age (GA), or sex.

METHODS

Pulsatility index of middle (MCA), anterior (ACA), posterior cerebral (PCA), umbilical (UA), uterine (UtA), and branch of the pulmonary arteries (PA) were obtained, by ultrasound, before (baseline), during (hyperoxia) and after 15 minutes of maternal administration of 8 L/min of 100% oxygen, through a non-rebreathing face mask, in normal singleton pregnancies within 20 to 38 weeks' gestation. CVR_O2 was defined as changes greater than zero in z score of PI of the cerebral arteries from baseline to hyperoxia. Logistic modeling was applied to identify CVR_O2 predictors.

RESULTS

A total of 97 pregnancies were eligible. In the overall population, median z scores of PI of MCA, ACA, and PCA did not differ between study phases. Based on the logistic model, baseline z scores for cerebral PI and GA were the best predictors of CVR_O2 .

CONCLUSIONS

In low-risk pregnancies, fetal CVR_O2 to hyperoxia does not occur uniformly but depends on cerebral PI and GA at baseline. These findings may provide useful reference points when oxygen is administered in high-risk pregnancies.

Current and future role of fetal cardiovascular MRI in the setting of fetal cardiac interventions

Over recent years, technical developments resulting in the feasibility of fetal cardiovascular magnetic resonance (CMR) have provided a new diagnostic tool for studying the human fetal heart and circulation. During the same period, we have witnessed the arrival of several minimally invasive fetal cardiac interventions (FCI) as a possible form of treatment in selected congenital heart diseases (CHDs). The role of fetal CMR in the planning and monitoring of FCI is not yet clear. Indeed, high-quality fetal CMR is not available or routinely offered at most centers caring for patients with prenatally detected CHD. However, in theory, fetal CMR could have much to offer in the setting of FCI by providing complementary anatomic and physiologic information relating to the specific intervention under consideration. Similarly, fetal CMR may be useful as an alternative imaging modality when ultrasound is hampered by technical limitations, for example, in the setting of oligohydramnios and in late gestation. In this review, we summarize current experience of the use of fetal CMR in the diagnosis and monitoring of fetuses with cardiopathies in the setting of a range of invasive in utero cardiac and vascular interventions and medical treatments and speculate about future directions for this versatile imaging medium.