In-utero intervention for severe congenital heart disease

The Genetics of Neurodevelopment in Congenital Heart Disease

Congenital heart disease (CHD) is the most common birth anomaly, affecting almost 1% of infants. Neurodevelopmental delay is the most common extracardiac feature in people with CHD. Many factors may contribute to neurodevelopmental risk, including genetic factors, CHD physiology, and the prenatal/postnatal environment. Damaging variants are most highly enriched among individuals with extracardiac anomalies or neurodevelopmental delay in addition to CHD, indicating that genetic factors have an impact beyond cardiac tissues in people with CHD. Potential sources of genetic risk include large deletions or duplications that affect multiple genes, such as 22q11 deletion syndrome, single genes that alter both heart and brain development, such as CHD7, and common variants that affect neurodevelopmental resiliency, such as APOE. Increased use of genome-sequencing technologies in studies of neurodevelopmental outcomes in people with CHD will improve our ability to detect relevant genes and variants. Ultimately, such knowledge can lead to improved and more timely intervention of learning support for affected children.

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.

Quality Improvement in Congenital Heart Surgery

Congenital heart disease is a major public health concern in the United States. Outcomes of surgery for children with congenital heart disease have dramatically improved over the last several decades with current aggregate operative mortality rates approximating 3%, inclusive of all ages and defects. However, there remains significant variability among institutions, especially for higher-risk and more complex patients. As health care moves toward the quadruple aim of improving patient experience, improving the health of populations, lowering costs, and increasing satisfaction among providers, congenital heart surgery programs must evolve to meet the growing scrutiny, demands, and expectations of numerous stakeholders. Improved outcomes and reduced interinstitutional variability are achieved through prioritization of quality assurance and improvement.

Outcomes of hypoplastic left heart syndrome and fetal aortic valvuloplasty in a country with suboptimal postnatal management

BACKGROUND

Fetal aortic stenosis (AoS) may progress to hypoplastic left heart syndrome (HLHS) in utero. There are currently no data, prenatal or postnatal, describing survival of fetuses or neonates with AoS or HLHS in a country with suboptimal postnatal management.

STUDY DESIGN

Prospective cohort study performed in Mexico, including cases diagnosed with AoS and HLHS within a 6-year period. AoS patients fulfilling previously published criteria for evolving HLHS (eHLHS) were offered fetal aortic valvuloplasty. Outcome variables were perinatal mortality, postnatal management, type of postnatal circulation, and overall survival.

RESULTS

Fifty-four patients were included: 16 AoS and 38 HLHS. Eighteen patients had associated anomalies and/or an abnormal karyotype. Seventy-four percent of HLHS received comfort measures, with only three cases reporting an attempt at surgical palliation, and one survivor of the first stage. Fetal aortic valvuloplasty was performed successfully in nine cases of eHLHS. Overall postnatal survival was 44% in AoS with fetal aortic valvuloplasty, and one case (ongoing) in the HLHS group.

CONCLUSIONS

HLHS in Mexico carries more than a 95% risk of postnatal death, with little or no experience at surgical palliation in most centers. Fetal aortic valvuloplasty in AoS may prevent progression to HLHS and in this small cohort was associated with ≈50% survival.

Advanced ultrasound for prenatal interventions

Ultrasound is an integral part of prenatal interventions. Doppler studies and 3-dimensional ultrasound (3DUS) are frequently used to determine whether fetal surgery is required. The operator's experience remains crucial for reducing procedure-related morbidity. Real-time 3DUS (or 4DUS) can simultaneously display the needle tip in three orthogonal planes, providing reassurance that no fetal parts are in the path. In experienced hands, 4DUS guidance may not be more effective than B-mode, but its value for less-experienced operators remains to be determined. Recent developments in needle, shunt, and video endoscopic technologies may compliment the use of image-guided in utero procedures. Future developments of higher-dimensional transducers and image software may improve the utility of ultrasound for invasive obstetric interventions.

Protective effects of indomethacin and dexamethasone in a goat model with intrauterine balloon aortic valvuloplasty

BACKGROUND

Intrauterine balloon aortic valvuloplasty (IUBAV) has been used for critical aortic stenosis. However, it is necessary to determine the fetal impairments such as preterm birth after this approach and to find a way to prevent or reduce them.

METHODS

In the present study, we evaluated the therapeutic value of indomethacin (IDM) and dexamethasone (DXS) on reducing the preterm birth rate in experimental goats after IUBAV.

RESULTS

Our results indicated that the administration of IDM/DXS significantly reduced the rate of premature birth. IDM/DXS treatment led to preservation of myocardial ultrastructure with less damage, and amelioration of the fetal and placental circulation. Furthermore, we found that norepinephrine (NE) level was positively associated with the degree of myocardial damage. IDM/DXS administration led to a significant decrease of operation-induced increase of NE levels, which may be associated with the protective effects of IDM/DXS. Lastly, we found that the administration of IDM/DXS did not induce the risk of ductus arteriosus closure or slow down fetal growth.

CONCLUSIONS

Our results indicate that IDM/DXS promotes a better gestational outcome at least partially by reducing stress response during and after the operation of IUBAV in the goat model. IDM/DXS may be a useful application in human patients during IUBAV intervention.

Fetal cardiac interventions: myths and facts

An early, primary, in utero cardiac abnormality may prevent normal heart development and cause irreversible secondary structural changes. The idea of foetal cardiac intervention stems from this understanding and focuses on antenatal intervention targeting the primary abnormality to allow normal flow and haemodynamics and thus normal heart development. Crucial aspects of foetal vascular access, varying foetal lie and structural complexity make it very hard to set procedural standards. The procedures are complex and are associated with significant maternal and foetal morbidity and mortality. The high risk-benefit ratio clearly explains the investigational nature of such therapies. With the development of minimally invasive techniques and continued animal experiments, foetal interventional therapy may see a low rate of morbidity and mortality, improving the prognosis of newborns with congenital heart disease previously considered incurable.

Impact of intrauterine balloon aortic valvuloplasty on gestational outcome in a fetal goat model

OBJECTIVE

Intrauterine balloon aortic valvuloplasty (IUBAV) has been used to correct critical aortic valve stenosis. Evaluation of the intervention-related risk is necessary. The purpose of this study was to establish an experimental goat model for ultrasound-guided IUBAV intervention and investigate the immediate and long-term effects of IUBAV on the fetus, gestational outcome and mother's safety.

STUDY DESIGN

Fifteen pregnant goats with twin gestation in the 2nd and 3rd trimester were anesthetized to establish the surgical procedure. One fetus of the twins received IUBAV intervention, the other served as a control. The data were collected at three time points: immediately before and after IUBAV, and 24 h after birth. Critical organs including the heart, brain, lung and liver from the fetuses/newborns were collected after IUBAV or 24 h after birth.

RESULTS

IUBAV intervention immediately induced a significant decrease of pH and Ca(2+), as well as an increase of blood glucose and lactic acid levels (p < 0.05). IUBAV also caused an increase in stress hormones (epinephrine 1-fold, norepinephrine 4-fold, and cortisol 1-fold; p < 0.05). Following the operation, all of the mother goats recovered, but in 60% (6/10) preterm delivery occurred. Neither pathological changes in fetal critical organs nor a significant difference in metabolism or growth parameters were detected between IUBAV and control kids.

CONCLUSIONS

Ultrasound-guided IUBAV intervention induced a strong but transient stress response in the operated fetus, which did not result in irreversible histological changes in the fetus or the mother, but may disrupt the continuation of normal gestation in the long term. Preterm delivery is the major risk in this goat IUBAV model.

[Significance of magnetic resonance studies in prenatal diagnosis of malformations of the fetal central nervous system]

MRI investigation, as an imaging technique, has been gaining more and more importance in prenatal diagnostics. It has become essential due to its advantages in diagnosing the malformations of the central nervous system. Similarly to ultrasonography, its reliability is greatly dependent on the knowledge of the person performing the investigation. In addition to the knowledge of the exact anatomy of central nervous system, the researcher should have a multidisciplinary approach. In the case of malformations where repeated investigations are needed to provide a diagnosis in early pregnancy (e.g. neural tube defects), ultrasonography is more effective than MRI. In case of intrauterine infections and malformations of the posterior fossa, however, the two imaging techniques are excellent supplements to each other. MRI also plays an important role in making the prognosis for fetal ventriculomegaly, as well as in the short term diagnosis of ischaemias affecting the fetal nervous system. Difficulties in evaluating ultrasonographic images (owing to maternal obesity, oligohydramnion) render MRI an important technique in making the final diagnosis. Currently, the drawbacks of MRI include reduced accessibility, poor cost-effectiveness and shortage of skilled experts in this technique.

Cardiac tissue engineering: implications for pediatric heart surgery

Children with severe congenital malformations, such as single-ventricle anomalies, have a daunting prognosis. Heart transplantation would be a therapeutic option but is restricted due to a lack of suitable donor organs and, even in case of successful heart transplantation, lifelong immune suppression would frequently be associated with a number of serious side effects. As an alternative to heart transplantation and classical cardiac reconstructive surgery, tissue-engineered myocardium might become available to augment hypomorphic hearts and/or provide new muscle material for complex myocardial reconstruction. These potential applications of tissue engineered myocardium will, however, impose major challenges to cardiac tissue engineers as well as heart surgeons. This review will provide an overview of available cardiac tissue-engineering technologies, discuss limitations, and speculate on a potential application of tissue-engineered heart muscle in pediatric heart surgery.

The role of fetal echocardiography in fetal intervention: a symbiotic relationship

In this review, the authors explore the role of noninvasive and invasive fetal interventions in fetal cardiovascular disease guided by observations at fetal echocardiography. They first review fetal cardiac lesions that may be ameliorated by fetal intervention and then review noncardiac fetal pathologic findings for which fetal echocardiography can provide important insight into the pathophysiology and aid in patient selection for and timing of intervention and postintervention surveillance.

[Update on pediatric cardiology and congenital heart disease]

The fields of pediatric cardiology and congenital heart disease have experienced considerable progress in the last few years, with advances in new diagnostic and therapeutic techniques that can be applied at all stages of life from the fetus to the adult. This article reviews scientific publications in a number of areas that appeared between August 2007 and September 2008. In developed countries, congenital heart disease is becoming increasingly prevalent in nonpediatric patients, including pregnant women. Actions aimed at preventing coronary heart disease must be started early in infancy and should involve the promotion of a healthy diet and lifestyle. Recent developments in echocardiography include the introduction of three-dimensional echocardiography and of new techniques such as two-dimensional speckle tracking imaging, which can be used for both anatomical and functional investigations in patients with complex heart disease, including a univentricular heart. Progress has also occurred in fetal cardiology, with new data on prognosis and prognostic factors and developments in intrauterine interventions, though indications for these interventions have still to be established. Heart transplantation has become a routine procedure, supplemented in some cases by circulatory support devices. In catheter interventions, new devices have become available for the closure of atrial or ventricular septal defects and patent ductus arteriosus as well as for percutaneous pulmonary valve implantation. Surgery is also advancing, in some cases with hybrid techniques, particularly for the treatment of hypoplastic left heart syndrome. The article ends with a review of publications on cardiomyopathy, myocarditis and the treatment of bacterial endocarditis.