胎儿先天性心脏病介入治疗进展

既往观点认为,一旦胎儿患有左心发育不良综合征(HLHS)等严重心血管畸形,结局就只能是出生后功能性单心室循环、心脏移植或中止妊娠.到目前为止,开放性胎儿心脏外科技术尚不成熟,而通过胎儿心脏介入治疗技术可以在很大程度上阻止因先天性心脏病引起的胎儿水肿、自发性流产或胎儿死亡,促进发育不良的心室重新发育,形成生后的双心室循环,重塑右室流出道梗阻胎儿的肺血管床等,改善了胎儿严重心血管畸形的预后.这些进步在很大程度上依赖于对胎儿先天性心脏病病理生理学特点的准确判断.超声技术的发展以及其他评价手段的进步可促进目前还比较有限的胎儿先天性心脏病介入治疗进一步发展.     

Fetal interventions for cardiac defects

This article focuses on the current status of in utero catheter interventions for congenital heart disease. The discussion of fetal interventions for cardiac defects briefly reviews the evolution of approaches to congenital heart disease and issues surrounding the prenatal detection of cardiac defects, the rationale for fetal intervention, and optional candidates for the procedures. Finally, the technical aspects and procedural considerations are reviewed.     

Controversies of fetal cardiac intervention

Remarkable advances in ultrasound imaging technology have made it possible to diagnose fetal cardiovascular lesions as early as 12-14 weeks of gestation and to assess their physiological relevance by echocardiography. Moreover, invasive techniques have been developed and refined to relieve significant congenital heart disease (CHD), such as critical aortic and pulmonary stenoses in the pediatric population including neonates. Recognition of the fact that certain CHDs can evolve in utero, and early intervention may improve the outcome by altering the natural history of such conditions has led to the evolution of a new fetal therapy, i.e. fetal cardiac intervention. Two entities, pulmonary valvar atresia and intact ventricular septum (PA/IVS) and hypoplastic left heart syndrome (HLHS), are associated with significant morbidity and mortality even with postnatal surgical therapy. These cases are believed to occur due to restricted blood flow, leading to impaired growth and function of the right or left ventricle. Therefore, several centers started the approach of antenatal intervention with the primary goal of improving the blood flow through the stenotic/atretic valve orifices to allow growth of cardiac structures. Even though centers with a reasonable number of cases seem to have improved the technique and the immediate outcome of fetal interventions, the field is challenged by ethical issues as the intervention puts both the mother and the fetus at risk. Moreover, the perceived benefits of prenatal treatment have to be weighed against steadily improving postnatal surgical and hybrid procedures, which have been shown to reduce morbidity and mortality for these complex heart defects. This review is an attempt to provide a balanced opinion and an update on fetal cardiac intervention.     

Fetal Interventions for Congenital Heart Disease in Brazil

Fetal interventions have been performed for some congenital heart diseases. However, these procedures have not gained wide acceptance due to concerns about their efficacy and safety. The aim of this study was to report on a preliminary experience with fetal cardiac interventions in Brazil. Twenty-two cardiac interventions were performed in 21 fetuses. Thirteen fetuses had critical aortic stenosis (CAS), 4 had hypoplastic left heart syndrome (HLHS) and intact interatrial septum or small patent foramen ovale, 1 had pulmonary atresia with intact ventricular septum (IVS), and 3 had critical pulmonary stenosis (CPS). The main outcome variables evaluated were technical success and procedural complications as well as pregnancy and postnatal outcomes. Success was achieved in 20 of 22 procedures (91 %) with 1 failed aortic and 1 failed pulmonary valvuloplasties. There was 1 fetal death. No maternal complications occurred. One patient with CAS, severe mitral regurgitation, and hydrops died postnatally within 5 months of age. All patients with HLHS and restrictive atrial septum died after interventional or surgical procedures and prolonged hospitalizations. All patients with CPS/IVS survived and achieved a biventricular (BV) circulation after neonatal valvuloplasty and ductal stenting. A BV circulation was achieved in 4 of 8 patients with CAS and evolving HLHS (one still in utero), including 2 with initial borderline left ventricles (LV) in whom surgical LV overhaul was performed at 9 months of age. In this preliminary experience, the feasibility of fetal cardiac interventions and their outcomes were similar to those previously reported.     

The Adult Patient with Congenital Heart Disease in the Emergency Department

It is well recognized that adult survivors with congenital heart disease are at risk for several cardiac and noncardiac complications that can impact their long-term outcomes. Emergency departments are increasingly being used for the evaluation and management of acute complications in these patients. However, there are several issues that are unique to adults with congenital heart disease related to the complexity of their cardiac anatomy, previous surgical intervention, and residual hemodynamic lesions that can complicate their presentation and management. This review examines the many challenges faced in caring for adults with congenital heart disease presenting to the emergency department, including the issues related to underlying cardiac lesion, access to care, and the evaluation and management of common clinical presentations.     

Fetal Echocardiography: New Grounds to Explore During Fetal Cardiac Intervention

Over the past decade, revolutionary advances in ultrasound imaging technology have allowed the study of the evolution of congenital heart disease during fetal life. The frustration arising from watching the prenatal progression of severe semilunar valve obstructions and therapy-refractory fetal arrhythmias has prompted the interest in developing procedures for fetal cardiac intervention. Ultrasound techniques as the primary diagnostic and monitoring modalities in fetal medicine will play a key role in defining patient groups, peri-interventional assessment of fetal hemodynamics, and monitoring during these procedures. The purpose of this article is to provide pediatric cardiologists and perinatal medicine specialists an overview over the various technical approaches at fetal cardiac intervention and the special tasks that fetal echocardiography will have to accomplish. It also aims at illustrating the potential of fetal echocardiography for fetal selection.     

Fetal intervention for cardiac disease: the cutting edge of perinatal care

Fetal cardiac valvuloplasty has been proposed for progressive cardiac disease with a poor prognosis, such as critical aortic stenosis and pulmonary atresia with intact ventricular septum and balloon atrial septostomy for hypoplastic left heart syndrome, or simple transposition of the great arteries with closed or restrictive inter-atrial communication. It is anticipated that early rescue of ventricles or the pulmonary veins from an unfavourable environment may promote healthier ventricular and vascular growth and improve postnatal outcomes. While close collaboration between the fetal medicine specialist and perinatal cardiologist may optimize the chances of technical success, obstacles to progress include the relative rarity of suitable cases and late referral for therapy. In common with other interventions in fetal medicine, there is a learning curve, and it would benefit progress if the procedures were initially concentrated in just a few centres to enable them to develop skills and experience. Following careful evaluation, it may then be desirable to train further centres and roll out best practice models.     

Delivery room emergencies in critical congenital heart diseases

Transition from fetal to postnatal life is a complex process. Even in the absence of congenital heart disease, about 4–10% of newborns require some form of assistance in the delivery room. Neonates with complex congenital heart disease should be expected to require significant intervention and thus the resuscitation team must be well prepared for such a delivery. Prenatal assessment including fetal and maternal health in general and detailed information on fetal heart structure, function and hemodynamics in particular are crucial for planning the delivery and resuscitation. In addition, understanding the impact of cardiac structural anomaly and associated altered blood flow on early postnatal transition is essential for success of resuscitation in the delivery room. In this article, we will briefly review transitional circulation focusing on altered hemodynamics of the complex congenital heart diseases and then discuss the process of preparing for these high-risk deliveries. Finally, we will review the pathophysiology resulting from the cardiac structural anomaly with resultant altered fetal circulation and discuss delivery room management of specific critical congenital heart diseases.     

Use of a pressure guidewire in fetal cardiac intervention for critical aortic stenosis

Fetal cardiac intervention for critical aortic stenosis (AS) with evolving hypoplastic left heart syndrome is performed in an attempt to maintain a biventricular circulation postnatally. The procedure has been hindered by technical challenges and poor candidate selection. We report here the novel use of a pressure guidewire during aortic valvuloplasty in a fetus at 21 weeks' gestation with critical AS and evolving hypoplastic left heart syndrome. Use of a pressure guidewire during fetal cardiac intervention offers several potential advantages over existing protocols. This technique augments fetal ultrasound as it relates to operator awareness of catheter and wire position (with continuous monitoring of pressure waveforms), improves on intraprocedural fetal hemodynamic monitoring and responsiveness to resuscitation, and provides a rich new data set of invasive fetal hemodynamics. This data set offers tremendous potential with regards to improving candidate selection and postintervention prognostication. In addition, we provide the first, to our knowledge, characterization of intracardiac pressures in a human fetus with congenital heart disease. Given the realized and potential benefits associated with this technique, use of a pressure guidewire may become standard of care for all fetal cardiac interventions.     

Current techniques and procedures in paediatric and congenital cardiac catheter intervention

There has been marked innovation and progress in the techniques, technologies and outcomes in the field of paediatric and congenital cardiac catheter intervention over the past 4 decades. In the modern era, it is now possible to treat many forms of congenital heart disease through minimally invasive percutaneous therapies, with associated reduction in morbidity for this group of patients. This article provides an overview of current practice and developments in this field, with particular focus on the interventional procedures commonly performed in the paediatric population.     

Test characteristics of a level I or II fetal ultrasound in detecting structural heart disease

At the University of California Davis Medical Center, a screening fetal ultrasound examination (level I or II) incorporates a comprehensive segmental evaluation of the fetal heart. This study evaluated the reliability of the fetal ultrasound exam in the detection of abnormal heart anatomy. Our retrospective study reviewed results of 614 antenatal patients that had a screening fetal ultrasound exam. All patients subsequently underwent a detailed targeted fetal cardiac ultrasound exam performed by a pediatric cardiac sonographer and reviewed by a board-certified pediatric cardiologist. Of these 614 patients, 60 fetuses had structural heart disease by the targeted fetal exam. The screening fetal ultrasound exam correctly identified 55 of the 60, with 5 false negatives (8.3% false-negative rate) and 1 false positive (1.7% false-positive rate). Our study suggests that if a screening fetal ultrasound exam incorporates a segmental evaluation of the fetal heart it can reliably detect abnormal heart anatomy. At our institution a targeted fetal cardiac exam is now used to confirm and provide detailed assessment of the heart anatomy when a screening fetal exam is positive for heart disease.     

Neonatal cardiovascular physiology

The pediatric surgeon deals with a large number and variety of congenital defects in neonates that frequently involve early surgical intervention and care. Because the neonatal cardiac physiology is unique, starting with the transition from fetal circulation and including differences in calcium metabolism and myocardial microscopic structure and function, it serves the pediatric surgeon well to have a sound understanding of these principles and how they directly and indirectly affect their plans and treatments. In addition, many patients will have associated congenital heart disease that can also dramatically influence not only the surgical and anesthetic care but also the timing and planning of procedures. Finally, the pediatric surgeon is often called upon to treat conditions and complications associated with complex congenital heart disease such as feeding difficulties, bowel perforations, and malrotation in heterotaxy syndromes. In this article, we will review several unique aspects of neonatal cardiac physiology along with the basic physiology of the major groups of congenital heart disease to better prepare the training and practicing pediatric surgeon for care of these complex and often fragile patients.     

Prospects for fetal surgery

Until about forty years ago, the womb shielded the fetus from observation and therapy. The rapid changes in the diagnosis and treatment of human fetal anatomical abnormalities are due to improved fetal imaging studies as well as fetal sampling techniques (e.g. amniocentesis, chorionic villus sampling), and a better understanding of fetal pathophysiology derived from laboratory animals. Fetal therapy is the logical culmination of progress in fetal diagnosis. In other words, the fetus is now a patient. The fetal surgical treatment of the most severe form of spina bifida – myelomeningocele (MMC) – will be used as a paradigm to illustrate progress in and future prospects for fetal surgery. This review will focus on the rationale for in utero repair in the context of pathologic observations and animal models of MMC, outcomes from human fetal MMC repair including the recently completed Management of Myelomeningocele Study (MOMS trial), and future research directions.     

Advances in Fetal Cardiac Imaging

During the past 25 years, two-dimensional imaging of the fetal heart has evolved into a sophisticated and widely practiced clinical tool, but most heart disease still goes undetected until sometime after birth, despite routine fetal ultrasound evaluations. Over the next 25 years, tremendous advances in fetal cardiac imaging, including three-dimensional imaging, promise to revolutionize both the prenatal detection and diagnosis of congenital heart disease. Image resolution continues to improve year after year, allowing earlier (10-15 week) visualization of the fetal heart, as well as the detection of subtle valvar abnormalities that may progress to serious forms of ventricular hypoplasia at term. However, fetal cardiac imaging remains constrained by limited sonographic windows. To improve the prenatal detection of congenital heart disease, outflow tracts are increasingly included along with the routine screening four-chamber view. However, while the four-chamber view resides within a single plane, lending itself to tomographic evaluation with two-dimensional ultrasound, the outflow tracts (and most forms of congenital heart disease) do not reside within a single plane. For these and other reasons, three-dimensional imaging of the fetal heart ultimately may improve the detection of outflow tract abnormalities, and facilitate comprehension of complex forms of congenital heart disease. Finally, other imaging modalities, including but not limited to Doppler tissue imaging and magnetic resonance imaging, continue to evolve and to complement two- and three-dimensional sonographic imaging of the fetal heart. As a result of these ongoing advances in the prenatal detection and assessment of congenital heart disease, these are exciting and glorious times for the field of fetal cardiac imaging.     

Error traps in fetal surgery

The growth of the field of fetal surgery over the last two decades driven by new indications and data from prospective randomized trials supporting prenatal intervention has resulted in techniques protocols and methodologies that have gained confidence by insuring good outcomes. Error traps are methods or techniques that usually work well in most of the cases, but which are apt to fail under certain specific circumstances. The very confidence the surgeon develops in these techniques or methodologies makes them a trap for the unwary surgeon. The purpose of this article is to discuss common error traps in fetal interventions, including ultrasound guided procedures, fetoscopic surgery, open fetal surgery and EXIT procedures. Awareness of these error traps and approaches to avoid them may enhance fetal surgical outcomes and reduce complications rates.     

Progression of congenital heart disease in the prenatal period

BACKGROUND: Prenatal echocardiography has shown evidence of prenatal development of congenital heart disease. Prenatal cardiac anatomy, chamber size and function change during gestation, so that the appearance of cardiac structure in abnormal hearts may be different from that which is usually seen postnatally. METHODS: Published prenatal echocardiographic studies were reviewed and in utero development of congenital heart disease from midtrimester to the early postnatal period is discussed. RESULTS: The growth of the great vessels and ventricles is reduced in fetuses with ventricular outflow obstruction. Valve regurgitation may progress. The foramen ovale and ductus arteriosus have been reported to become restrictive in utero in several settings. Pulmonary vascular obstructive changes may progress prenatally. Fetal arrhythmia (both bradycardia and tachycardia) may develop in utero. Development of congestive heart failure is a very important issue during follow up of fetuses with significant cardiac or extracardiac problems. Some may progress to fetal hydrops and prognosis of the affected fetuses is usually very poor. CONCLUSIONS: Correct knowledge of possible development is important for accurate prenatal diagnosis. Information on prenatal progression of the cardiac anomaly is also important to make plans for follow up and perinatal management, to predict outcomes and to counsel family. Furthermore, the benefits of prenatal treatment instead of postnatal treatment should be assessed by the accurate prediction of the progression of the cardiac problem in utero. Further extensive studies using a large number of cases is required to predict progression accurately. In addition, further studies for elucidating the mechanisms of progression is important to provide better outcomes for fetuses with various congenital heart diseases.     

Perinatal management, counselling and outcome of fetuses with congenital heart disease

Prenatal treatment options for fetal heart disease are still limited but pharmacological treatment of fetal tachyarrhythmias is usually effective. Prenatal catheter interventions are likely to be an option in selected fetal cardiac defects in the future. Delivery should be at a tertiary care centre if the need for immediate neonatal transport is anticipated. When a cardiac problem is diagnosed in a fetus, the parents should be counselled by a paediatric cardiologist specialized in fetal cardiology in close co-operation with the obstetric team. The rate of termination is influenced by gestational age at diagnosis, the severity of the heart defect and the presence of associated malformations. In fetuses with isolated cardiac malformations who are in sinus rhythm with good myocardial function and no or trivial atrioventricular valve regurgitation, the risk of spontaneous intra-uterine death is low. Prenatal echocardiography has the potential to improve postnatal survival in infants with critical heart defects, especially those with duct-dependent systemic or pulmonary circulations.     

Prenatal diagnosis and treatment planning of congenital heart defects—possibilities and limits

Background  Newborns with hypoplastic left heart syndrome (HLHS) or right heart syndrome or other malformations with a single ventricle physiology and associated hypoplasia of the great arteries continue to be a challenge in terms of survival. The vast majority of these forms of congenital heart defects relate to abnormal morphogenesis during early intrauterine development and can be diagnosed accurately by fetal echocardiography. Early knowledge of these conditions not only permits a better understanding of the progression of these malformations but encourages some researchers to explore new minimally invasive therapeutic options with a view to early pre- and postnatal cardiac palliation. Data sources  PubMed database was searched with terms of “congenital heart defects”, “fetal echocardiography” and “neonatal cardiac surgery”. Results  At present, early prenatal detection has been applied for monitoring pregnancy to avoid intrauterine cardiac decompensation. In principle, the majority of congenital heart defects can be diagnosed by prenatal echocardiography and the detection rate is 85%–95% at tertiary perinatal centers. The majority, particularly of complex congenital lesions, show a steadily progressive course including subsequent secondary phenomena such as arrhythmias or myocardial insufficiency. So prenatal treatment of an abnormal fetus is an area of perinatal medicine that is undergoing a very dynamic development. Early postnatal treatment is established for some time, and prenatal intervention or palliation is at its best experimental stage in individual cases. Conclusion  The upcoming expansion of fetal cardiac intervention to ameliorate critically progressive fetal lesions intensifies the need to address issues about the adequacy of technological assessment and patient selection as well as the morbidity of those who undergo these procedures.     

The boundaries of fetal cardiac intervention: Expand or tighten?

Fetal cardiac intervention (FCI) is a relatively new and continually evolving field, and, for select cardiac defects, offers the potential to alter the progression of the disease and improve outcomes. It is a procedure that requires a collaborative effort between maternal–fetal medicine, interventional cardiology and fetal echo/ultrasound specialists, as well as fetal and maternal anesthesiologists, nursing specialists, and social workers. This article reviews the most recently reported data and advances in FCI. Currently, FCI is most frequently performed in fetuses with severe aortic stenosis (AS) with evolving hypoplastic left heart syndrome (eHLHS), established HLHS with intact or highly restrictive atrial septum (IAS), and pulmonary atresia with intact ventricular septum (PA-IVS) with evolving hypoplastic right heart syndrome (eHRHS). The goal of FCI for eHLHS and eHRHS is to promote a postnatal biventricular circulation with, theoretically, the potential for better long-term outcomes. In HLHS with IAS the aim is to improve survival. Contemporary data for FCI demonstrate limited maternal risks and improving technical success. With experience, FCI in severe AS with eHLHS has shown improved rates of biventricular outcome and early survival. Limited data for PA-IVS show promise for improving postnatal biventricular outcomes; however, for HLHS with IAS, FCI has yet to clearly demonstrate improved survival. FCI has an evolving role in the management of congenital heart defects. Ongoing analysis of disease progression, patient selection and postnatal outcomes, in conjuncture with technologic innovations and a multicenter collaborative approach, is essential as the field expands.     

Pediatric cardiopulmonary resuscitation: advances in science, techniques, and outcomes

More than 25% of children survive to hospital discharge after in-hospital cardiac arrests, and 5% to 10% survive after out-of-hospital cardiac arrests. This review of pediatric cardiopulmonary resuscitation addresses the epidemiology of pediatric cardiac arrests, mechanisms of coronary blood flow during cardiopulmonary resuscitation, the 4 phases of cardiac arrest resuscitation, appropriate interventions during each phase, special resuscitation circumstances, extracorporeal membrane oxygenation cardiopulmonary resuscitation, and quality of cardiopulmonary resuscitation. The key elements of pathophysiology that impact and match the timing, intensity, duration, and variability of the hypoxic-ischemic insult to evidence-based interventions are reviewed. Exciting discoveries in basic and applied-science laboratories are now relevant for specific subpopulations of pediatric cardiac arrest victims and circumstances (eg, ventricular fibrillation, neonates, congenital heart disease, extracorporeal cardiopulmonary resuscitation). Improving the quality of interventions is increasingly recognized as a key factor for improving outcomes. Evolving training strategies include simulation training, just-in-time and just-in-place training, and crisis-team training. The difficult issue of when to discontinue resuscitative efforts is addressed. Outcomes from pediatric cardiac arrests are improving. Advances in resuscitation science and state-of-the-art implementation techniques provide the opportunity for further improvement in outcomes among children after cardiac arrest.