Prenatal therapy of non-immunologic hydrops fetalis caused by severe aortic stenosis

Fetal aortic valvuloplasty may rescue fetuses with critical aortic stenosis and hydrops

OBJECTIVE

Critical aortic stenosis (CAS) with a restrictive interatrial septum may lead to fetal congestive heart failure and hydrops, usually culminating in fetal demise if left untreated. The aim of this study was to assess the effects of fetal aortic valvuloplasty (FAV) on hemodynamics and outcome in these patients.

METHODS

This was a retrospective review of fetuses with CAS and signs of hydrops that underwent FAV in our center between 2000 and 2020. Echocardiograms and patients' charts were analyzed for ventricular and valvular dimensions and for outcome.

RESULTS

Hydrops was present at the time of intervention in 15 fetuses with CAS that underwent FAV at our center during the study period. All but one patient had at least one technically successful procedure. There were no procedure-related deaths, but three intrauterine deaths occurred. Twelve subjects were liveborn, of whom two died within 24 h after birth owing to persistent hydrops. Ventricular function improved and hydrops resolved within 3-4 weeks after FAV in 71.4% (10/14) of fetuses with a technically successful intervention. A biventricular outcome was achieved in 50% of the successfully treated patients.

CONCLUSIONS

Fetuses with CAS and hydrops can be successfully treated with FAV. The procedure has the potential to restore sufficient fetal cardiac output, which may lead to resolution of hydrops. Surviving patients seem to be good candidates for a biventricular outcome. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Fetal cardiac interventions: an update of therapeutic options

Objective

This article aims to present updated therapeutic options for fetal congenital heart diseases.

Methods

Data source for the present study was based on comprehensive literature retrieval on fetal cardiac interventions in terms of indications, technical approaches and clinical outcomes.

Results

About 5% of fetal congenital heart diseases are critical and timely intrauterine intervention may alleviate heart function. Candidates for fetal cardiac interventions are limited. These candidates may include critical aortic valve stenosis with evolving hypoplastic left heart syndrome, pulmonary atresia with an intact ventricular septum and evolving hypoplastic right heart syndrome, and hypoplastic left heart syndrome with an intact or highly restrictive atrial septum as well as fetal heart block. The advocated option are prenatal aortic valvuloplasty, pulmonary valvuloplasty, creation of atrial communication and fetal cardiac pacing.

Conclusion

Fetal cardiac interventions are feasible at midgestation with gradually improved technical success and fetal/postnatal survival due mainly to a well-trained multidisciplinary team, sophisticated equipment and better postnatal care.

Fetal cardiac interventions: rationale, risk and benefit

Fetal congenital heart disease may progress during pregnancy and may lead to irreversible myocardial or pulmonary damage. The rationale of fetal intracardiac interventions is to change fetal hemodynamics, prevent secondary damage and improve long-term outcome at an acceptable risk for mother and fetus. This review focuses on the current experience about patient selection, risks and benefits of this technique.

Diagnosis and management of fetal heart failure

Congestive fetal heart failure, defined as inability of the heart to deliver adequate blood flow to organs such as the brain, liver, and kidneys, is a common final outcome of many intrauterine disease states that may lead to fetal demise. Advances in fetal medicine during the past 3 decades now provide the diagnostic tools to detect and also treat conditions that may lead to fetal heart failure. Fetal echocardiographic findings depend on severity of diastolic and systolic dysfunction of both ventricles. At an advanced stage, findings include cardiomegaly; valvar regurgitation; venous congestion; fetal edema and effusions; oligohydramnios; and preferential shunting of blood flow to the brain, heart, and adrenals in the distressed fetus. A useful diagnostic tool to quantify severity of heart failure is the cardiovascular profile score, which is a composite score based on 5 different echocardiographic parameters. To predict outcomes, the score should be interpreted in the context of the underlying disease, as different causes of intrauterine heart failure may have highly variable outcomes. Low fetal cardiac output may result from a myocardial disease (cardiomyopathy, myocarditis, ischemia), abnormal loading conditions (arterial hypertension, obstructive structural heart disease, atrioventricular malformations, twin-to-twin transfusion), arrhythmia, or external cardiac compression (pleural and/or pericardial effusions, cardiac tumours). Treatment options are available for several of these conditions.

Maternal mirror syndrome after in utero aortic valve dilation. A case report

Fetal hydrops of various etiologies can be associated with maternal mirror syndrome. The exact pathophysiology of this rare disorder remains unclear, yet it can result in significant maternal and fetal morbidity. The recent advances in prenatal diagnosis and therapeutic interventions have focused on altering the course of pathologies associated with an expected poor prognosis. Severe fetal aortic valve stenosis with its potential for hypoplastic left heart fit this category. We report a case of maternal mirror syndrome in a parturient following intrauterine therapy for severe fetal aortic stenosis and hydrops. Despite a technically successful intervention, the mother required emergency cesarean section. We review the few reports of mirror syndrome as well as the current approaches to fetal aortic stenosis. This case reinforces the need for in depth risk analysis prior to fetal interventions. It also emphasizes the advantage of earlier detection and therapy with fetal aortic stenosis since fetal hydrops carries a somber prognosis.

Advances in fetal cardiac intervention

Fetal cardiac intervention is in a rapid state of progress now. Attempts are being made to prevent fetal hydrops due to congenital heart defects, to recruit hypoplastic ventricles, to create a two-ventricle circulation after birth, and to remodel the fetal pulmonary vascular bed whose outlet is obstructed. Open heart surgery in the fetus has yet to be done successfully, but interventions for improved cardiac outcomes are now being tested. Their outcomes will depend, in large part, on their successful physiological effects. How to measure these and quantitate the effects of our interventions will require further advances in the understanding of these diseases-both their natural and unnatural courses. New ultrasound techniques and assessment tools to assess fetal cardiac wellness could enhance the limited progress in fetal intervention in the heart so far.

Complete spontaneous resolution of severe nonimmunological hydrops fetalis with unknown etiology in the second trimester--a case report

The incidence of nonimmunological fetal hydrops is between 1 in 1500 and 1 in 4000. Overall mortality for this condition is about 80%. This report describes a case of prenatally diagnosed hydrops fetalis with severe generalized edema, ascites and pleural effusion of unknown origin at 19 weeks of gestation. No symptoms were found of infections or anemia, no variabilities were observed in fetal blood analysis or in karyotyping. All signs of hydrops resolved completely after 6 weeks without treatment. The pregnancy continued with normal fetal development; labor was induced at 41 weeks of gestation. After vaginal delivery with vacuum extraction the child was completely healthy and demonstrated no signs of remaining hydrops fetalis or any other pathological parameters except an uncritical atrial septal defect type II which healed without any complications within 3 months post delivery.

Evaluation of the fetal coronary circulation

Prenatal ultrasound today allows the detailed study of small caliber vascular beds including the fetal coronary arteries and the coronary sinus. The coronary circulation is unique because of its critical role in myocardial metabolism and function and its ability to adapt in many fetal conditions. The ultrasound examination techniques for the evaluation of the fetal coronary circulation are presented. Evaluation of the coronary arteries is primarily achieved by color flow imaging and pulsed wave Doppler. Conditions such as fetal growth restriction, anemia, ductus arteriosus constriction and bradycardia are associated with evidence of enhanced coronary blood flow. These findings suggest that short-term autoregulation and long-term alterations in myocardial flow reserve are present in the human fetus. At present, examination of coronary sinus blood flow has limited clinical utility, while increases of the coronary sinus diameter or attenuation of coronary sinus dynamics may provide useful markers of abnormalities of central venous drainage. Abnormal vascular connections between the coronary arteries and the ventricular cavities may be observed in outflow tract obstructive cardiac lesions. In these conditions prenatal detection of coronary fistulae may have a potential impact on outcome and therefore counseling and perinatal management.