Early Experience With Reverse Double Switch Operation for the Borderline Left Heart.

This study reviews our early experience with the "reverse" double switch operation (R-DSO) for borderline left hearts. A retrospective review of children with borderline left hearts who underwent R-DSO between 2017 and 2021 was conducted. Patient characteristics and early hemodynamic and clinical outcomes were collected. R-DSO was performed in 8 patients with no operative or postoperative deaths; 5 underwent decompressing bidirectional Glenn. Left ventricular (LV) poor-compliance was the dominant pathophysiology. Four patients had undergone staged LV recruitment but were not candidates for anatomical biventricular circulation due to LV hypoplasia and/or diastolic dysfunction. 7/8 patients had risk factors for Fontan circulation including pulmonary vein stenosis, pulmonary hypertension, and pulmonary artery stenosis. Median age at R-DSO was 3.7 years (19 months-12 years). All patients were in sinus rhythm at discharge. At median follow-up of 15 months (57 days-4.1 years) no mortalities, reoperations or heart transplants had occurred. All patients had normal morphologic LV systolic function. In one patient, pre-existing pulmonary hypertension (HTN) resolved after R-DSO. Reinterventions included transcatheter mitral valve replacement for residual mitral stenosis and neo-pulmonary balloon valvuloplasty. In 4 patients follow-up catheterization done at a median of 519 days (320 days-4 years) demonstrated median cardiac index of 3.2 L/min/m2 (2.2-4); median sub-pulmonary left ventricular end diastolic pressure was 9 mm Hg (7-15); median inferior vena cava/baffle pressure was 8 mm Hg (7-13). R-DSO is an alternative to anatomical biventricular repair or single ventricle palliation in patients with borderline left hearts and can result in low inferior vena cava pressures and favorable early results. This approach can also relieve pulmonary HTN and allow future transplant candidacy.

Hemodynamic and anatomic changes after fetal aortic valvuloplasty are associated with procedural success and postnatal biventricular circulation.

BACKGROUND: There are minimal data characterizing the trajectory of left heart growth and hemodynamics following fetal aortic valvuloplasty (FAV). METHODS: This retrospective study included patients who underwent FAV between 2000 and 2019, with echocardiograms performed pre-FAV, immediately post-FAV, and in late gestation. RESULTS: Of 118 fetuses undergoing FAV, 106 (90%) underwent technically successful FAV, of which 55 (52%) had biventricular circulation. Technically successful FAV was associated with improved aortic valve growth (p < 0.001), sustained antegrade aortic arch (AoA) flow (p = 0.02), improved mitral valve (MV) inflow pattern (p = 0.002), and favorable patent foramen ovale (PFO) flow pattern (p = 0.004) from pre-FAV to late gestation. Compared to patients with univentricular outcome, patients with biventricular outcome had less decrement in size of the left ventricle (LV) (p < 0.001) and aortic valve (p = 0.005), as well as more physiologic PFO flow (p < 0.001) and antegrade AoA flow (p < 0.001) from pre-FAV to late gestation. In multivariable analysis, echocardiographic predictors of biventricular outcome were less decline in LV end diastolic dimension (p < 0.001), improved PFO flow (p = 0.004), and sustained antegrade AoA flow (p = 0.002) from pre-FAV to late gestation. CONCLUSION: Stabilization of left heart growth and improved hemodynamics following successful FAV through late gestation are associated with postnatal biventricular circulation.

Percutaneous transuterine fetal cerebral embolisation to treat vein of Galen malformations at risk of urgent neonatal decompensation: study protocol for a clinical trial of safety and feasibility.

INTRODUCTION: Although endovascular techniques have improved outcomes in vein of Galen malformations (VOGM), there is still a high rate of morbidity and mortality, particularly among cases with decompensation in the neonatal period. The dimension of the draining venous sinus on fetal imaging correlates with the risk of neonatal decompensation. In fetuses within this high-risk group who do not have end-organ injury, there is a theoretical therapeutic opportunity to reduce the arteriovenous shunt before the normal physiological changes of birth precipitate decompensation. This study investigates the safety and potential benefit of treating a VOGM in utero, which has not been previously studied. METHODS AND ANALYSIS: This study aims to enroll 20 subjects: pregnant women with a fetus harbouring a high-risk VOGM (defined on MRI by a narrowest medial-lateral width greater than 8 mm in the draining venous sinus). Unfortunately, the subset of fetuses with in utero end-organ injury is ineligible, because the late stage of pathology is not amenable to recovery from a cerebrovascular intervention, likely not even in utero. This study aims to alter the physiology before such developments accrue.At or after 23 weeks of gestation, a transuterine transposterior fontanelle needle puncture to the torcular allows ultrasound-guided deployment of coils to embolise the draining venous malformation.This study has 97.5% power to detect major safety events at 30% or greater, and 80% power to detect a reduction in the rate of neonatal intervention from 80% to 30%. In the staged study design, an interval evaluation after 11 patients invokes study termination if safety events occur above the allowed threshold. ETHICS AND DISSEMINATION: The institutional review boards at Mass General Brigham and Boston Children's Hospital (BCH) reviewed and approved this protocol. The BCH Department of Radiology and a patient family philanthropic donation fund this study. The trial results will be published in peer-reviewed journals and presented at scientific conferences. TRIAL REGISTRATION NUMBER: NCT04434729.

Fetal Brain Volume Predicts Neurodevelopment in Congenital Heart Disease.

BACKGROUND: Neurodevelopmental impairment is common in children with congenital heart disease (CHD), but postnatal variables explain only 30% of the variance in outcomes. To explore whether the antecedents for neurodevelopmental disabilities might begin in utero, we analyzed whether fetal brain volume predicted subsequent neurodevelopmental outcome in children with CHD. METHODS: Fetuses with isolated CHD and sociodemographically comparable healthy control fetuses underwent fetal brain magnetic resonance imaging and 2-year neurodevelopmental evaluation with the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III) and the Adaptive Behavior Assessment System, Third Edition (ABAS-3). Hierarchical regression evaluated potential predictors of Bayley-III and ABAS-3 outcomes in the CHD group, including fetal total brain volume adjusted for gestational age and sex, sociodemographic characteristics, birth measures, and medical history. RESULTS: The CHD group (n=52) had lower Bayley-III cognitive, language, and motor scores than the control group (n=26), but fetal brain volumes were similar. Within the CHD group, larger fetal total brain volume correlated with higher Bayley-III cognitive, language, and motor scores and ABAS-3 adaptive functioning scores (r=0.32-0.47; all P<0.05), but this was not noted in the control group. Fetal brain volume predicted 10% to 21% of the variance in neurodevelopmental outcome measures in univariate analyses. Multivariable models that also included social class and postnatal factors explained 18% to 45% of the variance in outcome, depending on developmental domain. Moreover, in final multivariable models, fetal brain volume was the most consistent predictor of neurodevelopmental outcome across domains. CONCLUSIONS: Small fetal brain volume is a strong independent predictor of 2-year neurodevelopmental outcomes and may be an important imaging biomarker of future neurodevelopmental risk in CHD. Future studies are needed to support this hypothesis. Our findings support inclusion of fetal brain volume in risk stratification models and as a possible outcome in fetal neuroprotective intervention studies.

Contemporary Outcomes in Tetralogy of Fallot With Absent Pulmonary Valve After Fetal Diagnosis.

Background Tetralogy of Fallot with absent pulmonary valve is associated with high mortality, but it remains difficult to predict outcomes prenatally. We aimed to identify risk factors for mortality in a large multicenter cohort. Methods and Results Fetal echocardiograms and clinical data from 19 centers over a 10-year period were collected. Primary outcome measures included fetal demise and overall mortality. Of 100 fetuses, pregnancy termination/postnatal nonintervention was elected in 22. Of 78 with intention to treat, 7 (9%) died in utero and 21 (27%) died postnatally. With median follow-up of 32.9 months, no deaths occurred after 13 months. Of 80 fetuses with genetic testing, 46% had chromosomal abnormalities, with 22q11.2 deletion in 35%. On last fetal echocardiogram, at a median of 34.6 weeks, left ventricular dysfunction independently predicted fetal demise (odds ratio [OR], 7.4; 95% CI 1.3, 43.0; P=0.026). Right ventricular dysfunction independently predicted overall mortality in multivariate analysis (OR, 7.9; 95% CI 2.1-30.0; P=0.002). Earlier gestational age at delivery, mediastinal shift, left ventricular/right ventricular dilation, left ventricular dysfunction, tricuspid regurgitation, and Doppler abnormalities were associated with fetal and postnatal mortality, although few tended to progress throughout gestation on serial evaluation. Pulmonary artery diameters did not correlate with outcomes. Conclusions Perinatal mortality in tetralogy of Fallot with absent pulmonary valve remains high, with overall survival of 64% in fetuses with intention to treat. Right ventricular dysfunction independently predicts overall mortality. Left ventricular dysfunction predicts fetal mortality and may influence prenatal management and delivery planning. Mediastinal shift may reflect secondary effects of airway obstruction and abnormal lung development and is associated with increased mortality.

Impact of Socioeconomic Status, Race and Ethnicity, and Geography on Prenatal Detection of Hypoplastic Left Heart Syndrome and Transposition of the Great Arteries.

BACKGROUND: Prenatal detection (PND) has benefits for infants with hypoplastic left heart syndrome (HLHS) and transposition of the great arteries (TGA), but associations between sociodemographic and geographic factors with PND have not been sufficiently explored. This study evaluated whether socioeconomic quartile (SEQ), public insurance, race and ethnicity, rural residence, and distance of residence (distance and driving time from a cardiac surgical center) are associated with the PND or timing of PND, with a secondary aim to analyze differences between the United States and Canada. METHODS: In this retrospective cohort study, fetuses and infants <2 months of age with HLHS or TGA admitted between 2012 and 2016 to participating Fetal Heart Society Research Collaborative institutions in the United States and Canada were included. SEQ, rural residence, and distance of residence were derived using maternal census tract from the maternal address at first visit. Subjects were assigned a SEQ z score using the neighborhood summary score or Canadian Chan index and separated into quartiles. Insurance type and self-reported race and ethnicity were obtained from medical charts. We evaluated associations among SEQ, insurance type, race and ethnicity, rural residence, and distance of residence with PND of HLHS and TGA (aggregate and individually) using bivariate analysis with adjusted associations for confounding variables and cluster analysis for centers. RESULTS: Data on 1862 subjects (HLHS: n=1171, 92% PND; TGA: n=691, 58% PND) were submitted by 21 centers (19 in the United States). In the United States, lower SEQ was associated with lower PND in HLHS and TGA, with the strongest association in the lower SEQ of pregnancies with fetal TGA (quartile 1, 0.78 [95% CI, 0.64-0.85], quartile 2, 0.77 [95% CI, 0.64-0.93], quartile 3, 0.83 [95% CI, 0.69-1.00], quartile 4, reference). Hispanic ethnicity (relative risk, 0.85 [95% CI, 0.72-0.99]) and rural residence (relative risk, 0.78 [95% CI, 0.64-0.95]) were also associated with lower PND in TGA. Lower SEQ was associated with later PND overall; in the United States, rural residence and public insurance were also associated with later PND. CONCLUSIONS: We demonstrate that lower SEQ, Hispanic ethnicity, and rural residence are associated with decreased PND for TGA, with lower SEQ also being associated with decreased PND for HLHS. Future work to increase PND should be considered in these specific populations.

Effect of In utero Non-steroidal anti-inflammatory drug therapy for severe ebstein anomaly or tricuspid valve dysplasia (NSAID therapy for fetal ebstein anomaly)

Abstract: Ebstein anomaly (EA) and tricuspid valve dysplasia (TVD) are rare congenital malformations associated with nearly 50% mortality when diagnosed in utero. The diseases often produce severe tricuspid regurgitation (TR) in the fetus and in some cases, pulmonary regurgitation (PR) and circular shunting ensue. Since the ductus arteriosus (DA) plays a critical role in the circular shunt and may be constricted by transplacental non-steroidal anti-inflammatory drugs (NSAIDs), we sought to assess the effect of NSAIDs on fetuses with EA/TVD. We reviewed mothers of singleton fetuses with EA/TVD and PR, indicative of circular shunting, who were offered NSAIDs at multiple centers from 2010-2018. Initial dosing consisted of indomethacin, followed by ibuprofen in most cases. Twenty-one patients at 10 centers were offered therapy 4 at a median gestational age (GA) of 30.0 weeks (range: 20.9-34.9). Most (15/21=71%) mothers received NSAIDs, and 12/15 (80%) achieved DA constriction after a median of 2.0 days (1.0-6.0). All fetuses with DA constriction had improved PR; 92% had improved Doppler patterns. Median GA at pregnancy outcome was 36.1 weeks (30.7-39.0) in fetuses with DA constriction vs. 33 weeks (23.3-37.3) in fetuses who did not receive NSAIDs or achieve DA constriction (p=0.040). Eleven of 12 patients (92%) with DA constriction survived to live-birth, whereas 4/9 patients (44%) who did not receive NSAIDs or achieve DA constriction survived (p=0.046). In conclusion, our findings demonstrate the proof of concept that NSAIDs mitigate circular shunt physiology by DA constriction and improve PR among fetuses with severe EA/TVD. Although the early results are encouraging, further investigation is necessary to determine safety and efficacy.

Late gestation predictors of a postnatal biventricular circulation after fetal aortic valvuloplasty.

OBJECTIVES: Fetal aortic valvuloplasty (FAV) for severe aortic stenosis (AS) has shown promise in averting progression to hypoplastic left heart syndrome. After FAV, predicting which fetuses will achieve a biventricular (BiV) circulation after birth remains challenging. Identifying predictors of postnatal circulation on late gestation echocardiography will improve parental counseling. METHODS: Liveborn patients who underwent FAV and had late gestation echocardiography available were included (2000-2017, n = 96). Multivariable logistic regression and classification and regression tree analysis were utilized to identify independent predictors of BiV circulation. RESULTS: Among 96 fetuses, 50 (52.1%) had BiV circulation at the time of neonatal discharge. In multivariable analysis, independent predictors of biventricular circulation included left ventricular (LV) long axis z-score (OR 3.2, 95% CI 1.8-5.7, p < 0.001), LV ejection fraction (OR 1.3, 95% CI 1.0-1.8, p = 0.023), anterograde aortic arch flow (OR 5.0, 95% CI 1.2-20.4, p = 0.024), and bidirectional or right-to-left foramen ovale flow (OR 4.6, 95% CI 1.4-15.8, p = 0.015). CONCLUSION: Several anatomic and physiologic parameters in late gestation were found to be independent predictors of BiV circulation after FAV. Identifying these predictors adds to our understanding of LV growth and hemodynamics after FAV and may improve parental counseling.

Regional Brain Growth Trajectories in Fetuses with Congenital Heart Disease.

OBJECTIVE: Congenital heart disease (CHD) is associated with abnormal brain development in utero. We applied innovative fetal magnetic resonance imaging (MRI) techniques to determine whether reduced fetal cerebral substrate delivery impacts the brain globally, or in a region-specific pattern. Our novel design included two control groups, one with and the other without a family history of CHD, to explore the contribution of shared genes and/or fetal environment to brain development. METHODS: From 2014 to 2018, we enrolled 179 pregnant women into 4 groups: "HLHS/TGA" fetuses with hypoplastic left heart syndrome (HLHS) or transposition of the great arteries (TGA), diagnoses with lowest fetal cerebral substrate delivery; "CHD-other," with other CHD diagnoses; "CHD-related," healthy with a CHD family history; and "optimal control," healthy without a family history. Two MRIs were obtained between 18 and 40 weeks gestation. Random effect regression models assessed group differences in brain volumes and relationships to hemodynamic variables. RESULTS: HLHS/TGA (n = 24), CHD-other (50), and CHD-related (34) groups each had generally smaller brain volumes than the optimal controls (71). Compared with CHD-related, the HLHS/TGA group had smaller subplate (-13.3% [standard error = 4.3%], p < 0.01) and intermediate (-13.7% [4.3%], p < 0.01) zones, with a similar trend in ventricular zone (-7.1% [1.9%], p = 0.07). These volumetric reductions were associated with lower cerebral substrate delivery. INTERPRETATION: Fetuses with CHD, especially those with lowest cerebral substrate delivery, show a region-specific pattern of small brain volumes and impaired brain growth before 32 weeks gestation. The brains of fetuses with CHD were more similar to those of CHD-related than optimal controls, suggesting genetic or environmental factors also contribute. ANN NEUROL 2021;89:143-157.

Extracardiac Doppler indices predict perinatal mortality in fetuses with Ebstein anomaly and tricuspid valve dysplasia.

OBJECTIVES: Ebstein anomaly and tricuspid valve dysplasia (EA/TVD) carry high perinatal mortality. Past studies have focused on cardiac predictors of mortality; we sought to describe the fetal echo (FE) extracardiac Dopplers in this cohort and determine their association with perinatal mortality. METHOD: Fetuses with EA/TVD at 23 centers from 2005-2011 were included for retrospective study. Doppler pattern and velocity of the umbilical artery (UA), umbilical vein (UV), ductus venosus (DV), and middle cerebral artery (MCA) were collected. Bivariate and multivariate analyzes were performed. The primary outcome measure was perinatal mortality, defined as fetal demise or neonatal death. RESULTS: Of 190 cases that met eligibility criteria, alterations were seen in 50% of UA, 16% of UV, 48% of DV, and 8% of MCA Doppler indices on the last FE (median 27.4 weeks). Independent predictors of perinatal mortality included abnormal UA Doppler pattern of absence or reversed end diastolic flow (OR 9.7) and UV velocity z score <1 (OR 2.5), in addition to diagnosis <32 weeks (OR 4.2) and tricuspid valve (TV) annulus z score ≥6 (OR 5.3). CONCLUSION: Abnormal UA Doppler pattern and decreased UV velocity are independent predictors of perinatal mortality in EA/TVD fetuses and should be used to refine mortality risk and guide perinatal management.

Effect of In Utero Non-Steroidal Anti-Inflammatory Drug Therapy for Severe Ebstein Anomaly or Tricuspid Valve Dysplasia (NSAID Therapy for Fetal Ebstein anomaly).

Ebstein anomaly (EA) and tricuspid valve dysplasia (TVD) are rare congenital malformations associated with nearly 50% mortality when diagnosed in utero. The diseases often produce severe tricuspid regurgitation (TR) in the fetus and in some cases, pulmonary regurgitation (PR) and circular shunting ensue. Since the ductus arteriosus (DA) plays a critical role in the circular shunt and may be constricted by transplacental nonsteroidal anti-inflammatory drugs (NSAIDs), we sought to assess the effect of NSAIDs on fetuses with EA/TVD. We reviewed mothers of singleton fetuses with EA/TVD and PR, indicative of circular shunting, who were offered NSAIDs at multiple centers from 2010 to 2018. Initial dosing consisted of indomethacin, followed by ibuprofen in most cases. Twenty-one patients at 10 centers were offered therapy at a median gestational age (GA) of 30.0 weeks (range: 20.9 to 34.9). Most (15/21 = 71%) mothers received NSAIDs, and 12 of 15 (80%) achieved DA constriction after a median of 2.0 days (1.0 to 6.0). All fetuses with DA constriction had improved PR; 92% had improved Doppler patterns. Median GA at pregnancy outcome (live-birth or fetal demise) was 36.1 weeks (30.7 to 39.0) in fetuses with DA constriction versus 33 weeks (23.3 to 37.3) in fetuses who did not receive NSAIDs or achieve DA constriction (p = 0.040). Eleven of 12 patients (92%) with DA constriction survived to live-birth, whereas 4 of 9 patients (44%) who did not receive NSAIDs or achieve DA constriction survived (p = 0.046). In conclusion, our findings demonstrate the proof of concept that NSAIDs mitigate circular shunt physiology by DA constriction and improve PR among fetuses with severe EA/TVD. Although the early results are encouraging, further investigation is necessary to determine safety and efficacy.

Risk Factors for Mortality and Circulatory Outcome Among Neonates Prenatally Diagnosed With Ebstein Anomaly or Tricuspid Valve Dysplasia: A Multicenter Study.

Background In a recent multicenter study of perinatal outcome in fetuses with Ebstein anomaly or tricuspid valve dysplasia, we found that one third of live-born patients died before hospital discharge. We sought to further describe postnatal management strategies and to define risk factors for neonatal mortality and circulatory outcome at discharge. Methods and Results This 23-center, retrospective study from 2005 to 2011 included 243 fetuses with Ebstein anomaly or tricuspid valve dysplasia. Among live-born patients, clinical and echocardiographic factors were evaluated for association with neonatal mortality and palliated versus biventricular circulation at discharge. Of 176 live-born patients, 7 received comfort care, 11 died <24 hours after birth, and 4 had insufficient data. Among 154 remaining patients, 38 (25%) did not survive to discharge. Nearly half (46%) underwent intervention. Mortality differed by procedure; no deaths occurred in patients who underwent right ventricular exclusion. At discharge, 56% of the cohort had a biventricular circulation (13% following intervention) and 19% were palliated. Lower tricuspid regurgitation jet velocity (odds ratio [OR], 2.3 [1.1-5.0], 95% CI, per m/s; P=0.025) and lack of antegrade flow across the pulmonary valve (OR, 4.5 [1.3-14.2]; P=0.015) were associated with neonatal mortality by multivariable logistic regression. These variables, along with smaller pulmonary valve dimension, were also associated with a palliated outcome. Conclusions Among neonates with Ebstein anomaly or tricuspid valve dysplasia diagnosed in utero, a variety of management strategies were used across centers, with poor outcomes overall. High-risk patients with low tricuspid regurgitation jet velocity and no antegrade pulmonary blood flow should be considered for right ventricular exclusion to optimize their chance of survival.

1.5-Ventricle Repair Using Left Ventricle as the Subpulmonary Ventricle.

The use of the left ventricle as the subpulmonary ventricle to achieve a 1.5 or biventricular circulation is feasible in heterotaxy patients with complex intracardiac anatomy and acceptable right ventricular function. It is an alternative in patients who are not ideal candidates for single-ventricle palliation. We highlight 2 cases in which patients were rescued from a failed Fontan palliation and demonstrated improved functional status with normal saturations.

Low prenatal detection rate of valvar pulmonary stenosis: What are we missing?

OBJECTIVES: Critical pulmonary stenosis (PS) and pulmonary atresia with intact ventricular septum (PAIVS) require urgent neonatal intervention. Since PS may be more insidious than PAIVS during gestation, we hypothesized that neonates with PS would have lower rates of prenatal detection than PAIVS. METHODS: We performed a retrospective chart review of all neonates who underwent diagnostic or interventional cardiac catheterization between 2000 and 2014 for critical PS or PAIVS. The rates of prenatal diagnosis were calculated for PS and PAIVS. Prenatal and postnatal echocardiographic data were reviewed. RESULTS: 178 patients met inclusion criteria: 91 with critical PS and 87 with PAIVS. The prenatal diagnosis rate for critical PS was lower than for PAIVS at 37% (34/91) vs 60% (52/87) (P = .003). At the time of diagnosis at a median gestational age of 25 weeks, the median TV z-score for patients with critical PS was larger than in PAIVS (-0.15 vs -3.0 P = .004). CONCLUSION: Critical PS had a lower prenatal detection rate than PAIVS, likely due to a relatively normal 4-chamber view at the time of routine second trimester screening in patients with PS. Color flow Doppler of the outflow tracts may improve detection, since outflow tracts may appear normal by 2D imaging.

Fetal Aortic Valvuloplasty for Evolving Hypoplastic Left Heart Syndrome: A Decision Analysis.

BACKGROUND: Fetal aortic valvuloplasty (FAV) may prevent progression of midgestation aortic stenosis to hypoplastic left heart syndrome. However, FAV has well-established risks, and its survival benefit remains unknown. Our primary aim was to determine whether FAV for midgestation aortic stenosis increases survival from fetal diagnosis to age 6 years. METHODS AND RESULTS: We performed a retrospective analysis of 143 fetuses who underwent FAV from 2000 to 2017 and a secondary analysis of the Pediatric Heart Network Single Ventricle Reconstruction trial. Using these results, we developed a decision model to estimate probability of transplant-free survival from fetal diagnosis to age 6 years and postnatal restricted mean transplant-free survival time. FAV was technically successful in 84% of 143 fetuses with fetal demise in 8%. Biventricular circulation was achieved in 50% of 111 live-born infants with successful FAV but in only 16% of the 19 patients with unsuccessful FAV. The model projected overlapping probabilities of transplant-free survival to age 6 years at 75% (95% CI, 67%-82%) with FAV versus 72% (95% CI, 61%-82%) with expectant fetal management, resulting in a restricted mean transplant-free survival time benefit of 1.2 months. When limiting analyses to the improved FAV experience since 2009 to reflect current practice, (probability of technical success [94%], fetal demise [4%], and biventricular circulation [66%]), the model projected that FAV increased the probability of survival to age 6 years to 82% (95% CI, 73%-89%). Expectant management is favored if risk of fetal demise exceeded 12% or probability of biventricular circulation fell below 26%, but FAV remained favored over plausible recent range of technical success. CONCLUSIONS: Our model suggests that FAV provides a modest, medium-term survival benefit over expectant fetal management. Appropriate patient selection and low risk of fetal demise with FAV are critical factors for obtaining a survival benefit.

Fetal cardiac interventions: Where do we stand?

Fetal cardiac intervention (FCI) is a novel and evolving technique that allows for in utero treatment of a subset of congenital heart disease. This review describes the rationale, selection criteria, technical features, and current outcomes for the three most commonly performed FCI: fetal aortic stenosis with evolving hypoplastic left heart syndrome (HLHS); HLHS with intact or restrictive atrial septum; and pulmonary atresia with intact ventricular septum, with concern for worsening right ventricular (RV) hypoplasia.