Background Aortic stenosis in the midgestation fetus with a normal-sized or dilated left ventricle predictably progresses to hypoplastic left heart syndrome when associated with certain physiological findings. Prenatal balloon aortic valvuloplasty may improve left heart growth and function, possibly preventing evolution to hypoplastic left heart syndrome. Methods and Results Between March 2000 and October 2008, 70 fetuses underwent attempted aortic valvuloplasty for critical aortic stenosis with evolving hypoplastic left heart syndrome. We analyzed this experience to determine factors associated with procedural and postnatal outcome. The median gestational age at intervention was 23 weeks. The procedure was technically successful in 52 fetuses (74%). Relative to 21 untreated comparison fetuses, subsequent prenatal growth of the aortic and mitral valves, but not the left ventricle, was improved after intervention. Nine pregnancies (13%) did not reach a viable term or preterm birth. Seventeen patients had a biventricular circulation postnatally, 15 from birth. Larger left heart structures and higher left ventricular pressure at the time of intervention were associated with biventricular outcome. A multivariable threshold scoring system was able to discriminate fetuses with a biventricular outcome with 100% sensitivity and modest positive predictive value. Conclusions Technically successful aortic valvuloplasty alters left heart valvar growth in fetuses with aortic stenosis and evolving hypoplastic left heart syndrome and, in a subset of cases, appeared to contribute to a biventricular outcome after birth. Fetal aortic valvuloplasty carries a risk of fetal demise. Fetuses undergoing in utero aortic valvuloplasty with an unfavorable multivariable threshold score at the time of intervention are very unlikely to achieve a biventricular circulation postnatally.

Prenatal cardiac intervention (PCI) may favorably alter the in utero course of some congenital heart defects. In our preliminary experience with PCI, fetal hemodynamic instability (FHI) characterized by bradycardia and ventricular dysfunction was common. This study evaluated the pathophysiology, management, and short-term outcomes of FHI during PCI for aortic stenosis with evolving hypoplastic left heart syndrome (HLHS), HLHS with restrictive atrial septum, pulmonary atresia with intact ventricular septum, and hydrops due to structural heart disease. From 2000 to 2006, 83 fetuses underwent PCI, with ventricular access in 63, atrial access in 17, and both in three. FHI occurred in 37 fetuses (45%). FHI was associated with transventricular PCI (all but one case of FHI; p Ͻ 0.001) and large hemopericardium (n ϭ 9; p ϭ 0.07). Prolonged FHI was associated with severe ventricular distortion during ventricular puncture (p ϭ 0.06). FHI was treated with resuscitation medications in 31 of 37 fetuses and resolved in all 37. Five fetuses died within 1 d of PCI: four had FHI and one had a massive hemopericardium. FHI is common and clinically important during transventricular PCI and may be caused by a ventricular reflex or reduced cardiac output from cardiac distortion during ventricular puncture. Hemopericardium may be causative in a subset of fetuses. I n some forms of congenital heart disease, relatively simple obstructive anomalies causing physiologic changes in utero may lead to more serious abnormalities of cardiovascular growth and development. For example, severe left ventricular (LV) outflow obstruction in the early fetus may produce myocardial and hemodynamic abnormalities resulting in growth arrest of the entire left heart complex, culminating in HLHS. Similarly, in fetuses with established HLHS, closure of the foramen ovale may cause left atrial hypertension, with subsequent abnormalities of lung parenchymal and vascular development that contribute to high mortality after birth (1,2). Although such processes have not been well defined, the hypothesis that flow disturbances early in gestation can lead to abnormal cardiac growth is supported by experimental animal data (3-5) and by documented progression of isolated LV or right ventricular (RV) outflow obstruction to ventricular hypoplasia in human fetuses (6,7).In fetuses with such congenital heart defects, PCI may limit the secondary abnormalities of growth or development that result from primary structural anomalies by restoring more normal hemodynamic conditions. Since 2000, we have offered PCI for selected fetuses with (1) severe aortic stenosis (AS) with evolving HLHS, (2) critically restrictive or intact atrial septum and established HLHS, (3) pulmonary atresia with evolving hypoplastic right heart syndrome (HRHS), and (4) hydrops fetalis due to structural heart disease (8 -10).Almost immediately, we observed that FHI characterized by bradycardia and ventricular dysfunction was common during PCI. Although cases of fetal cardiac arrest or bradycardi...

Ultrasound-guided atrial septal stent placement is feasible in some fetuses with HLHS/IAS. Visualization of the septum and catheter tip is critical to technical success. Additional experience is necessary to determine the clinical impact of this intervention. © 2013 Wiley Periodicals, Inc.

Objectives: The objective of this study was to describe our single-institution experience with prenatal atrial septal stent placement for fetuses with hypoplastic left heart syndrome and an intact atrial septum (HLHS/IAS). Background: Infants born with HLHS/IAS are at high risk for neonatal death, despite maximal postnatal therapy. Prenatal atrial septoplasty by static balloon dilation has been effective in decompressing the left atrium (LA) in utero, but several factors have limited the size of septal defects. We attempted to overcome the limitations of balloon septoplasty using transcatheter atrial septal stents. Methods: All records from our institution of fetuses with HLHS/IAS that underwent prenatal atrial septal stent placement were reviewed, including operative notes and echocardiograms. Results: Nine fetuses between 24 and 31 weeks gestation with HLHS/IAS underwent attempted fetal atrial septal stent placement. A stent was deployed across the atrial septum in five fetuses, with four fetuses demonstrating flow across the stent at the time of intervention. In four cases, stent placement failed due to malposition or embolization, but in three of the four cases, atrial balloon septoplasty at the same in-utero procedure successfully and acutely decompressed the LA. There were no maternal complications. There was one fetal demise. The remaining eight fetuses survived to delivery, but four died in the neonatal period (two of which had been stented). Conclusions: Ultrasound-guided atrial septal stent placement is feasible in some fetuses with HLHS/IAS. Visualization of the septum and catheter tip is critical to technical success. Additional experience is necessary to determine the clinical impact of this intervention. V C 2013 Wiley Periodicals, Inc.