Results of in utero atrial septoplasty in fetuses with hypoplastic left heart syndrome

Neonates with hypoplastic left heart syndrome and intact or highly restrictive atrial septum have a high rate of mortality. We sought to assess the effect of prenatal intervention intended to create atrial septal defects in fetuses with this diagnosis.We reviewed the medical records and imaging of all fetuses undergoing intervention for atrial septal defect creation in the setting of hypoplastic left heart syndrome and intact atrial septum. The procedures were performed with a percutaneous cardiac puncture under the guidance of ultrasonography. For the 21 interventions, patient and procedural characteristics were analyzed to identify predictors of neonatal outcome.Of 21 procedures attempted between 24 and 34 weeks' gestation, 19 were technically successful. Fetal demise occurred in two cases. The size of the created defect varied and measured at least 3 mm in six fetuses. Among 19 neonates, a larger atrial septal defect was associated with higher oxygen saturation and less need for intervention prior to surgical single-ventricle palliation.Technically successful atrial septal defect creation in fetuses with hypoplastic left heart syndrome and intact atrial septum results in atrial septal defects of varying size; defects of at least 3 mm in diameter appear to confer postnatal benefit.