Marshall AC et al. (2004) Creation of an atrial septal defect in utero for fetuses with hypoplastic left heart syndrome and intact or highly restrictive atrial septum. Circulation 110: 253–258

Hypoplastic left heart syndrome (HLHS) with intact atrial septum (IAS) is associated with a particularly high mortality rate. This may be due, in part, to secondary anatomic changes in the lung arising from prenatal left atrial hypertension. Marshall et al. hypothesized that decompression of the fetal left atrium might improve outcomes. On this basis, they have devised a method for creating an atrial septal defect in utero.

Procedures were performed at 26–34 weeks' gestation on fetuses diagnosed with HLHS and left atrial hypertension, with either an intact (n = 4) or a highly restrictive (n = 3) atrial septum. Under ultrasound guidance and using transcatheter techniques similar to those used previously in neonates, attempts were made to create an interatrial communication. Briefly, a needle was introduced percutaneously from the maternal abdominal surface into the fetal right atrium. The atrial septum was then perforated and the new defect was dilated and maintained using an angioplasty balloon.

Perforation of the atrial septum was achieved in six fetuses but pulmonary venous flow reversal persisted. One fetus died following the septoplasty procedure and the remainder were liveborn at term, although four died as neonates. There were no maternal complications.

The authors conclude that the procedure is feasible and that, following further technical development, it may offer clinical benefits in HLHS with IAS.