Fetal cardiac interventions are currently performed for critical aortic stenosis (CAS), pulmonary atresia intact septum (PA/IVS) and closed atrial septum in hypoplastic left heart syndrome (HLHS). The rational is to change fetal hemodynamics, prevent secondary damage and improve long term outcome at an acceptable risk for mother and fetus.
In fetal CAS the left ventricle (LV) dilates, shortening decreases and endocardial fibroelastosis develops. The most important issue is to identify those patients, who will benefit from this procedure.
Intervention has been shown to improve fetal hemodynamics. The risk of intrauterine death is around 12%. A biventricular outcome has been reported in 1/3 to 2/3 of these fetuses.
At the Children’s Heart Centre Linz, 57 procedures were performed in 50 fetuses, with a success rate of 83% and a biventricular outcome after a median follow-up period of 43 months of 56%.
Intervention in fetal PAIVS is technically more challenging. In our centre 12 attempts have been performed in 10 fetuses all with suprasystemic RV pressures. There was no serious complication so far. Successful intervention (in 8 fetuses) resulted in better RV filling and continuous, but slower than normal growth of tricuspid valve and RV. After 1 year, 4/5 newborns are biventricular and well, 1 child received a Glenn shunt. One 6 months old patient still has a Blalock Taussig shunt, 2 fetuses are still in-utero.
Intact atrial septum in fetal HLHS has to be treated with transseptal stent placement to prevent re-occlusion. Results however are still poor (Own experience with 5 procedures).