Ex-utero intrapartum treatment as a novel bridging strategy to surgery in hypoplastic left heart syndrome with intact atrial septum—cross-circulation revisited

Abstract

Hypoplastic left heart syndromewith an intact or nearly intact septum (HLHS-IS/NIS) constitutes 6%-20% of hypoplastic left heart syndrome cases and represents themost severe form of the disease. Unless there is a pathway for pulmonary venous decompression, hemodynamic instability and death ensue within minutes to hours after birth. Survival depends upon emergent relief of this obstruction, either by operative or interventional techniques. The optimal strategy to bridge a newborn to a stable circulation remains undefined. We describe a novel EXIT (ex-utero intrapartum treatment) strategy using maternal-placental support to bridge a fetus with HLHS-IS/NIS to palliative intervention. A 26-year-old mother was referred for a fetal echocardiogram (at 30 weeks gestation), and the diagnosis of HLHSIS/NIS (with aortic atresia, mitral stenosis) was confirmed (Figure 1, A). The family elected to proceed with fetal intervention, which was performed (at 31 weeks) in another institution. This intervention was complicated by interatrial stent malposition with no demonstrable flow across the septum, and pleural effusion (Figure 1, B). As delivery neared, the parents requested aggressive management. Although our usual approach at birth is immediate catheter intervention, this strategy would be complicated by the oblique stent position in the right atrium. An EXIT to achieve cardiopulmonary bypass (CPB) was proposed to allow the fetus to remain on placental support while undergoing median sternotomy and initiation of CPB. The strategy was the consensus from a multidisciplinary fetal care conference as the safest means of maintaining hemodynamic stability before establishing interatrial communication. After the mother suffered premature rupture of membranes, a multidisciplinary team was mobilized for an emergent EXIT procedure. General anesthesia was induced using