The aim of this study was to describe atrial septal defect morphology in hypoplastic left heart syndrome, to report the incidence of restrictiveness and its relationship with defect morphology, to correlate restriction with midterm outcome, and to describe our interventional approach to restrictive defect.

From 2011 to 2015, 31 neonates with hypoplastic left heart syndrome underwent hybrid procedure with pulmonary artery banding and ductal stenting at our Institution. Restrictive physiology of the atrial septal defect was based on Doppler gradient >6 mmHg through the defect and on clinical signs of pulmonary hypertension. The mean gradient was then measured invasively. Restrictive defect occurred in 11/27 patients (40%). The restrictive group showed three ostium secundum defects (27%) and eight complex morphologies (73%). Conversely, in the non-restrictive group, we observed 11 ostium secundum defects (69%) and five complex morphologies (31%). Early balloon atrioseptostomy was required in three cases. Late restriction occurred in eight patients and was dealt with balloon dilation, stenting, or atrioseptectomy. There was no significant difference between restrictive and non-restrictive groups in terms of early or 12-month survival.

Complex morphologies were more frequently related to restrictiveness. Stenting technique has a crucial role, as the procedure carries a significant risk for stent migration. Effective treatment of restrictive atrial septal defect is related to a better outcome, as it leads to equalisation of survival between patients with and those without restrictive atrial septal defect.

The reported incidence of necrotising enterocolitis in neonates with complex CHD with ductus-dependent systemic circulation ranges from 6.8 to 13% despite surgical treatment; the overall mortality is between 25 and 97%. The incidence of gastrointestinal complications after hybrid palliation for neonates with ductus-dependent systemic circulation still has to be defined, but seems comparable with that following the Norwood procedure.

We reviewed the incidence of gastrointestinal complications in a series of 42 consecutive neonates with ductus-dependent systemic circulation, who received early hybrid palliation associated with a standardised feeding protocol.

The median age and birth weight at the time of surgery were 3 days (with a range from 1 to 10 days) and 3.07 kg (with a range from 1.5 to 4.5 kg), respectively. The median ICU length of stay was 7 days (1–70 days), and the median hospital length of stay was 16 days (6–70 days). The median duration of mechanical ventilation was 3 days. Hospital mortality was 16% (7/42). In the postoperative period, 26% of patients were subjected to early extubation, and all of them received treatment with systemic vasodilatory agents. Feeding was started 6 hours after extubation according to a dedicated feeding protocol. After treatment, none of our patients experienced any grade of necrotising enterocolitis or major gastrointestinal adverse events.

Our experience indicates that the combination of an “early hybrid approach”, systemic vasodilator therapy, and dedicated feeding protocol adherence could reduce the incidence of gastrointestinal complications in this group of neonates. Fast weaning from ventilatory support, which represents a part of our treatment strategy, could be associated with low incidence of necrotising enterocolitis.