Atrial septal defect (ASD) incidence is more frequent in preterm infants and is associated with an increased risk of bronchopulmonary dysplasia (BPD) and pulmonary hypertension (PH). In this population, ASD closure is controversial because of high procedural risks.

To describe a novel modified percutaneous technique for ASD closure at bedside in preterm infants with BPD and PH presenting with a significant left-to-right shunt.

A retrospective monocentric study included infants with PH who underwent percutaneous ASD closure with the modified technique. Device size was selected before the intervention according to the largest ASD transthoracic echocardiographic diameter plus 1 mm. Four interventions were performed in the cathlab and three in the NICU under mobile Fluoroscopy. Through the femoral vein, a 45-cm, 45°, 6-Fr Destination sheath (Terumo, Japan) was advanced into the inferior vena cava to its junction to the right atrium. A 60-cm, 4-Fr multipurpose catheter was then advanced under echocardiographic and fluoroscopic guidance into the left atrium. The sheath was subsequently advanced over the catheter, avoiding intracardiac use of a 0.035-inch guidewire in these fragile patients. The device was deployed in the standard technique under echocardiographic guidance mainly.

Seven infants were included between 2020 and 2026. Median age at intervention was 104 days (36–214) and median weight 3.8 kg (2.7–5.0). Median ASD diameter was 7 mm (6–9). Procedural success was 100%. No device embolization, erosion or major periprocedural complications occured. The left ventricular eccentricity index decreased from 1.59 ± 0.37 before closure to 1.32 ± 0.32 at 48 hours after the procedure reflecting a reduction in right ventricular pressure overload. Right ventricular Z -scores (Cantinotti, 2014) decreasing from 1.9 (0.8–3.85) before closure to 1.1 (0.5–2.17) after closure.

During follow-up, pulmonary hypertension resolved in all but one patient in whom a SOX17 mutation associated with pulmonary vascular disease was identified; this patient died six months later due to severe PH progression.

ASD closure using this modified guidewire-free technique appears feasible and safe in infants with severe BPD and PH, including when performed at bedside in the NICU. ASD closure improves promptly echocardiographic markers of pulmonary hypertension, suggesting a beneficial impact on cardiopulmonary remodeling in this fragile population.