Percutaneous Deployment of the Sinus-SuperFlex-DS Stent for Hybrid Stage I Palliation in Neonates Weighing ≤ 2.5 kg: A Multicenter Study.

BACKGROUND: Hybrid stage I palliation (HS1P) has developed as an alternative to the Norwood stage I palliation for neonates with hypoplastic left heart and related left-sided obstructive lesions. HS1P is currently used in various clinical settings, such as single ventricle palliation, bridge to decision, bridge to biventricular repair, or destination therapy. The procedure comprises bilateral pulmonary artery banding and duct stenting, thus avoiding the need for cardiopulmonary bypass surgery, which may be particularly beneficial in high-risk patients.

AIMS: The aim of this multicenter retrospective observational study was to evaluate the feasibility, procedural safety, and clinical effectiveness of percutaneous deployment of the self-expanding sinus-SuperFlex-DS (SSF-DS) stent for duct stenting as part of HS1P in neonates weighing ≤ 2.5 kg.

METHODS: All neonates weighing ≤ 2.5 kg who underwent percutaneous SSF-DS implantation as part of HS1P at five German centers between August 2011 and 2019 were included. Procedural characteristics, complications, reinterventions, and outcomes were analyzed until stent explantation or death.

RESULTS: Thirty-two patients with a median age of 11 days (range 2-37 days) and a median weight of 2200 g (1600-2500 g) at stent implantation were included. Of those, 50% were preterm and 25% had known chromosomal abnormalities. Percutaneous stent implantation was successful in all patients. It was performed exclusively via femoral access, with retrograde arterial access used in 62.5% of procedures, including infants with a minimal weight of 1900 g. No procedure-related deaths occurred. In 25% of patients, two SSF-DS stents were implanted during the index procedure to achieve complete duct coverage. Twelve stent-related reinterventions were performed in 10 patients (31%), with a median time to first reintervention of 42 days (18-135 days). Implantation of more than one duct stent as part of the index procedure was associated with a higher reintervention rate (63% vs. 29%). The mean time to the subsequent surgical step did not differ between patients with and without stent-related reintervention. The overall reintervention rate until stent removal was 63% (20/32 patients). Twenty-five patients (78%) were successfully bridged to surgery (72% univentricular surgery, 28% biventricular repair). Median time to stent removal was 127 days (25-500 days), with a median weight of 4300 g (2800-7000 g) and a median weight gain of 2200 g (500-5400 g). In one patient, HS1P was the destination therapy. Six patients (19%) died before the subsequent surgical step. Mortality was related to severe comorbidities and the high-risk nature of the cohort rather than the stenting procedure itself. Procedure-related complications included atrial arrhythmias (6%) and stent migration/embolization (6%), all managed successfully without conversion to open-heart surgery. Occlusion of the primary access vessel occurred in two patients (6%; one femoral artery, one femoral vein).

CONCLUSIONS: Percutaneous deployment of the SSF-DS stent as part of HS1P in neonates weighing ≤ 2.5 kg is feasible and associated with acceptable procedural and access-related complication rates. This strategy successfully bridges most patients to the next planned surgical stage despite the high-risk characteristics of this population. Close clinical monitoring during the interstage period is warranted because of the substantial rate of reinterventions, including treatment of stent stenosis and restrictive atrial communications.