Transcatheter Palliation With Pulmonary Artery Flow Restrictors in Neonates With Congenital Heart Disease: Feasibility, Outcomes, and Comparison With a Historical Hybrid Stage 1 Cohort

Abstract

Background: Neonates with complex congenital heart disease and pulmonary overcirculation have been historically treated surgically. However, subcohorts may benefit from less invasive procedures. Data on transcatheter palliation are limited.

Methods: We present our experience with pulmonary flow restrictors (PFRs) for palliation of neonates with congenital heart disease, including procedural feasibility, technical details, and outcomes. We then compared our subcohort of high-risk single ventricle neonates palliated with PFRs with a similar historical cohort who underwent a hybrid Stage 1. Cox regression was used to evaluate the association between palliation strategy and 6-month mortality.

Results: From 2021 to 2023, 17 patients (median age, 4 days; interquartile range [IQR], 2-8; median weight, 2.5 kilograms [IQR, 2.1-3.3]) underwent a PFR procedure; 15 (88%) had single ventricle physiology; 15 (88%) were high-risk surgical candidates. All procedures were technically successful. At a median follow-up of 6.2 months (IQR, 4.0-10.8), 13 patients (76%) were successfully bridged to surgery (median time since PFR procedure, 2.6 months [IQR, 1.1-4.4]; median weight, 4.9 kilograms [IQR, 3.4-5.8]). Pulmonary arteries grew adequately for age, and devices were easily removed without complications. The all-cause mortality rate before target surgery was 24% (n=4). Compared with the historical hybrid stage 1 cohort (n=23), after adjustment for main confounding (age, weight, intact/severely restrictive atrial septum or left ventricle to coronary fistulae), the PFR procedure was associated with a significantly lower all-cause 6-month mortality risk (adjusted hazard ratio, 0.26 [95% CI, 0.08-0.82]).

Conclusions: Transcatheter palliation with PFR is feasible, safe, and represents an effective strategy for bridging high-risk neonates with congenital heart disease to surgical palliation, complete repair, or transplant while allowing for clinical stabilization and somatic growth.

Keywords: cardiac catheterization; heart defects, congenital; stage 1 Norwood procedure; univentricular heart.

Figure 1.. Pulmonary flow restrictor fenestration techniques and graphical example of placement in a single ventricle heart.

A, Fenestration types. B, Two-millimeter triangular fenestration. C, Cross-shaped slit fenestration. D, Electrocautery-created fenestration. E, Pulmonary flow restrictors placed in a hypoplastic left heart.

Figure 2.. Angiographic evaluation of the implanted pulmonary flow restrictor (PFR).

A, Appropriately positioned PFR in the right pulmonary artery. B, Right PFR delivered with the right upper pulmonary artery (RUPA) technique (star indicates the distal tip of the PFR lodged inside the takeoff of the RUPA). C, Two-device technique (dashed black arrows indicate the distal tips of the PFR in the RUPA and R lower pulmonary artery [PA]). D, Partial migration of a right PFR, partially uncovering the origin of the RUPA (black arrow). E, Complete migration of a right PFR, leaving the RUPA completely uncovered (white arrow). F, Partial proximal collapse (dashed white arrow) of a right PFR deployed with the RUPA technique (star), discovered after 3 mo.

Figure 3.. Patient-level hospital course and outcomes.

PFR indicates pulmonary flow restrictor.

Figure 4.. Changes over time in somatic growth and pulmonary artery diameters.

A, Changes in body weight. B, Changes in pulmonary artery Z-scores. PFR indicates pulmonary flow restrictor.

Figure 5.. Kaplan-Meier of 6-mo survival.

Figure 6.. Kaplan-Meier of 6-mo survival for high-risk single ventricle by palliation strategy (PFR vs hybrid stage 1).

Model is adjusted for age, weight, presence of intact/severely restrictive atrial septum or left ventricle to coronary fistulae. HR indicates hazard ratio; and PFR, pulmonary flow restrictor.