The Use of Pulmonary Vasodilators in Pediatric Patients with Single-Ventricle Palliation: A Ten-Year Experience in a Tertiary Care Center

Abstract

In single-ventricle circulation, pulmonary vascular resistances (PVR) play a crucial role at various stages of surgical palliation. Increased PVR detected at cardiac catheterization represents a contraindication to Fontan completion and may lead to an early circuit failure in the postoperative period. Pulmonary vasodilator therapy (PVT) may lower PVR and enhance pre- and post-surgical outcomes in Fontan patients. This study reports the experience with the use of PVT in a tertiary center, focusing on its role in lowering PVR before Fontan procedure and assessing its impact on postoperative outcomes. We analyzed 151 pediatric patients with single-ventricle heart diseases in pre-Fontan stage at our institution from January 2014 to December 2023, collecting demographics, anatomical diagnoses, clinical history, administration of PVT, surgical complications, pre-Fontan hemodynamic parameters, duration of intubation, chest tube retention, oxygen therapy needs, and total hospitalization time. In 17 out of 18 patients (94.4%) who were previously considered unsuitable for Fontan completion, a significant decrease in PVR (p = 0.006) was observed after starting PVT, enabling surgery to be performed. Among 113 patients (74.8%) undergoing Fontan, no differences in postoperative outcomes were observed between those who received PVT in the pre-Fontan stage and those who did not. PVT was started in 50 out of 113 patients (44.2%) after surgery, primarily due to elevated pulmonary pressures on invasive monitoring; among them, 24 patients (48%) had already been on therapy prior to the operation. PVT in the postoperative period was associated with worse outcomes compared to patients not receiving therapy, likely due to the more severe conditions of treated patients. The use of PVT during the pre-Fontan stage increases the number of individuals eligible for surgical palliation, with minimal impact on postoperative outcomes.

Keywords: Cardiac catheterization; Congenital heart disease; Fontan; Pulmonary vasodilator therapy; Univentricular physiology.