# Extracellular Matrix Tissue Patch for Pulmonary Artery Repair in Pediatric Cardiac Surgery: A Single-Center Experience

## TL;DR

This study evaluates the safety and effectiveness of ProxiCor® patches for repairing pulmonary artery defects in children, showing promising early results.

## Contribution

The study provides a single-center clinical experience on using ProxiCor® extracellular matrix patches for pediatric pulmonary artery and RVOT reconstruction.

## Key findings

- No patch-related complications like restenosis or dilation were observed in 25 pediatric patients over a median follow-up of 483 days.
- Early outcomes showed a mortality rate of 8% due to causes unrelated to the patch, with no patch-specific adverse events.
- ProxiCor® patches demonstrated feasibility and safety for pulmonary artery and RVOT reconstruction in a pediatric cohort.

## Abstract

Introduction: Congenital structural anomalies of the pulmonary artery in children, encompassing defects such as pulmonary atresia (PA), pulmonary stenosis (PS), pulmonary artery hypoplasia, and tetralogy of Fallot (ToF), pose significant challenges in pediatric cardiac surgery due to impaired blood flow in pulmonary circulation. Traditional options for conventional repair—including autologous materials such as the native pericardium and synthetic materials such as artificial patches—have limitations including a lack of growth potential and vulnerability to restenosis over time. ProxiCor® patches, based on the extracellular matrix (ECM), have emerged as biologically compatible substitutes capable of fostering tissue regeneration. The primary outcomes of this study were the safety (absence of patch-related complications such as restenosis, dilation, aneurysm, infection, or thrombosis) and feasibility (intraoperative handling and surgical success) of ProxiCor® for pulmonary artery and right ventricular outflow tract (RVOT) reconstruction in a single-center pediatric cohort. Secondary outcomes included mortality, postoperative complications (prolonged mechanical ventilation > 72 h, need for continuous renal replacement therapy (CRRT), and intensive care unit (ICU) and hospital stay), and qualitative echocardiographic assessment of vessel patency during follow-up. Patients and methods: A retrospective analysis was conducted in 25 consecutive pediatric patients who underwent pulmonary artery or RVOT reconstruction with ProxiCor® at the Department of Pediatric Cardiac Surgery in Poznań (Poland) between the years 2023 and 2024. Surgical techniques, clinical outcomes, and follow-up data were assessed using transthoracic echocardiography (TTE). Results: The median age was 224 (Q1–Q3: 124–362) days, and median weight was 4.2 (Q1–Q3: 2.8–8.5) kg. Procedures targeted repairs of the main pulmonary artery (MPA), right pulmonary artery (RPA), left pulmonary artery (LPA), and RVOT. Diagnoses included tetralogy of Fallot (ToF), pulmonary artery stenosis (PS), pulmonary atresia (PA), pulmonary artery hypoplasia, and anomalous left coronary artery from the pulmonary artery (ALCAPA). The mortality rate stood at 8% (2/25), stemming from multiorgan failure and hemorrhagic stroke, unrelated to the patch. Over a median observation period of 483 (Q1–Q3: 363–584) days, no patch-related complications (e.g., restenosis or dilation) arose. The median hospitalization time was 22 (Q1–Q3: 8.5–38.5) days. Conclusions: ProxiCor® ECM patches appear to be safe and feasible for use in pulmonary artery and RVOT reconstruction, with favorable early outcomes. However, the small cohort size, lack of a control group, and limited mid- to long-term echocardiographic data preclude definitive conclusions about long-term outcomes or comparative effectiveness.