Fontan Outcomes in Oligemia vs Plethora in Univentricular CHD

Univentricular heart physiology represents a complex form of congenital heart disease requiring staged surgical palliation. The Fontan procedure has improved survival; however, outcomes remain variable and are influenced by pulmonary vascular conditions. Pulmonary blood flow abnormalities-oligemia (reduced flow) and plethora (increased flow)-may affect lung development from fetal life. Oligemia has been associated with pulmonary hypoplasia, impaired alveolar formation, and increased pulmonary vascular resistance, which may adversely affect Fontan circulation.

This prospective cohort study aims to compare outcomes between patients with oligemia and those with plethora. Participants will undergo standard clinical care, including staged procedures (Bidirectional Glenn and Fontan), and comprehensive assessments (clinical, laboratory, imaging, and hemodynamic). Follow-up will be conducted for approximately 1.5 years post-Fontan.

The study will evaluate mortality, morbidity, pulmonary hemodynamics, biomarkers (NT-proBNP, ET-1, Activin-A), exercise capacity, neurocognitive outcomes, and quality of life. Findings are expected to improve risk stratification and management strategies in univentricular CHD.

• Number of Participants with Postoperative Complications [Срок оценки: From Fontan procedure through study completion (up to 12 months post-Fontan)]
• Number of Participants with Rehospitalization [Срок оценки: From hospital discharge post-Fontan through study completion (up to 12 months post-Fontan)]
• Concentration of Activin-A in Blood [Срок оценки: Baseline (pre-BCPS procedure), Perioperative at Stage II (Bidirectional Cavopulmonary Shunt [BCPS]), Perioperative at Stage III (Fontan procedure)]
• Concentration of Activin-A in Pulmonary Artery Tissue [Срок оценки: - At time of tissue collection during Stage II (Bidirectional Cavopulmonary Shunt [BCPS]) - At time of tissue collection during Stage III (Fontan procedure) Analysis performed within 1 month after each collection]
• Distance Covered in Six-Minute Walk Test (6MWT) [Срок оценки: Follow-up (6 months post-Fontan procedure)]
• Neurodevelopmental Score Using Bayley Scales of Infant and Toddler Development, Fourth Edition (BSID-IV) [Срок оценки: Follow-up (6 months post-Fontan procedure)]
• Cognitive Function Score Using Montreal Cognitive Assessment (MoCA) [Срок оценки: Follow-up (6 months post-Fontan Procedure)]
• Quality of Life Score Using Child Health Questionnaire (CHQ) [Срок оценки: Follow-up (6 months post-Fontan procedure)]
• Quality of Life Score Using 36-Item Short Form Survey (SF-36) [Срок оценки: Follow-up (6 months post-Fontan Procedure)]
• Histopathological Score of Pulmonary Artery Remodeling Using Hematoxylin and Eosin (H&E) Staining [Срок оценки: At time of tissue collection during BCPS and Fontan procedures; analysis performed within 1 month after each collection]
• Percentage of Collagen Deposition Using Masson's Trichrome Staining [Срок оценки: At time of tissue collection during BCPS and Fontan procedures; analysis performed within 1 month after each collection]
• Elastin Density Measured by Verhoeff-Van Gieson (VVG) Staining [Срок оценки: At time of tissue collection during BCPS and Fontan procedures; analysis performed within 1 month after each collection]