Cerebral Blood Flow, Brain Injury, and Aortic-Pulmonary Collateral Flow After the Fontan Operation

Area of Science:

• Pediatric Cardiology
• Neurodevelopmental Outcomes
• Medical Imaging

Background:

• Patients with single ventricle physiology often develop aortopulmonary collaterals (APCs).
• APC flow is inversely related to cerebral blood flow (CBF), which may affect neurodevelopment.
• Longitudinal data on CBF and APC flow in Fontan patients, accounting for brain injury (BI), is lacking.

Purpose of the Study:

• To longitudinally assess the relationship between changes in CBF and APC flow in patients with Fontan physiology.
• To evaluate the impact of brain injury (BI) on this relationship.
• To determine if APC flow is a modifiable risk factor for neurodevelopmental outcomes.

Main Methods:

• A prospective longitudinal cohort of 27 Fontan patients (aged 10 ± 1.9 years) underwent serial cardiac and brain MRI.
• Measurements included CBF (via jugular venous flow) and APC flow (aortic flow minus caval return) at two time points, ~6 years apart.
• Multivariate modeling was used to analyze the relationship between changes in APC flow, CBF, and BI.

Main Results:

• A significant inverse relationship was observed between changes in CBF and APC flow (R² = 0.70-0.72, p < 0.02).
• Over 6 years, CBF decreased by 9 ± 11% and APC flow decreased by 0.73 ± 0.67 L/min/m².
• Each unit increase in APC flow change correlated with an 8% decrease in CBF change, independent of time, gender, and BI.

Conclusions:

• CBF and APC flow change are inversely related in Fontan patients over time, even after adjusting for BI.
• The observed decrease in CBF and APC flow may negatively impact neurodevelopment.
• Targeting APCs, potentially through embolization, may represent a modifiable risk factor for improving neurodevelopmental outcomes.