Aortopulmonary collaterals after bidirectional cavopulmonary connection or Fontan completion: quantification with MRI
Lars Grosse-Wortmann1, Abdulmajeed Al-Otay, Shi-Joon Yoo
1The Labatt Family Heart Center and the Department of Diagnostic Imaging, The Hospital for Sick Children, The University of Toronto, Toronto, Ontario, Canada.
Circulation. Cardiovascular Imaging
|October 8, 2009
Summary
Aortopulmonary collaterals (APCs) can be measured using MRI after Fontan procedures. Higher APC flow is linked to younger age at bidirectional cavopulmonary connection and older age at Fontan completion.
Area of Science:
- Cardiovascular Imaging
- Pediatric Cardiology
- Congenital Heart Disease
Background:
- Aortopulmonary collaterals (APCs) are linked to worse outcomes after the Fontan operation.
- Quantifying APC flow is crucial for understanding patient morbidity.
Purpose of the Study:
- To quantify APC blood flow after bidirectional cavopulmonary connections (BCPC) and Fontan completion using phase-contrast MRI.
- To identify risk factors associated with APC development.
Main Methods:
- Retrospective analysis of 36 MRI studies in patients who underwent BCPC or Fontan completion.
- APC blood flow calculated by subtracting pulmonary artery flow from pulmonary vein flow.
- Ratio of pulmonary to systemic blood flow (Qp/Qs) determined.
Main Results:
- APC blood flow was quantifiable in 24 patients (16 post-BCPC, 8 post-Fontan).
- Qp/Qs ratios were 0.93±0.26 (BCPC) and 1.27±0.16 (Fontan).
- Younger age at BCPC and older age at Fontan completion correlated with higher Qp/Qs. Previous Blalock-Taussig shunt was associated with increased collateral flow.
Conclusions:
- Phase-contrast MRI can reliably measure APC blood flow in BCPC and Fontan patients.
- Measured APC flow indicates a significant left-to-right shunt.
- Findings aid in identifying patients at risk for APC-related complications.
