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Longitudinal Trends of Vascular Flow and Growth in Patients Undergoing Fontan Operation
Reena M Ghosh1, Kevin K Whitehead1, Matthew A Harris1
1Division of Cardiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
Insights
Serial cardiac magnetic resonance (CMR) imaging reveals significant longitudinal changes in single ventricle (SV) patient anatomy and hemodynamics after Fontan surgery. These findings provide a framework for interpreting CMR data and identifying early deviations from normal patterns.
Area of Science:
- Cardiology
- Pediatric Cardiology
- Medical Imaging
Background:
- Single ventricle (SV) physiology necessitates complex surgical palliation.
- Longitudinal data on anatomical and hemodynamic changes in SV patients are limited.
- Cardiac magnetic resonance (CMR) is crucial for assessing these changes.
Purpose of the Study:
- To evaluate long-term anatomical and hemodynamic alterations in single ventricle patients.
- To establish a normative reference for serial CMR assessments in this population.
- To identify trends that may predict clinical deterioration.
Main Methods:
- Retrospective review of serial CMR scans from 2008-2019 in 119 single ventricle patients.
- Mixed-effects linear regression analysis to assess changes over time post-Fontan.
- Analysis included indexed vascular areas and blood flow parameters.
Main Results:
- Indexed vascular areas (SVC, IVC, neoaortic, descending aorta) and associated flows decreased over time.
- Inferior vena cava (IVC) flow and its contribution to total caval flow increased.
- Systemic-to-pulmonary collateral flow decreased significantly beyond the early post-Fontan period.
Conclusions:
- Significant, predictable trends exist in vascular dimensions and flow dynamics in single ventricle patients post-Fontan.
- Serial CMR provides valuable insights into the evolving hemodynamics of SV physiology.
- These findings can aid in the noninvasive identification of suboptimal outcomes before clinical manifestation.
Background:
Single ventricle (SV) patients undergo multiple surgeries with subsequent changes in anatomy and hemodynamics. There are little cardiac magnetic resonance (CMR) data on serial changes in these patients. This study aimed to assess longitudinal changes of SV anatomy and hemodynamics in a large cohort.
Methods:
Anatomy and flow in SV patients with serial CMRs performed between 2008 and 2019 at a single institution were retrospectively reviewed. Mixed-effects linear regression was used to estimate changes over time at 3 to 9 months, 1 to 5 years, and >5 years after Fontan.
Results:
A total of 119 patients were included (51% with hypoplastic left heart syndrome; 77% underwent extracardiac Fontan). A total of 88 patients had 3 serial CMRs. Indexed right superior vena cava, inferior vena cava, neoaortic valve, and descending aorta area decreased over time (beta = -0.19, -0.44, and -0.23, respectively; P < .01), as did indexed right superior vena cava, neoaorta and native aorta, and descending aorta flow (beta = -0.49, -0.53, and -0.59, respectively; P < .0001). Inferior vena cava flow and its contribution to total caval flow increased (beta = 0.33; P < .0001). Indexed right and left pulmonary artery flow did not change; however, indexed left pulmonary artery area decreased (beta = -0.16; P = .0014) with time. Systemic-to-pulmonary collateral flow remained unchanged before and early after Fontan (beta = -0.54; P = .42) but decreased with time from Fontan (beta = -0.22; P < .0001).
Conclusions:
In this cohort of longitudinally followed SV patients, there are significant trends in vascular size and flow over time from Fontan. These findings can be used as a framework to interpret serial CMR data in the SV and noninvasively identify deviations from expected patterns before the development of clinical symptoms.
