Prevalence of Venovenous Shunting and High-Output State Quantified with 4D Flow MRI in Patients with Fontan Circulation

Francesca Raimondi; Duarte Martins; Raluca Coenen; Elena Panaioli; Diala Khraiche; Nathalie Boddaert; Damien Bonnet; Melany Atkins; Howaida El-Said; Laith Alshawabkeh; Albert Hsiao

doi:10.1148/ryct.210161

Prevalence of Venovenous Shunting and High-Output State Quantified with 4D Flow MRI in Patients with Fontan Circulation

Radiol Cardiothorac Imaging. 2021 Dec 16;3(6):e210161. doi: 10.1148/ryct.210161. eCollection 2021 Dec.

Affiliation

¹ Unité Médico-Chirurgicale de Cardiologie Congénitale et Pédiatrique, Centre de Référence des Maladies Cardiaques Congénitales Complexes-M3C, Hôpital Universitaire Necker-Enfants Malades, Université de Paris, Paris, France (F.R., D.K., D.B.); Pediatric Radiology Unit, Hôpital Universitaire Necker-Enfants Malades, Université de Paris, Paris, France (F.R., E.P., N.B.); Decision and Bayesian Computation, Computation Biology Department, CNRS, URS 3756, Neuroscience Department, CNRS UMR 3571, Institut Pasteur, Paris, France (F.R.); School of Biomedical Engineering & Imaging Sciences, King's College London, Lambeth Wing, St Thomas' Hospital, London, England (F.R.); Department of Pediatric Cardiology, Hospital de Santa Cruz, Centro Hospitalar Lisboa Ocidental, Lisbon, Portugal (D.M.); Radiology and Cardiology Unit, Erasmus MC, Rotterdam, the Netherlands (R.C.); Fairfax Radiological Consultants, Fairfax, Va (M.A.); and Departments of Pediatric Cardiology (H.E.S.), Cardiovascular Medicine (L.A.), and Radiology (A.H.), University of California, San Diego, 9300 Campus Point Dr, Room 7756, La Jolla, CA 92037-7756.

Abstract

Purpose: To assess the ability of four-dimensional (4D) flow MRI to quantify flow volume of the Fontan circuit, including the frequency and hemodynamic contribution of systemic-to-pulmonary venovenous collateral vessels.

Materials and methods: In this retrospective study, patients with Fontan circulation were included from three institutions (2017-2021). Flow measurements were performed at several locations along the circuit by two readers, and collateral shunt volumes were quantified. The frequency of venovenous collaterals and structural defects were tabulated from concurrent MR angiography, contemporaneous CT, or catheter angiography and related to Fontan clinical status. Statistical analysis included Pearson and Spearman correlation and Bland-Altman analysis.

Results: Seventy-five patients (mean age, 20 years; range, 5-58 years; 46 female and 29 male patients) were included. Interobserver agreement was high for aortic output, pulmonary arteries, pulmonary veins, superior vena cava (Glenn shunt), and inferior vena cava (Fontan conduit) (range, ρ = 0.913-0.975). Calculated shunt volume also showed strong agreement, on the basis of the difference between aortic and pulmonary flow (ρ = 0.935). A total of 37 of 75 (49%) of the patients exhibited shunts exceeding 1.00 L/min, 81% (30 of 37) of whom had pulmonary venous or atrial flow volume step-ups and corresponding venovenous collaterals. A total of 12% of patients (nine of 75) exhibited a high-output state (>4 L/min/m²), most of whom had venovenous shunts exceeding 30% of cardiac output.

Conclusion: Fontan flow and venovenous shunting can be reliably quantified at 4D flow MRI; high-output states were found in a higher proportion of patients than expected, among whom venovenous collaterals were common and constituted a substantial proportion of cardiac output.Keywords: Pediatrics, MR Angiography, Cardiac, Technology Assessment, Hemodynamics/Flow Dynamics, Congenital Supplemental material is available for this article. © RSNA, 2021.

Keywords: Cardiac; Congenital; Hemodynamics/Flow Dynamics; MR Angiography; Pediatrics; Technology Assessment.

2021 by the Radiological Society of North America, Inc.