Abstract 15519: Fluid Dynamics and Flow Profiles in the Great Arteries in Patients with Transposition of the Great Arteries (TGA) after Arterial Switch Operation with or without Lecompte Maneuver on Long-term Follow-up
Background: Complex fluid dynamics (vorticity, helicity and wall shear stress) in the transposed great arteries in TGA patients after arterial switch operation (ASO) with spiral course or anterior branching of the pulmonary arteries (Lecompte) has been scarcely studied.
The aim of this study was a comprehensive assessment of blood flow in the great arteries utilizing advanced MRI techniques two decades after ASO.
Methods: 15 TGA patients (Lecompte: n=9, 20.7±2.3 yrs post ASO; non-Lecompte, spiral: n=6, 21.0±1.5 yrs post ASO; single surgeon) and 5 healthy volunteers (22.9±2.2) were studied with high field MRI at 3 Tesla. Blood flow dynamics were calculated from time-resolved 3D flow measurements ("4D flow") using novel phase contrast MR-techniques (FOV 250-337 mm2, venc 150 cm/s in 3 othogonal directions, true spatial resolution: 2.5mm3 isotropic, temp. resol 35 ms, TR/TE 4.6/3.2; α=5-10°). A dedicated software was used for colour coded 4D visualisation and grading of blood flow profiles and streamlines (GT-Flow™, Gyrotools Inc., Zurich). Vorticity, helicity and wall shear stress were calculated with our own custom-developed software. Additionally, a comprehensive anatomical and functional cardiovascular MR-protocol was applied to all patients and controls.
Results: In patients with a spiral course (non-Lecompte) of the great arteries, vorticity index and helicity were more favourable as compared to the Lecompte group (Aorta: 234.51±35 vs. 289.36±24 m2/s, pulmonary artery: 72.54±15 vs. 93.53±13 m2/s; p<0.01). With increased cross sectional area of the ascending aorta, vorticity was increased and shear stress correlated inversely (p<0.05). Flow measurements showed a significantly reduced cross-sectional area of the left pulmonary artery with impaired blood flow after Lecompte (p<0.01).
Conclusions: Two decades after operation, a spiral course of the great arteries in TGA patients post ASO showed more physiologically normal blood flow dynamics and balanced pulmonary flow as compared to those with anterior branching of the pulmonary arteries (post Lecompte). Therefore, in elegible patients, a spiral course should be considered before ASO.
Author Disclosures: C. Rickers: None. K. Arash: None. A. Falahatpisheh: None. P. Wegner: None. D. Gabbert: None. C. Hart: None. I. Voges: None. H. Kramer: None. H. Sievers: None.
- © 2014 by American Heart Association, Inc.